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Class java.awt.Component

java.lang.Object
  |
  +--java.awt.Component
Subclasses:
Container, Label, TextComponent

public abstract class Component
extends Object
implements java.awt.image.ImageObserver, java.awt.MenuContainer, java.io.Serializable
A component is an object having a graphical representation that can be displayed on the screen and that can interact with the user. Examples of components are the buttons, checkboxes, and scrollbars of a typical graphical user interface.

The Component class is the abstract superclass of the nonmenu-related Abstract Window Toolkit components. Class Component can also be extended directly to create a lightweight component. A lightweight component is a component that is not associated with a native opaque window.

Version:
1.196, 06/06/98
See Also:
Serialized Form

Inner Class Summary
Component.NativeInLightFixer
          This odd class is to help out a native component that has been embedded in a lightweight component.
 
Field Summary
static String actionListenerK
          Internal, constants for serialization
static String adjustmentListenerK
           
static boolean assert
           
java.awt.Color background
          The background color for this component.
static float BOTTOM_ALIGNMENT
          Ease-of-use constant for getAlignmentY.
static float CENTER_ALIGNMENT
          Ease-of-use constant for getAlignmentY and getAlignmentX.
java.beans.PropertyChangeSupport changeSupport
           
java.awt.event.ComponentListener componentListener
           
static String componentListenerK
           
java.awt.ComponentOrientation componentOrientation
          The orientation for this component.
int componentSerializedDataVersion
           
static String containerListenerK
           
java.awt.Cursor cursor
          The cursor displayed when pointer is over this component.
java.awt.dnd.DropTarget dropTarget
          The DropTarget associated with this Component.
boolean enabled
          True when the object is enabled.
long eventMask
           
java.awt.event.FocusListener focusListener
           
static String focusListenerK
           
java.awt.Font font
          The font used by this component.
java.awt.Color foreground
          The foreground color for this component.
boolean hasFocus
          True if this component has enabled focus events and currently has the focus.
int height
          The height of the component.
static int incRate
           
java.awt.event.InputMethodListener inputMethodListener
           
static String inputMethodListenerK
           
static boolean isInc
          Static properties for incremental drawing.
static String itemListenerK
           
java.awt.event.KeyListener keyListener
           
static String keyListenerK
           
static float LEFT_ALIGNMENT
          Ease-of-use constant for getAlignmentX.
java.util.Locale locale
          The locale for the component.
static Object LOCK
          The locking object for AWT component-tree and layout operations.
java.awt.Dimension minSize
          Internal, cached size information
java.awt.event.MouseListener mouseListener
           
static String mouseListenerK
           
java.awt.event.MouseMotionListener mouseMotionListener
           
static String mouseMotionListenerK
           
String name
           
boolean nameExplicitlySet
           
boolean newEventsOnly
           
Container parent
          The parent of the object.
java.awt.peer.ComponentPeer peer
          The peer of the component.
java.util.Vector popups
           
java.awt.Dimension prefSize
          Internal, cached size information
static float RIGHT_ALIGNMENT
          Ease-of-use constant for getAlignmentX.
static long serialVersionUID
           
static String textListenerK
           
static float TOP_ALIGNMENT
          Ease-of-use constant for getAlignmentY().
boolean valid
          True when the object is valid.
boolean visible
          True when the object is visible.
int width
          The width of the component.
static String windowListenerK
           
int x
          The x position of the component in the parent's coordinate system.
int y
          The y position of the component in the parent's coordinate system.
 
Constructor Summary
Component()
          Constructs a new component.
 
Method Summary
static void ()
           
boolean action(Event evt, Object what)
          Deprecated.  
void add(java.awt.PopupMenu popup)
          Adds the specified popup menu to the component.
void addComponentListener(java.awt.event.ComponentListener l)
          Adds the specified component listener to receive component events from this component.
void addFocusListener(java.awt.event.FocusListener l)
          Adds the specified focus listener to receive focus events from this component when this component gains input focus.
void addInputMethodListener(java.awt.event.InputMethodListener l)
          Adds the specified input method listener to receive input method events from this component.
void addKeyListener(java.awt.event.KeyListener l)
          Adds the specified key listener to receive key events from this component.
void addMouseListener(java.awt.event.MouseListener l)
          Adds the specified mouse listener to receive mouse events from this component.
void addMouseMotionListener(java.awt.event.MouseMotionListener l)
          Adds the specified mouse motion listener to receive mouse motion events from this component.
void addNotify()
          Notifies this component that it has been added to a displayable containment hierarchy.
void addPropertyChangeListener(java.beans.PropertyChangeListener listener)
          Add a PropertyChangeListener to the listener list.
void addPropertyChangeListener(String propertyName, java.beans.PropertyChangeListener listener)
          Add a PropertyChangeListener for a specific property.
boolean areInputMethodsEnabled()
           
java.awt.Rectangle bounds()
          Deprecated.  
int checkImage(java.awt.Image image, java.awt.image.ImageObserver observer)
          Returns the status of the construction of a screen representation of the specified image.
int checkImage(java.awt.Image image, int width, int height, java.awt.image.ImageObserver observer)
          Returns the status of the construction of a screen representation of the specified image.
AWTEvent coalesceEvents(AWTEvent existingEvent, AWTEvent newEvent)
          Potentially coalesce an event being posted with an existing event.
String constructComponentName()
          Construct a name for this component.
boolean contains(int x, int y)
          Checks whether this component "contains" the specified point, where x and y are defined to be relative to the coordinate system of this component.
boolean contains(java.awt.Point p)
          Checks whether this component "contains" the specified point, where the point's x and y coordinates are defined to be relative to the coordinate system of this component.
java.awt.Image createImage(java.awt.image.ImageProducer producer)
          Creates an image from the specified image producer.
java.awt.Image createImage(int width, int height)
          Creates an off-screen drawable image to be used for double buffering.
void deliverEvent(Event e)
          Deprecated.  
void disable()
          Deprecated.  
void disableEvents(long eventsToDisable)
          Disables the events defined by the specified event mask parameter from being delivered to this component.
void dispatchEvent(AWTEvent e)
          Dispatches an event to this component or one of its sub components.
void dispatchEventImpl(AWTEvent e)
           
void doLayout()
          Prompts the layout manager to lay out this component.
void enable()
          Deprecated.  
void enable(boolean b)
          Deprecated.  
void enableEvents(long eventsToEnable)
          Enables the events defined by the specified event mask parameter to be delivered to this component.
void enableInputMethods(boolean enable)
          Enables or disables input method support for this component.
void ensureWindowActivation(AWTEvent event)
          Makes sure that the window(s) where this event occurred are active, depending upon the event.
boolean eventEnabled(AWTEvent e)
           
void firePropertyChange(String propertyName, Object oldValue, Object newValue)
          Support for reporting bound property changes.
float getAlignmentX()
          Returns the alignment along the x axis.
float getAlignmentY()
          Returns the alignment along the y axis.
java.awt.Color getBackground()
          Gets the background color of this component.
java.awt.Rectangle getBounds()
          Gets the bounds of this component in the form of a Rectangle object.
java.awt.Rectangle getBounds(java.awt.Rectangle rv)
          Store the bounds of this component into "return value" rv and return rv.
java.awt.image.ColorModel getColorModel()
          Gets the instance of ColorModel used to display the component on the output device.
Component getComponentAt(int x, int y)
          Determines if this component or one of its immediate subcomponents contains the (xy) location, and if so, returns the containing component.
Component getComponentAt(java.awt.Point p)
          Returns the component or subcomponent that contains the specified point.
java.awt.ComponentOrientation getComponentOrientation()
          Retrieve the language-sensitive orientation that is to be used to order the elements or text within this component.
java.awt.Cursor getCursor()
          Gets the cursor set on this component.
java.awt.dnd.DropTarget getDropTarget()
          Get the DropTarget associated with this Component
java.awt.Font getFont()
          Gets the font of this component.
java.awt.FontMetrics getFontMetrics(java.awt.Font font)
          Gets the font metrics for the specified font.
java.awt.Color getForeground()
          Gets the foreground color of this component.
java.awt.Graphics getGraphics()
          Creates a graphics context for this component.
int getHeight()
          Return the current height of this component.
java.awt.im.InputContext getInputContext()
          Gets the input context used by this component for handling the communication with input methods when text is entered in this component.
java.awt.im.InputMethodRequests getInputMethodRequests()
          Gets the input method request handler which supports requests from input methods for this component.
java.util.Locale getLocale()
          Gets the locale of this component.
java.awt.Point getLocation()
          Gets the location of this component in the form of a point specifying the component's top-left corner.
java.awt.Point getLocation(java.awt.Point rv)
          Store the x,y origin of this component into "return value" rv and return rv.
java.awt.Point getLocationOnScreen()
          Gets the location of this component in the form of a point specifying the component's top-left corner in the screen's coordinate space.
java.awt.Dimension getMaximumSize()
          Gets the maximum size of this component.
java.awt.Dimension getMinimumSize()
          Gets the mininimum size of this component.
String getName()
          Gets the name of the component.
Container getNativeContainer()
           
Container getParent()
          Gets the parent of this component.
java.awt.peer.ComponentPeer getPeer()
          Deprecated.  
java.awt.Dimension getPreferredSize()
          Gets the preferred size of this component.
java.awt.Dimension getSize()
          Returns the size of this component in the form of a Dimension object.
java.awt.Dimension getSize(java.awt.Dimension rv)
          Store the width/height of this component into "return value" rv and return rv.
java.awt.Toolkit getToolkit()
          Gets the toolkit of this component.
Object getTreeLock()
          Gets the locking object for AWT component-tree and layout Gets this component's locking object (the object that owns the thread sychronization monitor) for AWT component-tree and layout operations.
int getWidth()
          Return the current width of this component.
Window getWindowForObject(Object obj)
          Returns the Window subclass that contains this object.
int getX()
          Return the current x coordinate of the components origin.
int getY()
          Return the current y coordinate of the components origin.
boolean gotFocus(Event evt, Object what)
          Deprecated.  
boolean handleEvent(Event evt)
          Deprecated.  
boolean hasFocus()
          Returns true if this Component has the keyboard focus.
void hide()
          Deprecated.  
boolean imageUpdate(java.awt.Image img, int flags, int x, int y, int w, int h)
          Repaints the component when the image has changed.
static void initIDs()
          Initialize JNI field and method IDs
boolean inside(int x, int y)
          Deprecated.  
void invalidate()
          Invalidates this component.
boolean isDisplayable()
          Determines whether this component is displayable.
boolean isDoubleBuffered()
          Returns true if this component is painted to an offscreen image ("buffer") that's copied to the screen later.
boolean isEnabled()
          Determines whether this component is enabled.
boolean isFocusTraversable()
          Returns the value of a flag that indicates whether this component can be traversed using Tab or Shift-Tab keyboard focus traversal.
boolean isLightweight()
          A lightweight component doesn't have a native toolkit peer.
boolean isOpaque()
          Returns true if this component is completely opaque, returns false by default.
boolean isShowing()
          Determines whether this component is showing on screen.
boolean isValid()
          Determines whether this component is valid.
boolean isVisible()
          Determines whether this component is visible.
boolean keyDown(Event evt, int key)
          Deprecated.  
boolean keyUp(Event evt, int key)
          Deprecated.  
void layout()
          Deprecated.  
void list()
          Prints a listing of this component to the standard system output stream System.out.
void list(java.io.PrintStream out)
          Prints a listing of this component to the specified output stream.
void list(java.io.PrintStream out, int indent)
          Prints out a list, starting at the specified indention, to the specified print stream.
void list(java.io.PrintWriter out)
          Prints a listing to the specified print writer.
void list(java.io.PrintWriter out, int indent)
          Prints out a list, starting at the specified indention, to the specified print writer.
Component locate(int x, int y)
          Deprecated.  
java.awt.Point location()
          Deprecated.  
boolean lostFocus(Event evt, Object what)
          Deprecated.  
java.awt.Dimension minimumSize()
          Deprecated.  
boolean mouseDown(Event evt, int x, int y)
          Deprecated.  
boolean mouseDrag(Event evt, int x, int y)
          Deprecated.  
boolean mouseEnter(Event evt, int x, int y)
          Deprecated.  
boolean mouseExit(Event evt, int x, int y)
          Deprecated.  
boolean mouseMove(Event evt, int x, int y)
          Deprecated.  
boolean mouseUp(Event evt, int x, int y)
          Deprecated.  
void move(int x, int y)
          Deprecated.  
void nextFocus()
          Deprecated.  
void paintAll(java.awt.Graphics g)
          Paints this component and all of its subcomponents.
void paint(java.awt.Graphics g)
          Paints this component.
String paramString()
          Returns the parameter string representing the state of this component.
boolean postEvent(Event e)
          Deprecated.  
boolean postsOldMouseEvents()
           
java.awt.Dimension preferredSize()
          Deprecated.  
boolean prepareImage(java.awt.Image image, java.awt.image.ImageObserver observer)
          Prepares an image for rendering on this component.
boolean prepareImage(java.awt.Image image, int width, int height, java.awt.image.ImageObserver observer)
          Prepares an image for rendering on this component at the specified width and height.
void printAll(java.awt.Graphics g)
          Prints this component and all of its subcomponents.
void print(java.awt.Graphics g)
          Prints this component.
void processComponentEvent(ComponentEvent e)
          Processes component events occurring on this component by dispatching them to any registered ComponentListener objects.
void processEvent(AWTEvent e)
          Processes events occurring on this component.
void processFocusEvent(java.awt.event.FocusEvent e)
          Processes focus events occurring on this component by dispatching them to any registered FocusListener objects.
void processInputMethodEvent(java.awt.event.InputMethodEvent e)
          Processes input method events occurring on this component by dispatching them to any registered InputMethodListener objects.
void processKeyEvent(java.awt.event.KeyEvent e)
          Processes key events occurring on this component by dispatching them to any registered ode> objects.
void processMouseEvent(java.awt.event.MouseEvent e)
          Processes mouse events occurring on this component by dispatching them to any registered MouseListener objects.
void processMouseMotionEvent(java.awt.event.MouseEvent e)
          Processes mouse motion events occurring on this component by dispatching them to any registered MouseMotionListener objects.
void readObject(java.io.ObjectInputStream s)
           
void remove(java.awt.MenuComponent popup)
          Removes the specified popup menu from the component.
void removeComponentListener(java.awt.event.ComponentListener l)
          Removes the specified component listener so that it no longer receives component events from this component.
void removeFocusListener(java.awt.event.FocusListener l)
          Removes the specified focus listener so that it no longer receives focus events from this component.
void removeInputMethodListener(java.awt.event.InputMethodListener l)
          Removes the specified input method listener so that it no longer receives input method events from this component.
void removeKeyListener(java.awt.event.KeyListener l)
          Removes the specified key listener so that it no longer receives key events from this component.
void removeMouseListener(java.awt.event.MouseListener l)
          Removes the specified mouse listener so that it no longer receives mouse events from this component.
void removeMouseMotionListener(java.awt.event.MouseMotionListener l)
          Removes the specified mouse motion listener so that it no longer receives mouse motion events from this component.
void removeNotify()
          Notifies this component that it has been removed from its displayable containment hierarchy.
void removePropertyChangeListener(java.beans.PropertyChangeListener listener)
          Remove a PropertyChangeListener from the listener list.
void removePropertyChangeListener(String propertyName, java.beans.PropertyChangeListener listener)
          Remove a PropertyChangeListener for a specific property.
void repaint()
          Repaints this component.
void repaint(long tm)
          Repaints the component.
void repaint(int x, int y, int width, int height)
          Repaints the specified rectangle of this component.
void repaint(long tm, int x, int y, int width, int height)
          Repaints the specified rectangle of this component within tm milliseconds.
void requestFocus()
          Requests that this component get the input focus.
void reshape(int x, int y, int width, int height)
          Deprecated.  
void resize(int width, int height)
          Deprecated.  
void resize(java.awt.Dimension d)
          Deprecated.  
void setBackground(java.awt.Color c)
          Sets the background color of this component.
void setBounds(int x, int y, int width, int height)
          Moves and resizes this component.
void setBounds(java.awt.Rectangle r)
          Moves and resizes this component to conform to the new bounding rectangle r.
void setComponentOrientation(java.awt.ComponentOrientation o)
          Set the language-sensitive orientation that is to be used to order the elements or text within this component.
void setCursor(java.awt.Cursor cursor)
          Set the cursor image to a predefined cursor.
void setDropTarget(java.awt.dnd.DropTarget dt)
          Associate a DropTarget with this Component.
void setEnabled(boolean b)
          Enables or disables this component, depending on the value of the parameter b.
void setFont(java.awt.Font f)
          Sets the font of this component.
void setForeground(java.awt.Color c)
          Sets the foreground color of this component.
void setLocale(java.util.Locale l)
          Sets the locale of this component.
void setLocation(int x, int y)
          Moves this component to a new location.
void setLocation(java.awt.Point p)
          Moves this component to a new location.
void setName(String name)
          Sets the name of the component to the specified string.
void setSize(int width, int height)
          Resizes this component so that it has width width and height.
void setSize(java.awt.Dimension d)
          Resizes this component so that it has width d.width and height d.height.
void setVisible(boolean b)
          Shows or hides this component depending on the value of parameter b.
void show()
          Deprecated.  
void show(boolean b)
          Deprecated.  
java.awt.Dimension size()
          Deprecated.  
String toString()
          Returns a string representation of this component and its values.
void transferFocus()
          Transfers the focus to the next component.
void update(java.awt.Graphics g)
          Updates this component.
void validate()
          Ensures that this component has a valid layout.
void writeObject(java.io.ObjectOutputStream s)
           
 
Methods inherited from class java.lang.Object
, clone, equals, finalize, getClass, hashCode, notifyAll, notify, registerNatives, toString, wait, wait, wait
 

Field Detail

peer

transient java.awt.peer.ComponentPeer peer
The peer of the component. The peer implements the component's behaviour. The peer is set when the Component is added to a container that also is a peer.
See Also:
addNotify, removeNotify

parent

transient Container parent
The parent of the object. It may be null for top-level components.
See Also:
getParent

x

int x
The x position of the component in the parent's coordinate system.
See Also:
getLocation

y

int y
The y position of the component in the parent's coordinate system.
See Also:
getLocation

width

int width
The width of the component.
See Also:
getSize

height

int height
The height of the component.
See Also:
getSize

foreground

java.awt.Color foreground
The foreground color for this component.
See Also:
getForeground, setForeground

background

java.awt.Color background
The background color for this component.
See Also:
getBackground, setBackground

font

java.awt.Font font
The font used by this component.
See Also:
getFont, setFont

cursor

java.awt.Cursor cursor
The cursor displayed when pointer is over this component.
See Also:
getCursor, setCursor

locale

java.util.Locale locale
The locale for the component.
See Also:
getLocale, setLocale

visible

boolean visible
True when the object is visible. An object that is not visible is not drawn on the screen.
See Also:
isVisible, setVisible

enabled

boolean enabled
True when the object is enabled. An object that is not enabled does not interact with the user.
See Also:
isEnabled, setEnabled

valid

boolean valid
True when the object is valid. An invalid object needs to be layed out. This flag is set to false when the object size is changed.
See Also:
isValid, validate, invalidate

dropTarget

java.awt.dnd.DropTarget dropTarget
The DropTarget associated with this Component.
See Also:
setDropTarget, getDropTarget

hasFocus

boolean hasFocus
True if this component has enabled focus events and currently has the focus.
See Also:
hasFocus, processFocusEvent

popups

java.util.Vector popups

name

private String name

nameExplicitlySet

private boolean nameExplicitlySet

LOCK

static final Object LOCK
The locking object for AWT component-tree and layout operations.
See Also:
getTreeLock

minSize

java.awt.Dimension minSize
Internal, cached size information

prefSize

java.awt.Dimension prefSize
Internal, cached size information

componentOrientation

transient java.awt.ComponentOrientation componentOrientation
The orientation for this component.
See Also:
getComponentOrientation, setComponentOrientation(java.awt.ComponentOrientation)

newEventsOnly

boolean newEventsOnly

componentListener

transient java.awt.event.ComponentListener componentListener

focusListener

transient java.awt.event.FocusListener focusListener

keyListener

transient java.awt.event.KeyListener keyListener

mouseListener

transient java.awt.event.MouseListener mouseListener

mouseMotionListener

transient java.awt.event.MouseMotionListener mouseMotionListener

inputMethodListener

transient java.awt.event.InputMethodListener inputMethodListener

actionListenerK

static final String actionListenerK
Internal, constants for serialization

adjustmentListenerK

static final String adjustmentListenerK

componentListenerK

static final String componentListenerK

containerListenerK

static final String containerListenerK

focusListenerK

static final String focusListenerK

itemListenerK

static final String itemListenerK

keyListenerK

static final String keyListenerK

mouseListenerK

static final String mouseListenerK

mouseMotionListenerK

static final String mouseMotionListenerK

textListenerK

static final String textListenerK

windowListenerK

static final String windowListenerK

inputMethodListenerK

static final String inputMethodListenerK

eventMask

long eventMask

assert

private static final boolean assert

isInc

static boolean isInc
Static properties for incremental drawing.
See Also:
imageUpdate

incRate

static int incRate

TOP_ALIGNMENT

public static final float TOP_ALIGNMENT
Ease-of-use constant for getAlignmentY(). Specifies an alignment to the top of the component.
See Also:
getAlignmentY

CENTER_ALIGNMENT

public static final float CENTER_ALIGNMENT
Ease-of-use constant for getAlignmentY and getAlignmentX. Specifies an alignment to the center of the component
See Also:
getAlignmentX, getAlignmentY

BOTTOM_ALIGNMENT

public static final float BOTTOM_ALIGNMENT
Ease-of-use constant for getAlignmentY. Specifies an alignment to the bottom of the component.
See Also:
getAlignmentY

LEFT_ALIGNMENT

public static final float LEFT_ALIGNMENT
Ease-of-use constant for getAlignmentX. Specifies an alignment to the left side of the component.
See Also:
getAlignmentX

RIGHT_ALIGNMENT

public static final float RIGHT_ALIGNMENT
Ease-of-use constant for getAlignmentX. Specifies an alignment to the right side of the component.
See Also:
getAlignmentX

serialVersionUID

private static final long serialVersionUID

changeSupport

private java.beans.PropertyChangeSupport changeSupport

componentSerializedDataVersion

private int componentSerializedDataVersion
Constructor Detail

Component

protected Component()
Constructs a new component. Class Component can be extended directly to create a lightweight component that does not utilize an opaque native window. A lightweight component must be hosted by a native container somewhere higher up in the component tree (for example, by a Frame object).
Method Detail

static void ()

constructComponentName

String constructComponentName()
Construct a name for this component. Called by getName() when the name is null.

getName

public String getName()
Gets the name of the component.
Returns:
This component's name.
See Also:
setName

setName

public void setName(String name)
Sets the name of the component to the specified string.
Parameters:
name - The string that is to be this component's name.
See Also:
getName

getParent

public Container getParent()
Gets the parent of this component.
Returns:
The parent container of this component.

getPeer

public java.awt.peer.ComponentPeer getPeer()
Deprecated. As of JDK version 1.1, programs should not directly manipulate peers. replaced by boolean isDisplayable().

setDropTarget

public void setDropTarget(java.awt.dnd.DropTarget dt)
Associate a DropTarget with this Component.
Parameters:
dt - The DropTarget

getDropTarget

public java.awt.dnd.DropTarget getDropTarget()
Get the DropTarget associated with this Component

getTreeLock

public final Object getTreeLock()
Gets the locking object for AWT component-tree and layout Gets this component's locking object (the object that owns the thread sychronization monitor) for AWT component-tree and layout operations.
Returns:
This component's locking object.

getToolkit

public java.awt.Toolkit getToolkit()
Gets the toolkit of this component. Note that the frame that contains a component controls which toolkit is used by that component. Therefore if the component is moved from one frame to another, the toolkit it uses may change.
Returns:
The toolkit of this component.

isValid

public boolean isValid()
Determines whether this component is valid. Components are invalidated when they are first shown on the screen.
Returns:
true if the component is valid; false otherwise.
See Also:
validate, invalidate

isDisplayable

public boolean isDisplayable()
Determines whether this component is displayable. Components are displayable when they are added to a displayable containment hierarchy. A containment hierarchy becomes displayable when its root Window object is packed or made visible.
Returns:
true if the component is displayable; false otherwise.
See Also:
addNotify, removeNotify

isVisible

public boolean isVisible()
Determines whether this component is visible. Components are initially visible, with the exception of top level components such as Frame objects.
Returns:
true if the component is visible; false otherwise.
See Also:
setVisible

isShowing

public boolean isShowing()
Determines whether this component is showing on screen. This means that the component must be visible, and it must be in a container that is visible and showing.
Returns:
true if the component is showing; false otherwise.
See Also:
setVisible

isEnabled

public boolean isEnabled()
Determines whether this component is enabled. An enabled component can respond to user input and generate events. Components are enabled initially by default. A component may be enabled or disabled by calling its setEnabled method.
Returns:
true if the component is enabled; false otherwise.
See Also:
setEnabled

setEnabled

public void setEnabled(boolean b)
Enables or disables this component, depending on the value of the parameter b. An enabled component can respond to user input and generate events. Components are enabled initially by default.
Parameters:
b - If true, this component is enabled; otherwise this component is disabled.
See Also:
isEnabled

enable

public void enable()
Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).

enable

public void enable(boolean b)
Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).

disable

public void disable()
Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).

isDoubleBuffered

public boolean isDoubleBuffered()
Returns true if this component is painted to an offscreen image ("buffer") that's copied to the screen later. Component subclasses that support double buffering should override this method to return true if double buffering is enabled.
Returns:
false by default

enableInputMethods

public void enableInputMethods(boolean enable)
Enables or disables input method support for this component. If input method support is enabled and the component also processes key events, incoming events are offered to the current input method and will only be processed by the component or dispatched to its listeners if the input method does not consume them. By default, input method support is enabled.
Parameters:
enable - true to enable, false to disable.
See Also:
processKeyEvent

setVisible

public void setVisible(boolean b)
Shows or hides this component depending on the value of parameter b.
Parameters:
b - If true, shows this component; otherwise, hides this component.
See Also:
isVisible

show

public void show()
Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).

show

public void show(boolean b)
Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).

hide

public void hide()
Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).

getForeground

public java.awt.Color getForeground()
Gets the foreground color of this component.
Returns:
This component's foreground color. If this component does not have a foreground color, the foreground color of its parent is returned.
See Also:
#java.awt.Component#setForeground(java.awt.Color)

setForeground

public void setForeground(java.awt.Color c)
Sets the foreground color of this component.
Parameters:
c - The color to become this component's foreground color.
See Also:
getForeground

getBackground

public java.awt.Color getBackground()
Gets the background color of this component.
Returns:
This component's background color. If this component does not have a background color, the background color of its parent is returned.
See Also:
setBackground(java.awt.Color)

setBackground

public void setBackground(java.awt.Color c)
Sets the background color of this component.
Parameters:
c - The color to become this component's background color.
See Also:
getBackground

getFont

public java.awt.Font getFont()
Gets the font of this component.
Specified by:
getFont() in interface java.awt.MenuContainer
Returns:
This component's font. If a font has not been set for this component, the font of its parent is returned.
See Also:
setFont

setFont

public void setFont(java.awt.Font f)
Sets the font of this component.
Parameters:
f - The font to become this component's font.
See Also:
getFont

getLocale

public java.util.Locale getLocale()
Gets the locale of this component.
Returns:
This component's locale. If this component does not have a locale, the locale of its parent is returned.
Throws:
IllegalComponentStateException - If the Component does not have its own locale and has not yet been added to a containment hierarchy such that the locale can be determined from the containing parent.
See Also:
setLocale

setLocale

public void setLocale(java.util.Locale l)
Sets the locale of this component.
Parameters:
l - The locale to become this component's locale.
See Also:
getLocale

getColorModel

public java.awt.image.ColorModel getColorModel()
Gets the instance of ColorModel used to display the component on the output device.
Returns:
The color model used by this component.
See Also:
java.awt.image.ColorModel, getColorModel(), getColorModel()

getLocation

public java.awt.Point getLocation()
Gets the location of this component in the form of a point specifying the component's top-left corner. The location will be relative to the parent's coordinate space.
Returns:
An instance of Point representing the top-left corner of the component's bounds in the coordinate space of the component's parent.
See Also:
setLocation, getLocationOnScreen

getLocationOnScreen

public java.awt.Point getLocationOnScreen()
Gets the location of this component in the form of a point specifying the component's top-left corner in the screen's coordinate space.
Returns:
An instance of Point representing the top-left corner of the component's bounds in the coordinate space of the screen.
See Also:
setLocation, getLocation

location

public java.awt.Point location()
Deprecated. As of JDK version 1.1, replaced by getLocation().

setLocation

public void setLocation(int x,
                        int y)
Moves this component to a new location. The top-left corner of the new location is specified by the x and y parameters in the coordinate space of this component's parent.
Parameters:
x - The x-coordinate of the new location's top-left corner in the parent's coordinate space.
y - The y-coordinate of the new location's top-left corner in the parent's coordinate space.
See Also:
getLocation, setBounds

move

public void move(int x,
                 int y)
Deprecated. As of JDK version 1.1, replaced by setLocation(int, int).

setLocation

public void setLocation(java.awt.Point p)
Moves this component to a new location. The top-left corner of the new location is specified by point p. Point p is given in the parent's coordinate space.
Parameters:
p - The point defining the top-left corner of the new location, given in the coordinate space of this component's parent.
See Also:
getLocation, setBounds

getSize

public java.awt.Dimension getSize()
Returns the size of this component in the form of a Dimension object. The height field of the Dimension object contains this component's height, and the width field of the Dimension object contains this component's width.
Returns:
A Dimension object that indicates the size of this component.
See Also:
setSize

size

public java.awt.Dimension size()
Deprecated. As of JDK version 1.1, replaced by getSize().

setSize

public void setSize(int width,
                    int height)
Resizes this component so that it has width width and height.
Parameters:
width - The new width of this component in pixels.
height - The new height of this component in pixels.
See Also:
getSize, setBounds

resize

public void resize(int width,
                   int height)
Deprecated. As of JDK version 1.1, replaced by setSize(int, int).

setSize

public void setSize(java.awt.Dimension d)
Resizes this component so that it has width d.width and height d.height.
Parameters:
d - The dimension specifying the new size of this component.
See Also:
setSize, setBounds

resize

public void resize(java.awt.Dimension d)
Deprecated. As of JDK version 1.1, replaced by setSize(Dimension).

getBounds

public java.awt.Rectangle getBounds()
Gets the bounds of this component in the form of a Rectangle object. The bounds specify this component's width, height, and location relative to its parent.
Returns:
A rectangle indicating this component's bounds.
See Also:
setBounds, getLocation, getSize

bounds

public java.awt.Rectangle bounds()
Deprecated. As of JDK version 1.1, replaced by getBounds().

setBounds

public void setBounds(int x,
                      int y,
                      int width,
                      int height)
Moves and resizes this component. The new location of the top-left corner is specified by x and y, and the new size is specified by width and height.
Parameters:
x - The new x-coordinate of this component.
y - The new y-coordinate of this component.
width - The new width of this component.
height - The new height of this component.
See Also:
getBounds, setLocation(int, int), setLocation(java.awt.Point), setSize(int, int), setSize(java.awt.Dimension)

reshape

public void reshape(int x,
                    int y,
                    int width,
                    int height)
Deprecated. As of JDK version 1.1, replaced by setBounds(int, int, int, int).

setBounds

public void setBounds(java.awt.Rectangle r)
Moves and resizes this component to conform to the new bounding rectangle r. This component's new position is specified by r.x and r.y, and its new size is specified by r.width and r.height
Parameters:
r - The new bounding rectangle for this component.
See Also:
getBounds, setLocation(int, int), setLocation(java.awt.Point), setSize(int, int), setSize(java.awt.Dimension)

getX

public int getX()
Return the current x coordinate of the components origin. This method is preferable to writing component.getBounds().x, or component.getLocation().x because it doesn't cause any heap allocations.
Returns:
the current x coordinate of the components origin.

getY

public int getY()
Return the current y coordinate of the components origin. This method is preferable to writing component.getBounds().y, or component.getLocation().y because it doesn't cause any heap allocations.
Returns:
the current y coordinate of the components origin.

getWidth

public int getWidth()
Return the current width of this component. This method is preferable to writing component.getBounds().width, or component.getSize().width because it doesn't cause any heap allocations.
Returns:
the current width of this component.

getHeight

public int getHeight()
Return the current height of this component. This method is preferable to writing component.getBounds().height, or component.getSize().height because it doesn't cause any heap allocations.
Returns:
the current height of this component.

getBounds

public java.awt.Rectangle getBounds(java.awt.Rectangle rv)
Store the bounds of this component into "return value" rv and return rv. If rv is null a new Rectangle is allocated. This version of getBounds() is useful if the caller wants to avoid allocating a new Rectangle object on the heap.
Parameters:
rv - the return value, modified to the components bounds
Returns:
rv

getSize

public java.awt.Dimension getSize(java.awt.Dimension rv)
Store the width/height of this component into "return value" rv and return rv. If rv is null a new Dimension object is allocated. This version of getSize() is useful if the caller wants to avoid allocating a new Dimension object on the heap.
Parameters:
rv - the return value, modified to the components size
Returns:
rv

getLocation

public java.awt.Point getLocation(java.awt.Point rv)
Store the x,y origin of this component into "return value" rv and return rv. If rv is null a new Point is allocated. This version of getLocation() is useful if the caller wants to avoid allocating a new Point object on the heap.
Parameters:
rv - the return value, modified to the components location
Returns:
rv

isOpaque

public boolean isOpaque()
Returns true if this component is completely opaque, returns false by default.

An opaque component paints every pixel within its rectangular region. A non-opaque component paints only some of its pixels, allowing the pixels underneath it to "show through". A component that does not fully paint its pixels therefore provides a degree of transparency. Only lightweight components can be transparent.

Subclasses that guarantee to always completely paint their contents should override this method and return true. All of the "heavyweight" AWT components are opaque.

Returns:
true if this component is completely opaque.
See Also:
isLightweight


isLightweight

public boolean isLightweight()
A lightweight component doesn't have a native toolkit peer. Subclasses of Component and Container, other than the ones defined in this package like Button or Scrollbar, are lightweight. All of the Swing components are lightweights.
Returns:
true if this component doesn't have a native peer

getPreferredSize

public java.awt.Dimension getPreferredSize()
Gets the preferred size of this component.
Returns:
A dimension object indicating this component's preferred size.
See Also:
getMinimumSize, LayoutManager

preferredSize

public java.awt.Dimension preferredSize()
Deprecated. As of JDK version 1.1, replaced by getPreferredSize().

getMinimumSize

public java.awt.Dimension getMinimumSize()
Gets the mininimum size of this component.
Returns:
A dimension object indicating this component's minimum size.
See Also:
getPreferredSize, java.awtLayoutManager

minimumSize

public java.awt.Dimension minimumSize()
Deprecated. As of JDK version 1.1, replaced by getMinimumSize().

getMaximumSize

public java.awt.Dimension getMaximumSize()
Gets the maximum size of this component.
Returns:
A dimension object indicating this component's maximum size.
See Also:
getMinimumSize, getPreferredSize, LayoutManager

getAlignmentX

public float getAlignmentX()
Returns the alignment along the x axis. This specifies how the component would like to be aligned relative to other components. The value should be a number between 0 and 1 where 0 represents alignment along the origin, 1 is aligned the furthest away from the origin, 0.5 is centered, etc.

getAlignmentY

public float getAlignmentY()
Returns the alignment along the y axis. This specifies how the component would like to be aligned relative to other components. The value should be a number between 0 and 1 where 0 represents alignment along the origin, 1 is aligned the furthest away from the origin, 0.5 is centered, etc.

doLayout

public void doLayout()
Prompts the layout manager to lay out this component. This is usually called when the component (more specifically, container) is validated.
See Also:
validate, LayoutManager

layout

public void layout()
Deprecated. As of JDK version 1.1, replaced by doLayout().

validate

public void validate()
Ensures that this component has a valid layout. This method is primarily intended to operate on instances of Container.
See Also:
invalidate, doLayout(), LayoutManager, validate

invalidate

public void invalidate()
Invalidates this component. This component and all parents above it are marked as needing to be laid out. This method can be called often, so it needs to execute quickly.
See Also:
validate, doLayout, LayoutManager

getGraphics

public java.awt.Graphics getGraphics()
Creates a graphics context for this component. This method will return null if this component is currently not on the screen.
Returns:
A graphics context for this component, or null if it has none.
See Also:
paint

getFontMetrics

public java.awt.FontMetrics getFontMetrics(java.awt.Font font)
Gets the font metrics for the specified font.
Parameters:
font - The font for which font metrics is to be obtained.
font - the font.
Returns:
The font metrics for font.
See Also:
getFont, getPeer(), getFontMetrics(java.awt.Font), getFontMetrics(java.awt.Font)

setCursor

public void setCursor(java.awt.Cursor cursor)
Set the cursor image to a predefined cursor.
Parameters:
cursor - One of the constants defined by the Cursor class.
See Also:
getCursor, java.awt.Cursor

getCursor

public java.awt.Cursor getCursor()
Gets the cursor set on this component.
Returns:
The cursor for this component.
See Also:
setCursor, java.awt.Cursor

paint

public void paint(java.awt.Graphics g)
Paints this component. This method is called when the contents of the component should be painted in response to the component first being shown or damage needing repair. The clip rectangle in the Graphics parameter will be set to the area which needs to be painted.
Parameters:
g - The graphics context to use for painting.
See Also:
update

update

public void update(java.awt.Graphics g)
Updates this component.

The AWT calls the update method in response to a call to repainthe appearance of the component on the screen has not changed since the last call to update or paint. You can assume that the background is not cleared.

The updatemethod of Component does the following:

  • Clears this component by filling it with the background color.
  • Sets the color of the graphics context to be the foreground color of this component.
  • Calls this component's paint method to completely redraw this component.

The origin of the graphics context, its (00) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component.

Parameters:
g - the specified context to use for updating.
See Also:
paint, repaint()


paintAll

public void paintAll(java.awt.Graphics g)
Paints this component and all of its subcomponents.

The origin of the graphics context, its (00) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component.

Parameters:
g - the graphics context to use for painting.
See Also:
paint


repaint

public void repaint()
Repaints this component.

This method causes a call to this component's update method as soon as possible.

See Also:
update(java.awt.Graphics)


repaint

public void repaint(long tm)
Repaints the component. This will result in a call to update within tm milliseconds.
Parameters:
tm - maximum time in milliseconds before update
See Also:
paint, update(java.awt.Graphics)

repaint

public void repaint(int x,
                    int y,
                    int width,
                    int height)
Repaints the specified rectangle of this component.

This method causes a call to this component's update method as soon as possible.

Parameters:
x - the x coordinate.
y - the y coordinate.
width - the width.
height - the height.
See Also:
update(java.awt.Graphics)


repaint

public void repaint(long tm,
                    int x,
                    int y,
                    int width,
                    int height)
Repaints the specified rectangle of this component within tm milliseconds.

This method causes a call to this component's update method.

Parameters:
tm - maximum time in milliseconds before update.
x - the x coordinate.
y - the y coordinate.
width - the width.
height - the height.
See Also:
update(java.awt.Graphics)


print

public void print(java.awt.Graphics g)
Prints this component. Applications should override this method for components that must do special processing before being printed or should be printed differently than they are painted.

The default implementation of this method calls the paint method.

The origin of the graphics context, its (00) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component.

Parameters:
g - the graphics context to use for printing.
See Also:
paint(java.awt.Graphics)


printAll

public void printAll(java.awt.Graphics g)
Prints this component and all of its subcomponents.

The origin of the graphics context, its (00) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component.

Parameters:
g - the graphics context to use for printing.
See Also:
print(java.awt.Graphics)


imageUpdate

public boolean imageUpdate(java.awt.Image img,
                           int flags,
                           int x,
                           int y,
                           int w,
                           int h)
Repaints the component when the image has changed. This imageUpdate method of an ImageObserver is called when more information about an image which had been previously requested using an asynchronous routine such as the drawImage method of Graphics becomes available. See the definition of imageUpdate for more information on this method and its arguments.

The imageUpdate method of Component incrementally draws an image on the component as more of the bits of the image are available.

If the system property awt.image.incrementalDraw is missing or has the value true, the image is incrementally drawn, If the system property has any other value, then the image is not drawn until it has been completely loaded.

Also, if incremental drawing is in effect, the value of the system property awt.image.redrawrate is interpreted as an integer to give the maximum redraw rate, in milliseconds. If the system property is missing or cannot be interpreted as an integer, the redraw rate is once every 100ms.

The interpretation of the x, y, width, and height arguments depends on the value of the infoflags argument.

Specified by:
imageUpdate(java.awt.Image, int, int, int, int, int) in interface java.awt.image.ImageObserver
Parameters:
img - the image being observed.
infoflags - see imageUpdate for more information.
x - the x coordinate.
y - the y coordinate.
width - the width.
height - the height.
Returns:
true if the flags indicate that the image is completely loaded; false otherwise.
See Also:
java.awt.image.ImageObserver, drawImage(java.awt.Image, int, int, java.awt.Color, java.awt.image.ImageObserver), drawImage(java.awt.Image, int, int, java.awt.image.ImageObserver), drawImage(java.awt.Image, int, int, int, int, java.awt.Color, java.awt.image.ImageObserver), drawImage(java.awt.Image, int, int, int, int, java.awt.image.ImageObserver), imageUpdate(java.awt.Image, int, int, int, int, int)


createImage

public java.awt.Image createImage(java.awt.image.ImageProducer producer)
Creates an image from the specified image producer.
Parameters:
producer - the image producer
Returns:
the image produced.

createImage

public java.awt.Image createImage(int width,
                         int height)
Creates an off-screen drawable image to be used for double buffering.
Parameters:
width - the specified width.
height - the specified height.
Returns:
an off-screen drawable image, which can be used for double buffering.

prepareImage

public boolean prepareImage(java.awt.Image image,
                            java.awt.image.ImageObserver observer)
Prepares an image for rendering on this component. The image data is downloaded asynchronously in another thread and the appropriate screen representation of the image is generated.
Parameters:
image - the Image for which to prepare a screen representation.
observer - the ImageObserver object to be notified as the image is being prepared.
Returns:
true if the image has already been fully prepared; false otherwise.

prepareImage

public boolean prepareImage(java.awt.Image image,
                            int width,
                            int height,
                            java.awt.image.ImageObserver observer)
Prepares an image for rendering on this component at the specified width and height.

The image data is downloaded asynchronously in another thread, and an appropriately scaled screen representation of the image is generated.

Parameters:
image - the instance of Image for which to prepare a screen representation.
width - the width of the desired screen representation.
height - the height of the desired screen representation.
observer - the ImageObserver object to be notified as the image is being prepared.
Returns:
true if the image has already been fully prepared; false otherwise.
See Also:
java.awt.image.ImageObserver


checkImage

public int checkImage(java.awt.Image image,
                      java.awt.image.ImageObserver observer)
Returns the status of the construction of a screen representation of the specified image.

This method does not cause the image to begin loading. An application must use the prepareImage method to force the loading of an image.

Information on the flags returned by this method can be found with the discussion of the ImageObserver interface.

Parameters:
image - the Image object whose status is being checked.
observer - the ImageObserver object to be notified as the image is being prepared.
Returns:
the bitwise inclusive OR of ImageObserver flags indicating what information about the image is currently available.
See Also:
prepareImage(java.awt.Image, int, int, java.awt.image.ImageObserver), checkImage(java.awt.Image, int, int, java.awt.image.ImageObserver), java.awt.image.ImageObserver


checkImage

public int checkImage(java.awt.Image image,
                      int width,
                      int height,
                      java.awt.image.ImageObserver observer)
Returns the status of the construction of a screen representation of the specified image.

This method does not cause the image to begin loading. An application must use the prepareImage method to force the loading of an image.

The checkImage method of Component calls its peer's checkImage method to calculate the flags. If this component does not yet have a peer, the component's toolkit's checkImage method is called instead.

Information on the flags returned by this method can be found with the discussion of the ImageObserver interface.

Parameters:
image - the Image object whose status is being checked.
width - the width of the scaled version whose status is to be checked.
height - the height of the scaled version whose status is to be checked.
observer - the ImageObserver object to be notified as the image is being prepared.
Returns:
the bitwise inclusive OR of ImageObserver flags indicating what information about the image is currently available.
See Also:
prepareImage(java.awt.Image, int, int, java.awt.image.ImageObserver), checkImage(java.awt.Image, int, int, java.awt.image.ImageObserver), java.awt.image.ImageObserver#_top_


contains

public boolean contains(int x,
                        int y)
Checks whether this component "contains" the specified point, where x and y are defined to be relative to the coordinate system of this component.
Parameters:
x - the x coordinate of the point.
y - the y coordinate of the point.
See Also:
getComponentAt(int, int)

inside

public boolean inside(int x,
                      int y)
Deprecated. As of JDK version 1.1, replaced by contains(int, int).

contains

public boolean contains(java.awt.Point p)
Checks whether this component "contains" the specified point, where the point's x and y coordinates are defined to be relative to the coordinate system of this component.
Parameters:
p - the point.
See Also:
getComponentAt(java.awt.Point)

getComponentAt

public Component getComponentAt(int x,
                                int y)
Determines if this component or one of its immediate subcomponents contains the (xy) location, and if so, returns the containing component. This method only looks one level deep. If the point (xy) is inside a subcomponent that itself has subcomponents, it does not go looking down the subcomponent tree.

The locate method of Component simply returns the component itself if the (xy) coordinate location is inside its bounding box, and null otherwise.

Parameters:
x - the x coordinate.
y - the y coordinate.
Returns:
the component or subcomponent that contains the (xy) location; null if the location is outside this component.
See Also:
contains(int, int)


locate

public Component locate(int x,
                        int y)
Deprecated. As of JDK version 1.1, replaced by getComponentAt(int, int).

getComponentAt

public Component getComponentAt(java.awt.Point p)
Returns the component or subcomponent that contains the specified point.
Parameters:
p - the point.
See Also:
contains

deliverEvent

public void deliverEvent(Event e)
Deprecated. As of JDK version 1.1, replaced by dispatchEvent(AWTEvent e).

dispatchEvent

public final void dispatchEvent(AWTEvent e)
Dispatches an event to this component or one of its sub components.
Parameters:
e - the event

dispatchEventImpl

void dispatchEventImpl(AWTEvent e)

areInputMethodsEnabled

boolean areInputMethodsEnabled()

eventEnabled

boolean eventEnabled(AWTEvent e)

ensureWindowActivation

private void ensureWindowActivation(AWTEvent event)
Makes sure that the window(s) where this event occurred are active, depending upon the event. Currently, only focus events are watched.

getWindowForObject

private Window getWindowForObject(Object obj)
Returns the Window subclass that contains this object. Will return the object itself, if it is a window.

postEvent

public boolean postEvent(Event e)
Deprecated. As of JDK version 1.1, replaced by dispatchEvent(AWTEvent).
Description copied from interface:
 
Specified by:
postEvent(java.awt.Event) in interface java.awt.MenuContainer


addComponentListener

public void addComponentListener(java.awt.event.ComponentListener l)
Adds the specified component listener to receive component events from this component.
Parameters:
l - the component listener.
See Also:
ComponentEvent, java.awt.event.ComponentListener, removeComponentListener

removeComponentListener

public void removeComponentListener(java.awt.event.ComponentListener l)
Removes the specified component listener so that it no longer receives component events from this component.
Parameters:
l - the component listener.
See Also:
ComponentEvent, java.awt.event.ComponentListener, addComponentListener

addFocusListener

public void addFocusListener(java.awt.event.FocusListener l)
Adds the specified focus listener to receive focus events from this component when this component gains input focus.
Parameters:
l - the focus listener.
See Also:
java.awt.event.FocusEvent, java.awt.event.FocusListener, removeFocusListener

removeFocusListener

public void removeFocusListener(java.awt.event.FocusListener l)
Removes the specified focus listener so that it no longer receives focus events from this component.
Parameters:
l - the focus listener.
See Also:
java.awt.event.FocusEvent, java.awt.event.FocusListener, addFocusListener

addKeyListener

public void addKeyListener(java.awt.event.KeyListener l)
Adds the specified key listener to receive key events from this component.
Parameters:
l - the key listener.
See Also:
java.awt.event.KeyEvent, java.awt.event.KeyListener, removeKeyListener

removeKeyListener

public void removeKeyListener(java.awt.event.KeyListener l)
Removes the specified key listener so that it no longer receives key events from this component.
Parameters:
l - the key listener.
See Also:
java.awt.event.KeyEvent, java.awt.event.KeyListener, addKeyListener

addMouseListener

public void addMouseListener(java.awt.event.MouseListener l)
Adds the specified mouse listener to receive mouse events from this component.
Parameters:
l - the mouse listener.
See Also:
java.awt.event.MouseEvent, java.awt.event.MouseListener, removeMouseListener

removeMouseListener

public void removeMouseListener(java.awt.event.MouseListener l)
Removes the specified mouse listener so that it no longer receives mouse events from this component.
Parameters:
l - the mouse listener.
See Also:
java.awt.event.MouseEvent, java.awt.event.MouseListener, addMouseListener

addMouseMotionListener

public void addMouseMotionListener(java.awt.event.MouseMotionListener l)
Adds the specified mouse motion listener to receive mouse motion events from this component.
Parameters:
l - the mouse motion listener.
See Also:
java.awt.event.MouseMotionEvent, java.awt.event.MouseMotionListener, removeMouseMotionListener

removeMouseMotionListener

public void removeMouseMotionListener(java.awt.event.MouseMotionListener l)
Removes the specified mouse motion listener so that it no longer receives mouse motion events from this component.
Parameters:
l - the mouse motion listener.
See Also:
java.awt.event.MouseMotionEvent, java.awt.event.MouseMotionListener, addMouseMotionListener

addInputMethodListener

public void addInputMethodListener(java.awt.event.InputMethodListener l)
Adds the specified input method listener to receive input method events from this component. A component will only receive input method events if it also overrides getInputMethodRequests() to return an InputMethodRequests instance.
Parameters:
l - the input method listener.
See Also:
java.awt.event.InputMethodEvent, java.awt.event.InputMethodListener, removeInputMethodListener, getInputMethodRequests

removeInputMethodListener

public void removeInputMethodListener(java.awt.event.InputMethodListener l)
Removes the specified input method listener so that it no longer receives input method events from this component.
Parameters:
l - the input method listener.
See Also:
java.awt.event.InputMethodEvent, java.awt.event.InputMethodListener, addInputMethodListener

getInputMethodRequests

public java.awt.im.InputMethodRequests getInputMethodRequests()
Gets the input method request handler which supports requests from input methods for this component. A component that supports on-the-spot text input needs to override this method to return an InputMethodRequests instance. At the same time, it has to add an input method listener.
Returns:
the input method request handler for this component, null by default.
See Also:
addInputMethodListener

getInputContext

public java.awt.im.InputContext getInputContext()
Gets the input context used by this component for handling the communication with input methods when text is entered in this component. By default, the input context used for the parent component is returned. Components may override this to return a private input context.
Returns:
The input context used by this component. Null if no context can be determined.

enableEvents

protected final void enableEvents(long eventsToEnable)
Enables the events defined by the specified event mask parameter to be delivered to this component.

Event types are automatically enabled when a listener for that event type is added to the component.

This method only needs to be invoked by subclasses of Component which desire to have the specified event types delivered to processEvent regardless of whether or not a listener is registered.

Parameters:
eventsToEnable - the event mask defining the event types.
See Also:
processEvent, disableEvents


disableEvents

protected final void disableEvents(long eventsToDisable)
Disables the events defined by the specified event mask parameter from being delivered to this component.
Parameters:
eventsToDisable - the event mask defining the event types
See Also:
enableEvents

coalesceEvents

protected AWTEvent coalesceEvents(AWTEvent existingEvent,
                                  AWTEvent newEvent)
Potentially coalesce an event being posted with an existing event. This method is called by EventQueue.postEvent if an event with the same ID as the event to be posted is found in the queue (both events must have this component as their source). This method either returns a coalesced event which replaces the existing event (and the new event is then discarded), or null to indicate that no combining should be done (add the second event to the end of the queue). Either event parameter may be modified and returned, as the other one is discarded unless null is returned.

This implementation of coalesceEvents coalesces two event types: mouse move (and drag) events, and paint (and update) events. For mouse move events the last event is always returned, causing intermediate moves to be discarded. For paint events where the update rectangles intersect, an event is returned which has an update rectangle which is the union of the two events.

Note: this method must never be synchronized (nor methods it invokes), as it is called from the underlying native event code. Any deadlock with an overwritten version of this method is the responsibility of the party who overwrote this method!

Parameters:
existingEvent - the event already on the EventQueue.
newEvent - the event being posted to the EventQueue.
Returns:
a coalesced event, or null indicating that no coalescing was done.


processEvent

protected void processEvent(AWTEvent e)
Processes events occurring on this component. By default this method calls the appropriate process<event type>Event method for the given class of event.
Parameters:
e - the event.
See Also:
processComponentEvent, processFocusEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, processInputMethodEvent

processComponentEvent

protected void processComponentEvent(ComponentEvent e)
Processes component events occurring on this component by dispatching them to any registered ComponentListener objects.

This method is not called unless component events are enabled for this component. Component events are enabled when one of the following occurs:

Parameters:
e - the component event.
See Also:
ComponentEvent, java.awt.event.ComponentListener, addComponentListener, enableEvents


processFocusEvent

protected void processFocusEvent(java.awt.event.FocusEvent e)
Processes focus events occurring on this component by dispatching them to any registered FocusListener objects.

This method is not called unless focus events are enabled for this component. Focus events are enabled when one of the following occurs:

Parameters:
e - the focus event.
See Also:
java.awt.event.FocusEvent, java.awt.event.FocusListener, addFocusListener, enableEvents


processKeyEvent

protected void processKeyEvent(java.awt.event.KeyEvent e)
Processes key events occurring on this component by dispatching them to any registered ode> objects.

This method is not called unless key events are enabled for this component. Key events are enabled when one of the following occurs:

  • A KeyListener object is registered via addKeyListener.
  • Key events are enabled via enableEvents.
Parameters:
e - the key event.
See Also:
java.awt.event.KeyEvent, java.awt.event.KeyListener, addKeyListener, enableEvents


processMouseEvent

protected void processMouseEvent(java.awt.event.MouseEvent e)
Processes mouse events occurring on this component by dispatching them to any registered MouseListener objects.

This method is not called unless mouse events are enabled for this component. Mouse events are enabled when one of the following occurs:

Parameters:
e - the mouse event.
See Also:
java.awt.event.MouseEvent, java.awt.event.MouseListener, addMouseListener, enableEvents


processMouseMotionEvent

protected void processMouseMotionEvent(java.awt.event.MouseEvent e)
Processes mouse motion events occurring on this component by dispatching them to any registered MouseMotionListener objects.

This method is not called unless mouse motion events are enabled for this component. Mouse motion events are enabled when one of the following occurs:

Parameters:
e - the mouse motion event.
See Also:
java.awt.event.MouseMotionEvent, java.awt.event.MouseMotionListener, addMouseMotionListener, enableEvents


postsOldMouseEvents

boolean postsOldMouseEvents()

processInputMethodEvent

protected void processInputMethodEvent(java.awt.event.InputMethodEvent e)
Processes input method events occurring on this component by dispatching them to any registered InputMethodListener objects.

This method is not called unless input method events are enabled for this component. Input method events are enabled when one of the following occurs:

Parameters:
e - the input method event
See Also:
java.awt.event.InputMethodEvent, java.awt.event.InputMethodListener, addInputMethodListener, enableEvents


handleEvent

public boolean handleEvent(Event evt)
Deprecated. As of JDK version 1.1 replaced by processEvent(AWTEvent).

mouseDown

public boolean mouseDown(Event evt,
                         int x,
                         int y)
Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).

mouseDrag

public boolean mouseDrag(Event evt,
                         int x,
                         int y)
Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).

mouseUp

public boolean mouseUp(Event evt,
                       int x,
                       int y)
Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).

mouseMove

public boolean mouseMove(Event evt,
                         int x,
                         int y)
Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).

mouseEnter

public boolean mouseEnter(Event evt,
                          int x,
                          int y)
Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).

mouseExit

public boolean mouseExit(Event evt,
                         int x,
                         int y)
Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).

keyDown

public boolean keyDown(Event evt,
                       int key)
Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).

keyUp

public boolean keyUp(Event evt,
                     int key)
Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).

action

public boolean action(Event evt,
                      Object what)
Deprecated. As of JDK version 1.1, should register this component as ActionListener on component which fires action events.

addNotify

public void addNotify()
Notifies this component that it has been added to a displayable containment hierarchy. Once this method completes, the component will be "displayable". This method is called by the toolkit internally, and should not be invoked by user code directly.
See Also:
isDisplayable, removeNotify

removeNotify

public void removeNotify()
Notifies this component that it has been removed from its displayable containment hierarchy. Once this method completes, this component will no longer be "displayable". This method is called by the toolkit internally and should not be invoked by user code directly.
See Also:
addNotify, isDisplayable

gotFocus

public boolean gotFocus(Event evt,
                        Object what)
Deprecated. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).

lostFocus

public boolean lostFocus(Event evt,
                         Object what)
Deprecated. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).

isFocusTraversable

public boolean isFocusTraversable()
Returns the value of a flag that indicates whether this component can be traversed using Tab or Shift-Tab keyboard focus traversal. If this method returns "false", this component may still request the keyboard focus using requestFocus(), but it will not automatically be assigned focus during tab traversal.
Returns:
true if this component is focus-traverable; false otherwise.

requestFocus

public void requestFocus()
Requests that this component get the input focus. The component must be visible on the screen for this request to be granted
See Also:
java.awt.event.FocusEvent, addFocusListener, processFocusEvent, isFocusTraversable

transferFocus

public void transferFocus()
Transfers the focus to the next component.
See Also:
requestFocus

nextFocus

public void nextFocus()
Deprecated. As of JDK version 1.1, replaced by transferFocus().

hasFocus

public boolean hasFocus()
Returns true if this Component has the keyboard focus.
Returns:
true if this Component has the keyboard focus.

add

public void add(java.awt.PopupMenu popup)
Adds the specified popup menu to the component.
Parameters:
popup - the popup menu to be added to the component.
See Also:
remove(java.awt.MenuComponent)

remove

public void remove(java.awt.MenuComponent popup)
Removes the specified popup menu from the component.
Specified by:
remove(java.awt.MenuComponent) in interface java.awt.MenuContainer
Parameters:
popup - the popup menu to be removed.
See Also:
add(java.awt.PopupMenu)

paramString

protected String paramString()
Returns the parameter string representing the state of this component. This string is useful for debugging.
Returns:
the parameter string of this component.

toString

public String toString()
Returns a string representation of this component and its values.
Returns:
a string representation of this component.
Overrides:
toString in class Object

list

public void list()
Prints a listing of this component to the standard system output stream System.out.
See Also:
java.lang.System#out

list

public void list(java.io.PrintStream out)
Prints a listing of this component to the specified output stream.
Parameters:
out - a print stream.

list

public void list(java.io.PrintStream out,
                 int indent)
Prints out a list, starting at the specified indention, to the specified print stream.
Parameters:
out - a print stream.
indent - number of spaces to indent.
See Also:
println(java.lang.Object)

list

public void list(java.io.PrintWriter out)
Prints a listing to the specified print writer.
Parameters:
out - The print writer to print to.

list

public void list(java.io.PrintWriter out,
                 int indent)
Prints out a list, starting at the specified indention, to the specified print writer.
Parameters:
out - The print writer to print to.
indent - The number of spaces to indent.
See Also:
println(java.lang.Object)

getNativeContainer

Container getNativeContainer()

addPropertyChangeListener

public void addPropertyChangeListener(java.beans.PropertyChangeListener listener)
Add a PropertyChangeListener to the listener list. The listener is registered for all properties.

A PropertyChangeEvent will get fired in response to an explicit setFont, setBackground, or SetForeground on the current component. Note that if the current component is inheriting its foreground, background, or font from its container, then no event will be fired in response to a change in the inherited property.

Parameters:
listener - The PropertyChangeListener to be added


removePropertyChangeListener

public void removePropertyChangeListener(java.beans.PropertyChangeListener listener)
Remove a PropertyChangeListener from the listener list. This removes a PropertyChangeListener that was registered for all properties.
Parameters:
listener - The PropertyChangeListener to be removed

addPropertyChangeListener

public void addPropertyChangeListener(String propertyName,
                                      java.beans.PropertyChangeListener listener)
Add a PropertyChangeListener for a specific property. The listener will be invoked only when a call on firePropertyChange names that specific property.
Parameters:
propertyName - The name of the property to listen on.
listener - The PropertyChangeListener to be added

removePropertyChangeListener

public void removePropertyChangeListener(String propertyName,
                                         java.beans.PropertyChangeListener listener)
Remove a PropertyChangeListener for a specific property.
Parameters:
propertyName - The name of the property that was listened on.
listener - The PropertyChangeListener to be removed

firePropertyChange

protected void firePropertyChange(String propertyName,
                                  Object oldValue,
                                  Object newValue)
Support for reporting bound property changes. This method can be called when a bound property has changed and it will send the appropriate PropertyChangeEvent to any registered PropertyChangeListeners.

writeObject

private void writeObject(java.io.ObjectOutputStream s)
                 throws java.io.IOException

readObject

private void readObject(java.io.ObjectInputStream s)
                throws java.lang.ClassNotFoundException,
                       java.io.IOException

setComponentOrientation

public void setComponentOrientation(java.awt.ComponentOrientation o)
Set the language-sensitive orientation that is to be used to order the elements or text within this component. Language-sensitive LayoutManager and Component subclasses will use this property to determine how to lay out and draw components.

At construction time, a component's orientation is set to ComponentOrientation.UNKNOWN, indicating that it has not been specified explicitly. The UNKNOWN orientation behaves the same as ComponentOrientation.LEFT_TO_RIGHT.

To set the orientation of a single component, use this method. To apply a ResourceBundle's orientation to an entire component hierarchy, use java.awt.Window.applyResourceBundle.

See Also:
java.awt.ComponentOrientation, java.awt.Window#ApplyResourceBundle(java.util.ResourceBundle)


getComponentOrientation

public java.awt.ComponentOrientation getComponentOrientation()
Retrieve the language-sensitive orientation that is to be used to order the elements or text within this component. LayoutManager and Component subclasses that wish to respect orientation should call this method to get the component's orientation before performing layout or drawing.
See Also:
java.awt.ComponentOrientation

initIDs

private static void initIDs()
Initialize JNI field and method IDs

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