bikeshed/src/com/google/gwt/sample/tree/client/TreeNodeView.java - gwt - Git at Google

 /*
  * Copyright 2010 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.sample.tree.client;

 import com.google.gwt.cells.client.Cell;
 import com.google.gwt.dom.client.Document;
 import com.google.gwt.dom.client.Element;
 import com.google.gwt.dom.client.NativeEvent;
 import com.google.gwt.list.shared.ListEvent;
 import com.google.gwt.list.shared.ListHandler;
 import com.google.gwt.list.shared.ListModel;
 import com.google.gwt.list.shared.ListRegistration;
 import com.google.gwt.list.shared.SizeChangeEvent;
 import com.google.gwt.sample.tree.client.TreeViewModel.NodeInfo;
 import com.google.gwt.user.client.ui.Composite;

 import java.util.ArrayList;
 import java.util.List;

 /**
  * A view of a tree node.
  *
  * @param <T> the type that this {@link TreeNodeView} contains
  */
 public class TreeNodeView<T> extends Composite {

   /**
    * The element used in place of an image when a node has no children.
    */
   private static final String LEAF_IMAGE = "<div style='position:absolute;display:none;'></div>";

   /**
    * The children of this {@link TreeNodeView}.
    */
   private List<TreeNodeView<?>> children;

   /**
    * A reference to the element that contains the children.
    */
   private Element childContainer;

   /**
    * The list registration for the list of children.
    */
   private ListRegistration listReg;

   /**
    * The info about children of this node.
    */
   private NodeInfo<?> nodeInfo;

   /**
    * Indicates whether or not we've loaded the node info.
    */
   private boolean nodeInfoLoaded;

   /**
    * Indicates whether or not this node is open.
    */
   private boolean open;

   /**
    * The parent {@link TreeNodeView}.
    */
   private TreeNodeView<?> parent;

   /**
    * The info about this node.
    */
   private NodeInfo<T> parentNodeInfo;

   /**
    * The containing {@link TreeView}.
    */
   private TreeView tree;

   /**
    * This node's value.
    */
   private T value;

   /**
    * Construct a {@link TreeNodeView}.
    *
    * @param tree the parent {@link TreeView}
    * @param parent the parent {@link TreeNodeView}
    * @param parentNodeInfo the {@link NodeInfo} of the parent
    * @param elem the outer element of this {@link TreeNodeView}.
    * @param value the value of this node
    */
   TreeNodeView(final TreeView tree, final TreeNodeView<?> parent,
       NodeInfo<T> parentNodeInfo, Element elem, T value) {
     this.value = value;
     this.tree = tree;
     this.parent = parent;
     // We pass in parentNodeInfo so we know that it is type T.
     this.parentNodeInfo = parentNodeInfo;
     setElement(elem);
   }

   /**
    * Get the child at the specified index.
    *
    * @return the child node
    */
   public TreeNodeView<?> getChild(int index) {
     if ((index < 0) || (index >= getChildCount())) {
       return null;
     }
     return children.get(index);
   }

   /**
    * Get the number of children under this node.
    *
    * @return the child count
    */
   public int getChildCount() {
     return children == null ? 0 : children.size();
   }

   /**
    * Get the parent {@link TreeNodeView}.
    */
   public TreeNodeView<?> getParentTreeNodeView() {
     return parent;
   }

   /**
    * Check whether or not this {@link TreeNodeView} is open.
    *
    * @return true if open, false if closed
    */
   public boolean getState() {
     return open;
   }

   /**
    * Get the value contained in this node.
    *
    * @return the value of the node
    */
   public T getValue() {
     return value;
   }

   /**
    * Sets whether this item's children are displayed.
    *
    * @param open whether the item is open
    */
   public void setState(boolean open) {
     setState(open, true);
   }

   /**
    * Sets whether this item's children are displayed.
    *
    * @param open whether the item is open
    * @param fireEvents <code>true</code> to allow open/close events to be
    */
   public void setState(boolean open, boolean fireEvents) {
     // TODO(jlabanca) - allow people to add open/close handlers.

     // Early out.
     if (this.open == open) {
       return;
     }

     this.open = open;
     if (open) {
       if (!nodeInfoLoaded) {
         nodeInfo = tree.getTreeViewModel().getNodeInfo(value, this);
         nodeInfoLoaded = true;
       }
       if (nodeInfo != null) {
         onOpen(nodeInfo);
       }
     } else {
       // Unregister the list handler.
       if (listReg != null) {
         listReg.removeHandler();
         listReg = null;
       }

       // Remove the children.
       childContainer.setInnerHTML("");
       children.clear();
     }

     // Update the image.
     updateImage();
   }

   /**
    * Fire an event to the {@link Cell}.
    *
    * @param event the native event
    */
   void fireEventToCell(NativeEvent event) {
     parentNodeInfo.onBrowserEvent(getCellParent(), value, event);
   }

   /**
    * @return the element that contains the rendered cell
    */
   Element getCellParent() {
     return getElement().getChild(1).cast();
   }

   /**
    * @return the image element
    */
   Element getImageElement() {
     return getElement().getFirstChildElement();
   }

   NodeInfo<T> getParentNodeInfo() {
     return parentNodeInfo;
   }

   /**
    * Set the {@link Element} that will contain the children. Used by
    * {@link TreeView}.
    *
    * @param elem the child container element
    */
   void initChildContainer(Element elem) {
     assert this.childContainer == null : "childContainer already initialized.";
     this.childContainer = elem;
   }

   /**
    * Setup the node when it is opened.
    *
    * @param nodeInfo the {@link NodeInfo} that provides information about the
    *          child values
    * @param <C> the child data type of the node.
    */
   private <C> void onOpen(final NodeInfo<C> nodeInfo) {
     // Get the node info.
     ListModel<C> listModel = nodeInfo.getListModel();
     listReg = listModel.addListHandler(new ListHandler<C>() {
       public void onDataChanged(ListEvent<C> event) {
         // TODO - handle event start and length

         // Construct the child contents.
         TreeViewModel model = tree.getTreeViewModel();
         int imageWidth = tree.getImageWidth();
         Cell<C> theCell = nodeInfo.getCell();
         StringBuilder sb = new StringBuilder();
         children = new ArrayList<TreeNodeView<?>>();
         for (C childValue : event.getValues()) {
           sb.append("<div style=\"position:relative;padding-left:");
           sb.append(imageWidth);
           sb.append("px;\">");
           if (model.isLeaf(childValue)) {
             sb.append(LEAF_IMAGE);
           } else {
             sb.append(tree.getClosedImageHtml());
           }
           sb.append("<div>");
           theCell.render(childValue, sb);
           sb.append("</div>");
           sb.append("</div>");
         }

         // Replace contents of the child container.
         if (childContainer == null) {
           Element elem = getElement();
           initChildContainer(Document.get().createDivElement());
           elem.appendChild(childContainer);
         }
         childContainer.setInnerHTML(sb.toString());

         // Create the child TreeNodeViews from the new elements.
         children = new ArrayList<TreeNodeView<?>>();
         Element childElem = childContainer.getFirstChildElement();
         for (C childValue : event.getValues()) {
           TreeNodeView<C> child = new TreeNodeView<C>(tree, TreeNodeView.this,
               nodeInfo, childElem, childValue);
           children.add(child);
           childElem = childElem.getNextSiblingElement();
         }
       }

       public void onSizeChanged(SizeChangeEvent event) {
         if (children == null) {
           return;
         }

         // Shrink the list based on the new size.
         int size = event.getSize();
         int currentSize = children.size();
         for (int i = currentSize - 1; i >= size; i--) {
           childContainer.getLastChild().removeFromParent();
           children.remove(i);
         }
       }
     });
     listReg.setRangeOfInterest(0, 100);
   }

   /**
    * Update the image based on the current state.
    */
   private void updateImage() {
     // Early out if this is a root node.
     if (getParentTreeNodeView() == null) {
       return;
     }

     // Replace the image element with a new one.
     String html = open ? tree.getOpenImageHtml() : tree.getClosedImageHtml();
     if (nodeInfoLoaded && nodeInfo == null) {
       html = LEAF_IMAGE;
     }
     Element tmp = Document.get().createDivElement();
     tmp.setInnerHTML(html);
     Element imageElem = tmp.getFirstChildElement();
     getElement().replaceChild(imageElem, getImageElement());
   }
 }
	/*
	* Copyright 2010 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.sample.tree.client;

	import com.google.gwt.cells.client.Cell;
	import com.google.gwt.dom.client.Document;
	import com.google.gwt.dom.client.Element;
	import com.google.gwt.dom.client.NativeEvent;
	import com.google.gwt.list.shared.ListEvent;
	import com.google.gwt.list.shared.ListHandler;
	import com.google.gwt.list.shared.ListModel;
	import com.google.gwt.list.shared.ListRegistration;
	import com.google.gwt.list.shared.SizeChangeEvent;
	import com.google.gwt.sample.tree.client.TreeViewModel.NodeInfo;
	import com.google.gwt.user.client.ui.Composite;

	import java.util.ArrayList;
	import java.util.List;

	/**
	* A view of a tree node.
	*
	* @param <T> the type that this {@link TreeNodeView} contains
	*/
	public class TreeNodeView<T> extends Composite {

	/**
	* The element used in place of an image when a node has no children.
	*/
	private static final String LEAF_IMAGE = "<div style='position:absolute;display:none;'></div>";

	/**
	* The children of this {@link TreeNodeView}.
	*/
	private List<TreeNodeView<?>> children;

	/**
	* A reference to the element that contains the children.
	*/
	private Element childContainer;

	/**
	* The list registration for the list of children.
	*/
	private ListRegistration listReg;

	/**
	* The info about children of this node.
	*/
	private NodeInfo<?> nodeInfo;

	/**
	* Indicates whether or not we've loaded the node info.
	*/
	private boolean nodeInfoLoaded;

	/**
	* Indicates whether or not this node is open.
	*/
	private boolean open;

	/**
	* The parent {@link TreeNodeView}.
	*/
	private TreeNodeView<?> parent;

	/**
	* The info about this node.
	*/
	private NodeInfo<T> parentNodeInfo;

	/**
	* The containing {@link TreeView}.
	*/
	private TreeView tree;

	/**
	* This node's value.
	*/
	private T value;

	/**
	* Construct a {@link TreeNodeView}.
	*
	* @param tree the parent {@link TreeView}
	* @param parent the parent {@link TreeNodeView}
	* @param parentNodeInfo the {@link NodeInfo} of the parent
	* @param elem the outer element of this {@link TreeNodeView}.
	* @param value the value of this node
	*/
	TreeNodeView(final TreeView tree, final TreeNodeView<?> parent,
	NodeInfo<T> parentNodeInfo, Element elem, T value) {
	this.value = value;
	this.tree = tree;
	this.parent = parent;
	// We pass in parentNodeInfo so we know that it is type T.
	this.parentNodeInfo = parentNodeInfo;
	setElement(elem);
	}

	/**
	* Get the child at the specified index.
	*
	* @return the child node
	*/
	public TreeNodeView<?> getChild(int index) {
	if ((index < 0) \|\| (index >= getChildCount())) {
	return null;
	}
	return children.get(index);
	}

	/**
	* Get the number of children under this node.
	*
	* @return the child count
	*/
	public int getChildCount() {
	return children == null ? 0 : children.size();
	}

	/**
	* Get the parent {@link TreeNodeView}.
	*/
	public TreeNodeView<?> getParentTreeNodeView() {
	return parent;
	}

	/**
	* Check whether or not this {@link TreeNodeView} is open.
	*
	* @return true if open, false if closed
	*/
	public boolean getState() {
	return open;
	}

	/**
	* Get the value contained in this node.
	*
	* @return the value of the node
	*/
	public T getValue() {
	return value;
	}

	/**
	* Sets whether this item's children are displayed.
	*
	* @param open whether the item is open
	*/
	public void setState(boolean open) {
	setState(open, true);
	}

	/**
	* Sets whether this item's children are displayed.
	*
	* @param open whether the item is open
	* @param fireEvents <code>true</code> to allow open/close events to be
	*/
	public void setState(boolean open, boolean fireEvents) {
	// TODO(jlabanca) - allow people to add open/close handlers.

	// Early out.
	if (this.open == open) {
	return;
	}

	this.open = open;
	if (open) {
	if (!nodeInfoLoaded) {
	nodeInfo = tree.getTreeViewModel().getNodeInfo(value, this);
	nodeInfoLoaded = true;
	}
	if (nodeInfo != null) {
	onOpen(nodeInfo);
	}
	} else {
	// Unregister the list handler.
	if (listReg != null) {
	listReg.removeHandler();
	listReg = null;
	}

	// Remove the children.
	childContainer.setInnerHTML("");
	children.clear();
	}

	// Update the image.
	updateImage();
	}

	/**
	* Fire an event to the {@link Cell}.
	*
	* @param event the native event
	*/
	void fireEventToCell(NativeEvent event) {
	parentNodeInfo.onBrowserEvent(getCellParent(), value, event);
	}

	/**
	* @return the element that contains the rendered cell
	*/
	Element getCellParent() {
	return getElement().getChild(1).cast();
	}

	/**
	* @return the image element
	*/
	Element getImageElement() {
	return getElement().getFirstChildElement();
	}

	NodeInfo<T> getParentNodeInfo() {
	return parentNodeInfo;
	}

	/**
	* Set the {@link Element} that will contain the children. Used by
	* {@link TreeView}.
	*
	* @param elem the child container element
	*/
	void initChildContainer(Element elem) {
	assert this.childContainer == null : "childContainer already initialized.";
	this.childContainer = elem;
	}

	/**
	* Setup the node when it is opened.
	*
	* @param nodeInfo the {@link NodeInfo} that provides information about the
	* child values
	* @param <C> the child data type of the node.
	*/
	private <C> void onOpen(final NodeInfo<C> nodeInfo) {
	// Get the node info.
	ListModel<C> listModel = nodeInfo.getListModel();
	listReg = listModel.addListHandler(new ListHandler<C>() {
	public void onDataChanged(ListEvent<C> event) {
	// TODO - handle event start and length

	// Construct the child contents.
	TreeViewModel model = tree.getTreeViewModel();
	int imageWidth = tree.getImageWidth();
	Cell<C> theCell = nodeInfo.getCell();
	StringBuilder sb = new StringBuilder();
	children = new ArrayList<TreeNodeView<?>>();
	for (C childValue : event.getValues()) {
	sb.append("<div style=\"position:relative;padding-left:");
	sb.append(imageWidth);
	sb.append("px;\">");
	if (model.isLeaf(childValue)) {
	sb.append(LEAF_IMAGE);
	} else {
	sb.append(tree.getClosedImageHtml());
	}
	sb.append("<div>");
	theCell.render(childValue, sb);
	sb.append("</div>");
	sb.append("</div>");
	}

	// Replace contents of the child container.
	if (childContainer == null) {
	Element elem = getElement();
	initChildContainer(Document.get().createDivElement());
	elem.appendChild(childContainer);
	}
	childContainer.setInnerHTML(sb.toString());

	// Create the child TreeNodeViews from the new elements.
	children = new ArrayList<TreeNodeView<?>>();
	Element childElem = childContainer.getFirstChildElement();
	for (C childValue : event.getValues()) {
	TreeNodeView<C> child = new TreeNodeView<C>(tree, TreeNodeView.this,
	nodeInfo, childElem, childValue);
	children.add(child);
	childElem = childElem.getNextSiblingElement();
	}
	}

	public void onSizeChanged(SizeChangeEvent event) {
	if (children == null) {
	return;
	}

	// Shrink the list based on the new size.
	int size = event.getSize();
	int currentSize = children.size();
	for (int i = currentSize - 1; i >= size; i--) {
	childContainer.getLastChild().removeFromParent();
	children.remove(i);
	}
	}
	});
	listReg.setRangeOfInterest(0, 100);
	}

	/**
	* Update the image based on the current state.
	*/
	private void updateImage() {
	// Early out if this is a root node.
	if (getParentTreeNodeView() == null) {
	return;
	}

	// Replace the image element with a new one.
	String html = open ? tree.getOpenImageHtml() : tree.getClosedImageHtml();
	if (nodeInfoLoaded && nodeInfo == null) {
	html = LEAF_IMAGE;
	}
	Element tmp = Document.get().createDivElement();
	tmp.setInnerHTML(html);
	Element imageElem = tmp.getFirstChildElement();
	getElement().replaceChild(imageElem, getImageElement());
	}
	}