PCanvas.java 文件源码

/**
 * Construct a canvas with the basic scene graph consisting of a root,
 * camera, and layer. Zooming and panning are automatically installed.
 */
public PCanvas() {
    cursorStack = new PStack();
    setCamera(createDefaultCamera());
    setDefaultRenderQuality(PPaintContext.HIGH_QUALITY_RENDERING);
    setAnimatingRenderQuality(PPaintContext.LOW_QUALITY_RENDERING);
    setInteractingRenderQuality(PPaintContext.LOW_QUALITY_RENDERING);
    setPanEventHandler(new PPanEventHandler());
    setZoomEventHandler(new PZoomEventHandler());
    setBackground(Color.WHITE);
    setOpaque(true);

    addHierarchyListener(new HierarchyListener() {
        public void hierarchyChanged(final HierarchyEvent e) {
            if (e.getComponent() == PCanvas.this) {
                if (getParent() == null) {
                    removeInputSources();
                }
                else if (isEnabled()) {
                    installInputSources();
                }
            }
        }
    });
}