panel.java

linux下建立JAVA虚拟机的源码KAFFE

package java.awt;


/**
 *
 * Copyright (c) 1998
 *	Transvirtual Technologies, Inc.  All rights reserved.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file.
 *
 */
public class Panel
  extends Container
{
	final private static long serialVersionUID = -2728009084054400034L;
	private static LayoutManager defaultLayout = new FlowLayout();
	private static int counter;

public Panel() {
	this( defaultLayout );
}

public Panel( LayoutManager layout) {
	// Panels usually get their own update events, not being updated
	// sync within their parents
	flags |= IS_ASYNC_UPDATED;

	setLayout( layout);
	setName("panel" + counter++);
}

ClassProperties getClassProperties () {
	return ClassAnalyzer.analyzeAll( getClass(), true);
}

public Graphics getGraphics () {
	if ( (flags & IS_ADD_NOTIFIED) != 0 ){
		NativeGraphics g = NativeGraphics.getClippedGraphics( null, this,
		                                                      0, 0, 0, 0,
		                                                      width, height, false);
		if ( g != null )
			linkGraphics( g);

		return g;
	}
	else {
		return null;
	}
}

public boolean isFocusTraversable () {
	// for some obscure reason, Panels are not focusTraversable by default
	return false;
}

void processPaintEvent ( int id, int ux, int uy, int uw, int uh ) {
	NativeGraphics g = NativeGraphics.getClippedGraphics( null, this, 0,0,
	                                                      ux, uy, uw, uh,
	                                                      false);
	if ( g != null ){
		markRepaints( ux, uy, uw, uh);

		if ( id == PaintEvt.UPDATE ) {
			update( g);
		}
		else {
			// Another anoying anomaly: on some window systems, the
			// background of native Components is automatically blanked (by the
			// native window system or native peer), which is simulated here.
			// Note that we don't do that for UPDATE events, since the update() spec
			// explicitly states "you can assume that the background is not cleared..",
			// and we take that literally! This also shows up in Canvas
			g.clearRect( 0, 0, width, height);

			paint( g);
		}
		g.dispose();

		if ( hasDirties() )
			emitRepaints( ux, uy, uw, uh);
	}
}
}