EventQueue.java 文件源码

private boolean coalescePaintEvent(PaintEvent e) {                                 
    ComponentPeer sourcePeer = ((Component)e.getSource()).peer;                
    if (sourcePeer != null) {                                                  
        sourcePeer.coalescePaintEvent(e);                                      
    }                                                                          
    EventQueueItem[] cache = ((Component)e.getSource()).eventCache;               
    if (cache == null) {                                                       
        return false;                                                          
    }                                                                          
    int index = eventToCacheIndex(e);                                          

    if (index != -1 && cache[index] != null) {
        PaintEvent merged = mergePaintEvents(e, (PaintEvent)cache[index].event);
        if (merged != null) {
            cache[index].event = merged;
            return true;
        }
    }
    return false;
}