com.google.gwt.user.cellview.client.CellTree Maven / Gradle / Ivy
/*
* 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.user.cellview.client;
import com.google.gwt.animation.client.Animation;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.dom.client.BrowserEvents;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Style.Display;
import com.google.gwt.dom.client.Style.Overflow;
import com.google.gwt.dom.client.Style.Position;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.i18n.client.LocaleInfo;
import com.google.gwt.i18n.client.LocalizableResource.DefaultLocale;
import com.google.gwt.i18n.client.Messages;
import com.google.gwt.resources.client.ClientBundle;
import com.google.gwt.resources.client.CssResource;
import com.google.gwt.resources.client.CssResource.ImportedWithPrefix;
import com.google.gwt.resources.client.ImageResource;
import com.google.gwt.resources.client.ImageResource.ImageOptions;
import com.google.gwt.resources.client.ImageResource.RepeatStyle;
import com.google.gwt.safecss.shared.SafeStyles;
import com.google.gwt.safecss.shared.SafeStylesBuilder;
import com.google.gwt.safehtml.client.SafeHtmlTemplates;
import com.google.gwt.safehtml.shared.SafeHtml;
import com.google.gwt.safehtml.shared.SafeHtmlUtils;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.ui.AbstractImagePrototype;
import com.google.gwt.user.client.ui.Focusable;
import com.google.gwt.user.client.ui.HasAnimation;
import com.google.gwt.user.client.ui.SimplePanel;
import com.google.gwt.view.client.TreeViewModel;
import com.google.gwt.aria.client.Roles;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Set;
/**
* A view of a tree.
*
*
* This widget will only work in standards mode, which requires that
* the HTML page in which it is run have an explicit <!DOCTYPE>
* declaration.
*
*
*
*
Examples
*
* - Trivial example
* - {@example com.google.gwt.examples.cellview.CellTreeExample}
* - Complex example
* - {@example com.google.gwt.examples.cellview.CellTreeExample2}
*
*/
public class CellTree extends AbstractCellTree implements HasAnimation,
Focusable {
/**
* Resources that match the GWT standard style theme.
*/
public interface BasicResources extends Resources {
@ImageOptions(flipRtl = true)
ImageResource cellTreeClosedItem();
@ImageOptions(flipRtl = true)
@Source("cellTreeLoadingBasic.gif")
ImageResource cellTreeLoading();
@ImageOptions(flipRtl = true)
ImageResource cellTreeOpenItem();
/**
* The styles used in this widget.
*/
@Source(BasicStyle.DEFAULT_CSS)
BasicStyle cellTreeStyle();
}
/**
* Constants for labeling the cell tree. Provides just English messages by default.
*/
@DefaultLocale("en_US")
public interface CellTreeMessages extends Messages {
@DefaultMessage("Show more")
String showMore();
@DefaultMessage("Empty")
String emptyTree();
}
/**
* A node animation.
*/
public abstract static class NodeAnimation extends Animation {
/**
* The default animation delay in milliseconds.
*/
private static final int DEFAULT_ANIMATION_DURATION = 450;
/**
* The duration of the animation in milliseconds.
*/
private int duration = DEFAULT_ANIMATION_DURATION;
NodeAnimation() {
}
/**
* Return the duration of the animation in milliseconds.
*
* @see #setDuration(int)
*/
public int getDuration() {
return duration;
}
/**
* Set the duration of the animation in milliseconds.
*
* @param duration the duration in milliseconds
* @see #getDuration()
*/
public void setDuration(int duration) {
this.duration = duration;
}
/**
* Animate a tree node into its new state.
*
* @param node the node to animate
* @param isAnimationEnabled true to animate
*/
abstract void animate(CellTreeNodeView node, boolean isAnimationEnabled);
}
/**
* A ClientBundle that provides images for this widget.
*/
public interface Resources extends ClientBundle {
/**
* An image indicating a closed branch.
*/
@ImageOptions(flipRtl = true)
@Source("cellTreeClosedArrow.png")
ImageResource cellTreeClosedItem();
/**
* An image indicating that a node is loading.
*/
@ImageOptions(flipRtl = true)
ImageResource cellTreeLoading();
/**
* An image indicating an open branch.
*/
@ImageOptions(flipRtl = true)
@Source("cellTreeOpenArrow.png")
ImageResource cellTreeOpenItem();
/**
* The background used for selected items.
*/
@ImageOptions(repeatStyle = RepeatStyle.Horizontal, flipRtl = true)
ImageResource cellTreeSelectedBackground();
/**
* The styles used in this widget.
*/
@Source(Style.DEFAULT_CSS)
Style cellTreeStyle();
}
/**
* A {@link NodeAnimation} that reveals the contents of child nodes.
*/
public static class RevealAnimation extends NodeAnimation {
/**
* Create a new {@link RevealAnimation}.
*
* @return the new animation
*/
public static RevealAnimation create() {
return new RevealAnimation();
}
/**
* The container that holds the content, includind the children.
*/
Element contentContainer;
/**
* The target height when opening, the start height when closing.
*/
int height;
/**
* True if the node is opening, false if closing.
*/
boolean opening;
/**
* The container that holds the child container.
*/
private Element animFrame;
/**
* The container that holds the children.
*/
private Element childContainer;
/**
* Not instantiable.
*/
private RevealAnimation() {
}
@Override
protected void onComplete() {
cleanup();
}
@Override
protected void onStart() {
if (opening) {
animFrame.getStyle().setHeight(1.0, Unit.PX);
animFrame.getStyle().setPosition(Position.RELATIVE);
animFrame.getStyle().clearDisplay();
height = contentContainer.getScrollHeight();
} else {
height = contentContainer.getOffsetHeight();
}
}
@Override
protected void onUpdate(double progress) {
if (opening) {
double curHeight = progress * height;
animFrame.getStyle().setHeight(curHeight, Unit.PX);
} else {
double curHeight = (1.0 - progress) * height;
animFrame.getStyle().setHeight(curHeight, Unit.PX);
}
// Remind IE6 that we want the overflow to be hidden.
animFrame.getStyle().setOverflow(Overflow.HIDDEN);
animFrame.getStyle().setPosition(Position.RELATIVE);
}
/**
* Animate a {@link CellTreeNodeView} into its new state.
*
* @param node the {@link CellTreeNodeView} to animate
* @param isAnimationEnabled true to animate
*/
@Override
void animate(CellTreeNodeView node, boolean isAnimationEnabled) {
// Cancel any pending animations.
cancel();
// Initialize the fields.
this.opening = node.isOpen();
animFrame = node.ensureAnimationFrame();
contentContainer = node.ensureContentContainer();
childContainer = node.ensureChildContainer();
if (isAnimationEnabled) {
// Animated.
int duration = getDuration();
int childCount = childContainer.getChildCount();
if (childCount < 4) {
// Reduce the duration if there are less than four items or it will
// look really slow.
duration = (int) ((childCount / 4.0) * duration);
}
run(duration);
} else {
// Non animated.
cleanup();
}
}
/**
* Put the node back into a clean state and clear fields.
*/
private void cleanup() {
if (opening) {
animFrame.getStyle().clearDisplay();
} else {
animFrame.getStyle().setDisplay(Display.NONE);
childContainer.setInnerHTML("");
}
animFrame.getStyle().clearHeight();
animFrame.getStyle().clearPosition();
this.contentContainer = null;
this.childContainer = null;
this.animFrame = null;
}
}
/**
* A {@link NodeAnimation} that slides children into view.
*/
public static class SlideAnimation extends RevealAnimation {
/**
* Create a new {@link RevealAnimation}.
*
* @return the new animation
*/
public static SlideAnimation create() {
return new SlideAnimation();
}
/**
* Not instantiable.
*/
private SlideAnimation() {
}
@Override
protected void onComplete() {
contentContainer.getStyle().clearPosition();
contentContainer.getStyle().clearTop();
contentContainer.getStyle().clearWidth();
super.onComplete();
}
@Override
protected void onStart() {
super.onStart();
if (opening) {
contentContainer.getStyle().setTop(-height, Unit.PX);
} else {
contentContainer.getStyle().setTop(0, Unit.PX);
}
contentContainer.getStyle().setPosition(Position.RELATIVE);
}
@Override
protected void onUpdate(double progress) {
super.onUpdate(progress);
if (opening) {
double curTop = (1.0 - progress) * -height;
contentContainer.getStyle().setTop(curTop, Unit.PX);
} else {
double curTop = progress * -height;
contentContainer.getStyle().setTop(curTop, Unit.PX);
}
}
}
/**
* Styles used by this widget.
*/
@ImportedWithPrefix("gwt-CellTree")
public interface Style extends CssResource {
/**
* The path to the default CSS styles used by this resource.
*/
String DEFAULT_CSS = "com/google/gwt/user/cellview/client/CellTree.css";
/**
* Applied to the empty message.
*/
String cellTreeEmptyMessage();
/**
* Applied to tree items.
*/
String cellTreeItem();
/**
* Applied to open/close icon.
*/
String cellTreeItemImage();
/**
* Applied to the wrapper around the image and value.
*/
String cellTreeItemImageValue();
/**
* Applied to the value in an item.
*/
String cellTreeItemValue();
/**
* Applied to the keyboard selected item.
*/
String cellTreeKeyboardSelectedItem();
/**
* Applied to open tree items.
*/
String cellTreeOpenItem();
/**
* Applied to selected tree items.
*/
String cellTreeSelectedItem();
/**
* Applied to the show more button.
*/
String cellTreeShowMoreButton();
/**
* Applied to top level items.
*/
String cellTreeTopItem();
/**
* Applied to open/close icon at the top level.
*/
String cellTreeTopItemImage();
/**
* Applied to the wrapper around the image and value of top level items.
*/
String cellTreeTopItemImageValue();
/**
* Applied to the widget.
*/
String cellTreeWidget();
}
/**
* Styles used by {@link BasicResources}.
*/
@ImportedWithPrefix("gwt-CellTree")
interface BasicStyle extends Style {
/**
* The path to the default CSS styles used by this resource.
*/
String DEFAULT_CSS = "com/google/gwt/user/cellview/client/CellTreeBasic.css";
}
interface Template extends SafeHtmlTemplates {
@Template("{2}")
SafeHtml imageWrapper(String classes, SafeStyles cssLayout, SafeHtml image);
}
/**
* The default number of children to show under a tree node.
*/
private static final int DEFAULT_LIST_SIZE = 25;
private static Resources DEFAULT_RESOURCES;
private static Template template;
private static Resources getDefaultResources() {
if (DEFAULT_RESOURCES == null) {
DEFAULT_RESOURCES = GWT.create(Resources.class);
}
return DEFAULT_RESOURCES;
}
/**
* A boolean indicating whether or not a cell is being edited.
*/
boolean cellIsEditing;
/**
* A boolean indicating that the widget has focus.
*/
boolean isFocused;
/**
* Set to true while the elements are being refreshed. Events are ignored
* during this time.
*/
boolean isRefreshing;
/**
* The hidden root node in the tree. Visible for testing.
*/
final CellTreeNodeView rootNode;
private char accessKey = 0;
/**
* The animation.
*/
private NodeAnimation animation;
/**
* The HTML used to generate the closed image.
*/
private final SafeHtml closedImageHtml;
/**
* The HTML used to generate the closed image for the top items.
*/
private final SafeHtml closedImageTopHtml;
/**
* The default number of children to display under each node.
*/
private int defaultNodeSize = DEFAULT_LIST_SIZE;
/**
* The maximum width of the open and closed images.
*/
private final int imageWidth;
/**
* Indicates whether or not animations are enabled.
*/
private boolean isAnimationEnabled;
/**
* The {@link CellTreeNodeView} whose children are currently being selected
* using the keyboard.
*/
private CellTreeNodeView keyboardSelectedNode;
/**
* The HTML used to generate the loading image.
*/
private final SafeHtml loadingImageHtml;
/**
* The HTML used to generate the open image.
*/
private final SafeHtml openImageHtml;
/**
* The HTML used to generate the open image for the top items.
*/
private final SafeHtml openImageTopHtml;
/**
* The styles used by this widget.
*/
private final Style style;
private int tabIndex;
/**
* Construct a new {@link CellTree}.
*
* @param the type of data in the root node
* @param viewModel the {@link TreeViewModel} that backs the tree
* @param rootValue the hidden root value of the tree
*/
public CellTree(TreeViewModel viewModel, T rootValue) {
this(viewModel, rootValue, getDefaultResources());
}
/**
* Construct a new {@link CellTree}. Uses default translations that means
* that messages will be always in English.
*
* @param the type of data in the root node
* @param viewModel the {@link TreeViewModel} that backs the tree
* @param rootValue the hidden root value of the tree
* @param resources the resources used to render the tree
*/
public CellTree(TreeViewModel viewModel, T rootValue, Resources resources) {
this(viewModel, rootValue, resources,
GWT.create(CellTreeMessages.class));
}
/**
* Construct a new {@link CellTree}.
*
* @param the type of data in the root node
* @param viewModel the {@link TreeViewModel} that backs the tree
* @param rootValue the hidden root value of the tree
* @param resources the resources used to render the tree
* @param messages translation messages. Users should inherit an empty interface from
* {@link CellTreeMessages} and add annotations needed for their specific
* translation systems. Then create the new interface with GWT.create and pass
* as this argument.
*/
public CellTree(TreeViewModel viewModel, T rootValue, Resources resources,
CellTreeMessages messages) {
this(viewModel, rootValue, resources, messages, DEFAULT_LIST_SIZE);
}
/**
* Construct a new {@link CellTree}.
*
* @param the type of data in the root node
* @param viewModel the {@link TreeViewModel} that backs the tree
* @param rootValue the hidden root value of the tree
* @param resources the resources used to render the tree
* @param messages translation messages. Users should inherit an empty interface from
* {@link CellTreeMessages} and add annotations needed for their specific
* translation systems. Then create the new interface with GWT.create and pass
* as this argument.
* @param defaultNodeSize default number of children to display beneath each child node
*/
public CellTree(TreeViewModel viewModel, T rootValue, Resources resources,
CellTreeMessages messages, int defaultNodeSize) {
super(viewModel);
this.defaultNodeSize = defaultNodeSize;
if (template == null) {
template = GWT.create(Template.class);
}
this.style = resources.cellTreeStyle();
this.style.ensureInjected();
initWidget(new SimplePanel());
setStyleName(this.style.cellTreeWidget());
// Initialize the open and close images strings.
ImageResource treeOpen = resources.cellTreeOpenItem();
ImageResource treeClosed = resources.cellTreeClosedItem();
ImageResource treeLoading = resources.cellTreeLoading();
openImageHtml = getImageHtml(treeOpen, false);
closedImageHtml = getImageHtml(treeClosed, false);
openImageTopHtml = getImageHtml(treeOpen, true);
closedImageTopHtml = getImageHtml(treeClosed, true);
loadingImageHtml = getImageHtml(treeLoading, false);
imageWidth = Math.max(Math.max(treeOpen.getWidth(), treeClosed.getWidth()),
treeLoading.getWidth());
// We use one animation for the entire tree.
setAnimation(SlideAnimation.create());
// Add event handlers.
Set eventTypes = new HashSet();
eventTypes.add(BrowserEvents.FOCUS);
eventTypes.add(BrowserEvents.BLUR);
eventTypes.add(BrowserEvents.KEYDOWN);
eventTypes.add(BrowserEvents.KEYUP);
eventTypes.add(BrowserEvents.MOUSEDOWN);
eventTypes.add(BrowserEvents.CLICK);
CellBasedWidgetImpl.get().sinkEvents(this, eventTypes);
// Associate a view with the item.
CellTreeNodeView root = new CellTreeNodeView(this, null, null,
getElement(), rootValue, messages);
keyboardSelectedNode = rootNode = root;
root.setOpen(true, false);
Roles.getTreeRole().set(getElement());
}
/**
* Get the animation used to open and close nodes in this tree if animations
* are enabled.
*
* @return the animation
* @see #isAnimationEnabled()
* @see #setAnimation(NodeAnimation)
*/
public NodeAnimation getAnimation() {
return animation;
}
/**
* Get the default maximum number of children to display under each tree node.
*
* @return the default node size
* @see #setDefaultNodeSize(int)
*/
public int getDefaultNodeSize() {
return defaultNodeSize;
}
@Override
public TreeNode getRootTreeNode() {
return rootNode.getTreeNode();
}
public int getTabIndex() {
return tabIndex;
}
public boolean isAnimationEnabled() {
return isAnimationEnabled;
}
@Override
public void onBrowserEvent(Event event) {
CellBasedWidgetImpl.get().onBrowserEvent(this, event);
if (isRefreshing) {
// Ignore spurious events (onblur) while replacing elements.
return;
}
super.onBrowserEvent(event);
String eventType = event.getType();
if (BrowserEvents.FOCUS.equals(eventType)) {
// Remember the focus state.
isFocused = true;
onFocus();
} else if (BrowserEvents.BLUR.equals(eventType)) {
// Remember the blur state.
isFocused = false;
onBlur();
} else if (BrowserEvents.KEYDOWN.equals(eventType) && !cellIsEditing) {
int keyCode = event.getKeyCode();
switch (keyCode) {
// Handle keyboard navigation.
case KeyCodes.KEY_DOWN:
case KeyCodes.KEY_UP:
case KeyCodes.KEY_RIGHT:
case KeyCodes.KEY_LEFT:
handleKeyNavigation(keyCode);
// Prevent scrollbars from scrolling.
event.preventDefault();
return;
case 32:
// Prevent scrollbars from scrolling.
event.preventDefault();
}
}
final Element target = event.getEventTarget().cast();
ArrayList chain = new ArrayList();
collectElementChain(chain, getElement(), target);
final boolean isMouseDown = BrowserEvents.MOUSEDOWN.equals(eventType);
final boolean isClick = BrowserEvents.CLICK.equals(eventType);
final CellTreeNodeView nodeView = findItemByChain(chain, 0, rootNode);
if (nodeView != null) {
if (isMouseDown) {
Element showMoreElem = nodeView.getShowMoreElement();
if (!nodeView.isRootNode() && nodeView.getImageElement().isOrHasChild(target)) {
// Open the node when the open image is clicked.
nodeView.setOpen(!nodeView.isOpen(), true);
return;
} else if (showMoreElem != null && showMoreElem.isOrHasChild(target)) {
// Show more rows when clicked.
nodeView.showMore();
return;
}
}
// Forward the event to the cell
if (nodeView != rootNode && nodeView.getSelectionElement().isOrHasChild(target)) {
// Move the keyboard focus to the clicked item.
if (isClick) {
/*
* If the selected element is natively focusable, then we do not want to
* steal focus away from it.
*/
boolean isFocusable = CellBasedWidgetImpl.get().isFocusable(target);
isFocused = isFocused || isFocusable;
keyboardSelect(nodeView, !isFocusable);
}
nodeView.fireEventToCell(event);
}
}
}
/**
* {@inheritDoc}
*
*
* Setting the key to (int) 0 will disable the access key.
*
*
* @see #getAccessKey()
*/
public void setAccessKey(char key) {
this.accessKey = key;
keyboardSelectedNode.setKeyboardSelected(true, false);
}
/**
* Set the animation used to open and close nodes in this tree. You must call
* {@link #setAnimationEnabled(boolean)} to enable or disable animation.
*
* @param animation a {@link NodeAnimation}
* @see #setAnimationEnabled(boolean)
* @see #getAnimation()
*/
public void setAnimation(NodeAnimation animation) {
assert animation != null : "animation cannot be null";
this.animation = animation;
}
public void setAnimationEnabled(boolean enable) {
this.isAnimationEnabled = enable;
if (!enable && animation != null) {
animation.cancel();
}
}
/**
* Set the default number of children to display beneath each child node. If
* more nodes are available, a button will appear at the end of the list
* allowing the user to show more items. Changing this value will not affect
* other tree nodes that are already open (including the hidden root node).
*
* @param defaultNodeSize the max
* @see #getDefaultNodeSize()
*/
public void setDefaultNodeSize(int defaultNodeSize) {
this.defaultNodeSize = defaultNodeSize;
}
public void setFocus(boolean focused) {
keyboardSelectedNode.setKeyboardSelected(true, true);
}
public void setTabIndex(int index) {
this.tabIndex = index;
keyboardSelectedNode.setKeyboardSelected(true, false);
}
/**
* Get the access key.
*
* @return the access key, or -1 if not set
* @see #setAccessKey(char)
*/
protected char getAccessKey() {
return accessKey;
}
/**
* Called when the keyboard selected node loses focus.
*/
protected void onBlur() {
keyboardSelectedNode.setKeyboardSelectedStyle(false);
}
/**
* Called when the keyboard selected node gains focus.
*/
protected void onFocus() {
keyboardSelectedNode.setKeyboardSelectedStyle(true);
}
/**
* Cancel a pending animation.
*/
void cancelTreeNodeAnimation() {
animation.cancel();
}
/**
* Get the HTML to render the closed image.
*
* @param isTop true if the top element, false if not
* @return the HTML string
*/
SafeHtml getClosedImageHtml(boolean isTop) {
return isTop ? closedImageTopHtml : closedImageHtml;
}
/**
* Get the width required for the images.
*
* @return the maximum width required for images.
*/
int getImageWidth() {
return imageWidth;
}
/**
* Return the node that has keyboard selection.
*/
CellTreeNodeView getKeyboardSelectedNode() {
return keyboardSelectedNode;
}
/**
* Return the HTML to render the loading image.
*/
SafeHtml getLoadingImageHtml() {
return loadingImageHtml;
}
/**
* Get the HTML to render the open image.
*
* @param isTop true if the top element, false if not
* @return the HTML string
*/
SafeHtml getOpenImageHtml(boolean isTop) {
return isTop ? openImageTopHtml : openImageHtml;
}
/**
* Return the Style used by the tree.
*/
Style getStyle() {
return style;
}
/**
* Select a node using the keyboard.
*
* @param node the new node to select
* @param stealFocus true to steal focus, false not to
*/
void keyboardSelect(CellTreeNodeView node, boolean stealFocus) {
if (isKeyboardSelectionDisabled()) {
return;
}
// Deselect the old node if it not destroyed.
if (keyboardSelectedNode != null && !keyboardSelectedNode.isDestroyed()) {
keyboardSelectedNode.setKeyboardSelected(false, false);
}
keyboardSelectedNode = node;
keyboardSelectedNode.setKeyboardSelected(true, stealFocus);
}
/**
* Animate the current state of a {@link CellTreeNodeView} in this tree.
*
* @param node the node to animate
*/
void maybeAnimateTreeNode(CellTreeNodeView node) {
if (animation != null) {
animation.animate(node, node.consumeAnimate() && isAnimationEnabled()
&& !node.isRootNode());
}
}
/**
* If this widget has focus, reset it.
*/
void resetFocus() {
CellBasedWidgetImpl.get().resetFocus(new Scheduler.ScheduledCommand() {
public void execute() {
if (isFocused && !keyboardSelectedNode.isDestroyed()
&& !keyboardSelectedNode.resetFocusOnCell()) {
keyboardSelectedNode.setKeyboardSelected(true, true);
}
}
});
}
/**
* Collects parents going up the element tree, terminated at the tree root.
*/
private void collectElementChain(ArrayList chain, Element hRoot,
Element hElem) {
if ((hElem == null) || (hElem == hRoot)) {
return;
}
collectElementChain(chain, hRoot, hElem.getParentElement());
chain.add(hElem);
}
private CellTreeNodeView findItemByChain(ArrayList chain,
int idx, CellTreeNodeView parent) {
if (idx == chain.size()) {
return parent;
}
Element hCurElem = chain.get(idx);
for (int i = 0, n = parent.getChildCount(); i < n; ++i) {
CellTreeNodeView child = parent.getChildNode(i);
if (child.getElement() == hCurElem) {
CellTreeNodeView retItem = findItemByChain(chain, idx + 1, child);
if (retItem == null) {
return child;
}
return retItem;
}
}
return findItemByChain(chain, idx + 1, parent);
}
/**
* Get the HTML representation of an image.
*
* @param res the {@link ImageResource} to render as HTML
* @param isTop true if the image is for a top level element.
* @return the rendered HTML
*/
private SafeHtml getImageHtml(ImageResource res, boolean isTop) {
// Build the classes.
StringBuilder classesBuilder = new StringBuilder(style.cellTreeItemImage());
if (isTop) {
classesBuilder.append(" ").append(style.cellTreeTopItemImage());
}
// Build the css.
SafeStylesBuilder cssBuilder = new SafeStylesBuilder();
if (LocaleInfo.getCurrentLocale().isRTL()) {
cssBuilder.appendTrustedString("right: 0px;");
} else {
cssBuilder.appendTrustedString("left: 0px;");
}
cssBuilder.appendTrustedString("width: " + res.getWidth() + "px;");
cssBuilder.appendTrustedString("height: " + res.getHeight() + "px;");
AbstractImagePrototype proto = AbstractImagePrototype.create(res);
SafeHtml image = SafeHtmlUtils.fromTrustedString(proto.getHTML());
return template
.imageWrapper(classesBuilder.toString(), cssBuilder.toSafeStyles(), image);
}
/**
* Handle keyboard navigation.
*
* @param keyCode the key code that was pressed
*/
private void handleKeyNavigation(int keyCode) {
CellTreeNodeView parent = keyboardSelectedNode.getParentNode();
int parentChildCount = (parent == null) ? 0 : parent.getChildCount();
int index = keyboardSelectedNode.getIndex();
int childCount = keyboardSelectedNode.getChildCount();
switch (keyCode) {
case KeyCodes.KEY_DOWN:
if (keyboardSelectedNode.isOpen() && childCount > 0) {
// Select first child.
keyboardSelect(keyboardSelectedNode.getChildNode(0), true);
} else if (index < parentChildCount - 1) {
// Next sibling.
keyboardSelect(parent.getChildNode(index + 1), true);
} else {
// Next available sibling of parent hierarchy.
CellTreeNodeView curParent = parent;
CellTreeNodeView nextSibling = null;
while (curParent != null && curParent != rootNode) {
CellTreeNodeView grandparent = curParent.getParentNode();
if (grandparent == null) {
break;
}
int curParentIndex = grandparent.indexOf(curParent);
if (curParentIndex < grandparent.getChildCount() - 1) {
nextSibling = grandparent.getChildNode(curParentIndex + 1);
break;
}
curParent = grandparent;
}
if (nextSibling != null) {
keyboardSelect(nextSibling, true);
}
}
break;
case KeyCodes.KEY_UP:
if (index > 0) {
// Deepest node of previous sibling hierarchy.
CellTreeNodeView prevSibling = parent.getChildNode(index - 1);
if (prevSibling.isOpen() && prevSibling.getChildCount() > 0) {
prevSibling = prevSibling.getChildNode(prevSibling.getChildCount() - 1);
}
keyboardSelect(prevSibling, true);
} else if (parent != null && parent != rootNode) {
// Parent.
keyboardSelect(parent, true);
}
break;
case KeyCodes.KEY_RIGHT:
if (LocaleInfo.getCurrentLocale().isRTL()) {
keyboardNavigateShallow();
} else {
keyboardNavigateDeep();
}
break;
case KeyCodes.KEY_LEFT:
if (LocaleInfo.getCurrentLocale().isRTL()) {
keyboardNavigateDeep();
} else {
keyboardNavigateShallow();
}
break;
}
}
/**
* Navigate to a deeper node. If the node is closed, open it. If it is open,
* move to the first child.
*/
private void keyboardNavigateDeep() {
if (!keyboardSelectedNode.isLeaf()) {
boolean isOpen = keyboardSelectedNode.isOpen();
if (isOpen && keyboardSelectedNode.getChildCount() > 0) {
// First child.
keyboardSelect(keyboardSelectedNode.getChildNode(0), true);
} else if (!isOpen) {
// Open the node.
keyboardSelectedNode.setOpen(true, true);
}
}
}
/**
* Navigate to a shallower node. If the node is open, close it. If it is
* closed, move to the parent.
*/
private void keyboardNavigateShallow() {
CellTreeNodeView parent = keyboardSelectedNode.getParentNode();
if (keyboardSelectedNode.isOpen()) {
// Close the node.
keyboardSelectedNode.setOpen(false, true);
} else if (parent != null && parent != rootNode) {
// Select the parent.
keyboardSelect(parent, true);
}
}
}