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Java AWT

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java.awt Reference
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Toolkit

Name

Toolkit

[Graphic: Figure from the text]

Description

The abstract Toolkit class provides access to platform-specific details like window size and available fonts. It also deals with creating all the components' peer objects when you call addNotify().

Class Definition

public abstract class java.awt.Toolkit
    extends java.lang.Object {
  // Class Methods
  public static synchronized Toolkit getDefaultToolkit();
  protected static Container getNativeContainer (Component c); (New)
  public static String getProperty (String key, String defaultValue); (New)
  
  // Instance Methods
  public abstract void beep(); (New)
  public abstract int checkImage (Image image, int width, int height, 
    ImageObserver observer);
  public abstract Image createImage (ImageProducer producer);
  public Image createImage (byte[] imagedata); (New)
  public abstract Image createImage (byte[ ] imagedata, int imageoffset, 
    int imagelength); (New)
  public abstract ColorModel getColorModel();
  public abstract String[] getFontList();
  public abstract FontMetrics getFontMetrics (Font font);
  public abstract Image getImage (String filename);
  public abstract Image getImage (URL url);
  public int getMenuShortcutKeyMask(); (New)
  public abstract PrintJob getPrintJob (Frame frame, String jobtitle, 
    Properties props); (New)
  public abstract int getScreenResolution();
  public abstract Dimension getScreenSize();
  public abstract Clipboard getSystemClipboard(); (New)
  public final EventQueue getSystemEventQueue(); (New)
  public abstract boolean prepareImage (Image image, int width, int height, 
    ImageObserver observer);
  public abstract void sync();
  
  // Protected Instance Methods
  protected abstract ButtonPeer createButton (Button b);
  protected abstract CanvasPeer createCanvas (Canvas c);
  protected abstract CheckboxPeer createCheckbox (Checkbox cb);
  protected abstract CheckboxMenuItemPeer createCheckboxMenuItem 
    (CheckboxMenuItem cmi);
  protected abstract ChoicePeer createChoice (Choice c);
  protected LightweightPeer createComponent(Component target); (New)
  protected abstract DialogPeer createDialog (Dialog d);
  protected abstract FileDialogPeer createFileDialog (FileDialog fd);
  protected abstract FramePeer createFrame (Frame f);
  protected abstract LabelPeer createLabel (Label l);
  protected abstract ListPeer createList (List l);
  protected abstract MenuPeer createMenu (Menu m);
  protected abstract MenuBarPeer createMenuBar (MenuBar mb);
  protected abstract MenuItemPeer createMenuItem (MenuItem mi);
  protected abstract PanelPeer createPanel (Panel p);
  protected abstract PopupMenuPeer createPopupMenu (PopupMenu target); (New)
  protected abstract ScrollPanePeer createScrollPane (ScrollPane target);  (New)
  protected abstract ScrollbarPeer createScrollbar (Scrollbar sb);
  protected abstract TextAreaPeer createTextArea (TextArea ta);
  protected abstract TextFieldPeer createTextField (TextField tf);
  protected abstract WindowPeer createWindow (Window w);
  protected abstract FontPeer getFontPeer (String name, int style); (New)
  protected abstract EventQueue getSystemEventQueueImpl(); (New)
  protected void loadSystemColors (int[] systemColors);  (New)
}

Class Methods

getDefaultToolkit

public static synchronized Toolkit getDefaultToolkit()

Throws

AWTError

If the toolkit for the current platform cannot be found.

Returns

The system's default Toolkit.

getNativeContainer

protected static Container getNativeContainer (Component c) (New)

Returns

The native container for the given component. The component's immediate parent may be a lightweight component.

getProperty

public static String getProperty (String key, String defaultValue) (New)

Parameters

key

The name of a property.

defaultValue

A default value to return if the property is not found.

Returns

The value of the property described by key, or defaultValue if it is not found.

Instance Methods

beep

public abstract void beep() (New)

Description

Produces an audible beep.

checkImage

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

Parameters

image

Image to check.

width

Width of the scaled image; -1 if image will be rendered unscaled.

height

Height of the scaled image; -1 if image will be rendered unscaled.

observer

The Component that image will be rendered on.

Returns

The ImageObserver flags ORed together for the data that is now available.

Description

Checks on the status of the construction of a screen representation of image on observer.

createImage

public abstract Image createImage (ImageProducer producer)

Parameters

producer

An ImageProducer that generates data for the desired image.

Returns

Newly created Image.

Description

Creates a new Image from an ImageProducer.

public abstract Image createImage (byte[] imagedata) (New)

Parameters

imagedata

Raw data representing an image.

Returns

Newly created Image.

Description

Creates a new Image from the imagedata provided.

public abstract Image createImage (byte[] imagedata, int imageoffset, int imagelength) (New)

Parameters

imagedata

Raw data representing one or more images.

imageoffset

An offset into the data given.

imagelength

The length of data to use.

Returns

Newly created Image.

Description

Creates a new Image from the imagedata provided, starting at imageoffset bytes and reading imagelength bytes.

getColorModel

public abstract ColorModel getColorModel()

Returns

The current ColorModel used by the system.

getFontList

public abstract String[] getFontList()

Returns

A String array of the set of Java fonts available with this Toolkit.

getFontMetrics

public abstract FontMetrics getFontMetrics (Font font)

Parameters

font

A Font whose metrics are desired

Returns

The current FontMetrics for the font on the user's system.

getImage

public abstract Image getImage (String filename)

Parameters

filename

Location of Image on local filesystem

Returns

The Image that needs to be fetched.

Description

Fetches an image from the local file system.

public abstract Image getImage (URL url)

Parameters

url

Location of Image.

Returns

The Image that needs to be fetched.

Description

Fetches an image from a URL.

getMenuShortcutKeyMask

public int getMenuShortcutKeyMask() (New)

Returns

The modifier key mask used for menu shortcuts. This will be one of the mask constants defined in java.awt.Event.

getPrintJob

public abstract PrintJob getPrintJob (Frame frame, String jobtitle, Properties props) (New)

Parameters

frame

The frame to be used as the parent of a platform-specific printing dialog.

jobtitle

The name of the job.

props

Properties for this print job.

Returns

A PrintJob object. If the user canceled the printing operation, null is returned.

getScreenResolution

public abstract int getScreenResolution()

Returns

The current resolution of the user's screen, in dots-per-inch.

getScreenSize

public abstract Dimension getScreenSize()

Returns

The size of the screen available to the Toolkit, in pixels, as a Dimension object.

getSystemClipboard

public abstract Clipboard getSystemClipboard() (New)

Returns

A Clipboard object that can be used for cut, copy, and paste operations.

getSystemEventQueue

public final EventQueue getSystemEventQueue() (New)

Returns

A reference to the system's event queue, allowing the program to post new events or inspect the queue.

prepareImage

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

Parameters

image

Image to check.

width

Width of the scaled image; -1 if image will be rendered unscaled.

height

Height of the scaled image; -1 if image will be rendered unscaled.

observer

The Component that image will be rendered on.

Returns

true if image fully loaded, false otherwise.

Description

Forces the system to start loading the image.

sync

public abstract void sync()

Description

Flushes the display of the underlying graphics context.

Protected Instance Methods

createButton

protected abstract ButtonPeer createButton (Button b)

Parameters

b

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the Button.

createCanvas

protected abstract CanvasPeer createCanvas (Canvas c)

Parameters

c

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the Canvas.

createCheckbox

protected abstract CheckboxPeer createCheckbox (Checkbox cb)

Parameters

cb

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the Checkbox.

createCheckboxMenuItem

protected abstract CheckboxMenuItemPeer createCheckboxMenuItem (CheckboxMenuItem cmi)

Parameters

cmi

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the CheckboxMenuItem.

createChoice

protected abstract ChoicePeer createChoice (Choice c)

Parameters

c

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the Choice.

createComponent

protected LightweightPeer createComponent (Component target) (New)

Parameters

target

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the Component.

createDialog

protected abstract DialogPeer createDialog (Dialog d)

Parameters

d

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the Dialog.

createFileDialog

protected abstract FileDialogPeer createFileDialog (FileDialog fd)

Parameters

fd

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the FileDialog.

createFrame

protected abstract FramePeer createFrame (Frame f)

Parameters

f

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the Frame.

createLabel

protected abstract LabelPeer createLabel (Label l)

Parameters

l

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the Label.

createList

protected abstract ListPeer createList (List l)

Parameters

l

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the List.

createMenu

protected abstract MenuPeer createMenu (Menu m)

Parameters

m

Menu whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the given Menu.

createMenuBar

protected abstract MenuBarPeer createMenuBar (MenuBar mb)

Parameters

mb

MenuBar whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the MenuBar.

createMenuItem

protected abstract MenuItemPeer createMenuItem (MenuItem mi)

Parameters

mi

MenuItem whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the MenuItem.

createPanel

protected abstract PanelPeer createPanel (Panel p)

Parameters

p

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the Panel.

createPopupMenu

protected abstract PopupMenuPeer createPopupMenu (PopupMenu target) (New)

Parameters

target

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the PopupMenu.

createScrollPane

protected abstract ScrollPanePeer createScrollPane (ScrollPane target) (New)

Parameters

target

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the ScrollPane.

createScrollbar

protected abstract ScrollbarPeer createScrollbar (Scrollbar sb)

Parameters

sb

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the Scrollbar.

createTextArea

protected abstract TextAreaPeer createTextArea (TextArea ta)

Parameters

ta

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the TextArea.

createTextField

protected abstract TextFieldPeer createTextField (TextField tf)

Parameters

tf

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the TextField.

createWindow

protected abstract WindowPeer createWindow (Window w)

Parameters

w

Component whose peer needs to be created.

Returns

Newly created peer.

Description

Creates a peer for the Window.

getFontPeer

protected abstract FontPeer getFontPeer (String name, int style) (New)

Parameters

name

Name of the font to be created.

style

Style of the font to be created.

Returns

Newly created peer.

Description

Creates a FontPeer.

getSystemEventQueueImpl

protected abstract getSystemEventQueueImpl()(New)

Returns

A toolkit-specific EventQueue object.

loadSystemColors

protected abstract void loadSystemColors (int[] systemColors) (New)

Description

Fills the given integer array with the current system colors.

See Also

Button, ButtonPeer, Canvas, CanvasPeer, Checkbox, CheckboxMenuItem, CheckboxMenuItemPeer, CheckboxPeer, Choice, ChoicePeer, Clipboard, ColorModel, Component, Container, Dialog, DialogPeer, Dimension, FileDialog, FileDialogPeer, Font, FontMetrics, FontPeer, Frame, FramePeer, Image, ImageObserver, ImageProducer, Label, LabelPeer, LightweightPeer, List, ListPeer, Menu, MenuBar, MenuBarPeer, MenuItem, MenuItemPeer, MenuPeer, Panel, PanelPeer, PrintJob, Scrollbar, ScrollbarPeer, ScrollPane, ScrollPanePeer, String, TextArea, TextAreaPeer, TextField, TextFieldPeer, Window, WindowPeer


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