LimpetDecorator.java

/*****************************************************************************
 *  Limpet - the Lightweight InforMation ProcEssing Toolkit
 *  http://limpet.info
 *
 *  (C) 2015-2016, Deep Blue C Technologies Ltd
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the Eclipse Public License v1.0
 *  (http://www.eclipse.org/legal/epl-v10.html)
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *****************************************************************************/
package info.limpet.ui.decorators;

import info.limpet.ICollection;
import info.limpet.ICommand;
import info.limpet.ui.Activator;
import info.limpet.ui.data_provider.data.CollectionWrapper;
import info.limpet.ui.data_provider.data.CommandWrapper;
import info.limpet.ui.data_provider.data.GroupWrapper;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.viewers.IDecoration;
import org.eclipse.jface.viewers.ILabelProviderListener;
import org.eclipse.jface.viewers.ILightweightLabelDecorator;
import org.eclipse.ui.plugin.AbstractUIPlugin;

public class LimpetDecorator implements ILightweightLabelDecorator
{

  private static final ImageDescriptor TIME;

  private static final ImageDescriptor SINGLE;

  private static final ImageDescriptor LEFT_ARROW;

  private static final ImageDescriptor RIGHT_ARROW;

  private static final ImageDescriptor TWO_WAY_ARROW;

  private static final ImageDescriptor DYNAMIC;

  static
  {
    LEFT_ARROW =
        AbstractUIPlugin.imageDescriptorFromPlugin(Activator.PLUGIN_ID,
            "icons/left.png");
    RIGHT_ARROW =
        AbstractUIPlugin.imageDescriptorFromPlugin(Activator.PLUGIN_ID,
            "icons/right.png");
    TWO_WAY_ARROW =
        AbstractUIPlugin.imageDescriptorFromPlugin(Activator.PLUGIN_ID,
            "icons/left_right.png");
    TIME =
        AbstractUIPlugin.imageDescriptorFromPlugin(Activator.PLUGIN_ID,
            "icons/clock.png");
    SINGLE =
        AbstractUIPlugin.imageDescriptorFromPlugin(Activator.PLUGIN_ID,
            "icons/singleton.png");

    // TODO: switch to better "dynamic/connected" icon.
    DYNAMIC =
        AbstractUIPlugin.imageDescriptorFromPlugin(Activator.PLUGIN_ID,
            "icons/plus.png");
  }

  @Override
  public void addListener(ILabelProviderListener listener)
  {
  }

  @Override
  public void dispose()
  {
  }

  @Override
  public boolean isLabelProperty(Object element, String property)
  {
    return false;
  }

  @Override
  public void removeListener(ILabelProviderListener listener)
  {
  }

  @Override
  public void decorate(Object element, IDecoration decoration)
  {
    if (element instanceof CollectionWrapper)
    {
      decorateWrapper((CollectionWrapper) element, decoration);
    }
    if (element instanceof CommandWrapper)
    {
      decorateWrapper((CommandWrapper) element, decoration);
    }
    if (element instanceof GroupWrapper)
    {
      decorateWrapper((GroupWrapper) element, decoration);
    }
  }

  protected void decorateWrapper(GroupWrapper element, IDecoration decoration)
  {
    // we don't currently apply and decorations to groups
  }

  protected void
      decorateWrapper(CommandWrapper element, IDecoration decoration)
  {
    final ICommand<?> coll = element.getCommand();

    boolean in = coll.getInputs() != null && coll.getInputs().size() > 0;
    boolean out = coll.getOutputs() != null && coll.getOutputs().size() > 0;
    decorateInOut(decoration, in, out);

    // also apply a decoration to indicate that the symbol is dynamically updating
    if (coll.getDynamic())
    {
      decoration.addOverlay(DYNAMIC, IDecoration.BOTTOM_RIGHT);
    }
  }

  protected void decorateWrapper(CollectionWrapper element,
      IDecoration decoration)
  {
    final ICollection coll = element.getCollection();
    boolean out = coll.getPrecedent() != null;
    boolean in =
        coll.getDependents() != null && coll.getDependents().size() > 0;
    decorateInOut(decoration, in, out);

    if (coll.isTemporal())
    {
      decoration.addOverlay(TIME, IDecoration.BOTTOM_RIGHT);
    }
    if (coll.getValuesCount() == 1)
    {
      decoration.addOverlay(SINGLE, IDecoration.BOTTOM_LEFT);
    }
  }

  private void decorateInOut(IDecoration decoration, boolean in, boolean out)
  {
    if (in && out)
    {
      decoration.addOverlay(TWO_WAY_ARROW, IDecoration.TOP_RIGHT);
    }
    else if (out)
    {
      decoration.addOverlay(LEFT_ARROW, IDecoration.TOP_RIGHT);
    }
    else if (in)
    {
      decoration.addOverlay(RIGHT_ARROW, IDecoration.TOP_RIGHT);
    }
  }

}