// Copyright (C) 2010 The Android Open Source Project
//
// 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.gerrit.client.ui;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.event.dom.client.ChangeEvent;
import com.google.gwt.event.dom.client.ChangeHandler;
import com.google.gwt.event.dom.client.FocusEvent;
import com.google.gwt.event.dom.client.FocusHandler;
import com.google.gwt.event.dom.client.KeyDownEvent;
import com.google.gwt.event.dom.client.KeyDownHandler;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyPressHandler;
import com.google.gwt.event.dom.client.MouseUpEvent;
import com.google.gwt.event.dom.client.MouseUpHandler;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.GwtEvent;
import com.google.gwt.user.client.ui.CheckBox;
import com.google.gwt.user.client.ui.FocusWidget;
import com.google.gwt.user.client.ui.ListBox;
import com.google.gwt.user.client.ui.TextBoxBase;
import java.util.HashMap;
import java.util.Map;
/** Enables a FocusWidget (e.g. a Button) if an edit is detected from any
* registered input widget.
*/
public class OnEditEnabler implements KeyPressHandler, KeyDownHandler,
MouseUpHandler, ChangeHandler, ValueChangeHandler<Object> {
private final FocusWidget widget;
private Map<TextBoxBase, String> strings = new HashMap<TextBoxBase, String>();
// The first parameter to the contructors must be the FocusWidget to enable,
// subsequent parameters are widgets to listenTo.
public OnEditEnabler(final FocusWidget w, final TextBoxBase tb) {
this(w);
listenTo(tb);
}
public OnEditEnabler(final FocusWidget w, final ListBox lb) {
this(w);
listenTo(lb);
}
public OnEditEnabler(final FocusWidget w, final CheckBox cb) {
this(w);
listenTo(cb);
}
public OnEditEnabler(final FocusWidget w) {
widget = w;
}
// Register input widgets to be listened to
public void listenTo(final TextBoxBase tb) {
strings.put(tb, tb.getText());
tb.addKeyPressHandler(this);
// Is there another way to capture middle button X11 pastes in browsers
// which do not yet support ONPASTE events (Firefox)?
tb.addMouseUpHandler(this);
// Resetting the "original text" on focus ensures that we are
// up to date with non-user updates of the text (calls to
// setText()...) and also up to date with user changes which
// occured after enabling "widget".
tb.addFocusHandler(new FocusHandler() {
@Override
public void onFocus(FocusEvent event) {
strings.put(tb, tb.getText());
}
});
// CTRL-V Pastes in Chrome seem only detectable via BrowserEvents or
// KeyDownEvents, the latter is better.
tb.addKeyDownHandler(this);
}
public void listenTo(final ListBox lb) {
lb.addChangeHandler(this);
}
@SuppressWarnings({"unchecked", "rawtypes"})
public void listenTo(final CheckBox cb) {
cb.addValueChangeHandler((ValueChangeHandler) this);
}
// Handlers
@Override
public void onKeyPress(final KeyPressEvent e) {
on(e);
}
@Override
public void onKeyDown(final KeyDownEvent e) {
on(e);
}
@Override
public void onMouseUp(final MouseUpEvent e) {
on(e);
}
@Override
public void onChange(final ChangeEvent e) {
on(e);
}
@SuppressWarnings("rawtypes")
@Override
public void onValueChange(final ValueChangeEvent e) {
on(e);
}
private void on(final GwtEvent<?> e) {
if (widget.isEnabled() ||
! (e.getSource() instanceof FocusWidget) ||
! ((FocusWidget) e.getSource()).isEnabled() ) {
return;
}
if (e.getSource() instanceof TextBoxBase) {
onTextBoxBase((TextBoxBase) e.getSource());
} else {
// For many widgets, we can assume that a change is an edit. If
// a widget does not work that way, it should be special cased
// above.
widget.setEnabled(true);
}
}
private void onTextBoxBase(final TextBoxBase tb) {
// The text appears to not get updated until the handlers complete.
Scheduler.get().scheduleDeferred(new ScheduledCommand() {
@Override
public void execute() {
String orig = strings.get(tb);
if (orig == null) {
orig = "";
}
if (! orig.equals(tb.getText())) {
widget.setEnabled(true);
}
}
});
}
}