/*******************************************************************************
 * Copyright (c) 2005 Stefan Zeiger and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.novocode.com/legal/epl-v10.html
 * 
 * Contributors:
 *     Stefan Zeiger (szeiger@novocode.com) - initial API and implementation
 *******************************************************************************/

module dwtx.novocode.ishell.internal.CustomDrawnButton;

import dwt.DWT;
import dwt.graphics.Point;
import dwt.widgets.Canvas;
import dwt.widgets.Composite;
import dwt.widgets.Display;
import dwt.widgets.Event;
import dwt.widgets.Listener;


/**
 * A simple button control which needs to be subclassed to draw a specific
 * kind of button. This base class provides the event handling.
 * 
 * @author Stefan Zeiger (szeiger@novocode.com)
 * @since Jan 30, 2005
 * @version $Id: CustomDrawnButton.java 320 2005-02-26 13:37:02 +0000 (Sat, 26 Feb 2005) szeiger $
 */

class CustomDrawnButton : Canvas
{
  private bool pressed;
  private Display display;
  private bool drawnMouseIn = false;


  this(Composite parent, int style)
  {
    super(parent, style);
    this.display = getDisplay();

    addListener(DWT.Paint, dgListener(&paintListener));

    addListener(DWT.MouseDown, dgListener(&onMouseDown));

    addListener(DWT.MouseUp, dgListener(&onMouseUp));
    
    addListener(DWT.MouseMove, dgListener(&onMouseMove));
  }
  
  
  private void paintListener(Event event)
  {
        bool mouseIn = mouseIn();
        onPaint(event, pressed && mouseIn);
        drawnMouseIn = mouseIn;
  }


  private void onMouseDown(Event event)
  {
        if(event.button is 1)
        {
          pressed = true;
          redraw();
        }
        else if(event.button is 3 && (event.stateMask & DWT.BUTTON1) !is 0) // chord click
        {
          pressed = false;
          redraw();
        }
  }


  private void onMouseUp(Event event)
  {
        if(pressed && (event.stateMask & DWT.BUTTON1) !is 0)
        {
          pressed = false;
          if(mouseIn())
          {
            Event selectionEvent = new Event();
            notifyListeners(DWT.Selection, selectionEvent);
          }
          if(!isDisposed()) redraw();
        }
  }


  private void onMouseMove(Event event)
  {
        if(!pressed) return;
        bool mouseIn = mouseIn();
        if(mouseIn is drawnMouseIn) return;
        redraw();
  }


  private bool mouseIn()
  {
    Point p = toControl(display.getCursorLocation());
    if(p.x < -1 || p.y < -1) return false;
    Point size = getSize();
    return p.x <= size.x+1 && p.y <= size.y+1;
  }


  public Point computeSize(int wHint, int hHint, bool changed)
  {
    checkWidget();
    if(wHint is DWT.DEFAULT) wHint = 0;
    if(hHint is DWT.DEFAULT) hHint = 0;
    return new Point(wHint, hHint);
  }


  public bool setFocus()
  {
    checkWidget();
    return false;
  }


  public bool isReparentable ()
  {
    checkWidget();
    return false;
  }
  
  
  protected abstract void onPaint(Event event, bool pressed);
}