How to handle Click event or any other Event in GWT Cloud?
I am using tagcloud_0.4.jar for using Tag Clo开发者_如何学Goud in GWT. Now, when I click on any tag inside the tag cloud, then how can I handle that event or how can I do RPC call when user select any tag from cloud?
Thanks.
Here is an example to catch a ClickEvent on the cloud. But this is a workaround as the library may change. As the developper do not offer to manage events on the cloud neither on tags, this is perhaps for a good reason...
So use this code at your own risk. Pray for no change of the widget's structure DOM. I suggest you to ask the developper some enhancements on its widgets, like managing such events.
final TagCloud cloud = new TagCloud();
cloud.addWord(new WordTag("AAA"));
cloud.addWord(new WordTag("AAA"));
cloud.addWord(new WordTag("BBB"));
cloud.addWord(new WordTag("CCC"));
cloud.addWord(new WordTag("CCC"));
cloud.addWord(new WordTag("CCC"));
cloud.addDomHandler(new ClickHandler() {
@Override
public void onClick(ClickEvent event) {
// Prevent the click from the tag to be executed
event.preventDefault();
Element e;
// For each tag present in the cloud, look for the one that is triggered
for (int i = 0; i < cloud.getTags().size(); ++i) {
// Gets the element in the cloud, this really is the unsafe part of the code
// if the developer change the dom of its widget
e = DOM.getChild(DOM.getChild(cloud.getElement(), 0), i);
// Is the current element targeted by the event?
if (event.getClientX() >= e.getOffsetLeft() && event.getClientY() >= e.getOffsetTop()
&& event.getClientX() <= e.getOffsetLeft() + e.getOffsetWidth()
&& event.getClientY() <= e.getOffsetTop() + e.getOffsetHeight()) {
// Gets the abstract tag
Tag t = cloud.getTags().get(i);
// Gets tag descendant
if (t instanceof WordTag) {
// Do what you want with your WordTag, maybe an RPC call
} else if (t instanceof ImageTag) {
// Do what you want with your ImageTag, maybe an RPC call
}
break;
}
}
}
}, ClickEvent.getType());
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