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java.lang.Objectnet.rim.device.api.ui.Field
net.rim.device.api.ui.component.CheckboxField
public class CheckboxField
Contains a checkbox control.
Behaviour
Displays a checkbox before the text label. In the default font, this box
appears either empty, or containing a check mark, depending upon the state of
the field.
When this field has focus, the box appears inverted and the text label redrawn with the focus colors.
Pressing the spacebar when a checkbox field has the focus toggles its state.
Field Summary |
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Constructor Summary | ||
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CheckboxField()
Creates a new CheckboxField instance. |
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CheckboxField(String label,
boolean checked)
Constructs a new CheckboxField instance with label and starting state. |
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CheckboxField(String label,
boolean checked,
long style)
Constructs a new CheckboxField instance with label, starting state, and style. |
Method Summary | ||
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protected void |
drawFocus(Graphics graphics,
boolean on)
Draws the focus on both icon and the text label for this field. |
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AccessibleContext |
getAccessibleContext()
Returns accessible representation of the field for a screen reader. |
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boolean |
getChecked()
Retrieves this field's state. |
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void |
getFocusRect(XYRect rect)
Retrieves this field's current focus region. |
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String |
getLabel()
Retrieves this field's label string. |
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int |
getPreferredHeight()
Retrieves this field's preferred height. |
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int |
getPreferredWidth()
Retrieves this field's preferred width. |
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protected boolean |
invokeAction(int action)
Invokes an action on this field. |
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protected boolean |
keyChar(char key,
int status,
int time)
Traps SPACE key generation events. |
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protected boolean |
keyDown(int keycode,
int time)
Handles key down events. |
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protected void |
layout(int width,
int height)
Lays out this field's contents. |
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protected void |
makeContextMenu(ContextMenu contextMenu)
Builds this field's context menu. |
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protected int |
moveFocus(int amount,
int status,
int time)
Handles moving the focus within this field. |
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protected void |
onFocus(int direction)
Invoked when a field receives the focus. |
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protected void |
onUnfocus()
Invoked when a field loses the focus. |
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protected void |
paint(Graphics graphics)
Redraws this field. |
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void |
setChecked(boolean checked)
Sets the state of this field. |
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void |
setLabel(String label)
Sets this field's label. |
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String |
toString()
Returns state as a String, "[Yes]" or "[No]". |
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protected boolean |
trackwheelClick(int status,
int time)
Indicates a trackwheel click event. |
Methods inherited from class java.lang.Object |
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equals, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Constructor Detail |
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public CheckboxField()
This builds an unchecked checkbox field with no label.
If full available width is desired, then Field.USE_ALL_WIDTH
style
must be specified using the appropriate constructor.
public CheckboxField(String label, boolean checked)
This builds a checkbox field with the Field.EDITABLE
and
Field.FOCUSABLE
styles.
If full available width is desired, then Field.USE_ALL_WIDTH
style
must be specified using the appropriate constructor.
label
- Label string for this field.checked
- Initial state of this field; true for checked, false for
unchecked.public CheckboxField(String label, boolean checked, long style)
This builds a checkbox field with the Field.EDITABLE
and
Field.FOCUSABLE
styles.
If full available width is desired, then Field.USE_ALL_WIDTH
style
must be specified.
label
- Label string for this field.checked
- Initial state of this field; true for checked, false for
unchecked.style
- The style for this field.Method Detail |
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protected void drawFocus(Graphics graphics, boolean on)
drawFocus
in class Field
graphics
- Graphics context for drawing the focus.on
- True if the focus should be set; otherwise, false.public boolean getChecked()
public String getLabel()
public int getPreferredHeight()
Field.getPreferredHeight()
for more information.
Managers may make use of this value during layout.
getPreferredHeight
in class Field
public int getPreferredWidth()
Field.getPreferredWidth()
for more information.
Managers make use of this value during layout.
getPreferredWidth
in class Field
protected boolean invokeAction(int action)
Field.ACTION_INVOKE
, which toggles this field from being checked and unchecked.
If action
is not a recognized action then this method does nothing and
returns false
, indicating that the action was not consumed.
Note that if this field is not editable (ie. Field.isEditable()
returns false
)
then the action will not be consumed.
invokeAction
in class Field
action
- the action to be performed on this field.
true
if the action was consumed; false
if the action was not consumed.protected boolean keyChar(char key, int status, int time)
This method handles and consumes a key generation event, if it's the SPACE key that's generated; otherwise, this method does nothing and does not consume the event.
If the key pressed was the space bar, then this method toggles the state of this field (prompting a repaint to show the new state of the checkbox).
keyChar
in class Field
key
- Character generated by the event.status
- Modifier key status (this parameter is ignored).time
- Number of milliseconds since the device was turned on.
protected boolean keyDown(int keycode, int time)
This method handles and consumes a key generation event, if it's the "action"(5) key (for reduced keyboard device) that's generated; otherwise, this method does nothing and does not consume the event.
keyDown
in class Field
keycode
- Code of key pressed.time
- Number of milliseconds since the device was turned on.
protected void layout(int width, int height)
This field's manager invokes this method during the layout process to instruct this field to arrange its contents, given an amount of avilable space.
layout
in class Field
width
- Amount of available horizontal space.height
- Amount of available vertical space.protected void makeContextMenu(ContextMenu contextMenu)
The framework uses Field.getContextMenu()
to invoke this method to
construct this field's context menu. You shouldn't invoke this method
directly.
makeContextMenu
in class Field
contextMenu
- Context menu to create.ContextMenu
protected int moveFocus(int amount, int status, int time)
This field's manager invokes this method only when this field
already has the focus.
If this field is Field.EDITABLE
, then this method handles the case
where the user ALT-rolls the trackwheel (trapping these events to toggle
the state of the checkbox). Otherwise, this field simply passes the roll
amount of the event on.
moveFocus
in class Field
amount
- Amount rolled. This value is either entirely consumed if
the field is Field.EDITABLE
, or passed on entirely if the field is not
editable.status
- Modifier key state: if not
KeypadListener.STATUS_ALT
, then this method does nothing and
returns the entire roll amount.time
- Number of milliseconds since the device was turned on.
protected void onFocus(int direction)
Field
The method will not be invoked if this field already has focus. Also,
it will not be invoked if this field returns false from
Field.isFocusable()
.
Managers should find a child field that accepts focus and cascade this method's call to it.
The direction value indicates how the focus came to enter the field:
onFocus
in class Field
direction
- Indicates from which direction the focus enters the
field.protected void onUnfocus()
Field
The method will not be invoked if this field does not already have the focus.
By default, this method clears the muddy bit and removes selection. If your custom field requires special handling upon losing the focus, you must override this method. Don't forget to call this method on the parent though, or the muddy bit won't get cleared.
onUnfocus
in class Field
protected void paint(Graphics graphics)
This field's manager invokes this method during the repainting process to instruct this field to repaint itself.
paint
in class Field
graphics
- Graphics context for repainting this field.public void setChecked(boolean checked)
checked
- Pass true to check this field's checkbox; false to clear
this field's checkbox.public void setLabel(String label)
label
- Label string for this field: always appears just to the
right of the checkbox.public String toString()
toString
in class Object
protected boolean trackwheelClick(int status, int time)
The system invokes this method when passing on a trackwheel click event.
The ALT-click combination will enter selection mode, or if in selection mode will copy.
trackwheelClick
in class Field
status
- Bitfield of values defined by Keypad
.time
- Number of milliseconds since the device was turned on.
public AccessibleContext getAccessibleContext()
getAccessibleContext
in class Field
public void getFocusRect(XYRect rect)
Field
The framework uses this method to retrieve the current focus region for this field, in field-local coordinates; that is, the region that is made visible by the framework (by scrolling) when the field has the focus.
By default, the focus region is the same as the field's entire extent, in content coordinates.
getFocusRect
in class Field
rect
- Object to contain the focus rect for this field in local
coordinates.
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