ImageTextButton.java

/*
 * Copyright 2014-2016 CyberVision, 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 org.kaaproject.kaa.server.admin.client.mvp.view.widget;

import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.resources.client.ImageResource;
import com.google.gwt.safehtml.shared.SafeUri;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.ui.Button;

@SuppressWarnings("deprecation")
public class ImageTextButton extends Button {
  private String text;

  public ImageTextButton(ImageResource imageResource, String text) {
    this(imageResource, text, null);
  }

  /**
   * Instantiates a new ImageTextButton.
   */
  public ImageTextButton(ImageResource imageResource, String text, ClickHandler clickHandler) {
    super();
    if (clickHandler != null) {
      addClickHandler(clickHandler);
    }
    String definedStyles = getElement().getAttribute("style");
    getElement().setAttribute("style", definedStyles + "; vertical-align:middle;");
    this.text = text;
    Element span = DOM.createElement("span");
    span.setInnerText(text);
    DOM.insertChild(getElement(), span, 0);
    Element imageSpan = DOM.createElement("span");
    int spacing;
    if (this.text == null || this.text.trim().equals("")) {
      spacing = 0;
    } else {
      spacing = 16;
    }

    if (imageResource != null) {
      updateImageElementFromImageResource(imageSpan, imageResource, spacing);
    }
    DOM.insertBefore(getElement(), imageSpan, DOM.getFirstChild(getElement()));
  }

  @Override
  public String getText() {
    return this.text;
  }

  private void updateImageElementFromImageResource(Element imageSpan,
                                                   ImageResource res,
                                                   int spacing) {
    SafeUri url = res.getSafeUri();
    int width = res.getWidth();
    int height = res.getHeight();
    int paddingRight = width + spacing;
    String style = "url(\"" + url.asString() + "\") no-repeat scroll left center";
    imageSpan.getStyle().setProperty("background", style);
    imageSpan.getStyle().setPropertyPx("width", width);
    imageSpan.getStyle().setPropertyPx("height", height);
    imageSpan.getStyle().setPropertyPx("paddingRight", paddingRight);
  }

}