com.google.livingstories.client.ui.GlassPanel.java Source code

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Here is the source code for com.google.livingstories.client.ui.GlassPanel.java

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/**
 * Copyright 2010 Google Inc.
 *
 * 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.livingstories.client.ui;

import com.google.gwt.dom.client.BodyElement;
import com.google.gwt.dom.client.Document;
import com.google.gwt.event.logical.shared.ResizeEvent;
import com.google.gwt.event.logical.shared.ResizeHandler;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.SimplePanel;

/**
 * Semitransparent overlay that dims that page for dialog boxes and lightboxes.
 * 
 * There's an existing GlassPanel implementation in gwt-incubator, but this is
 * a tinier version that is sufficient for our needs.
 */
public class GlassPanel extends Composite {
    private SimplePanel glass;
    private Timer timer;

    public GlassPanel() {
        glass = new SimplePanel();
        glass.setStylePrimaryName("fixedGlass");
        Element element = glass.getElement();
        DOM.setStyleAttribute(element, "backgroundColor", "#000000");
        DOM.setStyleAttribute(element, "opacity", "0.50");
        DOM.setStyleAttribute(element, "MozOpacity", "0.50");
        DOM.setStyleAttribute(element, "filter", "alpha(opacity=50)");
        glass.setVisible(false);
        initWidget(glass);
        Window.addResizeHandler(new ResizeHandler() {
            @Override
            public void onResize(ResizeEvent event) {
                if (isVisible()) {
                    sizeToDocument();

                    if (timer != null) {
                        timer.cancel();
                    }
                    // We need to call sizeToDocument() a second time, asynchronously, to get inappropriate
                    // scrollbars to disappear when making the window smaller. We do this with a small
                    // timeout, though, so as not to repeatedly call extra sizeToDocument over
                    // the course of a drag.
                    timer = new Timer() {
                        @Override
                        public void run() {
                            // the size actually has to change to get the layout to reflow...
                            glass.setSize("1px", "1px");
                            sizeToDocument();
                            timer = null;
                        }
                    };
                    timer.schedule(100);
                }
            }
        });
    }

    @Override
    public void setVisible(boolean visible) {
        if (visible) {
            sizeToDocument();
        }
        super.setVisible(visible);
    }

    private void sizeToDocument() {
        BodyElement body = Document.get().getBody();
        glass.setSize(body.getScrollWidth() + "px", body.getScrollHeight() + "px");
    }
}