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# Class jclass.bwt.JCCheckbox

    java.lang.Object
       |
       +----java.awt.Component
               |
               +----java.awt.Canvas
                       |
                       +----jclass.bwt.JCComponent
                               |
                               +----jclass.bwt.JCLabel
                                       |
                                       +----jclass.bwt.JCCheckbox

public class JCCheckbox
extends JCLabel
implements JCItemSelectable

A component that is used for representing 2 or more states. It consists of an indicator and a label. It contains two functions for building groups of checkboxes:

- makeGroup takes an array of labels and an array of values and creates a group of radio buttons with associated values for each button.
- makeCollection takes the same parameters and produces an array of individual check boxes

Behavior

- When the checkbox is pressed, it will be displayed in its next state.
- If the checkbox is pressed and the mouse is dragged outside the button, the checkbox will be displayed in its previous state, ie the activation is temporarily cancelled until the mouse is dragged within the checkbox.
- If the mouse button is pressed and then released within the checkbox, the checkbox is cycled to its next state, and an event is generated.
- If the space key is hit, the checkbox will cycle to its next state. This is equivalent to clicking it.

Properties

Name | Method
--- | ---
Background | setBackground
DoubleBuffer | setDoubleBuffer
Font | setFont
Foreground | setForeground
HighlightColor | setHighlightColor
HighlightThickness | setHighlightThickness
Indicator | setIndicator
IndicatorImageList | setIndicatorImageList
Insets | setInsets
Label | setLabel
NumStates | setNumStates
PreferredSize | setPreferredSize
SelectColor | setSelectColor
ShadowThickness | setShadowThickness
State | setState
Traversable | setTraversable
UnselectColor | setUnselectColor
UserData | setUserData

Events

Class | Listener | Description
--- | --- | ---
JCItemEvent | addItemListener | Posted when the button's state changes

##

ind_height
  Calculated indicator size.
ind_width
  Calculated indicator size.
ind_x
  Calculated indicator position.
ind_y
  Calculated indicator position.
INDETERMINATE
INDICATOR_CHECK
INDICATOR_CIRCLE
INDICATOR_CROSS
INDICATOR_DIAMOND
INDICATOR_FILL
INDICATOR_IMAGE
indicator_set
  Whether setIndicator() has been called.
INDICATOR_SIZE
  Default indicator size.
itemListeners
  List of JCItemEvent listeners
label_offset
  Separation between the indicator and the label.
OFF
ON

##

JCCheckbox()
  Creates an empty checkbox.
JCCheckbox(Object)
  Creates a checkbox with the specified label.
JCCheckbox(Object, Applet, String)
  Creates a checkbox which reads parameters from the applet's HTML file.
JCCheckbox(Object, int, JCCheckboxGroup)
  Creates a button with the specified label, set to the specified state, and in the specified check box group.
JCCheckbox(Object, JCCheckboxGroup, int)
  Creates a button as part of a CheckboxGroup.

##

addItemListener(JCItemListener)
  Adds the specified item listener to receive item events from this checkbox.
addNotify()
  Calculates indicator size.
armAction(Event)
  Temporarily changes the state.
clickAction(Event)
  Changes the button's state and posts an JCItemEvent.
drawHighlight(Graphics, boolean)
  Draws or clears the highlight rectangle (called by paint).
drawIndicator(Graphics)
  Draws the indicator.
getCheckboxGroup()
  Returns the checkbox group.
getIndicator()
  Gets the Indicator value.
getIndicatorImageList()
  Gets the IndicatorImageList value.
getIndicatorImageURLList()
  Gets the IndicatorImageList value.
getNumStates()
  Gets the NumStates value.
getParameters()
  Reads the parameter values from the HTML page using the component's applet.
getSelectColor()
  Gets the SelectColor value.
getSelectedIndexes()
  Returns an array (length 1) containing the selected index (0), or null if the checkbox is not set.
getSelectedObjects()
  Returns the an array (length 1) containing the checkbox label, or null if the checkbox is not set.
getState()
  Gets the current state.
getUnselectColor()
  Gets the UnselectColor value.
keyDown(Event, int)
  If key is space, calls armAction, clickAction
layout()
  Lays out the label's internal elements.
makeGroup(Object[], int[], boolean)
  This static function creates a group of buttons.
mouseDown(Event, int, int)
  Calls armAction if btn1 was pressed.
mouseEnter(Event, int, int)
  If the mouse was pressed and is moved inside the button, the state is reset to its original value and the indicator is redrawn.
mouseExit(Event, int, int)
  If the mouse was pressed and is moved outside the button, the state is reset to its original value and the indicator is redrawn.
mouseUp(Event, int, int)
  If the cursor is within the button, calls clickAction
paintComponent(Graphics)
  Draws indicator and label
preferredHeight()
  Gets the subclass' preferred height (default: 100).
preferredWidth()
  Gets the subclass' preferred width (default: 100).
removeItemListener(JCItemListener)
  Removes the specified item listener so it no longer receives item events from this checkbox.
setCheckboxGroup(JCCheckboxGroup)
  Sets this button to the specified group.
setIndicator(int)
  Sets the indicator style:

      INDICATOR_FILL     Indicator is drawn, and its shadows are switched
      INDICATOR_CHECK    Checkmark
      INDICATOR_CIRCLE   Circle
      INDICATOR_CROSS    X (default)
      INDICATOR_DIAMOND  Diamond
      INDICATOR_IMAGE    Image specified by ImageList

  HTML param name/value: "Indicator"/enum

setIndicatorImageList(Image[])
  Sets a list of indicator images to be used if Indicator is INDICATOR_IMAGE.
setIndicatorImageURLList(URL[])
  Sets a list of indicator images to be used if Indicator is INDICATOR_IMAGE.
setIndicatorSize()
  Set the indicator size.
setNumStates(int)
  Sets the maximum number of states that can be set (default: 2).
setSelectColor(Color)
  The color of the indicator background when the button is set (default: Color.white).
setState(int)
  Sets the button's state.
setState(int, boolean)
  Sets the button's state, optionally specifying that the button's events are to be posted.
setUnselectColor(Color)
  The color of the indicator background when the button is not set (default: Color.white).

##

INDICATOR_FILL

     public static final int INDICATOR_FILL

INDICATOR_CHECK

     public static final int INDICATOR_CHECK

INDICATOR_CIRCLE

     public static final int INDICATOR_CIRCLE

INDICATOR_CROSS

     public static final int INDICATOR_CROSS

INDICATOR_DIAMOND

     public static final int INDICATOR_DIAMOND

INDICATOR_IMAGE

     public static final int INDICATOR_IMAGE

OFF

     public static final int OFF

ON

     public static final int ON

INDETERMINATE

     public static final int INDETERMINATE

label_offset

     protected int label_offset

  Separation between the indicator and the label.

ind_height

     protected int ind_height

  Calculated indicator size.

ind_width

     protected int ind_width

  Calculated indicator size.

ind_x

     protected int ind_x

  Calculated indicator position.

ind_y

     protected int ind_y

  Calculated indicator position.

indicator_set

     protected boolean indicator_set

  Whether setIndicator() has been called.

itemListeners

     protected JCVector itemListeners

  List of JCItemEvent listeners

INDICATOR_SIZE

     public static final int INDICATOR_SIZE

  Default indicator size.

##

JCCheckbox

     public JCCheckbox()

  Creates an empty checkbox. No parameters are read from an HTML file.

JCCheckbox

     public JCCheckbox(Object label)

  Creates a checkbox with the specified label. No parameters are read from an HTML file.

JCCheckbox

     public JCCheckbox(Object label,
                       Applet applet,
                       String name)

  Creates a checkbox which reads parameters from the applet's HTML file.

  Parameters:
    applet - the applet whose PARAM tags are to be read
    name - if this is not null, only parameters preceded by this name are read
  See Also:
    getParameter

JCCheckbox

     public JCCheckbox(Object label,
                       JCCheckboxGroup group,
                       int value)

  Creates a button as part of a CheckboxGroup.

  Parameters:
    label - the checkbox's label
    group - the "owner" of the box. This can be null.
    value - the userdata associated with the checkbox. This can be retrieved by calling getUserDataInt(). If the checkbox is currently selected, calling the group's getValue() method will return this value.
  See Also:
    getValue, getUserDataInt

JCCheckbox

     public JCCheckbox(Object label,
                       int state,
                       JCCheckboxGroup group)

  Creates a button with the specified label, set to the specified state, and in the specified check box group.

  Parameters:
    label - the label on the Checkbox
    state - is the initial state of this Checkbox
    group - the CheckboxGroup this Checkbox is in
  See Also:
    setState

##

getParameters

     protected void getParameters()

  Reads the parameter values from the HTML page using the component's applet. The values will override those previously set.

  Overrides:
    getParameters in class JCLabel

makeGroup

     public static JCCheckboxGroup makeGroup(Object labels[],
                                             int values[],
                                             boolean radio_behavior)

  This static function creates a group of buttons.

  Parameters:
    labels - a list of labels for each checkbox
    values - a list of values for each checkbox (may be null)
    radio_behavior - if true, setting one checkbox will deselect any other
  Returns:
    a JCCheckboxGroup containing the check boxes
  See Also:
    setRadioBehavior

getIndicator

     public int getIndicator()

  Gets the Indicator value.

  See Also:
    setIndicator

setIndicator

     public synchronized void setIndicator(int v)

  Sets the indicator style:

      INDICATOR_FILL     Indicator is drawn, and its shadows are switched
      INDICATOR_CHECK    Checkmark
      INDICATOR_CIRCLE   Circle
      INDICATOR_CROSS    X (default)
      INDICATOR_DIAMOND  Diamond
      INDICATOR_IMAGE    Image specified by ImageList

  HTML param name/value: "Indicator"/enum

  Throws: IllegalArgumentException
    If an invalid value is set
  See Also:
    setState, toEnum

getIndicatorImageList

     public Image[] getIndicatorImageList()

  Gets the IndicatorImageList value.

  See Also:
    setIndicatorImageList

setIndicatorImageList

     public synchronized void setIndicatorImageList(Image v[])

  Sets a list of indicator images to be used if Indicator is INDICATOR_IMAGE. If this property is not set, no indicator is displayed. The position of the image within the list is specified by the State value. HTML param name/value: "IndicatorImageList"/comma-separated list of images

  See Also:
    toImageList, setIndicator, setState

getIndicatorImageURLList

     public URL[] getIndicatorImageURLList()

  Gets the IndicatorImageList value.

  See Also:
    setIndicatorImageList

setIndicatorImageURLList

     public synchronized void setIndicatorImageURLList(URL list[])

  Sets a list of indicator images to be used if Indicator is INDICATOR_IMAGE. If this property is not set, no indicator is displayed. The position of the image within the list is specified by the State value. HTML param name/value: "IndicatorImageList"/comma-separated list of images

  See Also:
    toImageList, setIndicator, setState

getNumStates

     public int getNumStates()

  Gets the NumStates value.

  See Also:
    setNumStates

setNumStates

     public synchronized void setNumStates(int v)

  Sets the maximum number of states that can be set (default: 2). By default, the button can be set to OFF and ON.

  HTML param name/value: "NumStates"/int

getSelectColor

     public Color getSelectColor()

  Gets the SelectColor value.

  See Also:
    setSelectColor

setSelectColor

     public synchronized void setSelectColor(Color v)

  The color of the indicator background when the button is set (default: Color.white). If set to null, the indicator will be filled with the current background color.

  This value only applies to FILL and DIAMOND indicators. All other indicators are filled with a white background.

  HTML param name/value: "SelectColor"/Color

  See Also:
    setIndicator, toColor

getUnselectColor

     public Color getUnselectColor()

  Gets the UnselectColor value.

  See Also:
    setUnselectColor

setUnselectColor

     public synchronized void setUnselectColor(Color v)

  The color of the indicator background when the button is not set (default: Color.white). If set to null, the indicator will be filled with the current background color.

  This value only applies to FILL and DIAMOND indicators. All other indicators are filled with a white background.

  HTML param name/value: "UnselectColor"/Color

  See Also:
    setIndicator, toColor

getState

     public int getState()

  Gets the current state.

  See Also:
    setState

setState

     public void setState(int state)

  Sets the button's state. For convenience, the following ints are provided: OFF (0), ON (1) and INDETERMINATE (2). The number of states is specified by NumStates. As the user clicks on the button, the value of State increments through the states, and then back to 0 (OFF). The button's clickAction() method is not called, and thus no events are posted.

  HTML param name/value: "State"/int, "ON", or "OFF"

  See Also:
    setNumStates, getState, toInt

setState

     public void setState(int state,
                          boolean notify)

  Sets the button's state, optionally specifying that the button's events are to be posted.

  Parameters:
    notify - if true the button's clickAction() method is called
  See Also:
    clickAction

getCheckboxGroup

     public JCCheckboxGroup getCheckboxGroup()

  Returns the checkbox group.

  See Also:
    setCheckboxGroup

setCheckboxGroup

     public void setCheckboxGroup(JCCheckboxGroup g)

  Sets this button to the specified group. The previous group's current button is unset.

setIndicatorSize

     protected void setIndicatorSize()

  Set the indicator size.

getSelectedIndexes

     public int[] getSelectedIndexes()

  Returns an array (length 1) containing the selected index (0), or null if the checkbox is not set.

  See Also:
    JCItemSelectable

getSelectedObjects

     public Object[] getSelectedObjects()

  Returns the an array (length 1) containing the checkbox label, or null if the checkbox is not set.

  See Also:
    JCItemSelectable

addNotify

     public void addNotify()

  Calculates indicator size.

  Overrides:
    addNotify in class JCLabel

layout

     public synchronized void layout()

  Lays out the label's internal elements.

  Overrides:
    layout in class JCLabel

drawHighlight

     protected void drawHighlight(Graphics gc,
                                  boolean on)

  Draws or clears the highlight rectangle (called by paint).

  Parameters:
    on - if true, draws the highlight rectangle and a dashed rectangle around the label; otherwise clears the rect
  Overrides:
    drawHighlight in class JCComponent

paintComponent

     protected void paintComponent(Graphics gc)

  Draws indicator and label

  Overrides:
    paintComponent in class JCLabel

drawIndicator

     protected void drawIndicator(Graphics gc)

  Draws the indicator.

preferredWidth

     protected int preferredWidth()

  Gets the subclass' preferred width (default: 100).

  Overrides:
    preferredWidth in class JCLabel

preferredHeight

     protected int preferredHeight()

  Gets the subclass' preferred height (default: 100).

  Overrides:
    preferredHeight in class JCLabel

addItemListener

     public void addItemListener(JCItemListener l)

  Adds the specified item listener to receive item events from this checkbox.

  See Also:
    JCItemEvent

removeItemListener

     public void removeItemListener(JCItemListener l)

  Removes the specified item listener so it no longer receives item events from this checkbox.

armAction

     public void armAction(Event ev)

  Temporarily changes the state. The state is not set permanently until clickAction() is called, since the user may release the mouse button while the cursor is outside the checkbox.

  See Also:
    clickAction

clickAction

     public void clickAction(Event ev)

  Changes the button's state and posts an JCItemEvent.

  See Also:
    setState, addItemListener

mouseExit

     public boolean mouseExit(Event ev,
                              int x,
                              int y)

  If the mouse was pressed and is moved outside the button, the state is reset to its original value and the indicator is redrawn.

  Overrides:
    mouseExit in class Component

mouseEnter

     public boolean mouseEnter(Event ev,
                               int x,
                               int y)

  If the mouse was pressed and is moved inside the button, the state is reset to its original value and the indicator is redrawn.

  Overrides:
    mouseEnter in class Component

mouseDown

     public boolean mouseDown(Event ev,
                              int x,
                              int y)

  Calls armAction if btn1 was pressed.

  Overrides:
    mouseDown in class JCComponent
  See Also:
    armAction

mouseUp

     public boolean mouseUp(Event ev,
                            int x,
                            int y)

  If the cursor is within the button, calls clickAction

  Overrides:
    mouseUp in class JCLabel
  See Also:
    clickAction

keyDown

     public boolean keyDown(Event ev,
                            int key)

  If key is space, calls armAction, clickAction

  Overrides:
    keyDown in class JCComponent
  See Also:
    armAction, clickAction

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