[platform-swt-dev] Composite children composites repaint issue

["chenliang" <chenliangdeyouxiang@xxxxxxxxxxx>]

Hi guys :

    Good day !

    I have met a problem when developing UI with SWT, I created a Composite and add

Composites to it as children ,each child Composite has an image as data,my logic to control the repaint is like this :

  parentComposite.addPaintListener(new PaintListener(){
   public void paintControl(PaintEvent e) {
    System.out.println("Painting ...");
    GC gc = e.gc;
    Rectangle bounds = parentComposite.getBounds();
    int halfHeight = bounds.height >> 1;
    int halfWidth = bounds.width >> 1;
    gc.drawLine(0, halfHeight, bounds.width, halfHeight);
    gc.drawLine(halfWidth, 0, halfWidth, bounds.height);
    
    parentComposite.update();
    Control[] children = parentComposite.getChildren();
    int numChildren = children.length;
    if(numChildren > 0){
     System.out.println("Repaint composites in slice editor :" + numChildren);
     for(Control child : children){
      Composite composite = (Composite)child;
      System.out.println("drawing child :" + child +" :" + child.getData());
      composite.setRedraw(true);
      composite.redraw();
     } 
    }
    
   }
  });

 

    I created other composites with parentComposite as parent,I added paintListener to child Composite like this

Composite composite = new Composite(parentComposite,SWT.BORDER);

                                          File imageFile = (File)imageButton.getData();

                                          composite.setData(new Image(display,imageFile.getAbsolutePath()));

                                          composite.addPaintListener(new PaintListener(){

                                                 public void paintControl(PaintEvent e) {

                                                        if(composite.getData() != null){

                                                               Image image = (Image)composite.getData();

                                                               GC gc = e.gc;

                                                               gc.drawImage(image, 0, 0);

                                                        }

                                                 }

                                                

                                          });

but the children’s paintControl method never gets called , I do not know why ,

can anybody give me any clue ?

 

    Best regards !

 

    Liang chen