Revision: 7641
Author: [email protected]
Date: Tue Mar 2 09:49:29 2010
Log: Lazily initialize FocusImplStandard.focusHandler to avoid clinits.
http://gwt-code-reviews.appspot.com/154808/show
http://code.google.com/p/google-web-toolkit/source/detail?r=7641
Modified:
/trunk/user/src/com/google/gwt/user/client/ui/impl/FocusImplStandard.java
=======================================
---
/trunk/user/src/com/google/gwt/user/client/ui/impl/FocusImplStandard.java
Wed Jan 13 12:24:42 2010
+++
/trunk/user/src/com/google/gwt/user/client/ui/impl/FocusImplStandard.java
Tue Mar 2 09:49:29 2010
@@ -25,14 +25,12 @@
*/
public class FocusImplStandard extends FocusImpl {
- /*
- * Use isolated method calls to create all of the handlers to avoid
creating
- * memory leaks via handler-closures-element.
+ /**
+ * Single focusHandler shared by all focusable.
*/
- JavaScriptObject focusHandler = createFocusHandler();
-
- @Override
- public native Element createFocusable() /*-{
+ static JavaScriptObject focusHandler;
+
+ private static native Element createFocusable0(JavaScriptObject
focusHandler) /*-{
// Divs are focusable in all browsers, but only IE supports the
accessKey
// property on divs. We use the infamous 'hidden input' trick to add an
// accessKey to the focusable div. Note that the input is only used to
@@ -44,31 +42,38 @@
var input = $doc.createElement('input');
input.type = 'text';
input.tabIndex = -1;
- input.style.opacity = 0;
- input.style.height = '1px';
- input.style.width = '1px';
- input.style.zIndex = -1;
- input.style.overflow = 'hidden';
- input.style.position = 'absolute';
+ var style = input.style;
+ style.opacity = 0;
+ style.height = '1px';
+ style.width = '1px';
+ style.zIndex = -1;
+ style.overflow = 'hidden';
+ style.position = 'absolute';
// Note that we're using isolated lambda methods as the event listeners
// to avoid creating a memory leaks. (Lambdas here would create cycles
// involving the div and input). This also allows us to share a single
// set of handlers among every focusable item.
- input.addEventListener(
- 'focus',
-
[email protected]::focusHandler,
- false);
+ input.addEventListener('focus', focusHandler, false);
div.appendChild(input);
return div;
}-*/;
+
+ @Override
+ public Element createFocusable() {
+ return createFocusable0(ensureFocusHandler());
+ }
@Override
public native void setAccessKey(Element elem, char key) /*-{
elem.firstChild.accessKey = String.fromCharCode(key);
}-*/;
+ /**
+ * Use an isolated method call to create the handler to avoid creating
memory
+ * leaks via handler-closures-element.
+ */
private native JavaScriptObject createFocusHandler() /*-{
return function(evt) {
// This function is called directly as an event handler, so 'this' is
@@ -83,4 +88,8 @@
}
};
}-*/;
-}
+
+ private JavaScriptObject ensureFocusHandler() {
+ return focusHandler != null ? focusHandler : (focusHandler =
createFocusHandler());
+ }
+}
--
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