org.cloudcoder.app.client.view.ChoiceDialogBox.java Source code

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Here is the source code for org.cloudcoder.app.client.view.ChoiceDialogBox.java

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// CloudCoder - a web-based pedagogical programming environment
// Copyright (C) 2011-2012, Jaime Spacco <jspacco@knox.edu>
// Copyright (C) 2011-2012, David H. Hovemeyer <david.hovemeyer@gmail.com>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package org.cloudcoder.app.client.view;

import java.util.ArrayList;
import java.util.List;

import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.DialogBox;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Label;

/**
 * Dialog box asking the user to choose between choices.
 * 
 * @param <ChoiceType> the data type of the choice values to be selected
 * @author David Hovemeyer
 */
public class ChoiceDialogBox<ChoiceType> extends DialogBox {
    private class Choice {
        private String buttonText;
        private ChoiceType choice;

        public Choice(String buttonText, ChoiceType choice) {
            this.buttonText = buttonText;
            this.choice = choice;
        }

        public String getButtonText() {
            return buttonText;
        }

        public ChoiceType getChoice() {
            return choice;
        }
    }

    /**
     * Callback interface.
     *
     * @param <ChoiceType> choice value type
     */
    public interface ChoiceHandler<ChoiceType> {
        /**
         * Called when a choice is made.
         * 
         * @param choice the chosen choice value
         */
        public void handleChoice(ChoiceType choice);
    }

    private ChoiceHandler<ChoiceType> handler;
    private List<Choice> choiceList;
    private String bodyText;
    private boolean uiCreated;

    /**
     * Constructor.
     * 
     * @param title dialog title
     * @param text dialog caption
     */
    public ChoiceDialogBox(String title, String text, ChoiceHandler<ChoiceType> handler) {
        this.handler = handler;
        this.choiceList = new ArrayList<Choice>();
        setText(title);
        this.bodyText = text;
        setGlassEnabled(true);
    }

    /**
     * Add a choice.
     * 
     * @param buttonText  text to display on the choice's button
     * @param choice      the choice value
     */
    public void addChoice(String buttonText, ChoiceType choice) {
        choiceList.add(new Choice(buttonText, choice));
    }

    /* (non-Javadoc)
     * @see com.google.gwt.user.client.ui.DialogBox#show()
     */
    @Override
    public void show() {
        createUI();
        super.show();
    }

    /* (non-Javadoc)
     * @see com.google.gwt.user.client.ui.PopupPanel#center()
     */
    @Override
    public void center() {
        createUI();
        super.center();
    }

    private void createUI() {
        if (!uiCreated) {
            FlowPanel buttonPanel = new FlowPanel();

            FlowPanel div = new FlowPanel();
            div.add(new HTML("<br />"));
            div.add(new Label(bodyText));
            div.add(new HTML("<br />"));
            buttonPanel.add(div);

            FlowPanel buttonDiv = new FlowPanel();

            for (final Choice choice : choiceList) {
                Button button = new Button(choice.getButtonText());
                button.setStyleName("cc-choiceDialogButton", true);
                button.addClickHandler(new ClickHandler() {
                    @Override
                    public void onClick(ClickEvent event) {
                        hide();
                        // Invoke callback with the chosen choice value.
                        handler.handleChoice(choice.getChoice());
                    }
                });
                buttonDiv.add(button);
            }

            buttonPanel.add(buttonDiv);

            add(buttonPanel);

            uiCreated = true;
        }
    }
}