/**
 * Copyright 2011 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 org.waveprotocol.wave.client.doodad.selection;

import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.StyleInjector;
import com.google.gwt.dom.client.Text;

import org.waveprotocol.wave.client.common.util.DomHelper;
import org.waveprotocol.wave.client.editor.impl.NodeManager;
import org.waveprotocol.wave.model.document.util.FilteredView.Skip;

/**
 * DOM implementation of a caret view
 *
 * @author danilatos@google.com (Daniel Danilatos)
 */
public class CaretWidget implements CaretView {

  /** Resources for the renderer. */
  private static final CaretMarkerResources RESOURCES = GWT.create(CaretMarkerResources.class);
  public static final CaretMarkerResources.Css CSS = RESOURCES.css();
  static {
    StyleInjector.inject(CSS.getText());
  }

  private final Element caretMarkerElement;
  private final Element compositionStateSpan;
  private final Element outerSpan;
  private final Element innerSpan;
  private final Text nameTextNode;

  /**
   * Build a DOM element for storing a single user selection element.
   */
  public CaretWidget() {
    // TODO(danilatos): UiBinder?
    caretMarkerElement = Document.get().createSpanElement();
    compositionStateSpan = Document.get().createSpanElement();

    caretMarkerElement.appendChild(compositionStateSpan);
    compositionStateSpan.setClassName(CSS.compositionState());

    outerSpan = Document.get().createSpanElement();
    innerSpan = Document.get().createSpanElement();
    caretMarkerElement.appendChild(outerSpan);

    // Text node must come first, or rendering glitches ensue.
    // Also, there is code that depends on it being the first child!
    nameTextNode = Document.get().createTextNode("?");
    outerSpan.appendChild(nameTextNode);
    outerSpan.appendChild(innerSpan);

    outerSpan.setClassName(CSS.outer());
    innerSpan.setClassName(CSS.inner());

    DomHelper.makeUnselectable(caretMarkerElement);
    NodeManager.setTransparency(caretMarkerElement, Skip.DEEP);
  }

  @Override
  public void setName(String name) {
    nameTextNode.setData(name);
  }

  @Override
  public void setCompositionState(String state) {
    compositionStateSpan.setInnerText(state);
  }

  @Override
  public void setColor(RgbColor color) {
    String cssColour = color.getCssColor();
    compositionStateSpan.getStyle().setBorderColor(cssColour);
    outerSpan.getStyle().setBackgroundColor(cssColour);
    innerSpan.getStyle().setBorderColor(cssColour);
  }

  public Element getElement() {
    return caretMarkerElement;
  }
}