/**
 * Copyright (c) 2011 Forschungszentrum Juelich GmbH
 * 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.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 * 		Claudia Knobloch, FZ Juelich
 */

package org.eclipse.ptp.rm.lml.ui.providers;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Layout;

class BorderLayout extends Layout {
  public static final int NWFIELD = 0;
  public static final int NFIELD = 1;
  public static final int NEFIELD = 2;
  public static final int WFIELD = 3;
  public static final int MFIELD = 4;
  public static final int EFIELD = 5;
  public static final int SWFIELD = 6;
  public static final int SFIELD = 7;
  public static final int SEFIELD = 8;

  public static class BorderData {
    public int field;
    
    public static final BorderData NORTH=new BorderData(NFIELD);
    public static final BorderData WEST=new BorderData(WFIELD);
    public static final BorderData EAST=new BorderData(EFIELD);
    public static final BorderData SOUTH=new BorderData(SFIELD);
    public static final BorderData CENTER=new BorderData(MFIELD);
    
    public static final BorderData NORTHWEST=new BorderData(NWFIELD);
    public static final BorderData NORTHEAST=new BorderData(NEFIELD);
    public static final BorderData SOUTHWEST=new BorderData(SWFIELD);
    public static final BorderData SOUTHEAST=new BorderData(SEFIELD);

    public BorderData() {
	  this.field = MFIELD;
    }

    public BorderData(int field) {
      this.field = field;
    }
  }

  Point[] points;
  Control[] controls;
  
  
  int width;
  int height;
  /*
   * (non-Javadoc)
   * 
   * @see org.eclipse.swt.widgets.Layout#computeSize(org.eclipse.swt.widgets.Composite,
   *      int, int, boolean)
   */
  protected Point computeSize(Composite composite, int wHint, int hHint, boolean flushCache) {
	  if (flushCache || points == null) {
		  getControlsAndPoints(composite.getChildren(), flushCache);
	  }
	  
	  width = max(
			  points[NWFIELD].x + points[NFIELD].x + points[NEFIELD].x, 
			  points[WFIELD].x + points[MFIELD].x + points[EFIELD].x,
			  points[SWFIELD].x + points[SFIELD].x + points[SEFIELD].x);
	  height = max(
			  points[NWFIELD].y + points[NFIELD].y + points[NEFIELD].y, 
			  points[WFIELD].y + points[MFIELD].y + points[EFIELD].y,
			  points[SWFIELD].y + points[SFIELD].y + points[SEFIELD].y);

	  return new Point(wHint == SWT.DEFAULT ? width : wHint, hHint == SWT.DEFAULT ? height : hHint);
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.eclipse.swt.widgets.Layout#layout(org.eclipse.swt.widgets.Composite,
   *      boolean)
   */
  protected void layout(Composite composite, boolean flushCache) {
	  if (flushCache || points == null) {
		  getControlsAndPoints(composite.getChildren(), flushCache);  
	  }
	  Rectangle clientArea = composite.getClientArea();

	  if (controls[NWFIELD] !=  null) {
		  controls[NWFIELD].setBounds(
				  clientArea.x, 
				  clientArea.y, 
				  points[WFIELD].x, 
				  points[NFIELD].y);
	  }
	  if (controls[NFIELD] != null) {
		  controls[NFIELD].setBounds(
				  clientArea.x + points[WFIELD].x, 
				  clientArea.y, 
				  clientArea.width - points[WFIELD].x - points[EFIELD].x, 
				  points[NFIELD].y); 
	  }
	  if (controls[NEFIELD] != null) {
		  controls[NEFIELD].setBounds(
				  clientArea.x + clientArea.width - points[EFIELD].x, 
				  clientArea.y, 
				  points[EFIELD].x, 
				  points[NFIELD].y); 
	  }
	  if (controls[WFIELD] != null) {
		  controls[WFIELD].setBounds(
				  clientArea.x, 
				  clientArea.y + points[NFIELD].y, 
				  points[WFIELD].x, 
				  clientArea.height - points[NFIELD].y - points[SFIELD].y); 
	  }
	  if (controls[MFIELD] != null) {
		  controls[MFIELD].setBounds(
				  clientArea.x + points[WFIELD].x, 
				  clientArea.y + points[NFIELD].y, 
				  clientArea.width - points[WFIELD].x - points[EFIELD].x, 
				  clientArea.height - points[NFIELD].y - points[SFIELD].y); 
	  }
	  if (controls[EFIELD] != null) {
		  controls[EFIELD].setBounds(
				  clientArea.x + clientArea.width - points[EFIELD].x, 
				  clientArea.y + points[NFIELD].y, 
				  points[EFIELD].x, 
				  clientArea.height - points[NFIELD].y - points[SFIELD].y); 
	  }
	  if (controls[SWFIELD] != null) {
		  controls[SWFIELD].setBounds(
				  clientArea.x, 
				  clientArea.y + clientArea.height - points[NFIELD].y, 
				  points[WFIELD].x, 
				  points[SFIELD].y); 
	  }
	  if (controls[SFIELD] != null) {
		  controls[SFIELD].setBounds(
				  clientArea.x + points[WFIELD].x, 
				  clientArea.y + clientArea.height - points[SFIELD].y, 
				  clientArea.width - points[WFIELD].x - points[EFIELD].x, 
				  points[SFIELD].y); 
	  }
	  if (controls[SEFIELD] != null) {
		  controls[SEFIELD].setBounds(
				  clientArea.x + clientArea.width - points[EFIELD].x, 
				  clientArea.y + clientArea.height - points[SFIELD].y, 
				  points[EFIELD].x, 
				  points[SFIELD].y); 
	  }


  }
  
  private int max(int i1, int i2, int i3) {
	  int j = i1 >= i2 ? i1 : i2;
	  return j >= i3 ? j : i3;
  }

  private void getControlsAndPoints(Control[] children, boolean flushCache) {
	  controls = new Control[9];
	  points = new Point[9]; 
	  for (int i = 0; i < children.length; i++) {
		  BorderData borderData = (BorderData) children[i].getLayoutData();
		  if (borderData != null &&  borderData.field >= 0 && borderData.field <= 8) {
			  controls[borderData.field] = children[i];
			  points[borderData.field] = children[i].computeSize(SWT.DEFAULT, SWT.DEFAULT, flushCache);
		  }
	  }
	  	
	  for (int i = 0; i < controls.length; i++) {
		  Control control = controls[i];
		  if (control == null) {
			  points[i] = new Point(0, 0);
		  } 
	  }
  }

}