/** Sets the color used used for the ROI Manager "Show All" mode. */
 public static void setShowAllColor(Color c) {
   if (c == null) return;
   showAllColor = c;
   labelColor = null;
   ImagePlus img = WindowManager.getCurrentImage();
   if (img != null) {
     ImageCanvas ic = img.getCanvas();
     if (ic != null && ic.getShowAllROIs()) img.draw();
   }
 }
 protected void scroll(int sx, int sy) {
   int ox = xSrcStart + (int) (sx / magnification); // convert to offscreen coordinates
   int oy = ySrcStart + (int) (sy / magnification);
   // IJ.log("scroll: "+ox+" "+oy+" "+xMouseStart+" "+yMouseStart);
   int newx = xSrcStart + (xMouseStart - ox);
   int newy = ySrcStart + (yMouseStart - oy);
   if (newx < 0) newx = 0;
   if (newy < 0) newy = 0;
   if ((newx + srcRect.width) > imageWidth) newx = imageWidth - srcRect.width;
   if ((newy + srcRect.height) > imageHeight) newy = imageHeight - srcRect.height;
   srcRect.x = newx;
   srcRect.y = newy;
   // IJ.log(sx+"  "+sy+"  "+newx+"  "+newy+"  "+srcRect);
   imp.draw();
   Thread.yield();
 }