WorkbenchPartLabelProvider.java

/*
 * Copyright 2010 The Rabbit Eclipse Plug-in Project
 * 
 * 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 rabbit.ui.internal.viewers;

import rabbit.ui.internal.util.UndefinedWorkbenchPartDescriptor;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Image;
import org.eclipse.ui.IWorkbenchPartDescriptor;
import org.eclipse.ui.PlatformUI;

import java.util.HashMap;
import java.util.Map;

import javax.annotation.Nullable;

/**
 * Label provider for {@link IWorkbenchPartDescriptor}
 */
public final class WorkbenchPartLabelProvider extends NullLabelProvider {

  /** Keys are workbench part id, values may be null. */
  private final Map<String, Image> images;
  private final Color gray;

  public WorkbenchPartLabelProvider() {
    images = new HashMap<String, Image>();
    gray = PlatformUI.getWorkbench().getDisplay().getSystemColor(
        SWT.COLOR_DARK_GRAY);
  }

  @Override
  public void dispose() {
    super.dispose();
    for (Image img : images.values()) {
      if (img != null) {
        img.dispose();
      }
    }
  }

  @Override
  public Color getForeground(@Nullable Object element) {
    if (element instanceof UndefinedWorkbenchPartDescriptor) {
      return gray;
    }
    return super.getForeground(element);
  }

  @Override
  public Image getImage(@Nullable Object element) {
    if (element instanceof IWorkbenchPartDescriptor) {
      IWorkbenchPartDescriptor part = (IWorkbenchPartDescriptor) element;
      if (images.containsKey(part.getId())) {
        return images.get(part.getId());
      }
      ImageDescriptor des = part.getImageDescriptor();
      Image img = (des != null) ? des.createImage() : null;
      images.put(part.getId(), img);
      return img;
    }
    return super.getImage(element);
  }

  @Override
  public String getText(@Nullable Object element) {
    if (element instanceof IWorkbenchPartDescriptor) {
      return ((IWorkbenchPartDescriptor) element).getLabel();
    }
    return super.getText(element);
  }
}