SHOW Colour
 

net.rim.device.api.ui
Class Graphics

java.lang.Object
  |
  +--net.rim.device.api.ui.Graphics
All Implemented Interfaces:
DrawStyle

public class Graphics
extends Object
implements DrawStyle

Provides a surface on which applications can draw.

A graphics object encapsulates the state information needed for basic rendering operations, making it accessible to applications (for example, the current font, and drawing color).

Example

    g = getGraphics();
    // draw here
    pushContext(...);
    draw(g);
    popContext();

    draw(Graphics g) {
       // draw or fill various objects
       // might {push, recurse paint(), pop}
    }
 

The context stack
Typically your application maintains one graphics object for each screen it must present to the user. Each manager controlled by the screen uses that graphics object to handle the layout and painting of each field the manager contains.

To accomodate this model, the graphics object maintains an internal context stack. Each stack element contains information about the current drawing context, including the clipping region, the drawing offset and the current foreground colour.

Typically, a field's manager pushes a transform on the stack that describes the field's extent as the clipping region, and a drawing offset to position drawing. Then it hands the graphics object to the field when it requests the field to update itself.

Each transform pushed onto the stack describes the transform in terms of the parent coordinates, so that each draw operation can be done using local coordinates and translated back through the stack to finally appear on the appropriate location of the screen.

The drawing anchor
When you use one of this class's methods to draw an object, or text, you must set the drawing anchor. This anchor describes the pixel in the drawing region where the invoked method begins to draw. The coordinate system for the drawing anchor assumes that the top left pixel in the region is coordinate 0,0.

The drawing anchor is not persistent. Each time you call one of these methods, you must provide a position for the anchor, and if maintaining information about relative positions of the anchor is important, then your code must do that.

What happens to clipped objects
When you draw an object and the size of that object would have a portion of it fall outside the clipping region, then those portions are clipped off (i.e. the object or text is cropped to fit the clipping region).

Rendering text
This class provides a variety of drawText methods you use to render text on the drawing region. The most fundamental of these methods renders a single character's glyph on the drawing region. The exact position of the drawn glyph, with respect to the drawing anchor, is determined by a combination of constant drawing style values inherited from the DrawStyle interface.

The drawn glyph appears...
 LEFTRIGHTHCENTERHFULL
TOP Below and to the right of the drawing anchor. Below and to the left of the drawing anchor. Below and horizontally centered on the drawing anchor. N/A
BOTTOM Above and to the right of the drawing anchor. Above and to the left of the drawing anchor. Above and horizontally centered on the drawing anchor. N/A
BASELINE Baseline to the right of the drawing anchor. Baseline to the left of the drawing ancrho. Baseline horizontally centered on the drawing anchor. N/A
VCENTER Center of left edge to the right of the drawing anchor. Center of right edge to the left of the drawing anchor. Absolute center of glyph on the drawing anchor. N/A

Note: the HFULL drawing position flag, to fully justify text, has not yet been implemented.

By default, the drawText methods assume the drawing position flags (TOP | LEFT). You can request another method of drawing the glyphs by passing other combinations of this class's constant drawing position values.

What happens to clipped text
The mechanism for handling clipping with drawText operations is slightly more complex.

The text drawing methods clip in two ways: pixels that fall outside the general clipping region, and pixels that fall outside a text width parameter specified to the appropriate drawText method. Text drawing methods that don't support a text width parameter assume a width that's the equal to the width of the entire set of text glyphs they are to draw.

If you pass the ELLIPSIS constant to a drawText method, in combination with the drawing position constants, then clipping by the text width parameter is handled specially. The method replaces the last fully rendered glyph, and any pixels of a partially rendered glyph, with the ellipsis glyph. If the ellipsis glyph would be clipped by the text width parameter, then no ellipsis character appears to replace the glyphs clipped.

Width of text rendered
All of the drawText methods return the number of pixels of block width of text drawn. Imagine that each glyph is mounted on a little block that you would press onto paper to print the glyph. The block width of a glyph is the size of that block: in all cases, therefore, the block width is wider than the width of pixels used to actually draw the glyph, since the block width also includes spacing pixels along the right hand side to accomodate following glyphs.

You should also note that the block width of drawn text returned by the drawText methods includes any pixels that are clipped by the clipping region. However, if you pass a width parameter into the drawText method to constrain the region available for drawing, and this width parameter clips the drawn text, the clipped pixels do not count in the width of text rendered returned by the method.

Italic text
Note that the "blocks" of italic glyphs form a parallelogram, not a rectangle. The blocks lean over to ensure that italic characters positioned next to one another will kern properly. When rendering italic text, the block width returned by the drawText method measures the width from one side of the parallelogram block to the other just as it does with roman glyphs (and not from bottom-left corner across to a vertical line dropped from top-right corner).

This means that a non-italic glyhph rendered just next to an italic glyph may occlude the leaning corner of the italic glyph.


Field Summary
  static int BLACK
          Black (0x00101010).
  static byte CURVEDPATH_CUBIC_BEZIER_CONTROL_POINT
          Cubic bezier control-point type for drawing paths.
  static byte CURVEDPATH_END_POINT
          End-point type for drawing paths.
  static byte CURVEDPATH_QUADRATIC_BEZIER_CONTROL_POINT
          Quadratic bezier control-point type for drawing paths.
 Category: Colour static int DRAWSTYLE_AALINES
          Drawing style for anti-aliased rendering of lines, used by setDrawingStyle(int, boolean) and isDrawingStyleSet(int).
 Category: Colour static int DRAWSTYLE_AAPOLYGONS
          Drawing style for anti-aliased rendering of polygons, used by setDrawingStyle(int, boolean) and isDrawingStyleSet(int).
 Category: Colour static int DRAWSTYLE_FOCUS
          This style is set by the framework when painting is being done for focus drawing.
 Category: Colour static int DRAWSTYLE_SELECT
          This style is set by the framework when painting is being done for selection drawing.
  static int FULL_BLACK
          Full black (0x00000000).
  static int FULL_WHITE
          Full white (0x00ffffff).
 Category: Colour static int ROP_CONST_GLOBALALPHA
          Raster operation constant for blending the constant foreground colour, using a constant global alpha value with destination pixels.
  static int ROP_SRC_ALPHA
          Raster operation constant for normal bitmap copy with an alpha channel.
 Category: Colour static int ROP_SRC_ALPHA_GLOBALALPHA
          Raster operation constant for blending a source bitmap with an alpha channel and a constant global alpha value with destination pixels.
  static int ROP_SRC_COPY
          Raster operation constant for normal bitmap copy.
 Category: Colour static int ROP_SRC_GLOBALALPHA
          Raster operation constant for blending a source bitmap using a constant global alpha value with destination pixels.
  static int ROP_SRCMONOEXPAND_ALPHA
          Raster operation constant for expanding a monochrome source bitmap with current foreground and background drawing colours, respecting the alpha channel.
  static int ROP_SRCMONOEXPAND_COPY
          Raster operation constant for expanding a monochrome source bitmap with the current foreground and background drawing colours.
  static int ROP2_0
          Binary raster op constant for zeroing out the destination.
  static int ROP2_1
          Binary raster op constant for filling dest with 1 values.
  static int ROP2_D
          Binary raster op constant for nop.
  static int ROP2_Dn
          Binary raster op constant for invert destination.
  static int ROP2_DSa
          Binary raster op constant for masking ( source and dest ).
  static int ROP2_DSan
          Binary raster op constant for ( not ( source and dest ) ).
  static int ROP2_DSna
          Binary raster op constant for ( ( not source ) and dest ).
  static int ROP2_DSno
          Binary raster op constant for ( ( not source ) or dest ).
  static int ROP2_DSo
          Binary raster op constant for ( source or dest ).
  static int ROP2_DSon
          Binary raster op constant for ( not ( source or dest ) ).
  static int ROP2_DSx
          Binary raster op constant for selective invert ( source xor dest ).
  static int ROP2_DSxn
          Binary raster op constant for ( not ( source xor dest ) ).
  static int ROP2_S
          Binary raster op constant for normal source copy.
  static int ROP2_SDna
          Binary raster op constant for ( ( not dest ) and source ).
  static int ROP2_SDno
          Binary raster op constant for ( source or ( not dest ) ).
  static int ROP2_Sn
          Binary raster op constant for ( not source ).
  static boolean SCREEN_HAS_BORDER
          Does the screen have a lit border around the drawable area of the screen?
  static int WHITE
          White (0x00EBEBEB).
 
Fields inherited from interface net.rim.device.api.ui.DrawStyle
BASELINE, BOTTOM, ELLIPSIS, HALIGN_MASK, HCENTER, HDEFAULT, HFULL, LEADING, LEFT, RIGHT, TOP, TRAILING, TRUNCATE_BEGINNING, VALIGN_MASK, VCENTER, VDEFAULT, VFULL
 
Constructor Summary
Graphics(Bitmap bitmap)
          Deprecated. Instead use Graphics.create( Bitmap )
 
Method Summary
   void clear()
          Clears the entire graphics area to the current background.
   void clear(int x, int y, int width, int height)
          Clears a region to the current background.
   void clear(XYRect region)
          Clears a region specified by an XYRect object to the current background.
   boolean copyArea(int x, int y, int width, int height, int dx, int dy)
          Copies a region of this graphics canvas.
   boolean copyArea(XYRect region, int dx, int dy)
          Copies a region of this graphics canvas, specified by an XYRect.
  static Graphics create(Bitmap bitmap)
          Graphics object associated with display id
   void drawArc(int x, int y, int width, int height, int startAngle, int arcAngle)
          Draws an arc through a specified rectangle.
   void drawARGB(int[] data, int offset, int scanLength, int x, int y, int width, int height)
          Similar to drawRGB, but source data also contains alpha.
   void drawBitmap(int x, int y, int width, int height, Bitmap bitmap, int left, int top)
          Draws a bitmap.
   void drawBitmap(XYRect dest, Bitmap bitmap, int left, int top)
          Draws a bitmap on a region specified by an XYRect object.
   void drawEllipse(int cx, int cy, int px, int py, int qx, int qy, int startAngle, int arcAngle)
          Draws an ellipse.
   void drawFilledPath(int[] xPts, int[] yPts, byte[] pointTypes, int[] offsets)
          Draws a set of filled paths.
   void drawImage(int x, int y, int width, int height, EncodedImage image, int frameIndex, int left, int top)
          Draws an encoded image.
   void drawImage(XYRect dest, EncodedImage image, int frameIndex, int left, int top)
          Draws an encoded image on a region specified by an XYRect object.
   void drawLine(int x1, int y1, int x2, int y2)
          Draws a line.
   void drawPathOutline(int[] xPts, int[] yPts, byte[] pointTypes, int[] offsets, boolean closed)
          Draw a set of path outlines.
   void drawPoint(int x, int y)
          Draws a point.
   void drawRect(int x, int y, int width, int height)
          Draws a rectangle.
   void drawRGB(int[] data, int offset, int scanLength, int x, int y, int width, int height)
          Draws raw RGB data from an int array.
   void drawRoundRect(int x, int y, int width, int height, int arcWidth, int arcHeight)
          Draws a rectangle with rounded edges.
 Category: Colour  void drawShadedFilledPath(int[] xPts, int[] yPts, byte[] pointTypes, int[] colors, int[] offsets)
          Draws a set of shaded filled paths.
   int drawText(byte[] text, int offset, int len, int x, int y, int flags, int width)
          Draws text contained in a byte array.
   int drawText(char[] text, int offset, int len, int x, int y, int flags, int width)
          Draws text contained in a char array.
   int drawText(char character, int x, int y, int flags, int width)
          Draws a text character.
   int drawText(StringBuffer text, int offset, int len, int x, int y, int flags, int width)
          Draws text contained in a string buffer.
   int drawText(String text, int x, int y)
          Draws a text string.
   int drawText(String text, int x, int y, int flags)
          Draws a text string with specified positioning.
   int drawText(String text, int x, int y, int flags, int width)
          Draws text within a specified width.
   int drawText(String text, int offset, int len, int x, int y, int flags, int width)
          Draws text contained in a string.
   void drawTexturedPath(int[] xPts, int[] yPts, byte[] pointTypes, int[] offsets, int xOrigin, int yOrigin, int dux, int dvx, int duy, int dvy, Bitmap textureData)
          Draws a set of texture-filled paths.
   void fillArc(int x, int y, int width, int height, int startAngle, int arcAngle)
          Fills a circular or elliptical arc covering a specified rectangle.
   void fillEllipse(int cx, int cy, int px, int py, int qx, int qy, int startAngle, int arcAngle)
          Fills an ellipse.
   void fillRect(int x, int y, int width, int height)
          Fills a rectangle.
   void fillRoundRect(int x, int y, int width, int height, int arcWidth, int arcHeight)
          Fills a rectangle with rounded edges.
   void getAbsoluteClippingRect(XYRect clip)
          Retreives the absolute coordinates of current clipping region.
   int getBackgroundColor()
          Retrieves the current background color.
   XYRect getClippingRect()
          Retrieves the local coordinates of current clipping region.
   int getColor()
          Retrieves the current foreground drawing color.
   int getContextStackSize()
          Retrieves the size of the stack of drawing contexts.
   void getDrawingOffset(XYPoint offset)
          Retrieves the absolute coordinates for the current drawing offset.
   Font getFont()
          Retrieves the current font for the current graphics context.
 Category: Colour  int getGlobalAlpha()
          Retrieves the current global alpha value.
 Category: Colour static int getNumColors()
          Deprecated. Use DisplayInstance.getNumColors();
  static int getScreenHeight()
          Deprecated. Use Display.getHeight()
  static int getScreenHorizontalResolution()
          Deprecated. Use Display.getHorizontalResolution()
  static int getScreenVerticalResolution()
          Deprecated. Use Display.getVerticalResolution()
  static int getScreenWidth()
          Deprecated. Use Display.getWidth()
   int getStipple()
          Retrieves the current line stippling value.
   int getTranslateX()
          Retrieves the horizontal component of the current drawing offset.
   int getTranslateY()
          Retrieves the vertical component of the current drawing offset.
   void invert(int x, int y, int width, int height)
          Inverts a region.
   void invert(XYRect rect)
          Inverts a region specified by an XYRect object.
 Category: Colour static boolean isColor()
          Deprecated. Use DisplayInstance.isColor().
 Category: Colour  boolean isDrawingStyleSet(int drawStyle)
          Determines whether the specified drawing style is turned on.
 Category: Colour  boolean isRopSupported(int rop)
          Determines if a raster operation is supported.
   void popContext()
          Pops a drawing context off the stack.
   boolean pushContext(int x, int y, int width, int height, int xOffset, int yOffset)
          Pushes a clipping region (and optional drawing offset) onto the context stack.
   boolean pushContext(XYRect clip, int xOffset, int yOffset)
          Pushes a clipping region (and optional drawing offset) onto the context stack.
   boolean pushRegion(int x, int y, int width, int height, int xScroll, int yScroll)
          Pushes a drawing region (and optional scroll offset) onto the context stack.
   boolean pushRegion(XYRect region)
          Pushes a drawing region onto the context stack, specified by a XYRect object.
   boolean pushRegion(XYRect region, int xScroll, int yScroll)
          Pushes a drawing region (and optional scroll offset) onto the context stack.
   void rop(int rop, int x, int y, int width, int height, Bitmap source, int left, int top)
          Executes an area raster operation on the specified region.
   void setBackgroundColor(int RGB)
          Sets the current background color.
   void setColor(int RGB)
          Sets the current color.
 Category: Colour  void setDrawingStyle(int drawStyle, boolean on)
          Sets the current drawing style.
   void setFont(Font font)
          Sets the current font for the current graphics context.
 Category: Colour  void setGlobalAlpha(int alpha)
          Sets the current global alpha value for drawing operations.
   void setStipple(int mask)
          Sets the current line stippling value.
   void tileRop(int rop, int x, int y, int width, int height, Bitmap source, int left, int top)
          Executes an area raster operation on the specified region, tiling the source bitmap if necessary.
   void translate(int x, int y)
          Apply a translation to the current drawing offset.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

BLACK

public static final int BLACK
Black (0x00101010).

CURVEDPATH_CUBIC_BEZIER_CONTROL_POINT

public static final byte CURVEDPATH_CUBIC_BEZIER_CONTROL_POINT
Cubic bezier control-point type for drawing paths.

A control point of a cubic bezier is one of two points that "stretch" the curve awway from the end points. Cubic bezier control points must come in sets of two, with end points coming before the first control point and after the second.

Since:
JDE 3.6.0

CURVEDPATH_END_POINT

public static final byte CURVEDPATH_END_POINT
End-point type for drawing paths.

A curve or line ends on this point. The value of this constant will always be 0, so it is possible to just create a points array and set only the values of the curves' control points.

Since:
JDE 3.6.0

CURVEDPATH_QUADRATIC_BEZIER_CONTROL_POINT

public static final byte CURVEDPATH_QUADRATIC_BEZIER_CONTROL_POINT
Quadratic bezier control-point type for drawing paths.

The control point of a quadratic bezier is the single point that "stretches" the curve awway from the end points. If a point is a quadratic bezier control point, the points preceeding and succeeding it must be end points.

Since:
JDE 3.6.0

DRAWSTYLE_AALINES

public static final int DRAWSTYLE_AALINES
Drawing style for anti-aliased rendering of lines, used by setDrawingStyle(int, boolean) and isDrawingStyleSet(int).

If this style is set, lines and path outlines may be antialiased.

This style is off by default.

Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

DRAWSTYLE_AAPOLYGONS

public static final int DRAWSTYLE_AAPOLYGONS
Drawing style for anti-aliased rendering of polygons, used by setDrawingStyle(int, boolean) and isDrawingStyleSet(int).

If this style is set, filled paths and polygons may be antialiased.

This style is off by default.

Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

DRAWSTYLE_FOCUS

public static final int DRAWSTYLE_FOCUS
This style is set by the framework when painting is being done for focus drawing.
Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

DRAWSTYLE_SELECT

public static final int DRAWSTYLE_SELECT
This style is set by the framework when painting is being done for selection drawing.
Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

FULL_BLACK

public static final int FULL_BLACK
Full black (0x00000000).
Since:
JDE 3.6.0

FULL_WHITE

public static final int FULL_WHITE
Full white (0x00ffffff).
Since:
JDE 3.6.0

ROP_CONST_GLOBALALPHA

public static final int ROP_CONST_GLOBALALPHA
Raster operation constant for blending the constant foreground colour, using a constant global alpha value with destination pixels.

Set the global alpha value using setGlobalAlpha(int).

Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

ROP_SRC_ALPHA

public static final int ROP_SRC_ALPHA
Raster operation constant for normal bitmap copy with an alpha channel.
Since:
JDE 3.6.0

ROP_SRC_ALPHA_GLOBALALPHA

public static final int ROP_SRC_ALPHA_GLOBALALPHA
Raster operation constant for blending a source bitmap with an alpha channel and a constant global alpha value with destination pixels.

Set the global alpha value using setGlobalAlpha(int).

Since:
JDE 4.0.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

ROP_SRC_COPY

public static final int ROP_SRC_COPY
Raster operation constant for normal bitmap copy.
Since:
JDE 3.6.0

ROP_SRC_GLOBALALPHA

public static final int ROP_SRC_GLOBALALPHA
Raster operation constant for blending a source bitmap using a constant global alpha value with destination pixels.

Set the global alpha value using setGlobalAlpha(int).

Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

ROP_SRCMONOEXPAND_ALPHA

public static final int ROP_SRCMONOEXPAND_ALPHA
Raster operation constant for expanding a monochrome source bitmap with current foreground and background drawing colours, respecting the alpha channel. The behaves similar to a rubber stamp.
Since:
JDE 3.6.0

ROP_SRCMONOEXPAND_COPY

public static final int ROP_SRCMONOEXPAND_COPY
Raster operation constant for expanding a monochrome source bitmap with the current foreground and background drawing colours.
Since:
JDE 3.6.0

ROP2_0

public static final int ROP2_0
Binary raster op constant for zeroing out the destination.
Since:
JDE 3.6.0

ROP2_1

public static final int ROP2_1
Binary raster op constant for filling dest with 1 values.
Since:
JDE 3.6.0

ROP2_D

public static final int ROP2_D
Binary raster op constant for nop.
Since:
JDE 3.6.0

ROP2_Dn

public static final int ROP2_Dn
Binary raster op constant for invert destination.
Since:
JDE 3.6.0

ROP2_DSa

public static final int ROP2_DSa
Binary raster op constant for masking ( source and dest ).
Since:
JDE 3.6.0

ROP2_DSan

public static final int ROP2_DSan
Binary raster op constant for ( not ( source and dest ) ).
Since:
JDE 3.6.0

ROP2_DSna

public static final int ROP2_DSna
Binary raster op constant for ( ( not source ) and dest ).
Since:
JDE 3.6.0

ROP2_DSno

public static final int ROP2_DSno
Binary raster op constant for ( ( not source ) or dest ).
Since:
JDE 3.6.0

ROP2_DSo

public static final int ROP2_DSo
Binary raster op constant for ( source or dest ).
Since:
JDE 3.6.0

ROP2_DSon

public static final int ROP2_DSon
Binary raster op constant for ( not ( source or dest ) ).
Since:
JDE 3.6.0

ROP2_DSx

public static final int ROP2_DSx
Binary raster op constant for selective invert ( source xor dest ).
Since:
JDE 3.6.0

ROP2_DSxn

public static final int ROP2_DSxn
Binary raster op constant for ( not ( source xor dest ) ).
Since:
JDE 3.6.0

ROP2_S

public static final int ROP2_S
Binary raster op constant for normal source copy.
Since:
JDE 3.6.0

ROP2_SDna

public static final int ROP2_SDna
Binary raster op constant for ( ( not dest ) and source ).
Since:
JDE 3.6.0

ROP2_SDno

public static final int ROP2_SDno
Binary raster op constant for ( source or ( not dest ) ).
Since:
JDE 3.6.0

ROP2_Sn

public static final int ROP2_Sn
Binary raster op constant for ( not source ).
Since:
JDE 3.6.0

SCREEN_HAS_BORDER

public static final boolean SCREEN_HAS_BORDER
Does the screen have a lit border around the drawable area of the screen? Currently, this is false only for 7100-series and 8700-series devices.
Since:
JDE 4.0.2

WHITE

public static final int WHITE
White (0x00EBEBEB).
Constructor Detail

Graphics

public Graphics(Bitmap bitmap)
Deprecated. Instead use Graphics.create( Bitmap )

Constructs a Graphics object for drawing to a bitmap.
Parameters:
bitmap - Bitmap to draw into. Must be Bitmap.ROWWISE_MONOCHROME or the default type of the device.
Throws:
IllegalArgumentException - If the type of 'bitmap' is not supported, or the bitmap is readonly.
Method Detail

clear

public void clear()
Clears the entire graphics area to the current background.

clear

public void clear(int x,
                  int y,
                  int width,
                  int height)
Clears a region to the current background.

Use this method to clear only a region within the entire graphics area. You specify the region to clear by describing its extent in passed parameters.

Parameters:
x - Left edge of the region.
y - Top edge of the region.
width - Width of the region.
height - Height of the region.

clear

public void clear(XYRect region)
Clears a region specified by an XYRect object to the current background.

Use this method to clear only a region within the entire graphics area. You specify the region to clear with an XYRect that you pass to this method.

Parameters:
region - Rectangular region to clear.

copyArea

public boolean copyArea(int x,
                        int y,
                        int width,
                        int height,
                        int dx,
                        int dy)
Copies a region of this graphics canvas.

Use this method to copy a region of the drawing buffer. You specify the source region by describing its extent in passed parameters. The source region is left intact (i.e. not cleared).

To paste the copy of the region to the left of or above the drawing anchor, specify a negative value for the dx or dy parameters.

If a portion of the source rectangle lies outside the bounds of the clipping region, this method does not copy the associated pixels. You can refresh the omitted area by invoking paint on the component.

This method fails in situations where the pixels are not available. This can happen when a front buffer screen is obscuring this graphics context's screen. In this case, this method returns false; you should then prompt a full repaint by invoking invalidate on the screen.

Parameters:
x - Left edge of the source region.
y - Top edge of the source region
width - Width of the source region.
height - Height of the source region.
dx - Horizontal distance to move the region.
dy - Vertical distance to move the region.
Returns:
True if the copyArea was successful; otherwise, false.

copyArea

public boolean copyArea(XYRect region,
                        int dx,
                        int dy)
Copies a region of this graphics canvas, specified by an XYRect.

Use this method to copy a region of the drawing buffer. You specify the source region with an XYRect that you pass to this method. The source region is left intact (i.e. not cleared).

To paste the copy of the region to the left of or above the drawing anchor, specify a negative value for the dx and dy parameters.

If a portion of the source region lies outside the bounds of the clipping region, this method does not copy the associated pixels. You can refresh the omitted area by invoking Field.paint(net.rim.device.api.ui.Graphics) on the component.

This method fails in situations where the pixels are not available. This can happen when a front buffer screen is obscuring this graphics context's screen. In this case, this method returns false; you should then prompt a full repaint by invoking invalidate on the screen.

Parameters:
region - Source region to copy.
dx - Horizontal distance to move the region.
dy - Vertical distance to move the region.
Returns:
True if the copyArea was successful; otherwise, false.

create

public static Graphics create(Bitmap bitmap)
Graphics object associated with display id
Parameters:
displayId -  
Returns:
initalized graphics
Since:
JDE 4.7.0

drawArc

public void drawArc(int x,
                    int y,
                    int width,
                    int height,
                    int startAngle,
                    int arcAngle)
Draws an arc through a specified rectangle.

The center of the drawn arc is the center of a rectangle whose origin is (x,y) and whose size is specified by the width and height parameters.

The arc begins at startAngle and extends for arcAngle degrees, using the current draw color. The drawing algorithm assumes that the 0 degree position is in the center of the right edge of the rectangle. The direction of the arc drawn depends on the relative values of startAngle and arcAngle:

  • If (startAngle < arcAngle), this method draws the arc in a counterclockwise direction.
  • If startAngle > arcAngle, this method draws the arc in a clockwise direction.

The resulting arc covers an area width pixels wide by height pixels tall and end points are one pixel outside the extent of the rectangle). If either width or height is less than zero, this method draws nothing.

The angles are specified relative to the non-square extents of the bounding rectangle such that 45 degrees always falls on the line from the center of the ellipse to the upper right corner of the bounding rectangle. As a result, if the bounding rectangle is noticeably longer in one axis than the other, the angles to the start and end of the arc segment will be skewed farther along the longer axis of the bounds. ATTENTION: This method doesn't support transformations specified in the setTransformation method.

Parameters:
x - Horizontal coordinate of the arc's starting position.
y - Vertical coordinate of the arc's starting position.
width - Width of rectangle containing the arc.
height - Height of rectangle containing the arc.
startAngle - The angle position at which to commence drawing.
arcAngle - Angular extent of the arc, relative to the start angle.

drawARGB

public void drawARGB(int[] data,
                     int offset,
                     int scanLength,
                     int x,
                     int y,
                     int width,
                     int height)
Similar to drawRGB, but source data also contains alpha.
Parameters:
data -
offset -
scanLength -
x -
y -
width -
height -
Since:
JDE 4.2.0

drawBitmap

public void drawBitmap(int x,
                       int y,
                       int width,
                       int height,
                       Bitmap bitmap,
                       int left,
                       int top)
Draws a bitmap.

Use this method to draw a bitmap. You specify the destination region for the bitmap by describing the extent of the region with passed parameters.

You must also specify the extent of the bitmap to draw (the top left corner of this extent defined by the top and left parameters). If a portion of part of the bitmap you want to draw falls outside the size of the destination region, this method crops to fit.

Pixels are drawn exactly as in the Bitmap, with no color transformations. To have a monochrome image act like a rubber stamp, use rop(int, int, int, int, int, net.rim.device.api.system.Bitmap, int, int) with ROP_SRCMONOEXPAND_COPY or ROP_SRCMONOEXPAND_ALPHA.

Parameters:
x - Left edge of the destination region.
y - Top edge of the destination region.
width - Width of the destination region.
height - Height of the destination region.
bitmap - Bitmap to draw.
left - Left edge of region within bitmap to draw.
top - Top edge of region within bitmap to draw.

drawBitmap

public void drawBitmap(XYRect dest,
                       Bitmap bitmap,
                       int left,
                       int top)
Draws a bitmap on a region specified by an XYRect object.

Use this method to draw a bitmap. You specify the destination region for the bitmap with an XYRect that you pass to this method.

You must also specify the extent of the bitmap to draw (the top left corner of this extent defined by the top and left parameters). If a portion of part of the bitmap you want to draw falls outside the size of the destination region, this method crops to fit.

Parameters:
dest - Destination region in which to draw the bitmap.
bitmap - Bitmap to draw.
left - Left edge of region within bitmap to draw.
top - Top edge of region within bitmap to draw.

drawEllipse

public void drawEllipse(int cx,
                        int cy,
                        int px,
                        int py,
                        int qx,
                        int qy,
                        int startAngle,
                        int arcAngle)
Draws an ellipse.

Draws an ellipse with the specified endpoints P = (px, py) and Q = (qx, qy) of two conjugate diameters of the ellipse. The endpoints are specified as absolute coordinates.

This example shows an ellipse with the aligned p and q points.

This example shows how the p and q points can be used to draw a non-aligned ellipse.

Parameters:
cx - X-ordinate of the ellipse centre. cx is one of the coordinates of the center point of the ellipse.
cy - Y-ordinate of the ellipse centre.
px - X-ordinate of the point P. P is one of the coordinates of the tangents of a parallelogram that bounds the ellipse. By convention, if the ellipse is aligned with the screen axes, the p point defines the x-axis radius.
py - Y-ordinate of the point P. P is one of the coordinates of the tangents of a parallelogram that bounds the ellipse. By convention, if the ellipse is aligned with the screen axes, the p point defines the x-axis radius.
qx - X-ordinate of the point Q. Q is one of the coordinates of the tangents of a parallelogram that bounds the ellipse. By convention, if the ellipse is aligned with the screen axes, the q point defines the y-axis radius.
qy - Y-ordinate of the point Q. Q is one of the coordinates of the tangents of a parallelogram that bounds the ellipse. By convention, if the ellipse is aligned with the screen axes, the q point defines the y-axis radius.
startAngle - Arc start angle. Drawing starts at the angular position defined by the start angle (clockwise with zero degrees being the x-axis and x left, y down) and ends at an angular position equal to the start angle plus the arc angle. For example, if you set the start angle to 90 degrees and the arc angle to 90 degrees, the ellipse starts at the y axis and continues to the x axis.
arcAngle - Angular extent of the arc, relative to the start angle.
Since:
JDE 4.2.0

drawFilledPath

public void drawFilledPath(int[] xPts,
                           int[] yPts,
                           byte[] pointTypes,
                           int[] offsets)
Draws a set of filled paths.

Use this method to draw one or more filled non-intersecting paths that contain line segments or curves. You specify the x and y coordinates and point types of the paths desired.

The offsets indicate the beginnings of each path in the data array. The data in the ith path is defined to be the (xPts,yPts) values from offsets[i] to offsets[i+1]-1 inclusive. Thus if there are N values in offsets, there are N-1 paths defined, where the final value is one greater than the offset where the final point of the final path is located in the points data. If offsets is null, the xPts and yPts data will be treated as a single path, and these arrays must have the same length.

The xPts and yPts arrays keep track of each vertex in the polygon and each value in the xPts array must have a corresponding value at the same index in the yPts array, and a corresponding value at the same index in the pointTypes array.

None of the edges in a path may cross any other edge in any of the paths (including itself). If edges do cross, the drawing behaviour is undefined. A path may be fully contained within another path, e.g. a "donut" shape.

The paths are filled by the "even-odd" rule. Thus if a ray is drawn from any point, the area containing the point will be filled if the ray passes through an odd number of edges and will not be filled if is passes through an even number of edges.

Note that each non-null array parameter must be a different array.

Parameters:
xPts - Ordered list of x values for each vertex in the paths.
yPts - Ordered list of y values for each vertex in the paths.
pointTypes - One of CURVEDPATH_END_POINT, CURVEDPATH_QUADRATIC_BEZIER_CONTROL_POINT, or CURVEDPATH_CUBIC_BEZIER_CONTROL_POINT. There must be one of these values for each (x,y) point defined. If pointTypes is null, all point are assumed to be of type CURVEDPATH_END_POINT.

If a point's value is CURVEDPATH_END_POINT, then a line or curve ends on this point. If a curve control point is next to this point, a curve will have this point as an endpoint. Otherwise, straight lines are drawn between successive end points.

If a point's value is CURVEDPATH_QUADRATIC_BEZIER_CONTROL_POINT, the point is a control point for a quadratic bezier. The control point of a quadratic bezier is the single point that "stretches" the curve away from the end points. If a point is a quadratic bezier control point, the points preceeding and succeeding it must be end points (CURVEDPATH_END_POINT).

If a point's value is CURVEDPATH_CUBIC_BEZIER_CONTROL_POINT, the point is a control point for a cubic bezier. A cubic bezier has two control points that "stretch" the curve away from the end points. Cubic bezier control points must come in sets of two, with end points (CURVEDPATH_END_POINT) coming before the first control point and after the second.

offsets - List defining the beginnings of each path in the xPts/yPts data arrays, or null to indicate a single path. A path that begins at point (xPts[offsets[i]],yPts[offsets[i]]) will end at point (xPts[offsets[i+1]]-1,yPts[offsets[i+1]]-1).
Throws:
IllegalArgumentException - If the data is malformed. For example, the values in offsets is negative or not in increasing order, there are fewer than 2 points in a single path, the values in offsets index outside the points arrays, the values in pointTypes are invalid, or offsets is null and xPts and yPts are not the same length.
Since:
JDE 3.6.0

drawImage

public void drawImage(int x,
                      int y,
                      int width,
                      int height,
                      EncodedImage image,
                      int frameIndex,
                      int left,
                      int top)
Draws an encoded image.

Use this method to draw an encoded image. You specify the destination region for the bitmap by describing the extent of the region with passed parameters.

The region to be drawn is decoded, drawn and then thrown away. Thus if you plan to draw a full encoded image multiple times it is faster to first decode into a Bitmap object and draw that.

You must also specify the extent of the image to draw (the top left corner of this extent defined by the top and left parameters). If a portion of part of the image you want to draw falls outside the size of the destination region, this method crops to fit.

Pixels are drawn exactly as in the Bitmap, with no color transformations. To have a monochrome image act like a rubber stamp, use rop(int, int, int, int, int, net.rim.device.api.system.Bitmap, int, int) with ROP_SRCMONOEXPAND_COPY or ROP_SRCMONOEXPAND_ALPHA.

Parameters:
x - Left edge of the destination region.
y - Top edge of the destination region.
width - Width of the destination region.
height - Height of the destination region.
image - Encoded image to draw.
frameIndex - The frame to draw
left - Left edge of region within bitmap to draw.
top - Top edge of region within bitmap to draw.
Since:
JDE 3.7.0

drawImage

public void drawImage(XYRect dest,
                      EncodedImage image,
                      int frameIndex,
                      int left,
                      int top)
Draws an encoded image on a region specified by an XYRect object.

Use this method to draw an image. You specify the destination region for the image with an XYRect that you pass to this method.

The region to be drawn is decoded, drawn and then thrown away. Thus if you plan to draw a full encoded image multiple times it is faster to first decode into a Bitmap object and draw that.

You must also specify the extent of the image to draw (the top left corner of this extent defined by the top and left parameters). If a portion of part of the image you want to draw falls outside the size of the destination region, this method crops to fit.

Parameters:
dest - Destination region in which to draw the bitmap.
image - Encoded image to draw
frameIndex - The frame to draw
left - Left edge of region within bitmap to draw.
top - Top edge of region within bitmap to draw.
Since:
JDE 3.7.0

drawLine

public void drawLine(int x1,
                     int y1,
                     int x2,
                     int y2)
Draws a line.

Use this method to draw a line; you specify coordinates for the endpoints of the line.

Parameters:
x1 - Horizontal position of the line's starting point.
y1 - Vertical position of the line's starting point.
x2 - Horizontal position of the line's ending point.
y2 - Vertical position of the line's ending point.

drawPathOutline

public void drawPathOutline(int[] xPts,
                            int[] yPts,
                            byte[] pointTypes,
                            int[] offsets,
                            boolean closed)
Draw a set of path outlines.

Use this method to draw a set of path outlines that contains line segments and curves. The xPts and yPts arrays keep track of each vertex in the path. Each value in the xPts array must have corresponding values at the same index in the yPts array and the pointTypes array.

The offsets array keeps track of the locations of each path in the set of paths. If offsets is null, the xPts and yPts data will be treated as a single path, and these arrays must have the same length.

Note that each non-null array parameter must be a different array.

Parameters:
xPts - Ordered list of x values for each vertex in the paths.
yPts - Ordered list of y values for each vertex in the paths.
pointTypes - One of Graphics.CURVEDPATH_END_POINT, CURVEDPATH_QUADRATIC_BEZIER_CONTROL_POINT, or CURVEDPATH_CUBIC_BEZIER_CONTROL_POINT. There must be one of these values for each (x,y) point defined. If pointTypes is null, all point are assumed to be of type CURVEDPATH_END_POINT.

If a point's value is CURVEDPATH_END_POINT, then a line or curve ends on this point. If a curve control point is next to this point, a curve will have this point as an endpoint. Otherwise, straight lines are drawn between successive end points.

If a point's value is CURVEDPATH_QUADRATIC_BEZIER_CONTROL_POINT, the point is a control point for a quadratic bezier. The control point of a quadratic bezier is the single point that "stretches" the curve awway from the end points. If a point is a quadratic bezier control point, the points preceeding and succeeding it must be end points (CURVEDPATH_END_POINT).

If a point's value is CURVEDPATH_CUBIC_BEZIER_CONTROL_POINT, the point is a control point for a cubic bezier. A cubic bezier has two control points that "stretch" the curve away from the end points. Cubic bezier control points must come in sets of two, with end points (CURVEDPATH_END_POINT) coming before the first control point and after the second.

offsets - List defining the beginnings of each path in the xPts/yPts data arrays, or null to indicate a single path. A path that begins at point (xPts[offsets[i]],yPts[offsets[i]]) will end at point (xPts[offsets[i+1]]-1,yPts[offsets[i+1]]-1).
closed - If this value is true, each path in the set will be closed by connecting the final point in the path's data with the first point.
Throws:
IllegalArgumentException - If the data is malformed. e.g. the values in offsets is negative or not in increasing order, there are fewer than 2 points in a single path, the values in offsets index outside the points arrays, the values in pointTypes are invalid, or offsets is null and xPts and yPts are not the same length.
Since:
JDE 3.6.0

drawPoint

public void drawPoint(int x,
                      int y)
Draws a point.

This method draws the pixel located at a coordinate you specify.

Parameters:
x - Horizontal position of the point to draw.
y - Vertical position of the point to draw.

drawRect

public void drawRect(int x,
                     int y,
                     int width,
                     int height)
Draws a rectangle.

Use this method to draw a rectangle. You specify the top and left edges of the rectangle, and its width and height. This method draws the right edge of the rectangle at (x+width-1), the bottom edge at (y+height-1). The resulting rectangle will thus have an area of (width * height).

If you pass in a zero or negative value for either the height or width, this method draws nothing.

Parameters:
x - Left edge of the rectangle.
y - Top edge of the rectangle.
width - Width of the rectangle.
height - Height of the rectangle.

drawRGB

public void drawRGB(int[] data,
                    int offset,
                    int scanLength,
                    int x,
                    int y,
                    int width,
                    int height)
Draws raw RGB data from an int array.
Parameters:
data - Color data to use, of the form 0x00RRGGBB.
offset - Offset into the data to start drawing from.
scanLength - Width of a scanline within the data.
x - Left edge of rectangle.
y - Top edge of the rectangle.
width - Width of the rectangle.
height - Height of the rectangle.
Throws:
NullPointerException - If 'data' is null.
ArrayIndexOutOfBoundsException - If the data parameters are invalid.
Since:
JDE 3.6.0

drawRoundRect

public void drawRoundRect(int x,
                          int y,
                          int width,
                          int height,
                          int arcWidth,
                          int arcHeight)
Draws a rectangle with rounded edges.

Use this method to draw a rectangle with rounded edges. You specify the top and left edges of the rectangle, and its width and height. This method draws the right edge of the rectangle at (x+width-1), the bottom edge at (y+height-1). The resulting rectangle will thus have an area, assuming no rounded corners, of width * height.

If you pass in a zero or negative value for either the height or width, this method draws nothing.

Use the arcWdith and arcHeight parameters to describe the arcs used to round off the four corners.

Parameters:
x - Left edge of the rectangle.
y - Top edge of the rectangle.
width - Width of the rectangle.
height - Height of the rectangle.
arcWidth - Width of arc used to round the four corners.
arcHeight - Height of arc used to round the four corners.

drawShadedFilledPath

public void drawShadedFilledPath(int[] xPts,
                                 int[] yPts,
                                 byte[] pointTypes,
                                 int[] colors,
                                 int[] offsets)
Draws a set of shaded filled paths.

Use this method to draw one or more filled non-intersecting paths that contain line segments and curves. You specify the x and y coordinates and point types of the paths desired as well as the color values of each vertex which will be blended together creating the shading effect.

The offsets indicate the beginnings of each path in the data array. The data in the ith path is defined to be the (xPts,yPts) values from offsets[i] to offsets[i+1]-1 inclusive. Thus if there are N values in offsets, there are N-1 paths defined, where the final value is one greater than the offset where the final point of the final path is located in the points data. If offsets is null, the xPts and yPts data will be treated as a single path, and these arrays must have the same length.

The xPts and yPts arrays keep track of each vertex in the polygon and each value in the xPts array must have a corresponding value at the same index in the yPts array, and a corresponding value at the same index in the pointTypes array. Similarly the color array stores the RGB color of each vertex ( in 0x00RRGGBB format ) and its indices must correspond with those of both the xPts and yPts arrays.

None of the edges in a path may cross any other edge in any of the paths (including itself). If edges do cross, the drawing behaviour is undefined. A path may be fully contained within another path, for example, a "donut" shape.

The paths are filled by the "even-odd" rule. Thus if a ray is drawn from any point, the area containing the point will be filled if the ray passes through an odd number of edges and will not be filled if is passes through an even number of edges.

Note that each non-null array parameter must be a different array.

Parameters:
xPts - Ordered list of x values for each vertex in the paths.
yPts - Ordered list of y values for each vertex in the paths.
pointTypes - One of CURVEDPATH_END_POINT, CURVEDPATH_QUADRATIC_BEZIER_CONTROL_POINT, or CURVEDPATH_CUBIC_BEZIER_CONTROL_POINT. There must be one of these values for each (x,y) point defined. If pointTypes is null, all point are assumed to be of type CURVEDPATH_END_POINT.

If a point's value is CURVEDPATH_END_POINT, then a line or curve ends on this point. If a curve control point is next to this point, a curve will have this point as an endpoint. Otherwise, straight lines are drawn between successive end points.

If a point's value is CURVEDPATH_QUADRATIC_BEZIER_CONTROL_POINT, the point is a control point for a quadratic bezier. The control point of a quadratic bezier is the single point that "stretches" the curve awway from the end points. If a point is a quadratic bezier control point, the points preceeding and succeeding it must be end points (CURVEDPATH_END_POINT).

If a point's value is CURVEDPATH_CUBIC_BEZIER_CONTROL_POINT, the point is a control point for a cubic bezier. A cubic bezier has two control points that "stretch" the curve away from the end points. Cubic bezier control points must come in sets of two, with end points (CURVEDPATH_END_POINT) coming before the first control point and after the second.

colors - Ordered list of color values for each vertex ( 0x00RRGGBB format ). If null, a solid filled path will be drawn in the current foreground color.
offsets - List defining the beginnings of each path in the xPts/yPts data arrays, or null to indicate a single path. A path that begins at point (xPts[offsets[i]],yPts[offsets[i]]) will end at point (xPts[offsets[i+1]]-1,yPts[offsets[i+1]]-1).
Throws:
IllegalArgumentException - If the data is malformed. For example, the values in offsets is negative or not in increasing order, there are fewer than 2 points in a single path, the values in offsets index outside the points arrays, the values in pointTypes are invalid, or offsets is null and xPts and yPts are not the same length.
Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

drawText

public int drawText(byte[] text,
                    int offset,
                    int len,
                    int x,
                    int y,
                    int flags,
                    int width)
Draws text contained in a byte array.

Use this method to draw a string of text, with your specified position values, and within a specified drawing region.

Your text string is encapsulated in a byte array. Since the only character representation currently supported by the system is Unicode, we assume that all the high bytes are 0. Otherwise, you should use the drawText method that takes a char array.

Parameters:
text - String to draw.
offset - Element of the text byte array at which to start drawing.
len - Number of character glyphs to draw.
x - Horizontal position of drawing anchor.
y - Vertical position of drawing anchor.
flags - Combination of constant drawing position flags.
width - Width of region available for drawing.
Returns:
Actual block width of text drawn, in pixels. This includes any width of text clipped by the clipping region, but not text clipped by the width parameter.
Throws:
IndexOutOfBoundsException - If your offset+len parameters extend beyond the length of your byte array.

drawText

public int drawText(char[] text,
                    int offset,
                    int len,
                    int x,
                    int y,
                    int flags,
                    int width)
Draws text contained in a char array.

Use this method to draw a string of text (encapsulate in a char arry), with your specified position values, and within a specified drawing region.

Parameters:
text - String to draw.
offset - Element of the text char array at which to start drawing.
len - Number of character glyphs to draw.
x - Horizontal position of drawing anchor.
y - Vertical position of drawing anchor.
flags - Combination of constant drawing position flags.
width - Width of region available for drawing.
Returns:
Actual block width of text drawn, in pixels. This includes any width of text clipped by the clipping region, but not text clipped by the width parameter.
Throws:
IndexOutOfBoundsException - If your offset+len parameters extend beyond the length of your char array.

drawText

public int drawText(char character,
                    int x,
                    int y,
                    int flags,
                    int width)
Draws a text character.

Use this method to draw a text character. You specify the position of the drawing anchor, and this method renders the character's glyph using the default font.

If the glyph to draw is too large for the current clipping region, this method crops to fit.

Parameters:
character - Character to draw.
x - Horizontal position of drawing anchor.
y - Vertical position of drawing anchor.
flags - Combination of constant drawing position flags.
width - The width to draw. If the width of the rendered text is longer than the value of the width parameter, the text is clipped.
  • If ELLIPSIS is set in the draw style, the ellipsis and the text last character are fully drawn and no further characters are drawn.
  • If CENTER is set in draw style, the text is centered in the region from x to x+width.
  • If RIGHT is specified in the draw style, the text ends at x+width, with clipping and the ellipsis to the left of the text.
Returns:
Actual block width of the glyph, in pixels (including width of any clipped pixels).

drawText

public int drawText(StringBuffer text,
                    int offset,
                    int len,
                    int x,
                    int y,
                    int flags,
                    int width)
Draws text contained in a string buffer.

Use this method to draw a string of text with your specified position values, and within a specified drawing region.

Parameters:
text - StringBuffer to draw.
offset - Character in the string buffer at which to start drawing.
len - Number of character glyphs to draw.
x - Horizontal position of drawing anchor.
y - Vertical position of drawing anchor.
flags - Combination of constant drawing position flags.
width - Width of region available for drawing.
Returns:
Actual block width of text drawn, in pixels. This includes any width of text clipped by the clipping region, but not text clipped by the width parameter.
Throws:
IndexOutOfBoundsException - If your offset+len parameters extend beyond the length of your string buffer.

drawText

public int drawText(String text,
                    int x,
                    int y)
Draws a text string.

Use this method to draw a string of text using the default position values (LEFT|TOP).

If the string to draw is too large for the current clipping region, this method crops to fit.

Parameters:
text - String to draw.
x - Horizontal position of drawing anchor.
y - Vertical position of drawing anchor.
Returns:
Actual block widths of text drawn, in pixels (including width of any clipped text).

drawText

public int drawText(String text,
                    int x,
                    int y,
                    int flags)
Draws a text string with specified positioning.

Use this method to draw a string of text, with your specified position values.

Parameters:
text - String to draw.
x - Horizontal position of drawing anchor.
y - Vertical position of drawing anchor.
flags - Combination of constant drawing position flags.
Returns:
Actual block width of text drawn, in pixels (including width of any clipped text).

drawText

public int drawText(String text,
                    int x,
                    int y,
                    int flags,
                    int width)
Draws text within a specified width.

Use this method to draw a string of text, with your specified position values, and within a specified drawing region.

Parameters:
text - String to draw.
x - Horizontal position of drawing anchor.
y - Vertical position of drawing anchor.
flags - Combination of constant drawing position flags.
width - Width of region available for drawing.
Returns:
Actual block width of text drawn, in pixels. This includes any width of text clipped by the clipping region, but not text clipped by the width parameter.

drawText

public int drawText(String text,
                    int offset,
                    int len,
                    int x,
                    int y,
                    int flags,
                    int width)
Draws text contained in a string.

Use this method to draw a string of text with your specified position values, and within a specified drawing region.

Parameters:
text - String to draw.
offset - Character in the string at which to start drawing.
len - Number of character glyphs to draw.
x - Horizontal position of drawing anchor.
y - Vertical position of drawing anchor.
flags - Combination of constant drawing position flags.
width - Width of region available for drawing.
Returns:
Actual block width of text drawn, in pixels. This includes any width of text clipped by the clipping region, but not text clipped by the width parameter.
Throws:
IndexOutOfBoundsException - If your offset+len parameters extend beyond the length of your string.

drawTexturedPath

public void drawTexturedPath(int[] xPts,
                             int[] yPts,
                             byte[] pointTypes,
                             int[] offsets,
                             int xOrigin,
                             int yOrigin,
                             int dux,
                             int dvx,
                             int duy,
                             int dvy,
                             Bitmap textureData)
Draws a set of texture-filled paths.

Use this method to draw one or more texture-filled non-intersecting paths that contain line segments or curves. You specify the x and y coordinates and point types of the paths desired.

The offsets indicate the beginnings of each path in the data array. The data in the ith path is defined to be the (xPts,yPts) values from offsets[i] to offsets[i+1]-1 inclusive. Thus if there are N values in offsets, there are N-1 paths defined, where the final value is one greater than the offset where the final point of the final path is located in the points data. If offsets is null, the xPts and yPts data will be treated as a single path, and these arrays must have the same length.

The xPts and yPts arrays keep track of each vertex in the polygon and each value in the xPts array must have a corresponding value at the same index in the yPts array, and a corresponding value at the same index in the pointTypes array.

None of the edges in a path may cross any other edge in any of the paths (including itself). If edges do cross, the drawing behaviour is undefined. A path may be fully contained within another path, e.g. a "donut" shape.

The paths are filled by the "even-odd" rule. Thus if a ray is drawn from any point, the area containing the point will be filled if the ray passes through an odd number of edges and will not be filled if is passes through an even number of edges.

The texture used to fill the path is specified as a Bitmap. Starting from the texture origin (as specified in local coordinates by xOrigin and yOrigin), the texture is mapped into the path, being tiled as necessary to fill the region. The scale and angle used to map the texture are specified by the two walk vectors (dux, dvx) and (duy, dvy) (u and v are taked to correspond to x and y, but in texture space rather than in screen space). dux and dvx indicate how many u and v coordinates to skip in the texture per x coordinate on the screen. Likewise, duy and dvy indicate how texture coordinates to skip per y coordinate on the screen. These four values are represented in 15.16 fixed point, allowing for eight bits of decimal precision. Using these walk vectors it is possible to achieve arbitrary rotation, scaling, and skewing on a given texture.

Note that each non-null array parameter must be a different array.

Parameters:
xPts - Ordered list of x values for each vertex in the paths.
yPts - Ordered list of y values for each vertex in the paths.
pointTypes - One of CURVEDPATH_END_POINT, CURVEDPATH_QUADRATIC_BEZIER_CONTROL_POINT, or CURVEDPATH_CUBIC_BEZIER_CONTROL_POINT. There must be one of these values for each (x,y) point defined. If pointTypes is null, all point are assumed to be of type CURVEDPATH_END_POINT.

If a point's value is CURVEDPATH_END_POINT, then a line or curve ends on this point. If a curve control point is next to this point, a curve will have this point as an endpoint. Otherwise, straight lines are drawn between successive end points.

If a point's value is CURVEDPATH_QUADRATIC_BEZIER_CONTROL_POINT, the point is a control point for a quadratic bezier. The control point of a quadratic bezier is the single point that "stretches" the curve away from the end points. If a point is a quadratic bezier control point, the points preceeding and succeeding it must be end points (CURVEDPATH_END_POINT).

If a point's value is CURVEDPATH_CUBIC_BEZIER_CONTROL_POINT, the point is a control point for a cubic bezier. A cubic bezier has two control points that "stretch" the curve away from the end points. Cubic bezier control points must come in sets of two, with end points (CURVEDPATH_END_POINT) coming before the first control point and after the second.

offsets - List defining the beginnings of each path in the xPts/yPts data arrays, or null to indicate a single path. A path that begins at point (xPts[offsets[i]],yPts[offsets[i]]) will end at point (xPts[offsets[i+1]]-1,yPts[offsets[i+1]]-1).
xOrigin - X component of the texture origin in local screen coordinates.
yOrigin - Y component of the texture origin in local screen coordinates.
dux - Number of u points to skip in the texture per x point on screen (15.16 fixed point).
dvx - Number of v points to skip in the texture per x point on screen (15.16 fixed point).
duy - Number of u points to skip in the texture per y point on screen (15.16 fixed point).
dvy - Number of v points to skip in the texture per y point on screen (15.16 fixed point).
textureData - Non-null bitmap to be used as a texture.
Throws:
IllegalArgumentException - If the data is malformed. For example, the values in offsets is negative or not in increasing order, there are fewer than 2 points in a single path, the values in offsets index outside the points arrays, the values in pointTypes are invalid, or offsets is null and xPts and yPts are not the same length.
Since:
JDE 4.2.0

fillArc

public void fillArc(int x,
                    int y,
                    int width,
                    int height,
                    int startAngle,
                    int arcAngle)
Fills a circular or elliptical arc covering a specified rectangle.

The center of the filled arc is the center of a retangle whose origin is (x,y) and whose size is specified by the width and height parameters.

The arc begins at startAngle and extends for arcAngle degrees, using the current draw color. The drawing algorithm assumes that the 0 degree position is in the center of the right edge of the rectangle. The direction of the arc drawn depends on the relative values of startAngle and arcAngle:

  • If (startAngle < arcAngle), this method fills the arc in a counterclockwise direction.
  • If (startAngle > arcAngle), this method fills the arc in a clockwise direction.

The resulting filled region consist of the wedge bounded by the arc segment as if drawn by drawArc(), the radius extending from the center to this arc at startAngle degrees, and radius extending from the center to this arc at (startAngle+arcAngle) degrees.

If either width or height is less than zero, this method draws nothing.

The angles are specified relative to the non-square extents of the bounding rectangle such that 45 degrees always falls on the line from the center of the ellipse to the upper right corner of the bounding rectangle. As a result, if the bounding rectangle is noticeably longer in one axis than the other, the angles to the start and end of the arc segment will be skewed farther along the longer axis of the bounds. ATTENTION: This method doesn't support transformations specified in the setTransformation method.

Parameters:
x - Horizontal coordinate of the arc's starting position.
y - Vertical coordinate of the arc's starting position.
width - Width of rectangle containing the filled arc.
height - Height of rectangle containing the filled arc.
startAngle - Angle position at which to commence drawing the edge of the arc.
arcAngle - Angular extent of the arc, relative to the start angle.

fillEllipse

public void fillEllipse(int cx,
                        int cy,
                        int px,
                        int py,
                        int qx,
                        int qy,
                        int startAngle,
                        int arcAngle)
Fills an ellipse.

Fills an ellipse with the specified endpoints P = (px, py) and Q = (qx, qy) of two conjugate diameters of the ellipse. The endpoints are specified as absolute coordinates.

This example shows an ellipse with the aligned p and q points.

This example shows how the p and q points can be used to draw a non-aligned ellipse.

Parameters:
cx - X-ordinate of the ellipse centre. cx is one of the coordinates of the center point of the ellipse.
cy - Y-ordinate of the ellipse centre. cy is one of the coordinates of the center point of the ellipse.
px - X-ordinate of the point P. P is one of the coordinates of the tangents of a parallelogram that bounds the ellipse. By convention, if the ellipse is aligned with the screen axes, the p point defines the x-axis radius.
py - Y-ordinate of the point P. P is one of the coordinates of the tangents of a parallelogram that bounds the ellipse. By convention, if the ellipse is aligned with the screen axes, the p point defines the x-axis radius.
qx - X-ordinate of the point Q. Q is one of the coordinates of the tangents of a parallelogram that bounds the ellipse. By convention, if the ellipse is aligned with the screen axes, the q point defines the y-axis radius.
qy - Y-ordinate of the point Q. Q is one of the coordinates of the tangents of a parallelogram that bounds the ellipse. By convention, if the ellipse is aligned with the screen axes, the q point defines the y-axis radius.
startAngle - Arc start angle. Drawing starts at the angular position defined by the start angle (clockwise with zero degrees being the x-axis and x left, y down) and ends at an angular position equal to the start angle plus the arc angle. For example, if you set the start angle to 90 degrees and the arc angle to 90 degrees, the ellipse starts at the y axis and continues to the x axis.
arcAngle - Angular extent of the arc, relative to the start angle.
Since:
JDE 4.2.0

fillRect

public void fillRect(int x,
                     int y,
                     int width,
                     int height)
Fills a rectangle.

Use this method to fill a rectangle. You specify the top and left edges of the rectangle, and its width and height. This method paints the right edge of the rect at (x+width-1), the bottom edge at (y+height-1). The resulting rectangle will thus have an area of width * height.

If you pass in a zero or negative value for either the height or width, this method draws nothing.

Parameters:
x - Left edge of the rectangle.
y - Top edge of the rectangle.
width - Width of the rectangle.
height - Height of the rectangle.

fillRoundRect

public void fillRoundRect(int x,
                          int y,
                          int width,
                          int height,
                          int arcWidth,
                          int arcHeight)
Fills a rectangle with rounded edges.

Use this method to fill a rectangle with rounded edges. You specify the top and left edges of the rectangle, and its width and height. This method draws the right edge of the filled rectangle at (x+width-1), the bottom edge at (y+height-1). The resulting rectangle will thus have an area, assuming no rounded corners, of width * height.

If you pass in a zero or negative value for either the height or width, this method draws nothing.

Use the arcWidth and arcHeight parameters to describe the arcs used to round off the four corners.

Parameters:
x - Left edge of the rectangle.
y - Top edge of the rectangle.
width - Width of the rectangle.
height - Height of the rectangle.
arcWidth - Width of arc used to round the four corners.
arcHeight - Height of arc used to round the four corners.

getAbsoluteClippingRect

public void getAbsoluteClippingRect(XYRect clip)
Retreives the absolute coordinates of current clipping region.

Use this method to retrieve, into a provided XYRect object, the absolute coordinates of the current clipping region.

Since the out parameter contains only a copy of the clipping region, altering its contents has no effect on the current clipping region.

Parameters:
clip - Clipping region is returned in this parameter.

getBackgroundColor

public int getBackgroundColor()
Retrieves the current background color.
Returns:
Current color in the form 0x00RRGGBB.

getClippingRect

public XYRect getClippingRect()
Retrieves the local coordinates of current clipping region.

The returned XYRect is owned by this graphics object and you should not change it. Instead, use this class's various push and pop methods to change the extent of the current clipping region.

Returns:
Current clipping rect.

getColor

public int getColor()
Retrieves the current foreground drawing color.
Returns:
Current color in the form 0x00RRGGBB.

getContextStackSize

public int getContextStackSize()
Retrieves the size of the stack of drawing contexts.
Returns:
Number of elements on the context stack.
Since:
JDE 4.1.0

getDrawingOffset

public void getDrawingOffset(XYPoint offset)
Retrieves the absolute coordinates for the current drawing offset.

The drawing offset is the point, offset from the top left corner of the screen, which drawing operations use as their origin point.

Parameters:
offset - Drawing offset is returned in this paramater.

getFont

public Font getFont()
Retrieves the current font for the current graphics context.
Returns:
Current font used for text drawing operations.

getGlobalAlpha

public int getGlobalAlpha()
Retrieves the current global alpha value.
Returns:
Current alpha value in the range 0x00 to 0xff.
Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

getNumColors

public static int getNumColors()
Deprecated. Use DisplayInstance.getNumColors();

Retrieve the number of colors that the device's screen can display.
Returns:
Number of colors the screen can display.
Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

getScreenHeight

public static int getScreenHeight()
Deprecated. Use Display.getHeight()

Retrieves total drawing height of the screen.
Returns:
Height in pixels of the device screen's drawable area.

getScreenHorizontalResolution

public static int getScreenHorizontalResolution()
Deprecated. Use Display.getHorizontalResolution()

Retrieve screen's horizontal resolution in pixels per meter (PPM).
Returns:
Horizontal resolution (PPM) of screen.

getScreenVerticalResolution

public static int getScreenVerticalResolution()
Deprecated. Use Display.getVerticalResolution()

Retrieve screen's vertical resolution in pixels per meter (PPM).
Returns:
Vertical resolution (PPM) of screen.

getScreenWidth

public static int getScreenWidth()
Deprecated. Use Display.getWidth()

Retrieves total drawing width of the screen.
Returns:
Width in pixels of the device screen's drawable area.

getStipple

public int getStipple()
Retrieves the current line stippling value.
Returns:
Current stipple mask.

getTranslateX

public int getTranslateX()
Retrieves the horizontal component of the current drawing offset.
Returns:
X value of drawing offset.
Since:
JDE 3.6.0

getTranslateY

public int getTranslateY()
Retrieves the vertical component of the current drawing offset.
Returns:
Y value of drawing offset.
Since:
JDE 3.6.0

invert

public void invert(int x,
                   int y,
                   int width,
                   int height)
Inverts a region.

This method performs a one's complement operation on each pixel in your specified region.

Parameters:
x - Left edge of the region.
y - Top edge of the region.
width - Width of the region.
height - Height of the region.

invert

public void invert(XYRect rect)
Inverts a region specified by an XYRect object.

This method performs a one's complement operation on each pixel in your specified region.

Parameters:
rect - Region to invert.

isColor

public static boolean isColor()
Deprecated. Use DisplayInstance.isColor().

Determines if the device has a color display.
Returns:
True if the device has a color display; otherwise, false.
Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

isDrawingStyleSet

public boolean isDrawingStyleSet(int drawStyle)
Determines whether the specified drawing style is turned on.
Parameters:
drawStyle - Graphics drawing style to be checked.
Returns:
True if the specified style is turned on; otherwise, false.
Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

isRopSupported

public boolean isRopSupported(int rop)
Determines if a raster operation is supported.

Use this method to query if a particular raster operation is supported for the Graphics object. Note that all ROP2s as well as ROP_SRC_COPY, ROP_SRCMONOEXPAND_COPY, ROP_SRC_ALPHA and ROP_SRCMONOEXPAND_ALPHA are always supported.

Parameters:
rop - Constant for the raster operation to query.
Returns:
If true, specified raster operation is supported; otherwise, false.
Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

popContext

public void popContext()
Pops a drawing context off the stack.

Use this method to pop off the context stack the last context pushed.


pushContext

public boolean pushContext(int x,
                           int y,
                           int width,
                           int height,
                           int xOffset,
                           int yOffset)
Pushes a clipping region (and optional drawing offset) onto the context stack.

This clipping region is updated by intersecting with the previous clipping region. Unlike pushRegion(int, int, int, int, int, int), the drawing offset is not adjusted by the value of the region origin. You can also specify an additional drawing offset update by using the xOffset and yOffset parameters.

To setup a subregion for local drawing, pushRegion(int, int, int, int, int, int) should be used.

Parameters:
x - Left edge of clipping region.
y - Top edge of clipping region.
width - Width in pixels of clipping region.
height - Height in pixels of clipping region.
xOffset - Optional, additional horizontal scroll offset.
yOffset - Optional, additional vertical scroll offset.

pushContext

public boolean pushContext(XYRect clip,
                           int xOffset,
                           int yOffset)
Pushes a clipping region (and optional drawing offset) onto the context stack.

This clipping region is updated by intersecting with the previous clipping region. Unlike pushRegion(int, int, int, int, int, int), the drawing offset is not adjusted by the value of the region origin. You can also specify an additional drawing offset update by using the xOffset and yOffset parameters.

To setup a subregion for local drawing pushRegion should be used.

Parameters:
clip - New clipping region in local coordinates.
xOffset - Optional, additional horizontal scroll offset.
yOffset - Optional, additional vertical scroll offset.

pushRegion

public boolean pushRegion(int x,
                          int y,
                          int width,
                          int height,
                          int xScroll,
                          int yScroll)
Pushes a drawing region (and optional scroll offset) onto the context stack.

The clipping region is updated by intersecting with the previous clipping region. The drawing offset is adjusted by the value of the region origin. You can also specify an (optional) additional scroll offset with the xScroll and yScroll parameters.

This method is suitable for pushing a context for drawing into a subregion.

Parameters:
x - Left edge of the region.
y - Top edge of the region.
width - Width of the region.
height - Height of the region.
xScroll - Optional, additional scroll offset.
yScroll - Optional, additional scroll offset.

pushRegion

public boolean pushRegion(XYRect region)
Pushes a drawing region onto the context stack, specified by a XYRect object.

The clipping region is updated by intersecting with the previous clipping region. The drawing offset is adjusted by the value of the region origin.

This method is suitable for pushing a context for drawing into a subregion.

Parameters:
region - New drawing region rectangle in local coordinates.

pushRegion

public boolean pushRegion(XYRect region,
                          int xScroll,
                          int yScroll)
Pushes a drawing region (and optional scroll offset) onto the context stack.

This method behaves exactly like pushRegion(XYRect), except you can also specify an (optional) additional scroll offset with the xScroll and yScroll parameters.

Parameters:
region - New drawing region in local coordinates.
xScroll - Optional, additional horizontal scroll offset.
yScroll - Optional, additional vertical scroll offset.

rop

public void rop(int rop,
                int x,
                int y,
                int width,
                int height,
                Bitmap source,
                int left,
                int top)
Executes an area raster operation on the specified region.

Use this method to run a raster operation with or without a source bitmap.

You must specify the extent of the region to draw to, as well as the top left position in the (optional) source bitmap.

Parameters:
rop - Constant for the raster operation to execute.
x - Left edge of the destination region.
y - Top edge of the destination region.
width - Width of the destination region.
height - Height of the destination region.
source - Source bitmap to use (may be null for some raster operations)
left - Left edge of region within bitmap to use.
top - Top edge of region within bitmap to use.
Since:
JDE 3.6.0

setBackgroundColor

public void setBackgroundColor(int RGB)
Sets the current background color.
Parameters:
RGB - Color to use, of the form 0x00RRGGBB.

setColor

public void setColor(int RGB)
Sets the current color.

All subsequent rendering will be done in this color (more precisely, rendering will be done in a displayable colour that is nearest to the colour you specify).

Parameters:
RGB - Color to use, of the form 0x00RRGGBB.

setDrawingStyle

public void setDrawingStyle(int drawStyle,
                            boolean on)
Sets the current drawing style.
Parameters:
drawStyle - Graphics drawing style to turn on or off.
on - True to turn on the specified style, false to turn it off.
Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

setFont

public void setFont(Font font)
Sets the current font for the current graphics context.

Subsequent text rendering uses this font.

Parameters:
font - New font.
Throws:
NullPointerException - If font is null.

setGlobalAlpha

public void setGlobalAlpha(int alpha)
Sets the current global alpha value for drawing operations. It ranges from 0 (fully transparent) to 255 (fully opaque).

Be sure to reset the global alpha value when appropriate since all subsequent operations are done using the value specified. Global alpha is stored on the stack so popContext will restore it to the previous value.

Note that alpha will be clamped to the range 0-255.

Parameters:
alpha - Alpha value to use, from 0 (fully transparent) to 255 (fully opaque).
Since:
JDE 3.7.0
Category:
Colour: Pertains to devices' ability to display colour. May only be applicable on colour devices.

setStipple

public void setStipple(int mask)
Sets the current line stippling value.

All subsequent line rendering operations will be done with this stipple value. The stipple value is a 32 bit bitmask where a 1 indicates a pixel should be drawn and a 0 indicates the destination pixel should be left as is. The mask is cycled through as the line is drawn.

Parameters:
mask - The stipple mask to use for line drawing.

tileRop

public void tileRop(int rop,
                    int x,
                    int y,
                    int width,
                    int height,
                    Bitmap source,
                    int left,
                    int top)
Executes an area raster operation on the specified region, tiling the source bitmap if necessary.

Use this method to run a raster operation with or without a source bitmap.

You must specify the extent of the region to draw to, as well as the top left position in the (optional) source bitmap.

Parameters:
rop - Constant for the raster operation to execute.
x - Left edge of the destination region.
y - Top edge of the destination region.
width - Width of the destination region.
height - Height of the destination region.
source - Source bitmap to use (may be null for some raster operations)
left - Left edge of region within bitmap to use.
top - Top edge of region within bitmap to use.
Since:
JDE 3.6.0

translate

public void translate(int x,
                      int y)
Apply a translation to the current drawing offset.

The drawing offset is updated by adding the x and y offsets.

Parameters:
x - Horizontal offset to add to the current x drawing offset.
y - Vertical offset to add to the current y drawing offset.
Since:
JDE 3.6.0



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