/*******************************************************************************
 * 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.TitleBar;

import dwt.dwthelper.utils;
import dwt.dwthelper.Runnable;
import dwtx.dwtxhelper.Timer;
import dwtx.dwtxhelper.TimerTask;

import dwt.DWT;
import dwt.graphics.Color;
import dwt.graphics.Font;
import dwt.graphics.FontData;
import dwt.graphics.GC;
import dwt.graphics.Image;
import dwt.graphics.ImageData;
import dwt.graphics.PaletteData;
import dwt.graphics.Point;
import dwt.graphics.Rectangle;
import dwt.graphics.RGB;
import dwt.widgets.Canvas;
import dwt.widgets.Display;
import dwt.widgets.Event;
import dwt.widgets.Listener;
import dwt.widgets.Menu;
import dwt.widgets.MenuItem;
import dwt.widgets.Shell;

import dwtx.novocode.ishell.DesktopForm;
import dwtx.novocode.ishell.InternalShell;

import dwt.dwthelper.utils;


/**
 * A title bar for an InternalShell.
 *
 * @author Stefan Zeiger (szeiger@novocode.com)
 * @since Jan 21, 2005
 * @version $Id: TitleBar.java 342 2005-07-09 20:37:13 +0000 (Sat, 09 Jul 2005) szeiger $
 */

class TitleBar : Canvas
{
  private static const long UPDATE_DELAY = 25;
  private static const int MINIMUM_GRAB_AREA = 2;
  private static const String ELLIPSIS = "...";
  private static const int LEFT_PADDING = 2;
  private static const int RIGHT_PADDING = 2;
  private static const int IMAGE_SIZE = 16;
  private static const int TOOL_SIZE = 14;
  private static const int TOP_PADDING = 1;
  private static const int BOTTOM_PADDING = 1;

  private int mouseDownOffsetX, mouseDownOffsetY, snapBackX, snapBackY;
  private bool cancelled;
  private /**volatile*/ long lastUpdate;
  private Timer timer;
  private TimerTask timerTask;
  private InternalShell ishell;
  private DesktopForm desktop;
  private String text;
  private Image image;
  private bool styleClose, styleMax, styleTool, styleMin;
  private Image closeImage, restoreImage, maximizeImage, minimizeImage;
  private MenuItem restoreItem, closeItem, maximizeItem;
  private Menu defaultPopup;
  private Point minGrabSize;
  private Shell shell;
  private Color gradStartColor, gradEndColor, textColor, inactiveGradStartColor, inactiveGradEndColor, inactiveTextColor;
  private Listener activateListener, deactivateListener;


  this(InternalShell parent, int style)
  {
    super(parent, checkStyle(style));
    this.timer = new Timer(true);
    this.minGrabSize = new Point(MINIMUM_GRAB_AREA, MINIMUM_GRAB_AREA);
    this.ishell = parent;
    this.desktop = cast(DesktopForm)ishell.getParent();
    this.styleClose = (style & DWT.CLOSE) !is 0;
    this.styleMax = (style & DWT.MAX) !is 0;
    this.styleMin = (style & DWT.MIN) !is 0;
    this.styleTool = (style & DWT.TOOL) !is 0;

    Display display = getDisplay();
    shell = getShell();

    gradStartColor = display.getSystemColor(DWT.COLOR_TITLE_BACKGROUND);
    gradEndColor = display.getSystemColor(DWT.COLOR_TITLE_BACKGROUND_GRADIENT);
    textColor = display.getSystemColor(DWT.COLOR_TITLE_FOREGROUND);
    inactiveGradStartColor = display.getSystemColor(DWT.COLOR_TITLE_INACTIVE_BACKGROUND);
    inactiveGradEndColor = display.getSystemColor(DWT.COLOR_TITLE_INACTIVE_BACKGROUND_GRADIENT);
    inactiveTextColor = display.getSystemColor(DWT.COLOR_TITLE_INACTIVE_FOREGROUND);

    GC gc = new GC(this);
    int imgHeight = gc.getFontMetrics().getHeight()-1;
    if(imgHeight%2 is 0) imgHeight--;
    gc.dispose();

    closeImage = createMenuImage(IMAGE_TYPE_CLOSE, imgHeight);
    restoreImage = createMenuImage(IMAGE_TYPE_RESTORE, imgHeight);
    maximizeImage = createMenuImage(IMAGE_TYPE_MAXIMIZE, imgHeight);
    minimizeImage = createMenuImage(IMAGE_TYPE_MINIMIZE, imgHeight);

    setFont(createTitleFont(getFont(), styleTool));

    defaultPopup = new Menu(this);

    restoreItem = new MenuItem(defaultPopup, DWT.PUSH);
    restoreItem.setText("&Restore");
    restoreItem.setImage(restoreImage);
    restoreItem.addListener(DWT.Selection, dgListener(&restoreListener));

    MenuItem minimizeItem = new MenuItem(defaultPopup, DWT.PUSH);
    minimizeItem.setText("Mi&nimize");
    minimizeItem.setEnabled(styleMin);
    minimizeItem.setImage(minimizeImage);
    minimizeItem.addListener(DWT.Selection, dgListener(&minimizeListener));

    maximizeItem = new MenuItem(defaultPopup, DWT.PUSH);
    maximizeItem.setText("Ma&ximize");
    maximizeItem.setImage(maximizeImage);
    maximizeItem.addListener(DWT.Selection, dgListener(&maximizeListener));

    new MenuItem(defaultPopup, DWT.SEPARATOR);

    closeItem = new MenuItem(defaultPopup, DWT.PUSH);
    closeItem.setText("&Close");
    closeItem.setEnabled(styleClose);
    closeItem.setImage(closeImage);
    closeItem.addListener(DWT.Selection, dgListener(&closeListener));

    addListener(DWT.Paint, dgListener(&onPaint));
    addListener(DWT.MouseDown, dgListener(&onMouseDown));
    addListener(DWT.MenuDetect, dgListener(&onMenuDetect));
    addListener(DWT.MouseDoubleClick, dgListener(&onMouseDoubleClick));
    addListener(DWT.MouseMove, dgListener(&onMouseMove));
    addListener(DWT.MouseUp, dgListener(&onMouseUp));

    activateListener = dgListener(&onActivateListener);
    deactivateListener = dgListener(&onDeactivateListener);
    shell.addListener(DWT.Activate, activateListener);
    shell.addListener(DWT.Deactivate, deactivateListener);

    addListener(DWT.Dispose, dgListener(&onDispose));
  }


  private void restoreListener(Event event)
  {
    ishell.setMaximized(false);
  }


  private void minimizeListener(Event event)
  {
    ishell.setMinimized(true);
  }


  private void maximizeListener(Event event)
  {
    ishell.setMaximized(true);
  }


  private void closeListener(Event event)
  {
    ishell.close();
  }


  private void onPaint(Event event)
  {
        Rectangle r = getClientArea();
        if(r.width is 0 || r.height is 0) return;

        bool active = (shell is display.getActiveShell() && ishell.isActiveShell());

        GC gc = event.gc;
        gc.setForeground(active ? gradStartColor : inactiveGradStartColor);
        gc.setBackground(active ? gradEndColor : inactiveGradEndColor);
        gc.fillGradientRectangle(r.x, r.y, r.width, r.height, false);

        int textLeftPadding = LEFT_PADDING;
        if(image !is null)
        {
          Rectangle imageBounds = image.getBounds();
          if(imageBounds.width > IMAGE_SIZE || imageBounds.height > IMAGE_SIZE)
            gc.drawImage(image, 0, 0, imageBounds.width, imageBounds.height, LEFT_PADDING, TOP_PADDING, IMAGE_SIZE, IMAGE_SIZE);
          else
            gc.drawImage(image, LEFT_PADDING + (IMAGE_SIZE-imageBounds.width)/2, (r.height-imageBounds.height)/2);
          textLeftPadding += IMAGE_SIZE + LEFT_PADDING;
        }

        if(text !is null && text.length() > 0)
        {
          gc.setForeground(active ? textColor : inactiveTextColor);
          String s = text;
          int availableWidth = r.width - textLeftPadding - RIGHT_PADDING;
          if(gc.textExtent(s, DWT.DRAW_TRANSPARENT).x > availableWidth)
          {
            int ellipsisWidth = gc.textExtent(ELLIPSIS, DWT.DRAW_TRANSPARENT).x;
            while(s.length() > 0)
            {
              s = s.substring(0, s.length()-1);
              if(gc.textExtent(s, DWT.DRAW_TRANSPARENT).x + ellipsisWidth <= availableWidth)
              {
                s ~= ELLIPSIS;
                break;
              }
            }
            setToolTipText(text);
          }
          else setToolTipText(null);
          if(s.length() > 0) gc.drawString(s, textLeftPadding, (r.height-gc.getFontMetrics().getHeight())/2, true);
        }
        else setToolTipText(null);
  }


  private void onMouseDown(Event event)
  {
        if(event.button is 1)
        {
          if(image !is null && event.x < LEFT_PADDING + IMAGE_SIZE)
          {
            cancelled = true;
            // left-clicking on the image always shows the default popup menu
            instrumentDefaultPopup(true);
            defaultPopup.setLocation(toDisplay(0, getSize().y));
            defaultPopup.setVisible(true);
          }
          else
          {
            mouseDownOffsetX = event.x;
            mouseDownOffsetY = event.y;
            Point p = ishell.getLocation();
            snapBackX = p.x;
            snapBackY = p.y;
            cancelled = false;
          }
        }
        else if(event.button is 3)
        {
          if((event.stateMask & DWT.BUTTON1) !is 0 && snapBackX !is Integer.MIN_VALUE && snapBackY !is Integer.MIN_VALUE)
          {
            ishell.setLocation(snapBackX, snapBackY);
            snapBackX = Integer.MIN_VALUE;
            snapBackY = Integer.MIN_VALUE;
            cancelled = true;
          }
          else
          {
          }
        }
  }


  private void onMenuDetect(Event event)
  {
        event.doit = false;
        Menu m = getMenu();
        if(m is null || m.isDisposed())
        {
          m = defaultPopup;
          instrumentDefaultPopup(false);
        }
        m.setLocation(event.x, event.y);
        m.setVisible(true);
  }


  private void onMouseDoubleClick(Event event)
  {
        if(event.button is 1)
        {
          if(image !is null && event.x < LEFT_PADDING + IMAGE_SIZE)
          {
            if(styleClose) ishell.close();
          }
          else
          {
            if(styleMax) ishell.setMaximized(!ishell.getMaximized());
          }
          cancelled = true;
        }
  }


  private void onMouseMove(Event event)
  {
        if(!cancelled && (event.stateMask & DWT.BUTTON1) !is 0 && !ishell.getMaximized())
        {
          if(timerTask !is null)
          {
            timerTask.cancel();
            timerTask = null;
          }
          long now = System.currentTimeMillis();
          if(lastUpdate + UPDATE_DELAY < now)
          {
            performMove(event);
            lastUpdate = now;
          }
          else
          {
            timerTask = new class() TimerTask
            {
              public void run()
              {
                TimerTask executingTask = this;
                event.display.asyncExec(new class() Runnable
                {
                  public void run()
                  {
                    if(executingTask !is timerTask) return;
                    performMove(event);
                  }
                });
              }
            };
            timer.schedule(timerTask, UPDATE_DELAY);
          }
        }
  }


  private void onMouseUp(Event event)
  {
        if(ishell.getMaximized()) return;
        if(image is null || event.x >= LEFT_PADDING + IMAGE_SIZE)
        {
          if(timerTask !is null)
          {
            timerTask.cancel();
            timerTask = null;
          }
          if(!cancelled && (event.stateMask & DWT.BUTTON1) !is 0)
          {
            performMove(event);
          }
        }
  }


  private void onActivateListener(Event event)
  {
    redraw();
  }


  private void onDeactivateListener(Event event)
  {
    redraw();
  }


  private void onDispose(Event event)
  {
        timer.cancel();
        shell.removeListener(DWT.Activate, activateListener);
        shell.removeListener(DWT.Deactivate, deactivateListener);
        closeImage.dispose();
        maximizeImage.dispose();
        restoreImage.dispose();
        minimizeImage.dispose();
        defaultPopup.dispose();
  }


  private void performMove(Event event)
  {
    Point p = ishell.getLocation();
    int newX = p.x + event.x - mouseDownOffsetX;
    int newY = p.y + event.y - mouseDownOffsetY;

    // Make sure that the minimum grab area stays visible
    Rectangle deskCA = desktop.getClientArea();
    Rectangle bounds = getBounds();
    newX = Math.min(Math.max(newX, deskCA.x-bounds.x-bounds.width+MINIMUM_GRAB_AREA), deskCA.x-bounds.x+deskCA.width-minGrabSize.x);
    newY = Math.min(Math.max(newY, deskCA.y-bounds.y-bounds.height+MINIMUM_GRAB_AREA), deskCA.y-bounds.y+deskCA.height-MINIMUM_GRAB_AREA);

    if(newX !is p.x || newY !is p.y) ishell.setLocation(newX, newY);
  }


  public Point getMinGrabSize()
  {
    return minGrabSize;
  }


  public Point computeSize(int wHint, int hHint, bool changed)
  {
    checkWidget();
    if(wHint is DWT.DEFAULT) wHint = 50;
    if(hHint is DWT.DEFAULT)
    {
      GC gc = new GC(this);
      hHint = gc.getFontMetrics().getHeight();
      hHint = Math.max(hHint, styleTool ?  TOOL_SIZE : IMAGE_SIZE);
      hHint += TOP_PADDING + BOTTOM_PADDING;
      gc.dispose();
    }
    return new Point(wHint, hHint);
  }


  private static int checkStyle(int style)
  {
    //int mask = DWT.SHADOW_IN | DWT.FLAT;
    //style &= mask;
    style = DWT.NO_FOCUS;
    return style;
  }


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


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


  public void setText(String text)
  {
    checkWidget();
    this.text = text;
    redraw();
  }


  public String getText() { return text; }


  public void setImage(Image image)
  {
    checkWidget();
    if(styleTool) return;
    this.image = image;
    minGrabSize.x = MINIMUM_GRAB_AREA;
    if(image !is null) minGrabSize.x += LEFT_PADDING + IMAGE_SIZE;
    redraw();
  }


  public Image getImage() { return image; }


  private Font createTitleFont(Font f, bool tool)
  {
    FontData[] fds = f.getFontData();
    foreach(fd; fds)
    {
      fd.setStyle(fd.getStyle() | DWT.BOLD);
      if(tool) fd.setHeight(cast(int)(fd.getHeight()*0.9));
    }
    return new Font(getDisplay(), fds);
  }


  private void instrumentDefaultPopup(bool onImage)
  {
    restoreItem.setEnabled(styleMax && ishell.getMaximized());
    maximizeItem.setEnabled(styleMax && !ishell.getMaximized());
    MenuItem def = null;
    if(onImage)
    {
      if(styleClose) def = closeItem;
    }
    else if(styleMax)
    {
      def = ishell.getMaximized() ? restoreItem : maximizeItem;
    }
    defaultPopup.setDefaultItem(def);
  }


  private static const int IMAGE_TYPE_CLOSE    = 1;
  private static const int IMAGE_TYPE_MAXIMIZE = 2;
  private static const int IMAGE_TYPE_RESTORE  = 3;
  private static const int IMAGE_TYPE_MINIMIZE = 4;


  private Image createMenuImage(int type, int height)
  {
    final Point size = new Point(height, height);
    final int imgWidth = height + height/2;
    final Color fg = getForeground();
    final Color white = getDisplay().getSystemColor(DWT.COLOR_WHITE);
    final RGB blackRGB = new RGB(0,0,0);

    ImageData id = new ImageData(imgWidth, size.y, 1, new PaletteData([ blackRGB, fg.getRGB() ]));
    ImageData maskid = new ImageData(imgWidth, size.y, 1, new PaletteData([ blackRGB, white.getRGB() ]));

    Image img = new Image(getDisplay(), id);
    GC gc = new GC(img);
    gc.setForeground(fg);
    drawMenuImage(gc, size, type);
    gc.dispose();

    Image maskimg = new Image(getDisplay(), maskid);
    gc = new GC(maskimg);
    gc.setForeground(white);
    drawMenuImage(gc, size, type);
    gc.dispose();

    Image transp = new Image(getDisplay(), img.getImageData(), maskimg.getImageData());
    img.dispose();
    maskimg.dispose();
    return transp;
  }


  private void drawMenuImage(GC gc, Point size, int type)
  {
    switch(type)
    {
      case IMAGE_TYPE_CLOSE:
        gc.drawLine(1, 1, size.x-2, size.y-2);
        gc.drawLine(2, 1, size.x-2, size.y-3);
        gc.drawLine(1, 2, size.x-3, size.y-2);
        gc.drawLine(1, size.y-2, size.x-2, 1);
        gc.drawLine(1, size.y-3, size.x-3, 1);
        gc.drawLine(2, size.y-2, size.x-2, 2);
        break;

      case IMAGE_TYPE_RESTORE:
        gc.drawRectangle(0, 4, size.x-4, size.y-6);
        gc.drawLine(1, 5, size.x-5, 5);
        gc.drawLine(2, 1, size.x-2, 1);
        gc.drawLine(2, 2, size.x-2, 2);
        gc.drawPoint(2, 3);
        gc.drawLine(size.x-2, 3, size.x-2, size.y-5);
        gc.drawPoint(size.x-3, size.y-5);
        break;

      case IMAGE_TYPE_MAXIMIZE:
        gc.drawRectangle(0, 0, size.x-2, size.y-2);
        gc.drawLine(1, 1, size.x-3, 1);
        break;

      case IMAGE_TYPE_MINIMIZE:
        gc.drawLine(1, size.y-2, size.x-4, size.y-2);
        gc.drawLine(1, size.y-3, size.x-4, size.y-3);
        break;
    }
  }
}