/*
 * ActionSet.java - A set of actions
 * :tabSize=8:indentSize=8:noTabs=false:
 * :folding=explicit:collapseFolds=1:
 *
 * Copyright (C) 2001, 2003 Slava Pestov
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or any later version.
 *
 * This program 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.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

package org.gjt.sp.jedit;

import com.microstar.xml.*;
import java.io.*;
import java.net.URL;
import java.util.*;
import org.gjt.sp.jedit.gui.InputHandler;
import org.gjt.sp.util.Log;

/**
 * A set of actions, either loaded from an XML file, or constructed at runtime
 * by a plugin.

 *
 * 
Action sets loaded from XML files
 *
 * Action sets are read from these files inside the plugin JAR:
 * 

 * 
actions.xml - actions made available for use in jEdit views,
 * including the view's Plugins menu, the tool bar, etc.
 * 
browser.actions.xml - actions for the file system browser's
 * Plugins menu.
 * 
 *
 * An action definition file has the following form:
 *
 * 
<?xml version="1.0"?>
 *<!DOCTYPE ACTIONS SYSTEM "actions.dtd">
 *<ACTIONS>
 *    <ACTION NAME="some-action">
 *        <CODE>
 *            // BeanShell code evaluated when the action is invoked
 *        </CODE>
 *    </ACTION>
 *    <ACTION NAME="some-toggle-action">
 *        <CODE>
 *            // BeanShell code evaluated when the action is invoked
 *        </CODE>
 *        <IS_SELECTED>
 *            // BeanShell code that should evaluate to true or false
 *        </IS_SELECTED>
 *    </ACTION>
 *</ACTIONS>
 *
 * The following elements are valid:
 *
 * 

 * 

 * ACTIONS is the top-level element and refers
 * to the set of actions used by the plugin.
 * 
 * 

 * An ACTION contains the data for a particular action.
 * It has three attributes: a required NAME;
 * an optional NO_REPEAT, which is a flag
 * indicating whether the action should not be repeated with the
 * C+ENTER command; and an optional
 * NO_RECORD which is a a flag indicating whether the
 * action should be recorded if it is invoked while the user is recording a
 * macro. The two flag attributes
 * can have two possible values, "TRUE" or
 * "FALSE". In both cases, "FALSE" is the
 * default if the attribute is not specified.
 * 
 * 

 * An ACTION can have two child elements
 * within it: a required CODE element which
 * specifies the
 * BeanShell code that will be executed when the action is invoked,
 * and an optional IS_SELECTED element, used for
 * checkbox
 * menu items.  The IS_SELECTED element contains
 * BeanShell code that returns a boolean flag that will
 * determine the state of the checkbox.
 * 
 * 
 *
 * Each action must have a property name.label containing
 * the action's menu item label.
 *
 * 
View actions
 *
 * Actions defined in actions.xml can be added to the view's
 * Plugins menu; see {@link EditPlugin}.
 * The action code may use any standard predefined
 * BeanShell variable; see {@link BeanShell}.
 *
 * 
File system browser actions
 *
 * Actions defined in actions.xml can be added to the file
 * system browser's Plugins menu; see {@link EditPlugin}.
 * The action code may use any standard predefined
 * BeanShell variable, in addition to a variable browser which
 * contains a reference to the current
 * {@link org.gjt.sp.jedit.browser.VFSBrowser} instance.

 *
 * File system browser actions should not define
 * <IS_SELECTED> blocks.
 *
 * 
Custom action sets
 *
 * Call {@link jEdit#addActionSet(ActionSet)} to add a custom action set to
 * jEdit's action context. You must also call {@link #initKeyBindings()} for new
 * action sets. Don't forget to call {@link jEdit#removeActionSet(ActionSet)}
 * before your plugin is unloaded, too.
 *
 * @see jEdit#getActionContext()
 * @see org.gjt.sp.jedit.browser.VFSBrowser#getActionContext()
 * @see ActionContext#getActionNames()
 * @see ActionContext#getAction(String)
 * @see jEdit#addActionSet(ActionSet)
 * @see jEdit#removeActionSet(ActionSet)
 * @see PluginJAR#getActionSet()
 * @see BeanShell
 * @see View
 *
 * @author Slava Pestov
 * @author John Gellene (API documentation)
 * @version $Id: ActionSet.java,v 1.31 2004/07/12 19:25:07 spestov Exp $
 * @since jEdit 4.0pre1
 */
public class ActionSet
{
	//{{{ ActionSet constructor
	/**
	 * Creates a new action set.
	 * @since jEdit 4.0pre1
	 */
	public ActionSet()
	{
		actions = new Hashtable();
		loaded = true;
		label = "";
	} //}}}

	//{{{ ActionSet constructor
	/**
	 * Creates a new action set.
	 * @param plugin The plugin
	 * @param cachedActionNames The list of cached action names
	 * @param cachedActionToggleFlags The list of cached action toggle flags
	 * @param uri The actions.xml URI
	 * @since jEdit 4.2pre2
	 */
	public ActionSet(PluginJAR plugin, String[] cachedActionNames,
		boolean[] cachedActionToggleFlags, URL uri)
	{
		this();
		this.plugin = plugin;
		this.uri = uri;
		if(cachedActionNames != null)
		{
			for(int i = 0; i < cachedActionNames.length; i++)
			{
				actions.put(cachedActionNames[i],placeholder);
				jEdit.setTemporaryProperty(cachedActionNames[i]
					+ ".toggle",cachedActionToggleFlags[i]
					? "true" : "false");
			}
		}
		loaded = false;
	} //}}}

	//{{{ ActionSet constructor
	/**
	 * Creates a new action set.
	 * @param label The label, shown in the shortcuts option pane
	 * @since jEdit 4.0pre1
	 */
	public ActionSet(String label)
	{
		this();
		setLabel(label);
	} //}}}

	//{{{ getLabel() method
	/**
	 * Return the action source label.
	 * @since jEdit 4.0pre1
	 */
	public String getLabel()
	{
		return label;
	} //}}}

	//{{{ setLabel() method
	/**
	 * Sets the action source label.
	 * @param label The label
	 * @since jEdit 4.0pre1
	 */
	public void setLabel(String label)
	{
		if(label == null)
			throw new NullPointerException();
		this.label = label;
	} //}}}

	//{{{ getPluginJAR() method
	/**
	 * Return the plugin this action set was loaded from, or null.
	 * @since jEdit 4.2pre13
	 */
	public PluginJAR getPluginJAR()
	{
		return plugin;
	} //}}}

	//{{{ addAction() method
	/**
	 * Adds an action to the action set.
	 * @param action The action
	 * @since jEdit 4.0pre1
	 */
	public void addAction(EditAction action)
	{
		actions.put(action.getName(),action);
		if(context != null)
		{
			context.actionNames = null;
			context.actionHash.put(action.getName(),this);
		}
	} //}}}

	//{{{ removeAction() method
	/**
	 * Removes an action from the action set.
	 * @param name The action name
	 * @since jEdit 4.0pre1
	 */
	public void removeAction(String name)
	{
		actions.remove(name);
		if(context != null)
		{
			context.actionNames = null;
			context.actionHash.remove(name);
		}
	} //}}}

	//{{{ removeAllActions() method
	/**
	 * Removes all actions from the action set.
	 * @since jEdit 4.0pre1
	 */
	public void removeAllActions()
	{
		if(context != null)
		{
			context.actionNames = null;
			String[] actions = getActionNames();
			for(int i = 0; i < actions.length; i++)
			{
				context.actionHash.remove(actions[i]);
			}
		}
		this.actions.clear();
	} //}}}

	//{{{ getAction() method
	/**
	 * Returns an action with the specified name.

	 *
	 * Deferred loading: this will load the action set if necessary.
	 *
	 * @param name The action name
	 * @since jEdit 4.0pre1
	 */
	public EditAction getAction(String name)
	{
		Object obj = actions.get(name);
		if(obj == placeholder)
		{
			load();
			obj = actions.get(name);
			if(obj == placeholder)
			{
				Log.log(Log.WARNING,this,"Outdated cache");
				obj = null;
			}
		}

		return (EditAction)obj;
	} //}}}

	//{{{ getActionCount() method
	/**
	 * Returns the number of actions in the set.
	 * @since jEdit 4.0pre1
	 */
	public int getActionCount()
	{
		return actions.size();
	} //}}}

	//{{{ getActionNames() method
	/**
	 * Returns an array of all action names in this action set.
	 * @since jEdit 4.2pre1
	 */
	public String[] getActionNames()
	{
		String[] retVal = new String[actions.size()];
		Enumeration e = actions.keys();
		int i = 0;
		while(e.hasMoreElements())
		{
			retVal[i++] = (String)e.nextElement();
		}
		return retVal;
	} //}}}

	//{{{ getCacheableActionNames() method
	/**
	 * Returns an array of all action names in this action set that should
	 * be cached; namely, BeanShellActions.
	 * @since jEdit 4.2pre1
	 */
	public String[] getCacheableActionNames()
	{
		LinkedList retVal = new LinkedList();
		Enumeration e = actions.elements();
		while(e.hasMoreElements())
		{
			Object obj = e.nextElement();
			if(obj == placeholder)
			{
				// ??? this should only be called with
				// fully loaded action set
				Log.log(Log.WARNING,this,"Action set not up "
					+ "to date");
			}
			else if(obj instanceof BeanShellAction)
				retVal.add(((BeanShellAction)obj).getName());
		}
		return (String[])retVal.toArray(new String[retVal.size()]);
	} //}}}

	//{{{ getActions() method
	/**
	 * Returns an array of all actions in this action set.

	 *
	 * Deferred loading: this will load the action set if necessary.
	 *
	 * @since jEdit 4.0pre1
	 */
	public EditAction[] getActions()
	{
		load();

		EditAction[] retVal = new EditAction[actions.size()];
		Enumeration e = actions.elements();
		int i = 0;
		while(e.hasMoreElements())
		{
			retVal[i++] = (EditAction)e.nextElement();
		}
		return retVal;
	} //}}}

	//{{{ contains() method
	/**
	 * Returns if this action set contains the specified action.
	 * @param action The action
	 * @since jEdit 4.2pre1
	 */
	public boolean contains(String action)
	{
		return actions.containsKey(action);
	} //}}}

	//{{{ size() method
	/**
	 * Returns the number of actions in this action set.
	 * @since jEdit 4.2pre2
	 */
	public int size()
	{
		return actions.size();
	} //}}}

	//{{{ toString() method
	public String toString()
	{
		return label;
	} //}}}

	//{{{ initKeyBindings() method
	/**
	 * Initializes the action set's key bindings.
	 * jEdit calls this method for all registered action sets when the
	 * user changes key bindings in the Global Options dialog box.

	 *
	 * Note if your plugin adds a custom action set to jEdit's collection,
	 * it must also call this method on the action set after adding it.
	 *
	 * @since jEdit 4.2pre1
	 */
	public void initKeyBindings()
	{
		InputHandler inputHandler = jEdit.getInputHandler();

		Iterator iter = actions.entrySet().iterator();
		while(iter.hasNext())
		{
			Map.Entry entry = (Map.Entry)iter.next();
			String name = (String)entry.getKey();

			String shortcut1 = jEdit.getProperty(name + ".shortcut");
			if(shortcut1 != null)
				inputHandler.addKeyBinding(shortcut1,name);

			String shortcut2 = jEdit.getProperty(name + ".shortcut2");
			if(shortcut2 != null)
				inputHandler.addKeyBinding(shortcut2,name);
		}
	} //}}}

	//{{{ load() method
	/**
	 * Forces the action set to be loaded. Plugins and macros should not
	 * call this method.
	 * @since jEdit 4.2pre1
	 */
	public void load()
	{
		if(loaded)
			return;

		loaded = true;
		//actions.clear();

		Reader stream = null;

		try
		{
			Log.log(Log.DEBUG,this,"Loading actions from " + uri);

			ActionListHandler ah = new ActionListHandler(uri.toString(),this);
			stream = new BufferedReader(new InputStreamReader(
				uri.openStream()));
			XmlParser parser = new XmlParser();
			parser.setHandler(ah);
			parser.parse(null, null, stream);
		}
		catch(XmlException xe)
		{
			int line = xe.getLine();
			String message = xe.getMessage();
			Log.log(Log.ERROR,this,uri + ":" + line
				+ ": " + message);
		}
		catch(Exception e)
		{
			Log.log(Log.ERROR,uri,e);
		}
		finally
		{
			try
			{
				if(stream != null)
					stream.close();
			}
			catch(IOException io)
			{
				Log.log(Log.ERROR,this,io);
			}
		}
	} //}}}

	//{{{ Package-private members
	ActionContext context;

	//{{{ getActionNames() method
	void getActionNames(List vec)
	{
		Enumeration e = actions.keys();
		while(e.hasMoreElements())
			vec.add(e.nextElement());
	} //}}}

	//}}}

	//{{{ Private members
	private String label;
	private Hashtable actions;
	private PluginJAR plugin;
	private URL uri;
	private boolean loaded;

	private static final Object placeholder = new Object();

	//}}}
}