asquare.gwt.tk.client.ui.behavior.impl.GlassPanelControllerStandard.java Source code

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Here is the source code for asquare.gwt.tk.client.ui.behavior.impl.GlassPanelControllerStandard.java

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/*
 * Copyright 2006 Mat Gessel <mat.gessel@gmail.com>
 * 
 * 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 asquare.gwt.tk.client.ui.behavior.impl;

import asquare.gwt.tk.client.ui.behavior.ControllerAdaptor;
import asquare.gwt.tk.client.ui.behavior.GlassPanelController;
import asquare.gwt.tk.client.util.DomUtil;

import com.google.gwt.event.logical.shared.ResizeEvent;
import com.google.gwt.event.logical.shared.ResizeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Widget;

public class GlassPanelControllerStandard extends ControllerAdaptor implements GlassPanelController, ResizeHandler {
    private HandlerRegistration m_windowResizeRegistration;

    /*
     * These track the last known scrollbar state. They are helpful in
     * determining if the panel size needs to be updated when the window is
     * resized.
     */
    protected boolean m_xScroll;
    protected boolean m_yScroll;

    private Widget m_widget;

    public GlassPanelControllerStandard() {
        super(GlassPanelController.class);
    }

    @Override
    public void plugIn(Widget widget) {
        m_widget = widget;
        widget.setWidth(calculateWidth());
        widget.setHeight(calculateHeight());
        m_xScroll = canScrollX();
        m_yScroll = canScrollY();
        m_windowResizeRegistration = Window.addResizeHandler(this);
    }

    @Override
    public void unplug(Widget widget) {
        m_windowResizeRegistration.removeHandler();
        m_xScroll = m_yScroll = false;
        m_widget = null;
    }

    public Widget getWidget() {
        return m_widget;
    }

    public boolean canScrollX() {
        return DomUtil.getDocumentScrollWidth() > DomUtil.getViewportWidth();
    }

    public boolean canScrollY() {
        return DomUtil.getDocumentScrollHeight() > DomUtil.getViewportHeight();
    }

    public String calculateWidth() {
        if (canScrollX()) {
            return DomUtil.getDocumentScrollWidth() + "px";
        } else {
            return "100%";
        }
    }

    public String calculateHeight() {
        if (canScrollY()) {
            return DomUtil.getDocumentScrollHeight() + "px";
        } else {
            return "100%";
        }
    }

    protected void updateWidth() {
        boolean canScrollX = canScrollX();
        if (canScrollX != m_xScroll) {
            getWidget().setWidth(calculateWidth());
            m_xScroll = canScrollX;
        }
    }

    protected void updateHeight() {
        boolean canScrollY = canScrollY();
        // document height can change when width is resized, so always update if vertically scrollable
        if (canScrollY || canScrollY != m_yScroll) {
            getWidget().setHeight(calculateHeight());
            m_yScroll = canScrollY;
        }
    }

    public void onResize(ResizeEvent event) {
        updateWidth();
        updateHeight();
    }
}