xlibrubberband.java

定要上载质量高而定要上载质量高而定要上载质量高而定要上载质量高而定要上载质量高而

/*
 * Created on May 10, 2005
 */
package org.flexdock.docking.drag.outline.xlib;

import java.awt.Graphics;
import java.awt.Rectangle;
import java.util.Iterator;
import java.util.List;

import org.flexdock.docking.drag.effects.RubberBand;
import org.flexdock.util.OsInfo;
import org.flexdock.util.ResourceManager;

/**
 * @author Christopher Butler
 *
 */
public class XlibRubberBand extends RubberBand {
    private static final String NATIVE_RESOURCE_PATH = "org/flexdock/docking/drag/outline/xlib/";
    private static final String NATIVE_RESOURCE = "libRubberBand.so";
    private static final String NATIVE_RESOURCE_START = "libRubberBand";
    private static final String NATIVE_RESOURCE_END = ".so";
	private static final String NATIVE_LIB = "RubberBand";
	
	private static final XlibRubberBand SINGLETON = new XlibRubberBand();
	private Rectangle currentRect;
	
	private native void drawRectangle(int x, int y, int width, int height);
	private native void clearRectangle(int x, int y, int width, int height);
	private native void cleanup();
	
	static {
	    prime();
	}
	
	private static void prime() {
	    List keys = OsInfo.getInstance().getPrefixLibraryKeys();
	    
	    // we're going to cycle through various levels of os+arch accuracy
	    // until we're able to load a native library that matches the current
	    // system.
	    for(Iterator it=keys.iterator(); it.hasNext();) {
	        String key = (String)it.next();
	        String lib = NATIVE_LIB + key;
	        String resource = NATIVE_RESOURCE_PATH + NATIVE_RESOURCE_START + key + NATIVE_RESOURCE_END;
	        
	        try {
	            ResourceManager.loadLibrary(lib, resource);
	            // if the library was successfully loaded, then we don't 
	            // need to do anything else.
	            return;
	        } catch(UnsatisfiedLinkError err) {
	            // eat the error and let's try again
	        }
	    }
	    
	    // last chance.  if we throw an UnsatisfiedLinkError here, then
	    // the class will fail to load
	    ResourceManager.loadLibrary(NATIVE_LIB, NATIVE_RESOURCE_PATH + NATIVE_RESOURCE);
	}
	
	public XlibRubberBand() {
		
	}
	
	public void paint(Graphics g, Rectangle r) {
		clear();
		currentRect = r;
		draw(currentRect, true);
	}
	
	public void clear() {
		draw(currentRect, false);
		currentRect = null;
	}
	
	private void draw(Rectangle r, boolean xor) {
		if(r==null)
			return;
		
		if(xor)
			drawRectangle(r.x, r.y, r.width, r.height);
		else
			clearRectangle(r.x, r.y, r.width, r.height);
	}
}