java.awt
Class GraphicsDevice

java.lang.Object
  java.awt.GraphicsDevice

public abstract class GraphicsDevice

extends Object

The GraphicsDevice class describes the graphics devices that might be available in a particular graphics environment. These include screen and printer devices. Note that there can be many screens and many printers in an instance of GraphicsEnvironment. Each graphics device has one or more GraphicsConfiguration objects associated with it. These objects specify the different configurations in which the GraphicsDevice can be used.

In a multi-screen environment, the GraphicsConfiguration objects can be used to render components on multiple screens. The following code sample demonstrates how to create a JFrame object for each GraphicsConfiguration on each screen device in the GraphicsEnvironment:

   GraphicsEnvironment ge = GraphicsEnvironment.
   getLocalGraphicsEnvironment();
   GraphicsDevice[] gs = ge.getScreenDevices();
   for (int j = 0; j < gs.length; j++) { 
      GraphicsDevice gd = gs[j];
      GraphicsConfiguration[] gc =
 	gd.getConfigurations();
      for (int i=0; i < gc.length; i++) {
         JFrame f = new
         JFrame(gs[j].getDefaultConfiguration());
         Canvas c = new Canvas(gc[i]); 
         Rectangle gcBounds = gc[i].getBounds();
         int xoffs = gcBounds.x;
         int yoffs = gcBounds.y;
	   f.getContentPane().add(c);
	   f.setLocation((i*50)+xoffs, (i*60)+yoffs);
         f.show();
      }
   }
 

See Also:

GraphicsEnvironment, GraphicsConfiguration

Field Summary

static int	TYPE_IMAGE_BUFFER Device is an image buffer.
static int	TYPE_PRINTER Device is a printer.
static int	TYPE_RASTER_SCREEN Device is a raster screen.

Constructor Summary

protected

GraphicsDevice() This is an abstract class that cannot be instantiated directly.

Method Summary

int	getAvailableAcceleratedMemory() This method returns the number of bytes available in accelerated memory on this device.
GraphicsConfiguration	getBestConfiguration(GraphicsConfigTemplate gct) Returns the "best" configuration possible that passes the criteria defined in the GraphicsConfigTemplate.
abstract GraphicsConfiguration[]	getConfigurations() Returns all of the GraphicsConfiguration objects associated with this GraphicsDevice.
abstract GraphicsConfiguration	getDefaultConfiguration() Returns the default GraphicsConfiguration associated with this GraphicsDevice.
DisplayMode	getDisplayMode() Returns the current display mode of this GraphicsDevice.
DisplayMode[]	getDisplayModes() Returns all display modes available for this GraphicsDevice.
Window	getFullScreenWindow() Returns the Window object representing the full-screen window if the device is in full-screen mode.
abstract String	getIDstring() Returns the identification string associated with this GraphicsDevice.
abstract int	getType() Returns the type of this GraphicsDevice.
boolean	isDisplayChangeSupported() Returns true if this GraphicsDevice supports low-level display changes.
boolean	isFullScreenSupported() Returns true if this GraphicsDevice supports full-screen exclusive mode.
void	setDisplayMode(DisplayMode dm) Sets the display mode of this graphics device.
void	setFullScreenWindow(Window w) Enter full-screen mode, or return to windowed mode.

Methods inherited from class java.lang.Object

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

Field Detail

TYPE_RASTER_SCREEN

public static final int TYPE_RASTER_SCREEN

Device is a raster screen.

See Also:

Constant Field Values

TYPE_PRINTER

public static final int TYPE_PRINTER

Device is a printer.

See Also:

Constant Field Values

TYPE_IMAGE_BUFFER

public static final int TYPE_IMAGE_BUFFER

Device is an image buffer. This buffer can reside in device or system memory but it is not physically viewable by the user.

See Also:

Constant Field Values

Constructor Detail

GraphicsDevice

protected GraphicsDevice()

This is an abstract class that cannot be instantiated directly. Instances must be obtained from a suitable factory or query method.

See Also:

GraphicsEnvironment.getScreenDevices(), GraphicsEnvironment.getDefaultScreenDevice(), GraphicsConfiguration.getDevice()

Method Detail

getType

public abstract int getType()

Returns the type of this GraphicsDevice.

Returns:

the type of this GraphicsDevice, which can either be TYPE_RASTER_SCREEN, TYPE_PRINTER or TYPE_IMAGE_BUFFER.

See Also:

TYPE_RASTER_SCREEN, TYPE_PRINTER, TYPE_IMAGE_BUFFER

getIDstring

public abstract String getIDstring()

Returns the identification string associated with this GraphicsDevice.

A particular program might use more than one GraphicsDevice in a GraphicsEnvironment. This method returns a String identifying a particular GraphicsDevice in the local GraphicsEnvironment. Although there is no public method to set this String, a programmer can use the String for debugging purposes. Vendors of the Java^TM Runtime Environment can format the return value of the String. To determine how to interpret the value of the String, contact the vendor of your Java Runtime. To find out who the vendor is, from your program, call the getProperty method of the System class with "java.vendor".

Returns:

a String that is the identification of this GraphicsDevice.

getConfigurations

public abstract GraphicsConfiguration[] getConfigurations()

Returns all of the GraphicsConfiguration objects associated with this GraphicsDevice.

Returns:

an array of GraphicsConfiguration objects that are associated with this GraphicsDevice.

getDefaultConfiguration

public abstract GraphicsConfiguration getDefaultConfiguration()

Returns the default GraphicsConfiguration associated with this GraphicsDevice.

Returns:

the default GraphicsConfiguration of this GraphicsDevice.

getBestConfiguration

public GraphicsConfiguration getBestConfiguration(GraphicsConfigTemplate gct)

Returns the "best" configuration possible that passes the criteria defined in the GraphicsConfigTemplate.

Parameters:

gct - the GraphicsConfigTemplate object used to obtain a valid GraphicsConfiguration

Returns:

a GraphicsConfiguration that passes the criteria defined in the specified GraphicsConfigTemplate.

See Also:

GraphicsConfigTemplate

isFullScreenSupported

public boolean isFullScreenSupported()

Returns true if this GraphicsDevice supports full-screen exclusive mode.

Returns:

whether full-screen exclusive mode is available for this graphics device

Since:

1.4

setFullScreenWindow

public void setFullScreenWindow(Window w)

Enter full-screen mode, or return to windowed mode.

If isFullScreenSupported returns true, full screen mode is considered to be exclusive, which implies:

• Windows cannot overlap the full-screen window. All other application windows will always appear beneath the full-screen window in the Z-order.
• Input method windows are disabled. It is advisable to call Component.enableInputMethods(false) to make a component a non-client of the input method framework.

If isFullScreenSupported returns false, full-screen exclusive mode is simulated by resizing the window to the size of the screen and positioning it at (0,0).

When returning to windowed mode from an exclusive full-screen window, any display changes made by calling setDisplayMode are automatically restored to their original state.

Parameters:

w - a window to use as the full-screen window; null if returning to windowed mode.

Since:

1.4

See Also:

isFullScreenSupported(), getFullScreenWindow(), setDisplayMode(java.awt.DisplayMode), Component.enableInputMethods(boolean)

getFullScreenWindow

public Window getFullScreenWindow()

Returns the Window object representing the full-screen window if the device is in full-screen mode.

Returns:

the full-screen window, null if the device is not in full-screen mode.

Since:

1.4

See Also:

setFullScreenWindow(Window)

isDisplayChangeSupported

public boolean isDisplayChangeSupported()

Returns true if this GraphicsDevice supports low-level display changes.

Returns:

whether low-level display changes are supported for this graphics device. Note that this may or may not be dependent on full-screen exclusive mode.

Since:

1.4

See Also:

setDisplayMode(java.awt.DisplayMode)

setDisplayMode

public void setDisplayMode(DisplayMode dm)

Sets the display mode of this graphics device. This may only be allowed in full-screen, exclusive mode.

Parameters:

dm - the new display mode of this graphics device

Throws:

IllegalArgumentException - if the DisplayMode supplied is null, or is not available in the array returned by getDisplayModes

UnsupportedOperationException - if isDisplayChangeSupported returns false

Since:

1.4

See Also:

getDisplayMode(), getDisplayModes(), isDisplayChangeSupported()

getDisplayMode

public DisplayMode getDisplayMode()

Returns the current display mode of this GraphicsDevice.

Returns:

the current display mode of this graphics device.

Since:

1.4

See Also:

setDisplayMode(DisplayMode)

getDisplayModes

public DisplayMode[] getDisplayModes()

Returns all display modes available for this GraphicsDevice.

Returns:

all of the display modes available for this graphics device.

Since:

1.4

getAvailableAcceleratedMemory

public int getAvailableAcceleratedMemory()

This method returns the number of bytes available in accelerated memory on this device. Some images are created or cached in accelerated memory on a first-come, first-served basis. On some operating systems, this memory is a finite resource. Calling this method and scheduling the creation and flushing of images carefully may enable applications to make the most efficient use of that finite resource.
Note that the number returned is a snapshot of how much memory is available; some images may still have problems being allocated into that memory. For example, depending on operating system, driver, memory configuration, and thread situations, the full extent of the size reported may not be available for a given image. There are further inquiry methods on the ImageCapabilities object associated with a VolatileImage that can be used to determine whether a particular VolatileImage has been created in accelerated memory.

Returns:

number of bytes available in accelerated memory. A negative return value indicates that accelerated memory is unlimited.

See Also:

VolatileImage.flush(), ImageCapabilities.isAccelerated()