VariableFilterAction.java

package org.rubypeople.rdt.internal.debug.ui.actions;

/**********************************************************************
Copyright (c) 2000, 2002 IBM Corp.  All rights reserved.
This file is made available under the terms of the Common Public License v1.0
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/cpl-v10.html
**********************************************************************/

import org.eclipse.debug.ui.IDebugView;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.StructuredViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerFilter;
import org.eclipse.swt.widgets.Event;
import org.eclipse.ui.IActionDelegate2;
import org.eclipse.ui.IViewActionDelegate;
import org.eclipse.ui.IViewPart;
import org.eclipse.ui.texteditor.IUpdate;
import org.rubypeople.rdt.internal.debug.ui.RdtDebugUiPlugin;

/**
 * 
 */
public abstract class VariableFilterAction extends ViewerFilter implements IViewActionDelegate, IActionDelegate2, IUpdate {
	
	/**
	 * Current value of this filter - on/off.
	 */
	private boolean fValue;
	
	private IViewPart fView;
	private IAction fAction;

	public VariableFilterAction() {
		super();
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IViewActionDelegate#init(org.eclipse.ui.IViewPart)
	 */
	public void init(IViewPart view) {
		fView = view;
		setValue(getPreferenceValue(view));
		fAction.setChecked(getValue());
		run(fAction);
		IDebugView debugView = (IDebugView)view.getAdapter(IDebugView.class);
		if (debugView != null) {
			debugView.add(this);
		}
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IActionDelegate2#init(org.eclipse.jface.action.IAction)
	 */
	public void init(IAction action) {
		fAction = action;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IActionDelegate2#dispose()
	 */
	public void dispose() {
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IActionDelegate2#runWithEvent(org.eclipse.jface.action.IAction, org.eclipse.swt.widgets.Event)
	 */
	public void runWithEvent(IAction action, Event event) {
		run(action);
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IActionDelegate#run(org.eclipse.jface.action.IAction)
	 */
	public void run(IAction action) {
		setValue(action.isChecked());
		StructuredViewer viewer = getStructuredViewer();
		ViewerFilter[] filters = viewer.getFilters();
		ViewerFilter filter = null;
		for (int i = 0; i < filters.length; i++) {
			if (filters[i] == this) {
				filter = filters[i];
				break;
			}
		}
		if (filter == null) {
			viewer.addFilter(this);
		}
		viewer.refresh();
		IPreferenceStore store = getPreferenceStore();
		String key = getView().getSite().getId() + "." + getPreferenceKey(); //$NON-NLS-1$
		store.setValue(key, getValue());
		RdtDebugUiPlugin.getDefault().savePluginPreferences();
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IActionDelegate#selectionChanged(org.eclipse.jface.action.IAction, org.eclipse.jface.viewers.ISelection)
	 */
	public void selectionChanged(IAction action, ISelection selection) {
	}

	protected IPreferenceStore getPreferenceStore() {
		return RdtDebugUiPlugin.getDefault().getPreferenceStore();
	}
	
	/**
	 * Returns the value of this filters preference (on/off) for the given
	 * view.
	 * 
	 * @param part
	 * @return boolean
	 */
	protected boolean getPreferenceValue(IViewPart part) {
		String baseKey = getPreferenceKey();
		String viewKey = part.getSite().getId();
		String compositeKey = viewKey + "." + baseKey; //$NON-NLS-1$
		IPreferenceStore store = getPreferenceStore();
		boolean value = false;
		if (store.contains(compositeKey)) {
			value = store.getBoolean(compositeKey);
		} else {
			value = store.getBoolean(baseKey);
		}
		return value;		
	}
	
	/**
	 * Returns the key for this action's preference
	 * 
	 * @return String
	 */
	protected abstract String getPreferenceKey(); 
	
	protected void setValue(boolean value) {
		fValue = value;
	}
	
	/**
	 * Returns the current value of this toggle - on/off.
	 * 
	 * @return boolean
	 */
	protected boolean getValue() {
		return fValue;
	}
	
	protected IViewPart getView() {
		return fView;
	}
	
	protected StructuredViewer getStructuredViewer() {
		IDebugView view = (IDebugView)getView().getAdapter(IDebugView.class);
		if (view != null) {
			Viewer viewer = view.getViewer();
			if (viewer instanceof StructuredViewer) {
				return (StructuredViewer)viewer;
			}
		}		
		return null;
	}
	
	/**
	 * @see IUpdate#update()
	 */
	public void update() {
		fAction.setChecked(getValue());
	}
}