com.google.gwt.user.client.ui.ToggleButton.java Source code

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Here is the source code for com.google.gwt.user.client.ui.ToggleButton.java

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/*
 * Copyright 2007 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.user.client.ui;

import com.google.gwt.editor.client.IsEditor;
import com.google.gwt.editor.client.LeafValueEditor;
import com.google.gwt.editor.client.adapters.TakesValueEditor;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerRegistration;

/**
 * A <code>ToggleButton</code> is a stylish stateful button which allows the
 * user to toggle between <code>up</code> and <code>down</code> states.
 * 
 * <p>
 * <img class='gallery' src='doc-files/ToggleButton.png'/>
 * </p>
 * 
 * <h3>CSS Style Rules</h3>
 * <ul class="css">
 * <li>
 * .gwt-ToggleButton-up/down/up-hovering/down-hovering/up-disabled/down-disabled
 * {.html-face}</li>
 * </ul>
 * 
 * <p>
 * <h3>Example</h3> {@example com.google.gwt.examples.ToggleButtonExample}
 * </p>
 */
public class ToggleButton extends CustomButton implements HasValue<Boolean>, IsEditor<LeafValueEditor<Boolean>> {
    private static String STYLENAME_DEFAULT = "gwt-ToggleButton";

    private LeafValueEditor<Boolean> editor;

    {
        setStyleName(STYLENAME_DEFAULT);
    }

    /**
     * Constructor for <code>ToggleButton</code>.
     */
    public ToggleButton() {
        super();
    }

    /**
     * Constructor for <code>ToggleButton</code>. The supplied image is used to
     * construct the default face.
     * 
     * @param upImage image for the default face of the button
     */
    public ToggleButton(Image upImage) {
        super(upImage);
    }

    /**
     * Constructor for <code>ToggleButton</code>. The supplied image is used to
     * construct the default face of the button.
     * 
     * @param upImage image for the default (up) face of the button
     * @param handler the click handler
     */
    public ToggleButton(Image upImage, ClickHandler handler) {
        super(upImage, handler);
    }

    /**
     * Constructor for <code>ToggleButton</code>. The supplied image is used to
     * construct the default face of the button.
     * 
     * @param upImage image for the default (up) face of the button
     * @param listener the click listener
     * @deprecated Use {@link #ToggleButton(Image, ClickHandler)} instead
     */
    @Deprecated
    public ToggleButton(Image upImage, ClickListener listener) {
        super(upImage, listener);
    }

    /**
     * Constructor for <code>ToggleButton</code>.
     * 
     * @param upImage image for the default(up) face of the button
     * @param downImage image for the down face of the button
     */
    public ToggleButton(Image upImage, Image downImage) {
        super(upImage, downImage);
    }

    /**
     * Constructor for <code>ToggleButton</code>.
     * 
     * @param upImage image for the default(up) face of the button
     * @param downImage image for the down face of the button
     * @param handler the click handler
     */
    public ToggleButton(Image upImage, Image downImage, ClickHandler handler) {
        super(upImage, downImage, handler);
    }

    /**
     * Constructor for <code>ToggleButton</code>.
     * 
     * @param upImage image for the default(up) face of the button
     * @param downImage image for the down face of the button
     * @param listener clickListener
     * @deprecated Use {@link #ToggleButton(Image, Image, ClickHandler)} instead
     */
    @Deprecated
    public ToggleButton(Image upImage, Image downImage, ClickListener listener) {
        super(upImage, downImage, listener);
    }

    /**
     * Constructor for <code>ToggleButton</code>. The supplied text is used to
     * construct the default face of the button.
     * 
     * @param upText the text for the default (up) face of the button.
     */
    public ToggleButton(String upText) {
        super(upText);
    }

    /**
     * Constructor for <code>ToggleButton</code>. The supplied text is used to
     * construct the default face of the button.
     * 
     * @param upText the text for the default (up) face of the button
     * @param handler the click handler
     */
    public ToggleButton(String upText, ClickHandler handler) {
        super(upText, handler);
    }

    /**
     * Constructor for <code>ToggleButton</code>. The supplied text is used to
     * construct the default face of the button.
     * 
     * @param upText the text for the default (up) face of the button
     * @param listener the click listener
     * @deprecated Use {@link #ToggleButton(String, ClickHandler)} instead
     */
    @Deprecated
    public ToggleButton(String upText, ClickListener listener) {
        super(upText, listener);
    }

    /**
     * Constructor for <code>ToggleButton</code>.
     * 
     * @param upText the text for the default (up) face of the button
     * @param downText the text for down face of the button
     */
    public ToggleButton(String upText, String downText) {
        super(upText, downText);
    }

    /**
     * Constructor for <code>ToggleButton</code>.
     * 
     * @param upText the text for the default (up) face of the button
     * @param downText the text for down face of the button
     * @param handler the click handler
     */
    public ToggleButton(String upText, String downText, ClickHandler handler) {
        super(upText, downText, handler);
    }

    public HandlerRegistration addValueChangeHandler(ValueChangeHandler<Boolean> handler) {
        return addHandler(handler, ValueChangeEvent.getType());
    }

    public LeafValueEditor<Boolean> asEditor() {
        if (editor == null) {
            editor = TakesValueEditor.of(this);
        }
        return editor;
    }

    /**
     * Determines whether this button is currently down.
     * 
     * @return <code>true</code> if the button is pressed, false otherwise. Will
     *         not return null
     */
    public Boolean getValue() {
        return isDown();
    }

    @Override
    public boolean isDown() {
        // Changes access to public.
        return super.isDown();
    }

    /**
     * {@inheritDoc} Does not fire {@link ValueChangeEvent}. (If you want the
     * event to fire, use {@link #setValue(Boolean, boolean)})
     */
    @Override
    public void setDown(boolean down) {
        // Changes access to public.
        super.setDown(down);
    }

    /**
     * Sets whether this button is down.
     * 
     * @param value true to press the button, false otherwise; null value implies
     *          false
     */
    public void setValue(Boolean value) {
        setValue(value, false);
    }

    /**
     * Sets whether this button is down, firing {@link ValueChangeEvent} if
     * appropriate.
     * 
     * @param value true to press the button, false otherwise; null value implies
     *          false
     * @param fireEvents If true, and value has changed, fire a
     *          {@link ValueChangeEvent}
     */
    public void setValue(Boolean value, boolean fireEvents) {
        if (value == null) {
            value = Boolean.FALSE;
        }
        boolean oldValue = isDown();
        setDown(value);
        if (fireEvents) {
            ValueChangeEvent.fireIfNotEqual(this, oldValue, value);
        }
    }

    @Override
    protected void onClick() {
        toggleDown();
        super.onClick();
        ValueChangeEvent.fire(this, isDown());
    }
}