Java Platform 1.2 API Specification: Class Component

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java.awt
Class Component

java.lang.Object
  |
  +--java.awt.Component

Direct Known Subclasses:: Box.Filler, Button, Canvas, Checkbox, Choice, Container, Label, List, Scrollbar, TextComponent

public abstract class Component
extends Object
implements ImageObserver, MenuContainer, 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.

See Also:: Serialized Form

Field Summary
`static float`	`BOTTOM_ALIGNMENT` Ease-of-use constant for `getAlignmentY`.
`static float`	`CENTER_ALIGNMENT` Ease-of-use constant for `getAlignmentY` and `getAlignmentX`.
`static float`	`LEFT_ALIGNMENT` Ease-of-use constant for `getAlignmentX`.
`static float`	`RIGHT_ALIGNMENT` Ease-of-use constant for `getAlignmentX`.
`static float`	`TOP_ALIGNMENT` Ease-of-use constant for `getAlignmentY()`.

Constructor Summary
`protected`	`Component()` Constructs a new component.

Method Summary
`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.
`void`	`add(PopupMenu popup)` Adds the specified popup menu to the component.
`void`	`addComponentListener(ComponentListener l)` Adds the specified component listener to receive component events from this component.
`void`	`addFocusListener(FocusListener l)` Adds the specified focus listener to receive focus events from this component when this component gains input focus.
`void`	`addInputMethodListener(InputMethodListener l)` Adds the specified input method listener to receive input method events from this component.
`void`	`addKeyListener(KeyListener l)` Adds the specified key listener to receive key events from this component.
`void`	`addMouseListener(MouseListener l)` Adds the specified mouse listener to receive mouse events from this component.
`void`	`addMouseMotionListener(MouseMotionListener l)` Adds the specified mouse motion listener to receive mouse motion events from this component.
`void`	`addNotify()` Makes this Component displayable by connecting it to a native screen resource.
`void`	`addPropertyChangeListener(PropertyChangeListener listener)` Add a PropertyChangeListener to the listener list.
`void`	`addPropertyChangeListener(String propertyName, PropertyChangeListener listener)` Add a PropertyChangeListener for a specific property.
`Rectangle`	`bounds()` Deprecated. As of JDK version 1.1, replaced by `getBounds()`.
`int`	`checkImage(Image image, ImageObserver observer)` Returns the status of the construction of a screen representation of the specified image.
`int`	`checkImage(Image image, int width, int height, ImageObserver observer)` Returns the status of the construction of a screen representation of the specified image.
`protected AWTEvent`	`coalesceEvents(AWTEvent existingEvent, AWTEvent newEvent)` Potentially coalesce an event being posted with an existing event.
`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(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.
`Image`	`createImage(ImageProducer producer)` Creates an image from the specified image producer.
`Image`	`createImage(int width, int height)` Creates an off-screen drawable image to be used for double buffering.
`void`	`deliverEvent(Event e)` Deprecated. As of JDK version 1.1, replaced by `dispatchEvent(AWTEvent e)`.
`void`	`disable()` Deprecated. As of JDK version 1.1, replaced by `setEnabled(boolean)`.
`protected 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`	`doLayout()` Prompts the layout manager to lay out this component.
`void`	`enable()` Deprecated. As of JDK version 1.1, replaced by `setEnabled(boolean)`.
`void`	`enable(boolean b)` Deprecated. As of JDK version 1.1, replaced by `setEnabled(boolean)`.
`protected 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.
`protected 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.
`Color`	`getBackground()` Gets the background color of this component.
`Rectangle`	`getBounds()` Gets the bounds of this component in the form of a `Rectangle` object.
`Rectangle`	`getBounds(Rectangle rv)` Store the bounds of this component into "return value" rv and return rv.
`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 (x, y) location, and if so, returns the containing component.
`Component`	`getComponentAt(Point p)` Returns the component or subcomponent that contains the specified point.
`ComponentOrientation`	`getComponentOrientation()` Retrieve the language-sensitive orientation that is to be used to order the elements or text within this component.
`Cursor`	`getCursor()` Gets the cursor set on this component.
`DropTarget`	`getDropTarget()` Get the DropTarget associated with this Component
`Font`	`getFont()` Gets the font of this component.
`FontMetrics`	`getFontMetrics(Font font)` Gets the font metrics for the specified font.
`Color`	`getForeground()` Gets the foreground color of this component.
`Graphics`	`getGraphics()` Creates a graphics context for this component.
`int`	`getHeight()` Return the current height of this component.
`InputContext`	`getInputContext()` Gets the input context used by this component for handling the communication with input methods when text is entered in this component.
`InputMethodRequests`	`getInputMethodRequests()` Gets the input method request handler which supports requests from input methods for this component.
`Locale`	`getLocale()` Gets the locale of this component.
`Point`	`getLocation()` Gets the location of this component in the form of a point specifying the component's top-left corner.
`Point`	`getLocation(Point rv)` Store the x,y origin of this component into "return value" rv and return rv.
`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.
`Dimension`	`getMaximumSize()` Gets the maximum size of this component.
`Dimension`	`getMinimumSize()` Gets the mininimum size of this component.
`String`	`getName()` Gets the name of the component.
`Container`	`getParent()` Gets the parent of this component.
`java.awt.peer.ComponentPeer`	`getPeer()` Deprecated. As of JDK version 1.1, programs should not directly manipulate peers. replaced by `boolean isDisplayable()`.
`Dimension`	`getPreferredSize()` Gets the preferred size of this component.
`Dimension`	`getSize()` Returns the size of this component in the form of a `Dimension` object.
`Dimension`	`getSize(Dimension rv)` Store the width/height of this component into "return value" rv and return rv.
`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.
`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. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).
`boolean`	`handleEvent(Event evt)` Deprecated. As of JDK version 1.1 replaced by processEvent(AWTEvent).
`boolean`	`hasFocus()` Returns true if this Component has the keyboard focus.
`void`	`hide()` Deprecated. As of JDK version 1.1, replaced by `setVisible(boolean)`.
`boolean`	`imageUpdate(Image img, int flags, int x, int y, int w, int h)` Repaints the component when the image has changed.
`boolean`	`inside(int x, int y)` Deprecated. As of JDK version 1.1, replaced by contains(int, int).
`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 should be visible when its parent is visible.
`boolean`	`keyDown(Event evt, int key)` Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).
`boolean`	`keyUp(Event evt, int key)` Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).
`void`	`layout()` Deprecated. As of JDK version 1.1, replaced by `doLayout()`.
`void`	`list()` Prints a listing of this component to the standard system output stream `System.out`.
`void`	`list(PrintStream out)` Prints a listing of this component to the specified output stream.
`void`	`list(PrintStream out, int indent)` Prints out a list, starting at the specified indention, to the specified print stream.
`void`	`list(PrintWriter out)` Prints a listing to the specified print writer.
`void`	`list(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. As of JDK version 1.1, replaced by getComponentAt(int, int).
`Point`	`location()` Deprecated. As of JDK version 1.1, replaced by `getLocation()`.
`boolean`	`lostFocus(Event evt, Object what)` Deprecated. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).
`Dimension`	`minimumSize()` Deprecated. As of JDK version 1.1, replaced by `getMinimumSize()`.
`boolean`	`mouseDown(Event evt, int x, int y)` Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
`boolean`	`mouseDrag(Event evt, int x, int y)` Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).
`boolean`	`mouseEnter(Event evt, int x, int y)` Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
`boolean`	`mouseExit(Event evt, int x, int y)` Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
`boolean`	`mouseMove(Event evt, int x, int y)` Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).
`boolean`	`mouseUp(Event evt, int x, int y)` Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
`void`	`move(int x, int y)` Deprecated. As of JDK version 1.1, replaced by `setLocation(int, int)`.
`void`	`nextFocus()` Deprecated. As of JDK version 1.1, replaced by transferFocus().
`void`	`paint(Graphics g)` Paints this component.
`void`	`paintAll(Graphics g)` Paints this component and all of its subcomponents.
`protected String`	`paramString()` Returns a string representing the state of this component.
`boolean`	`postEvent(Event e)` Deprecated. As of JDK version 1.1, replaced by dispatchEvent(AWTEvent).
`Dimension`	`preferredSize()` Deprecated. As of JDK version 1.1, replaced by `getPreferredSize()`.
`boolean`	`prepareImage(Image image, ImageObserver observer)` Prepares an image for rendering on this component.
`boolean`	`prepareImage(Image image, int width, int height, ImageObserver observer)` Prepares an image for rendering on this component at the specified width and height.
`void`	`print(Graphics g)` Prints this component.
`void`	`printAll(Graphics g)` Prints this component and all of its subcomponents.
`protected void`	`processComponentEvent(ComponentEvent e)` Processes component events occurring on this component by dispatching them to any registered `ComponentListener` objects.
`protected void`	`processEvent(AWTEvent e)` Processes events occurring on this component.
`protected void`	`processFocusEvent(FocusEvent e)` Processes focus events occurring on this component by dispatching them to any registered `FocusListener` objects.
`protected void`	`processInputMethodEvent(InputMethodEvent e)` Processes input method events occurring on this component by dispatching them to any registered `InputMethodListener` objects.
`protected void`	`processKeyEvent(KeyEvent e)` Processes key events occurring on this component by dispatching them to any registered `KeyListener` objects.
`protected void`	`processMouseEvent(MouseEvent e)` Processes mouse events occurring on this component by dispatching them to any registered `MouseListener` objects.
`protected void`	`processMouseMotionEvent(MouseEvent e)` Processes mouse motion events occurring on this component by dispatching them to any registered `MouseMotionListener` objects.
`void`	`remove(MenuComponent popup)` Removes the specified popup menu from the component.
`void`	`removeComponentListener(ComponentListener l)` Removes the specified component listener so that it no longer receives component events from this component.
`void`	`removeFocusListener(FocusListener l)` Removes the specified focus listener so that it no longer receives focus events from this component.
`void`	`removeInputMethodListener(InputMethodListener l)` Removes the specified input method listener so that it no longer receives input method events from this component.
`void`	`removeKeyListener(KeyListener l)` Removes the specified key listener so that it no longer receives key events from this component.
`void`	`removeMouseListener(MouseListener l)` Removes the specified mouse listener so that it no longer receives mouse events from this component.
`void`	`removeMouseMotionListener(MouseMotionListener l)` Removes the specified mouse motion listener so that it no longer receives mouse motion events from this component.
`void`	`removeNotify()` Makes this Component undisplayable by destroying it native screen resource.
`void`	`removePropertyChangeListener(PropertyChangeListener listener)` Remove a PropertyChangeListener from the listener list.
`void`	`removePropertyChangeListener(String propertyName, PropertyChangeListener listener)` Remove a PropertyChangeListener for a specific property.
`void`	`repaint()` Repaints this component.
`void`	`repaint(int x, int y, int width, int height)` Repaints the specified rectangle of this component.
`void`	`repaint(long tm)` Repaints the 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. As of JDK version 1.1, replaced by `setBounds(int, int, int, int)`.
`void`	`resize(Dimension d)` Deprecated. As of JDK version 1.1, replaced by `setSize(Dimension)`.
`void`	`resize(int width, int height)` Deprecated. As of JDK version 1.1, replaced by `setSize(int, int)`.
`void`	`setBackground(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(Rectangle r)` Moves and resizes this component to conform to the new bounding rectangle `r`.
`void`	`setComponentOrientation(ComponentOrientation o)` Set the language-sensitive orientation that is to be used to order the elements or text within this component.
`void`	`setCursor(Cursor cursor)` Sets the cursor image to the specified cursor.
`void`	`setDropTarget(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(Font f)` Sets the font of this component.
`void`	`setForeground(Color c)` Sets the foreground color of this component.
`void`	`setLocale(Locale l)` Sets the locale of this component.
`void`	`setLocation(int x, int y)` Moves this component to a new location.
`void`	`setLocation(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(Dimension d)` Resizes this component so that it has width `d.width` and height `d.height`.
`void`	`setSize(int width, int height)` Resizes this component so that it has width `width` and `height`.
`void`	`setVisible(boolean b)` Shows or hides this component depending on the value of parameter `b`.
`void`	`show()` Deprecated. As of JDK version 1.1, replaced by `setVisible(boolean)`.
`void`	`show(boolean b)` Deprecated. As of JDK version 1.1, replaced by `setVisible(boolean)`.
`Dimension`	`size()` Deprecated. As of JDK version 1.1, replaced by `getSize()`.
`String`	`toString()` Returns a string representation of this component and its values.
`void`	`transferFocus()` Transfers the focus to the next component.
`void`	`update(Graphics g)` Updates this component.
`void`	`validate()` Ensures that this component has a valid layout.

Methods inherited from class java.lang.Object

clone, 
equals, 
finalize, 
getClass, 
hashCode, 
notify, 
notifyAll, 
wait, 
wait, 
wait

Field Detail

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()

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

getName

public String getName()

Gets the name of the component.

Returns:: This component's name.
Since:: JDK1.1
See Also:: setName(java.lang.String)

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.
Since:: JDK1.1
See Also:: getName()

getParent

public Container getParent()

Gets the parent of this component.

Returns:: The parent container of this component.
Since:: JDK1.0

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(DropTarget dt)

Associate a DropTarget with this Component.

Parameters:: dt - The DropTarget

getDropTarget

public 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 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.
Since:: JDK1.0

isValid

public boolean isValid()

Determines whether this component is valid. A component is valid when it is correctly sized and positioned within its parent container and all its children are also valid. Components are invalidated when they are first shown on the screen.

Returns:: true if the component is valid; false otherwise.
Since:: JDK1.0
See Also:: validate(), invalidate()

isDisplayable

public boolean isDisplayable()

Determines whether this component is displayable. A component is displayable when it is connected to a native screen resource.

A component is made displayable either when it is added to a displayable containment hierarchy or when its containment hierarchy is made displayable. A containment hierarchy is made displayable when its ancestor window is either packed or made visible.

A component is made undisplayable either when it is removed from a displayable containment hierarchy or when its containment hierarchy is made undisplayable. A containment hierarchy is made undisplayable when its ancestor window is disposed.

Returns:: true if the component is displayable; false otherwise.
Since:: JDK1.2
See Also:: Container.add(java.awt.Component), Window.pack(), Window.show(), Container.remove(java.awt.Component), Window.dispose()

isVisible

public boolean isVisible()

Determines whether this component should be visible when its parent 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.
Since:: JDK1.0
See Also:: setVisible(boolean)

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.
Since:: JDK1.0
See Also:: setVisible(boolean)

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.
Since:: JDK1.0
See Also:: setEnabled(boolean)

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.
Since:: JDK1.1
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.
Since:: JDK1.2
See Also:: processKeyEvent(java.awt.event.KeyEvent)

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.
Since:: JDK1.1
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 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.
Since:: JDK1.0
See Also:: #java.awt.Component#setForeground(java.awt.Color)

setForeground

public void setForeground(Color c)

Sets the foreground color of this component.

Parameters:: c - The color to become this component's foreground color. If this parameter is null then this component will inherit the foreground color of its parent.
Since:: JDK1.0
See Also:: getForeground()

getBackground

public 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.
Since:: JDK1.0
See Also:: setBackground(java.awt.Color)

setBackground

public void setBackground(Color c)

Sets the background color of this component.

Parameters:: c - The color to become this component's color. If this parameter is null then this component will inherit the background color of its parent. background color.
Since:: JDK1.0
See Also:: getBackground()

getFont

public Font getFont()

Gets the font of this component.

Specified by:: getFont in interface MenuContainer
Returns:: This component's font. If a font has not been set for this component, the font of its parent is returned.
Since:: JDK1.0
See Also:: setFont(java.awt.Font)

setFont

public void setFont(Font f)

Sets the font of this component.

Parameters:: f - The font to become this component's font. If this parameter is null then this component will inherit the font of its parent.
Since:: JDK1.0
See Also:: getFont()

getLocale

public 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.
Since:: JDK1.1
See Also:: setLocale(java.util.Locale)

setLocale

public void setLocale(Locale l)

Sets the locale of this component.

Parameters:: l - The locale to become this component's locale.
Since:: JDK1.1
See Also:: getLocale()

getColorModel

public ColorModel getColorModel()

Gets the instance of ColorModel used to display the component on the output device.

Returns:: The color model used by this component.
Since:: JDK1.0
See Also:: ColorModel, ComponentPeer.getColorModel(), Toolkit.getColorModel()

getLocation

public 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.
Since:: JDK1.1
See Also:: setLocation(int, int), getLocationOnScreen()

getLocationOnScreen

public 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(int, int), getLocation()

location

public 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.
Since:: JDK1.1
See Also:: getLocation(), setBounds(int, int, int, int)

move

public void move(int x,
                 int y)

Deprecated. As of JDK version 1.1, replaced by setLocation(int, int).

setLocation

public void setLocation(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.
Since:: JDK1.1
See Also:: getLocation(), setBounds(int, int, int, int)

getSize

public 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.
Since:: JDK1.1
See Also:: setSize(int, int)

size

public 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.
Since:: JDK1.1
See Also:: getSize(), setBounds(int, int, int, int)

resize

public void resize(int width,
                   int height)

Deprecated. As of JDK version 1.1, replaced by setSize(int, int).

setSize

public void setSize(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.
Since:: JDK1.1
See Also:: setSize(int, int), setBounds(int, int, int, int)

resize

public void resize(Dimension d)

Deprecated. As of JDK version 1.1, replaced by setSize(Dimension).

getBounds

public 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(int, int, int, int), getLocation(), getSize()

bounds

public 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(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.
Since:: JDK1.1
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.
Since:: JDK1.2

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.
Since:: JDK1.2

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.
Since:: JDK1.2

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.
Since:: JDK1.2

getBounds

public Rectangle getBounds(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 Dimension getSize(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 Point getLocation(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.
Since:: JDK1.2
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
Since:: JDK1.2

getPreferredSize

public 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 Dimension preferredSize()

Deprecated. As of JDK version 1.1, replaced by getPreferredSize().

getMinimumSize

public 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 Dimension minimumSize()

Deprecated. As of JDK version 1.1, replaced by getMinimumSize().

getMaximumSize

public 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.

Since:: JDK1.0
See Also:: invalidate(), doLayout(), LayoutManager, Container.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.

Since:: JDK1.0
See Also:: validate(), doLayout(), LayoutManager

getGraphics

public 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.
Since:: JDK1.0
See Also:: paint(java.awt.Graphics)

getFontMetrics

public FontMetrics getFontMetrics(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.
Since:: JDK1.0
See Also:: getFont(), getPeer(), ComponentPeer.getFontMetrics(java.awt.Font), Toolkit.getFontMetrics(java.awt.Font)

setCursor

public void setCursor(Cursor cursor)

Sets the cursor image to the specified cursor. This cursor image is displayed when the contains method for this component returns true for the current cursor location. Setting the cursor of a Container causes that cursor to be displayed within all of the container's subcomponents, except for any subcomponents that are using a non-default cursor.

Parameters:: cursor - One of the constants defined by the Cursor class. If this parameter is null then this component will inherit the cursor of its parent.
Since:: JDK1.1
See Also:: getCursor(), contains(int, int), Toolkit.createCustomCursor(java.awt.Image, java.awt.Point, java.lang.String), Cursor

getCursor

public Cursor getCursor()

Gets the cursor set on this component.

Returns:: The cursor for this component.
Since:: JDK1.1
See Also:: setCursor(java.awt.Cursor), Cursor

paint

public void paint(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.
Since:: JDK1.0
See Also:: update(java.awt.Graphics)

update

public void update(Graphics g)

Updates this component.

The AWT calls the update method in response to a call to repaintupdate 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 (0, 0) 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.
Since:: JDK1.0
See Also:: paint(java.awt.Graphics), repaint()

paintAll

public void paintAll(Graphics g)

Paints this component and all of its subcomponents.

The origin of the graphics context, its (0, 0) 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.
Since:: JDK1.0
See Also:: paint(java.awt.Graphics)

repaint

public void repaint()

Repaints this component.

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

Since:: JDK1.0
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
Since:: JDK1.0
See Also:: paint(java.awt.Graphics), 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.
Since:: JDK1.0
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.
Since:: JDK1.0
See Also:: update(java.awt.Graphics)

print

public void print(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

java.awt Class Component

TOP_ALIGNMENT

CENTER_ALIGNMENT

BOTTOM_ALIGNMENT

LEFT_ALIGNMENT

RIGHT_ALIGNMENT

Component

getName

setName

getParent

getPeer

setDropTarget

getDropTarget

getTreeLock

getToolkit

isValid

isDisplayable

isVisible

isShowing

isEnabled

setEnabled

enable

enable

disable

isDoubleBuffered

enableInputMethods

setVisible

show

show

hide

getForeground

setForeground

getBackground

setBackground

getFont

setFont

getLocale

setLocale

getColorModel

getLocation

getLocationOnScreen

location

setLocation

move

setLocation

getSize

size

setSize

resize

setSize

resize

getBounds

bounds

setBounds

reshape

setBounds

getX

getY

getWidth

getHeight

getBounds

getSize

getLocation

isOpaque

isLightweight

getPreferredSize

preferredSize

getMinimumSize

minimumSize

getMaximumSize

getAlignmentX

getAlignmentY

doLayout

layout

validate

invalidate

getGraphics

getFontMetrics

setCursor

getCursor

java.awt
Class Component