com.youtube.statistics.client.RecentQueriesPanel.java Source code

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Here is the source code for com.youtube.statistics.client.RecentQueriesPanel.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.youtube.statistics.client;

import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.ui.Anchor;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.Image;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.Panel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * Shows recent queries to the server.
 *
 * @author martinstrauss@google.com (Martin Strauss)
 */
public class RecentQueriesPanel {
    private static final String MSG_NO_RECENT_QUERIES = "No recent queries!";

    private static final String PROGRESS_SPINNER_STYLE = "progressSpinner";
    private static final String PROGRESS_SPINNER_IMAGE = "spin.gif";

    private final Panel panel;

    public RecentQueriesPanel(Widget parent) {
        panel = new VerticalPanel();
        panel.addStyleName("recentQueriesPanel");

        // Calculate the position to be twice the width of the button, and align
        // with the right hand edge of the parent, allowing for a margin.
        int margin = 2;
        int width = 2 * parent.getOffsetWidth();
        int top = parent.getAbsoluteTop() + parent.getOffsetHeight() + margin;
        int right = parent.getAbsoluteLeft() + parent.getOffsetWidth() - margin;
        int left = right - width;

        panel.getElement().getStyle().setPropertyPx("left", left);
        panel.getElement().getStyle().setPropertyPx("top", top);
        panel.getElement().getStyle().setPropertyPx("width", width);
        panel.setVisible(false);
    }

    public void fill(YouTubeStatisticsServiceAsync service, final TextBox queryField, final Button queryButton) {
        drawProgressIndicator();
        panel.setVisible(true);
        service.getRecentQueries(new AsyncCallback<String[]>() {

            @Override
            public void onSuccess(String[] result) {
                if (result.length <= 0) {
                    onFailure(null);
                    return;
                }
                panel.clear();
                for (final String query : result) {
                    Anchor anchor = new Anchor(query);
                    anchor.addClickHandler(new ClickHandler() {
                        @Override
                        public void onClick(ClickEvent event) {
                            queryField.setText(query);
                            queryButton.click();
                            destroy();
                        }
                    });
                    panel.add(anchor);
                }
            }

            @Override
            public void onFailure(Throwable caught) {
                panel.clear();
                Label label = new Label(MSG_NO_RECENT_QUERIES);
                panel.add(label);
            }
        });
    }

    private void drawProgressIndicator() {
        panel.clear();
        Image progress = new Image(PROGRESS_SPINNER_IMAGE);
        progress.addStyleName(PROGRESS_SPINNER_STYLE);
        panel.add(progress);
    }

    /**
     * Determines whether the underlying widget is currently attached to the
     * browser's document (i.e., there is an unbroken chain of widgets between
     * this widget and the underlying browser document).
     *
     * @return true if the widget is attached
     */
    public boolean isAttached() {
        return panel.isAttached();
    }

    /**
     * Determines whether or not the underlying object is visible.
     *
     * @return true if the object is visible
     */
    public boolean isVisible() {
        return panel.isVisible();
    }

    /**
     * Adds the widget to a parent.
     */
    public void addTo(Panel parent) {
        parent.add(panel);
    }

    /**
     * Hides the widget and removes it from its parent.
     */
    public void destroy() {
        panel.clear();
        panel.setVisible(false);
        panel.removeFromParent();
    }
}