user/src/com/google/gwt/user/client/ui/DockLayoutPanel.java - gwt - Git at Google

 /*
  * Copyright 2009 Google Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
  * use this file except in compliance with the License. You may obtain a copy of
  * the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  * License for the specific language governing permissions and limitations under
  * the License.
  */
 package com.google.gwt.user.client.ui;

 import com.google.gwt.dom.client.Document;
 import com.google.gwt.dom.client.Element;
 import com.google.gwt.dom.client.Style.Unit;
 import com.google.gwt.layout.client.Layout;
 import com.google.gwt.layout.client.Layout.Layer;

 /**
  * A panel that lays its child widgets out "docked" at its outer edges, and
  * allows its last widget to take up the remaining space in its center.
  *
  * <p>
  * Whenever children are added to, or removed from, this panel, you must call
  * one of {@link #layout()}, {@link #layout(int)}, or
  * {@link #layout(int, com.google.gwt.layout.client.Layout.AnimationCallback)}
  * to update the panel's layout.
  * </p>
  *
  * <p>
  * This widget will <em>only</em> work in standards mode, which requires
  * that the HTML page in which it is run have an explicit &lt;!DOCTYPE&gt;
  * declaration.
  * </p>
  *
  * <p>
  * NOTE: This class is still very new, and its interface may change without
  * warning. Use at your own risk.
  * </p>
  *
  * <p>
  * <h3>Example</h3>
  * {@example com.google.gwt.examples.DockLayoutPanelExample}
  * </p>
  *
  * TODO(jgw): RTL support.
  */
 public class DockLayoutPanel extends ComplexPanel implements RequiresLayout,
     RequiresResize, ProvidesResize {

   /**
    * Used in {@link DockLayoutPanel#add(Widget, Direction, double)} to specify
    * the direction in which a child widget will be added.
    */
   public enum Direction {
     NORTH, EAST, SOUTH, WEST, CENTER, LINE_START, LINE_END
   }

   /**
    * Layout data associated with each widget.
    */
   protected static class LayoutData {
     public Direction direction;
     public double oldSize, size;
     public double originalSize;
     public boolean hidden;
     public Layer layer;

     public LayoutData(Direction direction, double size, Layer layer) {
       this.direction = direction;
       this.size = size;
       this.layer = layer;
     }
   }

   private final Unit unit;
   private Widget center;
   private final Layout layout;

   /**
    * Creates an empty dock panel.
    *
    * @param unit the unit to be used for layout
    */
   public DockLayoutPanel(Unit unit) {
     this.unit = unit;

     setElement(Document.get().createDivElement());
     layout = new Layout(getElement());
   }

   /**
    * Adds a widget to the specified edge of the dock. If the widget is already a
    * child of this panel, this method behaves as though {@link #remove(Widget)}
    * had already been called.
    *
    * @param widget the widget to be added
    * @param direction the widget's direction in the dock
    * @param size the child widget's size
    *
    * @throws IllegalArgumentException when adding to the {@link #CENTER} and
    *           there is already a different widget there
    */
   public void add(Widget widget, Direction direction, double size) {
     insert(widget, direction, size, null);
   }

   /**
    * TODO(jgw): Is this really the best way to do this?
    */
   public Element getContainerElementFor(Widget widget) {
     assertIsChild(widget);
     return ((LayoutData) widget.getLayoutData()).layer.getContainerElement();
   }

   /**
    * Gets the layout direction of the given child widget.
    *
    * @param w the widget to be queried
    * @return the widget's layout direction, or <code>null</code> if it is not a
    *         child of this panel
    */
   public Direction getWidgetDirection(Widget w) {
     if (w.getParent() != this) {
       return null;
     }
     return ((LayoutData) w.getLayoutData()).direction;
   }

   /**
    * Adds a widget to the specified edge of the dock. If the widget is already a
    * child of this panel, this method behaves as though {@link #remove(Widget)}
    * had already been called.
    *
    * @param widget the widget to be added
    * @param direction the widget's direction in the dock
    * @param before the widget before which to insert the new child, or
    *          <code>null</code> to append
    *
    * @throws IllegalArgumentException when adding to the {@link #CENTER} and
    *           there is already a different widget there
    */
   public void insert(Widget widget, Direction direction, double size,
       Widget before) {
     assertIsChild(before);

     // Validation.
     if (before == null) {
       assert center == null : "No widget may be added after the CENTER widget";
     } else {
       assert direction != Direction.CENTER : "A CENTER widget must always be added last";
     }

     // Detach new child.
     widget.removeFromParent();

     // Logical attach.
     getChildren().add(widget);
     if (direction == Direction.CENTER) {
       center = widget;
     }

     // Physical attach.
     Layer layer = layout.attachChild(widget.getElement(),
         (before != null) ? before.getElement() : null, widget);
     LayoutData data = new LayoutData(direction, size, layer);
     widget.setLayoutData(data);

     // Adopt.
     adopt(widget);
   }

   public void layout() {
     layout(0);
   }

   public void layout(int duration) {
     layout(0, null);
   }

   public void layout(int duration, final Layout.AnimationCallback callback) {
     int left = 0, top = 0, right = 0, bottom = 0;

     for (Widget child : getChildren()) {
       LayoutData data = (LayoutData) child.getLayoutData();
       Layer layer = data.layer;

       switch (data.direction) {
         case NORTH:
           layer.setLeftRight(left, unit, right, unit);
           layer.setTopHeight(top, unit, data.size, unit);
           top += data.size;
           break;

         case SOUTH:
           layer.setLeftRight(left, unit, right, unit);
           layer.setBottomHeight(bottom, unit, data.size, unit);
           bottom += data.size;
           break;

         case WEST:
           layer.setTopBottom(top, unit, bottom, unit);
           layer.setLeftWidth(left, unit, data.size, unit);
           left += data.size;
           break;

         case EAST:
           layer.setTopBottom(top, unit, bottom, unit);
           layer.setRightWidth(right, unit, data.size, unit);
           right += data.size;
           break;

         case CENTER:
           layer.setLeftRight(left, unit, right, unit);
           layer.setTopBottom(top, unit, bottom, unit);
           break;
       }
     }

     layout.layout(duration, new Layout.AnimationCallback() {
       public void onAnimationComplete() {
         for (Widget child : getChildren()) {
           LayoutData data = (LayoutData) child.getLayoutData();
           if (data.size != data.oldSize) {
             data.oldSize = data.size;
             if (child instanceof RequiresResize) {
               ((RequiresResize) child).onResize();
             }
           }

           if (callback != null) {
             callback.onAnimationComplete();
           }
         }
       }

       public void onLayout(Layer layer, double progress) {
         Widget child = (Widget) layer.getUserObject();
         if (child instanceof RequiresResize) {
           ((RequiresResize) child).onResize();
         }

         if (callback != null) {
           callback.onLayout(layer, progress);
         }
       }
     });
   }

   public void onResize() {
     for (Widget child : getChildren()) {
       if (child instanceof RequiresResize) {
         ((RequiresResize) child).onResize();
       }
     }
   }

   @Override
   public boolean remove(Widget w) {
     boolean removed = super.remove(w);
     if (removed) {
       // Clear the center widget.
       if (w == center) {
         center = null;
       }

       LayoutData data = (LayoutData) w.getLayoutData();
       layout.removeChild(data.layer);
     }

     return removed;
   }

   protected Widget getCenter() {
     return center;
   }

   protected Unit getUnit() {
     return unit;
   }

   @Override
   protected void onLoad() {
     layout.onAttach();
   }

   @Override
   protected void onUnload() {
     layout.onDetach();
   }

   private void assertIsChild(Widget widget) {
     assert (widget == null) || (widget.getParent() == this) : "TODO";
   }
 }
	/*
	* Copyright 2009 Google Inc.
	*
	* Licensed under the Apache License, Version 2.0 (the "License"); you may not
	* use this file except in compliance with the License. You may obtain a copy of
	* the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
	* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
	* License for the specific language governing permissions and limitations under
	* the License.
	*/
	package com.google.gwt.user.client.ui;

	import com.google.gwt.dom.client.Document;
	import com.google.gwt.dom.client.Element;
	import com.google.gwt.dom.client.Style.Unit;
	import com.google.gwt.layout.client.Layout;
	import com.google.gwt.layout.client.Layout.Layer;

	/**
	* A panel that lays its child widgets out "docked" at its outer edges, and
	* allows its last widget to take up the remaining space in its center.
	*
	* <p>
	* Whenever children are added to, or removed from, this panel, you must call
	* one of {@link #layout()}, {@link #layout(int)}, or
	* {@link #layout(int, com.google.gwt.layout.client.Layout.AnimationCallback)}
	* to update the panel's layout.
	* </p>
	*
	* <p>
	* This widget will <em>only</em> work in standards mode, which requires
	* that the HTML page in which it is run have an explicit <!DOCTYPE>
	* declaration.
	* </p>
	*
	* <p>
	* NOTE: This class is still very new, and its interface may change without
	* warning. Use at your own risk.
	* </p>
	*
	* <p>
	* <h3>Example</h3>
	* {@example com.google.gwt.examples.DockLayoutPanelExample}
	* </p>
	*
	* TODO(jgw): RTL support.
	*/
	public class DockLayoutPanel extends ComplexPanel implements RequiresLayout,
	RequiresResize, ProvidesResize {

	/**
	* Used in {@link DockLayoutPanel#add(Widget, Direction, double)} to specify
	* the direction in which a child widget will be added.
	*/
	public enum Direction {
	NORTH, EAST, SOUTH, WEST, CENTER, LINE_START, LINE_END
	}

	/**
	* Layout data associated with each widget.
	*/
	protected static class LayoutData {
	public Direction direction;
	public double oldSize, size;
	public double originalSize;
	public boolean hidden;
	public Layer layer;

	public LayoutData(Direction direction, double size, Layer layer) {
	this.direction = direction;
	this.size = size;
	this.layer = layer;
	}
	}

	private final Unit unit;
	private Widget center;
	private final Layout layout;

	/**
	* Creates an empty dock panel.
	*
	* @param unit the unit to be used for layout
	*/
	public DockLayoutPanel(Unit unit) {
	this.unit = unit;

	setElement(Document.get().createDivElement());
	layout = new Layout(getElement());
	}

	/**
	* Adds a widget to the specified edge of the dock. If the widget is already a
	* child of this panel, this method behaves as though {@link #remove(Widget)}
	* had already been called.
	*
	* @param widget the widget to be added
	* @param direction the widget's direction in the dock
	* @param size the child widget's size
	*
	* @throws IllegalArgumentException when adding to the {@link #CENTER} and
	* there is already a different widget there
	*/
	public void add(Widget widget, Direction direction, double size) {
	insert(widget, direction, size, null);
	}

	/**
	* TODO(jgw): Is this really the best way to do this?
	*/
	public Element getContainerElementFor(Widget widget) {
	assertIsChild(widget);
	return ((LayoutData) widget.getLayoutData()).layer.getContainerElement();
	}

	/**
	* Gets the layout direction of the given child widget.
	*
	* @param w the widget to be queried
	* @return the widget's layout direction, or <code>null</code> if it is not a
	* child of this panel
	*/
	public Direction getWidgetDirection(Widget w) {
	if (w.getParent() != this) {
	return null;
	}
	return ((LayoutData) w.getLayoutData()).direction;
	}

	/**
	* Adds a widget to the specified edge of the dock. If the widget is already a
	* child of this panel, this method behaves as though {@link #remove(Widget)}
	* had already been called.
	*
	* @param widget the widget to be added
	* @param direction the widget's direction in the dock
	* @param before the widget before which to insert the new child, or
	* <code>null</code> to append
	*
	* @throws IllegalArgumentException when adding to the {@link #CENTER} and
	* there is already a different widget there
	*/
	public void insert(Widget widget, Direction direction, double size,
	Widget before) {
	assertIsChild(before);

	// Validation.
	if (before == null) {
	assert center == null : "No widget may be added after the CENTER widget";
	} else {
	assert direction != Direction.CENTER : "A CENTER widget must always be added last";
	}

	// Detach new child.
	widget.removeFromParent();

	// Logical attach.
	getChildren().add(widget);
	if (direction == Direction.CENTER) {
	center = widget;
	}

	// Physical attach.
	Layer layer = layout.attachChild(widget.getElement(),
	(before != null) ? before.getElement() : null, widget);
	LayoutData data = new LayoutData(direction, size, layer);
	widget.setLayoutData(data);

	// Adopt.
	adopt(widget);
	}

	public void layout() {
	layout(0);
	}

	public void layout(int duration) {
	layout(0, null);
	}

	public void layout(int duration, final Layout.AnimationCallback callback) {
	int left = 0, top = 0, right = 0, bottom = 0;

	for (Widget child : getChildren()) {
	LayoutData data = (LayoutData) child.getLayoutData();
	Layer layer = data.layer;

	switch (data.direction) {
	case NORTH:
	layer.setLeftRight(left, unit, right, unit);
	layer.setTopHeight(top, unit, data.size, unit);
	top += data.size;
	break;

	case SOUTH:
	layer.setLeftRight(left, unit, right, unit);
	layer.setBottomHeight(bottom, unit, data.size, unit);
	bottom += data.size;
	break;

	case WEST:
	layer.setTopBottom(top, unit, bottom, unit);
	layer.setLeftWidth(left, unit, data.size, unit);
	left += data.size;
	break;

	case EAST:
	layer.setTopBottom(top, unit, bottom, unit);
	layer.setRightWidth(right, unit, data.size, unit);
	right += data.size;
	break;

	case CENTER:
	layer.setLeftRight(left, unit, right, unit);
	layer.setTopBottom(top, unit, bottom, unit);
	break;
	}
	}

	layout.layout(duration, new Layout.AnimationCallback() {
	public void onAnimationComplete() {
	for (Widget child : getChildren()) {
	LayoutData data = (LayoutData) child.getLayoutData();
	if (data.size != data.oldSize) {
	data.oldSize = data.size;
	if (child instanceof RequiresResize) {
	((RequiresResize) child).onResize();
	}
	}

	if (callback != null) {
	callback.onAnimationComplete();
	}
	}
	}

	public void onLayout(Layer layer, double progress) {
	Widget child = (Widget) layer.getUserObject();
	if (child instanceof RequiresResize) {
	((RequiresResize) child).onResize();
	}

	if (callback != null) {
	callback.onLayout(layer, progress);
	}
	}
	});
	}

	public void onResize() {
	for (Widget child : getChildren()) {
	if (child instanceof RequiresResize) {
	((RequiresResize) child).onResize();
	}
	}
	}

	@Override
	public boolean remove(Widget w) {
	boolean removed = super.remove(w);
	if (removed) {
	// Clear the center widget.
	if (w == center) {
	center = null;
	}

	LayoutData data = (LayoutData) w.getLayoutData();
	layout.removeChild(data.layer);
	}

	return removed;
	}

	protected Widget getCenter() {
	return center;
	}

	protected Unit getUnit() {
	return unit;
	}

	@Override
	protected void onLoad() {
	layout.onAttach();
	}

	@Override
	protected void onUnload() {
	layout.onDetach();
	}

	private void assertIsChild(Widget widget) {
	assert (widget == null) \|\| (widget.getParent() == this) : "TODO";
	}
	}