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Java AWT

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java.awt.peer Reference
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ComponentPeer

Name

ComponentPeer

[Graphic: Figure from the text]

Description

ComponentPeer is an interface that defines the basis for all non-menu GUI peer interfaces.

Interface Definition

public abstract interface java.awt.peer.ComponentPeer {
  // Interface Methods
  public abstract int checkImage (Image image, int width, int height, 
    ImageObserver observer);
  public abstract Image createImage (ImageProducer producer);
  public abstract Image createImage (int width, int height);
  public abstract void disable(); (Deprecated)
  public abstract void dispose();
  public abstract void enable(); (Deprecated)
  public abstract ColorModel getColorModel();
  public abstract FontMetrics getFontMetrics (Font f);
  public abstract Graphics getGraphics();
  public abstract Point getLocationOnScreen(); (New)
  public abstract Dimension getMinimumSize(); (New)
  public abstract Dimension getPreferredSize(); (New)
  public abstract Toolkit getToolkit();
  public abstract boolean handleEvent (Event e);
  public abstract void hide(); (Deprecated)
  public abstract boolean isFocusTraversable(); (New)
  public abstract Dimension minimumSize(); (Deprecated)
  public abstract void paint (Graphics g);
  public abstract Dimension preferredSize (); (Deprecated)
  public abstract boolean prepareImage (Image image, int width, int height, 
    ImageObserver observer);
  public abstract void print (Graphics g);
  public abstract void repaint (long tm, int x, int y, int width, int height);
  public abstract void requestFocus();
  public abstract void reshape (int x, int y, int width, int height); (Deprecated)
  public abstract void setBackground (Color c);
  public abstract void setBounds (int x, int y, int width, int height); (New)
  public abstract void setCursor (Cursor cursor); (New)
  public abstract void setEnabled (boolean b); (New)
  public abstract void setFont (Font f);
  public abstract void setForeground (Color c);
  public abstract void setVisible (boolean b); (New)
  public abstract void show(); (Deprecated)
}

Interface Methods

checkImage

public abstract int checkImage (Image image, int width, int height, ImageObserver observer)

Parameters

image

Image to check.

width

Horizontal size to which the image will be scaled.

height

Vertical size to which the image will be scaled.

observer

An ImageObserver to monitor image loading; normally, the object on which the image will be rendered.

Returns

ImageObserver flags ORed together indicating status.

Description

Checks status of image construction.

createImage

public abstract Image createImage (ImageProducer producer)

Parameters

producer

An object that implements the ImageProducer interface to create a new image.

Returns

Newly created image instance.

Description

Creates an Image based upon an ImageProducer.

public abstract Image createImage (int width, int height)

Parameters

width

Horizontal size for in-memory Image.

height

Vertical size for in-memory Image.

Returns

Newly created image instance.

Description

Creates an in-memory Image for double buffering.

disable

public abstract void disable() (Deprecated)

Description

Disables component so that it is unresponsive to user interactions. Replaced by setEnabled(false).

dispose

public abstract void dispose()

Description

Releases resources used by peer.

enable

public abstract void enable() (Deprecated)

Description

Enables component so that it is responsive to user interactions. Replaced by setEnabled(true).

getColorModel

public abstract ColorModel getColorModel()

Returns

ColorModel used to display the current component.

getFontMetrics

public abstract FontMetrics getFontMetrics (Font f)

Parameters

f

A font whose metrics are desired.

Returns

Font sizing information for the desired font.

getGraphics

public abstract Graphics getGraphics()

Throws

InternalException

If acquiring a graphics context is unsupported

Returns

Component's graphics context.

getLocationOnScreen

public abstract Point getLocationOnScreen() (New)

Returns

The location of the component in the screen's coordinate space.

getMinimumSize

public abstract Dimension getMinimumSize() (New)

Returns

The minimum dimensions of the component.

getPreferredSize

public abstract Dimension getPreferredSize() (New)

Returns

The preferred dimensions of the component.

getToolkit

public abstract Toolkit getToolkit()

Returns

Toolkit of Component.

handleEvent

public abstract boolean handleEvent (Event e)

Parameters

e

Event instance identifying what caused the method to be called.

Returns

true if the peer handled the event, false to propagate the event to the parent container.

Description

High-level event handling routine.

hide

public abstract void hide() (Deprecated)

Description

Hides the component. Replaced by setVisible(false).

isFocusTraversable

public abstract boolean isFocusTraversable() (New)

Returns

true if the peer can be tabbed onto, false otherwise.

Description

Determines if this peer is navigable using the keyboard.

minimumSize

public abstract Dimension minimumSize() (Deprecated)

Returns

The minimum dimensions of the component. Replaced by getMinimumSize().

paint

public abstract void paint (Graphics g)

Parameters

g

Graphics context of the component.

Description

Draws something in graphics context.

preferredSize

public abstract Dimension preferredSize() (Deprecated)

Returns

The preferred dimensions of the component. Replaced by getPreferredSize().

prepareImage

public abstract boolean prepareImage (Image image, int width, int height, ImageObserver observer)

Parameters

image

Image to load.

width

Horizontal size to which the image will be scaled.

height

Vertical size to which the image will be scaled.

observer

An ImageObserver to monitor image loading; normally, the object on which the image will be rendered.

Returns

true if the image has already loaded, false otherwise.

Description

Forces the image to start loading.

print

public abstract void print (Graphics g)

Parameters

g

Graphics context of component.

Description

Print something from the graphics context.

repaint

public abstract void repaint (long tm, int x, int y, int width, int height)

Parameters

tm

Millisecond delay allowed before repaint.

x

Horizontal origin of bounding box to redraw.

y

Vertical origin of bounding box to redraw.

width

Width of bounding box to redraw.

height

Height of bounding box to redraw.

Description

Requests scheduler to redraw portion of component within a time period.

requestFocus

public abstract void requestFocus()

Description

Requests this Component gets the input focus.

reshape

public abstract void reshape (int x, int y, int width, int height) (Deprecated)

Parameters

x

New horizontal position for component.

y

New vertical position for component.

width

New width for component.

height

New height for component.

Description

Relocates and resizes the component's peer. Replaced by setBounds(int, int, int, int).

setBackground

public abstract void setBackground (Color c)

Parameters

c

New color for the background.

Description

Changes the background color of the component.

setBounds

public abstract void setBounds (int x, int y, int width, int height) (New)

Parameters

x

New horizontal position for component.

y

New vertical position for component.

width

New width for component.

height

New height for component.

Description

Relocates and resizes the component's peer.

setCursor

public abstract void setCursor (Cursor cursor) (New)

Parameters

cursor

New cursor.

Description

Changes the cursor of the component.

setEnabled

public abstract void setEnabled (boolean b) (New)

Parameters

b

true to enable the peer; false to disable it.

Description

Enables or disables the peer.

setFont

public abstract void setFont (Font f)

Parameters

f

New font for the component.

Description

Changes the font used to display text in the component.

setForeground

public abstract void setForeground (Color c)

Parameters

c

New foreground color for the component.

Description

Changes the foreground color of the component.

setVisible

public abstract void setVisible (boolean b) (New)

Parameters

b

true to show the peer; false to hide it.

Description

Shows or hides the peer.

show

public abstract void show() (Deprecated)

Description

Makes the peer visible. Replaced by setVisible(true).

See Also

ButtonPeer, CanvasPeer, CheckboxPeer, ChoicePeer, Color, ColorModel, ContainerPeer, Cursor, Dimension, Event, Font, FontMetrics, Graphics, Image, ImageObserver, ImageProducer, LabelPeer, ListPeer, ScrollbarPeer, TextComponentPeer, Toolkit


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