com.google.gwt.visualization.sample.visualizationshowcase.client.LeftTabPanel.java Source code

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Here is the source code for com.google.gwt.visualization.sample.visualizationshowcase.client.LeftTabPanel.java

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/*
 * Copyright 2008 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.gwt.visualization.sample.visualizationshowcase.client;

import com.google.gwt.dom.client.Style;
import com.google.gwt.event.logical.shared.SelectionEvent;
import com.google.gwt.event.logical.shared.SelectionHandler;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.DecoratorPanel;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.SimplePanel;
import com.google.gwt.user.client.ui.Tree;
import com.google.gwt.user.client.ui.TreeItem;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.ui.Widget;

import java.util.HashMap;
import java.util.Map;

/**
 * A panel with a tree on the left and a display case on the right. Selecting a
 * tree item displays the analogous widget.
 */
public class LeftTabPanel extends Composite {
    /**
     * Allows the caller to pass in objects that will create new widgets every
     * time a link is clicked, to work around the issue that some visualizations
     * become invalid when they are removed from a panel.
     */
    public interface WidgetProvider {
        Widget getWidget();
    }

    private static void setWidget(SimplePanel simple, WidgetProvider provider) {
        simple.clear();
        simple.add(provider.getWidget());
    }

    private final Map<String, WidgetProvider> cogs = new HashMap<String, WidgetProvider>();
    private final VerticalPanel left = new VerticalPanel();
    private final Tree leftTree = new Tree();
    private final HorizontalPanel main = new HorizontalPanel();
    private final SimplePanel right = new SimplePanel();

    public LeftTabPanel() {
        initWidget(main);
        main.add(left);
        left.add(leftTree);
        DecoratorPanel decorator = new DecoratorPanel();
        Style decoratorStyle = decorator.getElement().getStyle();
        decoratorStyle.setPropertyPx("marginLeft", 15);
        Style rightStyle = right.getElement().getStyle();
        rightStyle.setPropertyPx("margin", 5);
        decorator.add(right);

        main.add(decorator);
        leftTree.addSelectionHandler(new SelectionHandler<TreeItem>() {
            public void onSelection(SelectionEvent<TreeItem> event) {
                String name = event.getSelectedItem().getText();
                setWidget(right, cogs.get(name));
            }
        });
    }

    public void add(final WidgetProvider cog, String title) {
        cogs.put(title, cog);
        TreeItem item = new TreeItem(title);
        leftTree.addItem(item);
    }

    public void setWidget(WidgetProvider provider) {
        setWidget(right, provider);
    }
}