de.swm.commons.mobile.client.widgets.CheckBox.java Source code

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Here is the source code for de.swm.commons.mobile.client.widgets.CheckBox.java

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/*
 * Copyright 2011 SWM Services GmbH.
 * 
 * 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 de.swm.commons.mobile.client.widgets;

import com.google.gwt.dom.client.Node;
import com.google.gwt.event.dom.client.ClickEvent;
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;
import com.google.gwt.resources.client.ImageResource;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Image;
import de.swm.commons.mobile.client.SWMMobile;
import de.swm.commons.mobile.client.utils.IsSWMMobileWidgetHelper;
import de.swm.commons.mobile.client.utils.Utils;
import de.swm.commons.mobile.client.widgets.itf.IsSWMMobileWidget;
import de.swm.gwt.client.utils.ShimClickHandler;

/**
 * CheckBox widget.
 */
public class CheckBox extends com.google.gwt.user.client.ui.CheckBox implements IsSWMMobileWidget {

    private final IsSWMMobileWidgetHelper widgetHelper = new IsSWMMobileWidgetHelper();
    private Node imageNode = null;
    private final ShimClickHandler checkBoxClickHanlders = new ShimClickHandler();
    private boolean isEnabled = true;
    private boolean currentValue = false;

    /**
     * Default constructor.
     */
    public CheckBox() {
        super();
        if (SWMMobile.getOsDetection().isAndroid() && Utils.isWVGA()) {
            CheckBoxIndicator indicator = new CheckBoxIndicator();
            this.getElement().insertFirst(indicator.getElement());
        }
        addDomHandler(checkBoxClickHanlders, ClickEvent.getType());
        super.addValueChangeHandler(new ValueChangeHandler<Boolean>() {
            @Override
            public void onValueChange(ValueChangeEvent<Boolean> event) {
                if (event != null && event.getValue() != null) {
                    ensureValueWillNotChangeWhenDisabled(event.getValue());
                    if (isEnabled) {
                        currentValue = event.getValue();
                    }
                }
            }
        });
        addDomHandler(new ClickHandler() {
            @Override
            public void onClick(ClickEvent event) {
                ensureValueWillNotChangeWhenDisabled(getValue());
            }
        }, ClickEvent.getType());
    }

    private void ensureValueWillNotChangeWhenDisabled(boolean newValue) {
        if (!isEnabled && newValue != currentValue) {
            new Timer() {

                @Override
                public void run() {
                    setValue(currentValue, false);
                    if (!currentValue) {
                        removeStyleName(SWMMobile.getTheme().getMGWTCssBundle().getCheckRadioBoxCss().selected());
                    }
                }
            }.schedule(50);
        }
    }

    /**
     * Sets an image to be displayed as a label for the checkbox.
     *
     * @param imgRes ImageResource for the image to be displayed
     */
    public void setImage(ImageResource imgRes) {
        Node labelElem = findLabelElement();
        if (labelElem == null) {
            return;
        }

        if (imageNode != null) {
            labelElem.removeChild(imageNode);
        }

        Image img = new Image(imgRes);
        imageNode = img.getElement();
        labelElem.appendChild(imageNode);
    }

    @Override
    public void setEnabled(boolean enabled) {
        this.isEnabled = enabled;
        checkBoxClickHanlders.setEnabled(enabled);
        super.setEnabled(enabled);
    }

    @Override
    public HandlerRegistration addClickHandler(ClickHandler handler) {
        return checkBoxClickHanlders.addClickHandler(handler);
    }

    @Override
    protected void onLoad() {
        super.onLoad();
        widgetHelper.checkInitialLoad(this);
    }

    @Override
    public void setValue(Boolean value) {
        setValue(value, false);
    }

    @Override
    public void setValue(Boolean checked, boolean fireEvents) {
        if (this.isEnabled) {
            this.currentValue = checked;
            super.setValue(checked, fireEvents);
            if (checked) {
                addStyleName(SWMMobile.getTheme().getMGWTCssBundle().getCheckRadioBoxCss().selected());
            } else {
                removeStyleName(SWMMobile.getTheme().getMGWTCssBundle().getCheckRadioBoxCss().selected());
            }
        }
    }

    @Override
    public void onInitialLoad() {
    }

    @Override
    public void onTransitionEnd() {
    }

    @Override
    public void setSecondaryStyle(String style) {
        widgetHelper.setSecondaryStyle(this, style);
    }

    private Node findLabelElement() {
        for (Node child = getElement().getFirstChild(); child != null; child = child.getNextSibling()) {
            if (child.getNodeName().equalsIgnoreCase("label")) {
                return child;
            }
        }
        return null;
    }

    /**
     * Indicator class for Android devices.
     */
    public static class CheckBoxIndicator extends HTML {

        /**
         * Default constructor.
         */
        public CheckBoxIndicator() {
            super("<div><div></div></div><div></div><div></div><div></div>");
            setStyleName(SWMMobile.getTheme().getMGWTCssBundle().getCheckRadioBoxCss().checkBoxIndicator());
        }
    }
}