/*******************************************************************************
 * Copyright (c) 2000, 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.ui.actions;

import java.util.ResourceBundle;

import org.eclipse.jface.action.IAction;
import org.eclipse.jface.action.IMenuManager;
import org.eclipse.jface.preference.IPreferenceStore;

import org.eclipse.jface.text.ITextOperationTarget;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.source.projection.IProjectionListener;
import org.eclipse.jface.text.source.projection.ProjectionViewer;

import org.eclipse.ui.actions.ActionGroup;
import org.eclipse.ui.texteditor.ITextEditor;
import org.eclipse.ui.texteditor.IUpdate;
import org.eclipse.ui.texteditor.ResourceAction;
import org.eclipse.ui.texteditor.TextOperationAction;

import org.eclipse.ui.editors.text.IFoldingCommandIds;

import org.eclipse.jdt.ui.PreferenceConstants;
import org.eclipse.jdt.ui.actions.IJavaEditorActionDefinitionIds;

import org.eclipse.jdt.internal.ui.JavaPlugin;
import org.eclipse.jdt.internal.ui.javaeditor.JavaEditor;


/**
 * Groups the JDT folding actions.
 *  
 * @since 3.0
 */
public class FoldingActionGroup extends ActionGroup {
	private static abstract class PreferenceAction extends ResourceAction implements IUpdate {
		PreferenceAction(ResourceBundle bundle, String prefix, int style) {
			super(bundle, prefix, style);
		}
	}
	
	/**
	 * @since 3.2
	 */
	private class FoldingAction extends PreferenceAction {

		FoldingAction(ResourceBundle bundle, String prefix) {
			super(bundle, prefix, IAction.AS_PUSH_BUTTON);
		}

		public void update() {
			setEnabled(FoldingActionGroup.this.isEnabled() && fViewer.isProjectionMode());
		}
		
	}
	
	private ProjectionViewer fViewer;
	
	private final PreferenceAction fToggle;
	private final TextOperationAction fExpand;
	private final TextOperationAction fCollapse;
	private final TextOperationAction fExpandAll;
	private final IProjectionListener fProjectionListener;
	
	/* since 3.2 */
	private final PreferenceAction fRestoreDefaults;
	private final FoldingAction fCollapseMembers;
	private final FoldingAction fCollapseComments;
	private final TextOperationAction fCollapseAll;


	/**
	 * Creates a new projection action group for <code>editor</code>. If the
	 * supplied viewer is not an instance of <code>ProjectionViewer</code>, the
	 * action group is disabled.
	 * 
	 * @param editor the text editor to operate on
	 * @param viewer the viewer of the editor
	 */
	public FoldingActionGroup(final ITextEditor editor, ITextViewer viewer) {
		if (!(viewer instanceof ProjectionViewer)) {
			fToggle= null;
			fExpand= null;
			fCollapse= null;
			fExpandAll= null;
			fCollapseAll= null;
			fRestoreDefaults= null;
			fCollapseMembers= null;
			fCollapseComments= null;
			fProjectionListener= null;
			return;
		}
		
		fViewer= (ProjectionViewer) viewer;
		
		fProjectionListener= new IProjectionListener() {

			public void projectionEnabled() {
				update();
			}

			public void projectionDisabled() {
				update();
			}
		};
		
		fViewer.addProjectionListener(fProjectionListener);
		
		fToggle= new PreferenceAction(FoldingMessages.getResourceBundle(), "Projection.Toggle.", IAction.AS_CHECK_BOX) { //$NON-NLS-1$
			public void run() {
				IPreferenceStore store= JavaPlugin.getDefault().getPreferenceStore();
				boolean current= store.getBoolean(PreferenceConstants.EDITOR_FOLDING_ENABLED);
				store.setValue(PreferenceConstants.EDITOR_FOLDING_ENABLED, !current);
			}

			public void update() {
				ITextOperationTarget target= (ITextOperationTarget) editor.getAdapter(ITextOperationTarget.class);
					
				boolean isEnabled= (target != null && target.canDoOperation(ProjectionViewer.TOGGLE));
				setEnabled(isEnabled);
			}
		};
		fToggle.setChecked(true);
		fToggle.setActionDefinitionId(IFoldingCommandIds.FOLDING_TOGGLE);
		editor.setAction("FoldingToggle", fToggle); //$NON-NLS-1$
		
		fExpandAll= new TextOperationAction(FoldingMessages.getResourceBundle(), "Projection.ExpandAll.", editor, ProjectionViewer.EXPAND_ALL, true); //$NON-NLS-1$
		fExpandAll.setActionDefinitionId(IFoldingCommandIds.FOLDING_EXPAND_ALL);
		editor.setAction("FoldingExpandAll", fExpandAll); //$NON-NLS-1$
		
		fCollapseAll= new TextOperationAction(FoldingMessages.getResourceBundle(), "Projection.CollapseAll.", editor, ProjectionViewer.COLLAPSE_ALL, true); //$NON-NLS-1$
		fCollapseAll.setActionDefinitionId(IFoldingCommandIds.FOLDING_COLLAPSE_ALL);
		editor.setAction("FoldingCollapseAll", fCollapseAll); //$NON-NLS-1$
		
		fExpand= new TextOperationAction(FoldingMessages.getResourceBundle(), "Projection.Expand.", editor, ProjectionViewer.EXPAND, true); //$NON-NLS-1$
		fExpand.setActionDefinitionId(IFoldingCommandIds.FOLDING_EXPAND);
		editor.setAction("FoldingExpand", fExpand); //$NON-NLS-1$
		
		fCollapse= new TextOperationAction(FoldingMessages.getResourceBundle(), "Projection.Collapse.", editor, ProjectionViewer.COLLAPSE, true); //$NON-NLS-1$
		fCollapse.setActionDefinitionId(IFoldingCommandIds.FOLDING_COLLAPSE);
		editor.setAction("FoldingCollapse", fCollapse); //$NON-NLS-1$
		
		fRestoreDefaults= new FoldingAction(FoldingMessages.getResourceBundle(), "Projection.Restore.") { //$NON-NLS-1$
			public void run() {
				if (editor instanceof JavaEditor) {
					JavaEditor javaEditor= (JavaEditor) editor;
					javaEditor.resetProjection();
				}
			}
		};
		fRestoreDefaults.setActionDefinitionId(IFoldingCommandIds.FOLDING_RESTORE);
		editor.setAction("FoldingRestore", fRestoreDefaults); //$NON-NLS-1$
		
		fCollapseMembers= new FoldingAction(FoldingMessages.getResourceBundle(), "Projection.CollapseMembers.") { //$NON-NLS-1$
			public void run() {
				if (editor instanceof JavaEditor) {
					JavaEditor javaEditor= (JavaEditor) editor;
					javaEditor.collapseMembers();
				}
			}
		};
		fCollapseMembers.setActionDefinitionId(IJavaEditorActionDefinitionIds.FOLDING_COLLAPSE_MEMBERS);
		editor.setAction("FoldingCollapseMembers", fCollapseMembers); //$NON-NLS-1$
		
		fCollapseComments= new FoldingAction(FoldingMessages.getResourceBundle(), "Projection.CollapseComments.") { //$NON-NLS-1$
			public void run() {
				if (editor instanceof JavaEditor) {
					JavaEditor javaEditor= (JavaEditor) editor;
					javaEditor.collapseComments();
				}
			}
		};
		fCollapseComments.setActionDefinitionId(IJavaEditorActionDefinitionIds.FOLDING_COLLAPSE_COMMENTS);
		editor.setAction("FoldingCollapseComments", fCollapseComments); //$NON-NLS-1$
	}
	
	/**
	 * Returns <code>true</code> if the group is enabled. 
	 * <pre>
	 * Invariant: isEnabled() <=> fViewer and all actions are != null.
	 * </pre>
	 * 
	 * @return <code>true</code> if the group is enabled
	 */
	protected boolean isEnabled() {
		return fViewer != null;
	}
	
	/*
	 * @see org.eclipse.ui.actions.ActionGroup#dispose()
	 */
	public void dispose() {
		if (isEnabled()) {
			fViewer.removeProjectionListener(fProjectionListener);
			fViewer= null;
		}
		super.dispose();
	}
	
	/**
	 * Updates the actions.
	 */
	protected void update() {
		if (isEnabled()) {
			fToggle.update();
			fToggle.setChecked(fViewer.isProjectionMode());
			fExpand.update();
			fExpandAll.update();
			fCollapse.update();
			fCollapseAll.update();
			fRestoreDefaults.update();
			fCollapseMembers.update();
			fCollapseComments.update();
		}
	}
	
	/**
	 * Fills the menu with all folding actions.
	 * 
	 * @param manager the menu manager for the folding submenu
	 */
	public void fillMenu(IMenuManager manager) {
		if (isEnabled()) {
			update();
			manager.add(fToggle);
			manager.add(fExpandAll);
			manager.add(fExpand);
			manager.add(fCollapse);
			manager.add(fCollapseAll);
			manager.add(fRestoreDefaults);
			manager.add(fCollapseMembers);
			manager.add(fCollapseComments);
		}
	}
	
	/*
	 * @see org.eclipse.ui.actions.ActionGroup#updateActionBars()
	 */
	public void updateActionBars() {
		update();
	}
}