// Copyright 2012 Google Inc. All Rights Reserved.
//
// 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.collide.client.editor;
import com.google.collide.client.util.Elements;
import com.google.collide.shared.util.ListenerManager;
import com.google.collide.shared.util.ListenerRegistrar;
import com.google.collide.shared.util.ListenerManager.Dispatcher;
import elemental.events.Event;
import elemental.events.EventListener;
import elemental.html.Element;
/**
* Tracks the focus state of the editor.
*
*/
public class FocusManager {
/**
* A listener that is called when the editor receives or loses focus.
*/
public interface FocusListener {
void onFocusChange(boolean hasFocus);
}
private final ListenerManager<FocusManager.FocusListener> focusListenerManager = ListenerManager
.create();
private boolean hasFocus;
private final Element inputElement;
FocusManager(Buffer buffer, Element inputElement) {
this.inputElement = inputElement;
attachEventHandlers(buffer);
hasFocus = inputElement.equals(Elements.getActiveElement());
}
private void attachEventHandlers(Buffer buffer) {
inputElement.addEventListener(Event.FOCUS, new EventListener() {
private final Dispatcher<FocusManager.FocusListener> dispatcher =
new Dispatcher<FocusManager.FocusListener>() {
@Override
public void dispatch(FocusListener listener) {
listener.onFocusChange(true);
}
};
@Override
public void handleEvent(Event evt) {
hasFocus = true;
focusListenerManager.dispatch(dispatcher);
}
}, false);
inputElement.addEventListener(Event.BLUR, new EventListener() {
private final Dispatcher<FocusManager.FocusListener> dispatcher =
new Dispatcher<FocusManager.FocusListener>() {
@Override
public void dispatch(FocusListener listener) {
listener.onFocusChange(false);
}
};
@Override
public void handleEvent(Event evt) {
hasFocus = false;
focusListenerManager.dispatch(dispatcher);
}
}, false);
buffer.getMouseClickListenerRegistrar().add(new Buffer.MouseClickListener() {
@Override
public void onMouseClick(int x, int y) {
focus();
}
});
}
public ListenerRegistrar<FocusManager.FocusListener> getFocusListenerRegistrar() {
return focusListenerManager;
}
public boolean hasFocus() {
return hasFocus;
}
public void focus() {
inputElement.focus();
}
}