com.sun.jna.platform
Class WindowUtils

java.lang.Object
  com.sun.jna.platform.WindowUtils

public class WindowUtils
extends Object

Provides additional features on a Java Window.

• Non-rectangular shape (bitmap mask, no antialiasing)
• Transparency (constant alpha applied to window contents or transparent background)
• Fully transparent window (the transparency of all painted pixels is applied to the window).

NOTE: Neither shaped windows nor transparency currently works with Java 1.4 under X11. This is at least partly due to 1.4 using multiple X11 windows for a single given Java window. It *might* be possible to remedy by applying the window region/transparency to all descendants, but I haven't tried it. In addition, windows must be both displayable and visible before the corresponding native Drawable may be obtained; in later Java versions, the window need only be displayable.

NOTE: If you use setWindowMask(Window,Shape) and override Window.paint(Graphics) on OS X, you'll need to explicitly set the clip mask on the Graphics object with the window mask; only the content pane of the window and below have the window mask automatically applied.

NOTE: On OSX, the property apple.awt.draggableWindowBackground is set automatically when a window's background color has an alpha component. That property must be set to its final value before the heavyweight peer for the Window is created. Once Component.addNotify() has been called on the component, causing creation of the heavyweight peer, changing this property has no effect.

See Also:

Apple Technote 2007

MASK_NONE

public static final Shape MASK_NONE

Use this to clear a window mask.

WindowUtils

public WindowUtils()

setWindowMask

public static void setWindowMask(Window w,
                                 Shape mask)

Applies the given mask to the given window. Does nothing if the operation is not supported. The mask is treated as a bitmap and ignores transparency.

setComponentMask

public static void setComponentMask(Component c,
                                    Shape mask)

Applies the given mask to the given heavyweight component. Does nothing if the operation is not supported. The mask is treated as a bitmap and ignores transparency.

setWindowMask

public static void setWindowMask(Window w,
                                 Icon mask)

Applies the given mask to the given window. Does nothing if the operation is not supported. The mask is treated as a bitmap and ignores transparency.

isWindowAlphaSupported

public static boolean isWindowAlphaSupported()

Indicate a window can have a global alpha setting.

getAlphaCompatibleGraphicsConfiguration

public static GraphicsConfiguration getAlphaCompatibleGraphicsConfiguration()

Returns a GraphicsConfiguration comptible with alpha compositing.

setWindowAlpha

public static void setWindowAlpha(Window w,
                                  float alpha)

Set the overall window transparency. An alpha of 1.0 is fully opaque, 0.0 fully transparent. The alpha level is applied equally to all window pixels.

NOTE: Windows requires that sun.java2d.noddraw=true in order for alpha to work.

NOTE: On OSX, the property apple.awt.draggableWindowBackground must be set to its final value before the heavyweight peer for the Window is created. Once Component.addNotify() has been called on the component, causing creation of the heavyweight peer, changing this property has no effect.

See Also:

Apple Technote 2007

setWindowTransparent

public static void setWindowTransparent(Window w,
                                        boolean transparent)

Set the window to be transparent. Only explicitly painted pixels will be non-transparent. All pixels will be composited with whatever is under the window using their alpha values. On OSX, the property apple.awt.draggableWindowBackground must be set to its final value before the heavyweight peer for the Window is created. Once Component.addNotify() has been called on the component, causing creation of the heavyweight peer, changing this property has no effect.

See Also:

Apple Technote 2007