package standalone;

import org.eclipse.draw2d.Figure;
import org.eclipse.draw2d.FigureCanvas;
import org.eclipse.draw2d.IFigure;
import org.eclipse.draw2d.RoundedRectangle;
import org.eclipse.draw2d.geometry.Rectangle;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class FigureCanvasTransparency {

  private static int xStart = -1;
  private static int yStart = -1;
  private static int xEnd = -1;
  private static int yEnd = -1;
  private static boolean mouseDown = false;
  private static FigureCanvas canvas;
  private static FigureCanvasTransparency instance;

  public static void main(String[] args) {
    instance = new FigureCanvasTransparency();
    final Display display = new Display();
    final Shell figurecanvasTransparencyTestShell = new Shell();
    figurecanvasTransparencyTestShell.setLayout(new FillLayout());
    figurecanvasTransparencyTestShell.setText("FigureCanvas Transparency Test");

    canvas = new FigureCanvas(figurecanvasTransparencyTestShell, SWT.NONE);
    IFigure root = new Figure();
    root.setOpaque(false);
    root.setBounds(new Rectangle(0, 0, 575, 350));

    RoundedRectangle rect1 = new RoundedRectangle();
    rect1.setBackgroundColor(Display.getCurrent().getSystemColor(SWT.COLOR_YELLOW));
    rect1.setFill(true);
    rect1.setBounds(new Rectangle(100, 100, 200, 150));
    rect1.setOpaque(false);
    root.add(rect1);

    RoundedRectangle rect2 = new RoundedRectangle();
    rect2.setBackgroundColor(Display.getCurrent().getSystemColor(SWT.COLOR_TITLE_BACKGROUND_GRADIENT));
    rect2.setFill(true);
    rect2.setBounds(new Rectangle(250, 150, 200, 150));
    rect2.setOpaque(false);
    root.add(rect2);

    canvas.setContents(root);
    instance.createGesturePaintListener();
    instance.createGestureOnMouseMove();
    instance.createZoomGestureOnMouseClick();

    figurecanvasTransparencyTestShell.setSize(600, 400);
    figurecanvasTransparencyTestShell.open();
    figurecanvasTransparencyTestShell.layout();
    while (!figurecanvasTransparencyTestShell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
  }

  private void createZoomGestureOnMouseClick() {
    canvas.addMouseListener(new org.eclipse.swt.events.MouseAdapter() {
      public void mouseDown(org.eclipse.swt.events.MouseEvent event) {
        doGestureOnMouseDown(event);
      }

      public void mouseUp(org.eclipse.swt.events.MouseEvent event) {
        doGestureOnMouseUp(event);
      }
    });
  }

  private void doGestureOnMouseDown(org.eclipse.swt.events.MouseEvent event) {
    final org.eclipse.swt.events.MouseEvent e = event;
    if (e.widget instanceof FigureCanvas) {
      mouseDown = true;
      xStart = e.x;
      yStart = e.y;
    }
  }

  /**
   * @param event
   */
  private void doGestureOnMouseUp(org.eclipse.swt.events.MouseEvent event) {
    final org.eclipse.swt.events.MouseEvent e = event;
      mouseDown = false;
      xEnd = e.x;
      yEnd = e.y;
  }

  private void createGestureOnMouseMove() {
    canvas.addMouseMoveListener(new org.eclipse.swt.events.MouseMoveListener() {
      public void mouseMove(org.eclipse.swt.events.MouseEvent e) {
          if (!mouseDown) {
            return;
          }
          xEnd = e.x;
          yEnd = e.y;
          canvas.redraw();
        }
    });
  }

  /**
   * 
   */
  private void createGesturePaintListener() {
    canvas.addPaintListener(new PaintListener() {
      public void paintControl(PaintEvent event) {
          if (mouseDown) {
            drawGesture(event.gc);
          }
      }
    });
  }

  private void drawGesture(GC gc) {
    org.eclipse.swt.graphics.Rectangle mouseRect = new org.eclipse.swt.graphics.Rectangle(
        Math.min(xEnd, xStart), Math.min(yEnd, yStart),
        Math.abs(xEnd - xStart), Math.abs(yEnd - yStart));

    // draw gesture rectangle
    gc.setAlpha(192);
    gc.setBackground(new Color(canvas.getDisplay(), 240, 240, 240));
    gc.setForeground(new Color(canvas.getDisplay(), 64, 64, 64));
    gc.fillRectangle(mouseRect);
    gc.drawRectangle(mouseRect);
  }

}