This patch changes the behavior of the left and right arrow keys on
a Tree to reduce the number of keystrokes needed to navigate the Tree.
Left arrow:
- On a top-level node: no-op
- On an open node: closes the node
- On a closed node: selects and closes the parent node
Right arrow
- On a node with children: opens the node and selects the first child
Issue: 534
Patch by: bobv
Review by: jgw
git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@1032 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/user/src/com/google/gwt/user/client/ui/Tree.java b/user/src/com/google/gwt/user/client/ui/Tree.java
index 5e89bdd..56e22fe 100644
--- a/user/src/com/google/gwt/user/client/ui/Tree.java
+++ b/user/src/com/google/gwt/user/client/ui/Tree.java
@@ -346,43 +346,43 @@
return;
}
- // Handle keyboard events
- switch (DOM.eventGetKeyCode(event)) {
- case KeyboardListener.KEY_UP: {
- moveSelectionUp(curSelection);
- DOM.eventPreventDefault(event);
- break;
- }
- case KeyboardListener.KEY_DOWN: {
- moveSelectionDown(curSelection, true);
- DOM.eventPreventDefault(event);
- break;
- }
- case KeyboardListener.KEY_LEFT: {
- if (curSelection.getState()) {
- curSelection.setState(false);
- } else {
- TreeItem parent = curSelection.getParentItem();
- if (parent != null) {
- parent.setState(false);
- setSelectedItem(parent);
- }
+ // Handle keyboard events if keyboard navigation is enabled
+ if (isKeyboardNavigationEnabled(curSelection)) {
+ switch (DOM.eventGetKeyCode(event)) {
+ case KeyboardListener.KEY_UP: {
+ moveSelectionUp(curSelection);
+ DOM.eventPreventDefault(event);
+ break;
}
- DOM.eventPreventDefault(event);
- break;
- }
- case KeyboardListener.KEY_RIGHT: {
- if (!curSelection.getState()) {
- curSelection.setState(true);
- if (curSelection.getChildCount() > 0) {
- setSelectedItem(curSelection.getChild(0));
- }
+ case KeyboardListener.KEY_DOWN: {
+ moveSelectionDown(curSelection, true);
+ DOM.eventPreventDefault(event);
+ break;
}
- DOM.eventPreventDefault(event);
- break;
+ case KeyboardListener.KEY_LEFT: {
+ if (curSelection.getState()) {
+ curSelection.setState(false);
+ } else {
+ TreeItem parent = curSelection.getParentItem();
+ if (parent != null) {
+ setSelectedItem(parent);
+ }
+ }
+ DOM.eventPreventDefault(event);
+ break;
+ }
+ case KeyboardListener.KEY_RIGHT: {
+ if (!curSelection.getState()) {
+ curSelection.setState(true);
+ } else if (curSelection.getChildCount() > 0) {
+ setSelectedItem(curSelection.getChild(0));
+ }
+ DOM.eventPreventDefault(event);
+ break;
+ }
}
}
-
+
// Intentional fallthrough.
case Event.ONKEYUP:
if (eventType == Event.ONKEYUP) {
@@ -519,6 +519,19 @@
return accum.iterator();
}
+ /**
+ * Indicates if keyboard navigation is enabled for the Tree and for a given
+ * TreeItem. Subclasses of Tree can override this function to selectively
+ * enable or disable keyboard navigation.
+ *
+ * @param currentItem the currently selected TreeItem
+ * @return <code>true</code> if the Tree will response to arrow keys by
+ * changing the currently selected item
+ */
+ protected boolean isKeyboardNavigationEnabled(TreeItem currentItem) {
+ return true;
+ }
+
protected void onAttach() {
super.onAttach();
