org.jrydberg.ui.client.MenuButton.java Source code

Introduction

Here is the source code for org.jrydberg.ui.client.MenuButton.java

Source

/**
 * Copyright 2010 Johan Rydberg
 *
 * 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 org.jrydberg.ui.client;

import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.logical.shared.CloseEvent;
import com.google.gwt.event.logical.shared.CloseHandler;
import com.google.gwt.resources.client.ImageResource;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Image;
import com.google.gwt.user.client.ui.MenuBar;
import com.google.gwt.user.client.ui.PopupPanel;
import com.google.gwt.user.client.ui.PopupPanel.PositionCallback;

/**
 * @author jrydberg
 * 
 */
public class MenuButton extends Button implements ClickHandler, CloseHandler<PopupPanel> {

    public interface Resources extends MenuBar.Resources, Button.Resources {
        @Source("resources/MenuButton-arrow.png")
        ImageResource menuButtonIcon();
    }

    private PopupMenu menu;

    private static Resources DEFAULT_RESOURCES;

    private static Resources getDefaultResources() {
        if (DEFAULT_RESOURCES == null) {
            DEFAULT_RESOURCES = GWT.<Resources>create(Resources.class);
        }
        return DEFAULT_RESOURCES;
    }

    public MenuButton(String text, PopupMenu menu) {
        this(getDefaultResources(), text, menu);
    }

    public MenuButton(ImageResource image, PopupMenu menu) {
        this(getDefaultResources(), new Image(image), menu);
    }

    public MenuButton(Resources resources, ImageResource image, PopupMenu menu) {
        this(resources, new Image(image), menu);
    }

    public MenuButton(Resources resources, Image image, PopupMenu menu) {
        this(resources, menu);
        setImage(image);
    }

    public MenuButton(Resources resources, String text, PopupMenu menu) {
        this(resources, menu);
        setText(text);
    }

    public MenuButton(Resources resources, PopupMenu menu) {
        super(resources);
        // Setup the button content:
        getElement().appendChild(DOM.createSpan());
        Image image = new Image(resources.menuButtonIcon());
        getElement().appendChild(image.getElement());
        // Initialize popup-menu
        this.menu = menu;
        // Attach listener
        super.addClickHandler(this);
        menu.addCloseHandler(this);
    }

    public void setImage(Image image) {
        getElement().removeChild(getElement().getChild(0));
        getElement().insertFirst(image.getElement());
    }

    public void setText(String text) {
        getElement().removeChild(getElement().getChild(0));
        Element textElement = DOM.createSpan();
        textElement.setInnerText(text);
        getElement().insertFirst(textElement);
    }

    @Override
    public void onClick(ClickEvent event) {
        addStyleName(resources.buttonCss().active());
        menu.setPopupPositionAndShow(new PositionCallback() {
            @Override
            public void setPosition(int offsetWidth, int offsetHeight) {
                int top = (MenuButton.this.getAbsoluteTop() + MenuButton.this.getOffsetHeight());
                if ((top + offsetHeight + 50) >= Window.getClientHeight()) {
                    top = MenuButton.this.getAbsoluteTop() - offsetHeight;
                }

                int left = MenuButton.this.getAbsoluteLeft();
                menu.setPopupPosition(left, top);
            }
        });
    }

    @Override
    public void onClose(CloseEvent<PopupPanel> event) {
        removeStyleName(resources.buttonCss().active());
    }

}