uiengineimpl.java

非常接近C/S操作方式的Java Ajax框架－ZK 用ZK框架使你的B/S应用程序更漂亮更易操作。 官网：www.zkoss.org

/* UiEngineImpl.java

{{IS_NOTE
	Purpose:
		
	Description:
		
	History:
		Thu Jun  9 13:05:28     2005, Created by tomyeh
}}IS_NOTE

Copyright (C) 2005 Potix Corporation. All Rights Reserved.

{{IS_RIGHT
	This program is distributed under GPL Version 2.0 in the hope that
	it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.zk.ui.impl;

import java.util.Iterator;
import java.util.Map;
import java.util.HashMap;
import java.util.IdentityHashMap;
import java.util.Set;
import java.util.HashSet;
import java.util.List;
import java.util.LinkedList;
import java.util.Collections;
import java.io.Writer;
import java.io.IOException;

import javax.servlet.jsp.el.FunctionMapper;

import org.zkoss.lang.D;
import org.zkoss.lang.Classes;
import org.zkoss.lang.Objects;
import org.zkoss.lang.Threads;
import org.zkoss.lang.Exceptions;
import org.zkoss.lang.Expectable;
import org.zkoss.mesg.Messages;
import org.zkoss.util.logging.Log;

import org.zkoss.zk.mesg.MZk;
import org.zkoss.zk.ui.*;
import org.zkoss.zk.ui.sys.*;
import org.zkoss.zk.ui.event.*;
import org.zkoss.zk.ui.metainfo.*;
import org.zkoss.zk.ui.ext.AfterCompose;
import org.zkoss.zk.ui.util.*;
import org.zkoss.zk.au.*;

/**
 * An implementation of {@link UiEngine}.
 *
 * @author tomyeh
 */
public class UiEngineImpl implements UiEngine {
	private static final Log log = Log.lookup(UiEngineImpl.class);

	/** A pool of idle EventProcessingThread. */
	private final List _evtthds = new LinkedList();
	/** A map of suspended processing:
	 * (Desktop desktop, IdentityHashMap(Object mutex, List(EventProcessingThread)).
	 */
	private final Map _suspended = new HashMap();
	/** A map of resumed processing
	 * (Desktop desktop, List(EventProcessingThread)).
	 */
	private final Map _resumed = new HashMap();
	/** The maximal allowed # of event handling threads.*/
	private int _maxEvtThds;

	public UiEngineImpl() {
	}

	//-- UiEngine --//
	public void start(WebApp wapp) {
		final Integer v = wapp.getConfiguration().getMaxEventThreads();
		final int i = v != null ? v.intValue(): 100;
		_maxEvtThds = i > 0 ? i: 100;
	}
	public void stop(WebApp wapp) {
		synchronized (_evtthds) {
			for (Iterator it = _evtthds.iterator(); it.hasNext();)
				((EventProcessingThread)it.next()).cease();
			_evtthds.clear();
		}

		synchronized (_suspended) {
			for (Iterator it = _suspended.values().iterator(); it.hasNext();) {
				final Map map = (Map)it.next();
				synchronized (map) {
					for (Iterator i2 = map.values().iterator(); i2.hasNext();) {
						final List list = (List)i2.next();
						for (Iterator i3 = list.iterator(); i3.hasNext();)
							((EventProcessingThread)i3.next()).cease();
					}
				}
			}
			_suspended.clear();
		}
		synchronized (_resumed) {
			for (Iterator it = _resumed.values().iterator(); it.hasNext();) {
				final List list = (List)it.next();
				synchronized (list) {
					for (Iterator i2 = list.iterator(); i2.hasNext();)
						((EventProcessingThread)i2.next()).cease();
				}
			}
			_resumed.clear();
		}
	}

	public void cleanup(Desktop desktop) {
		if (log.debugable()) log.debug("Cleanup "+desktop);

		final Configuration conf = desktop.getWebApp().getConfiguration();
		final Map map;
		synchronized (_suspended) {
			map = (Map)_suspended.remove(desktop);
		}
		if (map != null) {
			synchronized (map) {
				for (Iterator it = map.values().iterator(); it.hasNext();) {
					final List list = (List)it.next();
					for (Iterator i2 = list.iterator(); i2.hasNext();) {
						final EventProcessingThread evtthd =
							(EventProcessingThread)i2.next();
						evtthd.ceaseSilently();
						conf.invokeEventThreadResumeAborts(
							evtthd.getComponent(), evtthd.getEvent());
					}
				}
			}
		}

		final List list;
		synchronized (_resumed) {
			list = (List)_resumed.remove(desktop);
		}
		if (list != null) {
			synchronized (list) {
				for (Iterator it = list.iterator(); it.hasNext();) {
					final EventProcessingThread evtthd =
						(EventProcessingThread)it.next();
					evtthd.ceaseSilently();
					conf.invokeEventThreadResumeAborts(
						evtthd.getComponent(), evtthd.getEvent());
				}
			}
		}
	}

	private static UiVisualizer getCurrentVisualizer() {
		final ExecutionCtrl execCtrl = ExecutionsCtrl.getCurrentCtrl();
		if (execCtrl == null)
			throw new IllegalStateException("Components can be accessed only in event listeners");
		return (UiVisualizer)execCtrl.getVisualizer();
	}
	public void pushOwner(Component comp) {
		getCurrentVisualizer().pushOwner(comp);
	}
	public void popOwner() {
		getCurrentVisualizer().popOwner();
	}
	public void addInvalidate(Page page) {
		if (page == null)
			throw new IllegalArgumentException();
		getCurrentVisualizer().addInvalidate(page);
	}
	public void addInvalidate(Component comp) {
		if (comp == null)
			throw new IllegalArgumentException();
		getCurrentVisualizer().addInvalidate(comp);
	}
	public void addSmartUpdate(Component comp, String attr, String value) {
		if (comp == null)
			throw new IllegalArgumentException();
		getCurrentVisualizer().addSmartUpdate(comp, attr, value);
	}
	public void addResponse(String key, AuResponse response) {
		getCurrentVisualizer().addResponse(key, response);
	}
	public void addMoved(Component comp, Component oldparent, Page oldpg, Page newpg) {
		if (comp == null)
			throw new IllegalArgumentException();
		getCurrentVisualizer().addMoved(comp, oldparent, oldpg, newpg);
	}
	/** Called before changing the component's UUID.
	 *
	 * @param addOnlyMoved if true, it is added only if it was moved
	 * before (see {@link #addMoved}).
	 */
	public void addUuidChanged(Component comp, boolean addOnlyMoved) {
		if (comp == null)
			throw new IllegalArgumentException();
		getCurrentVisualizer().addUuidChanged(comp, addOnlyMoved);
	}

	//-- Creating a new page --//
	public void execNewPage(Execution exec, Richlet richlet, Page page,
	Writer out) throws IOException {
		execNewPage0(exec, null, richlet, page, out);
	}
	public void execNewPage(Execution exec, PageDefinition pagedef,
	Page page, Writer out) throws IOException {
		execNewPage0(exec, pagedef, null, page, out);
	}
	/** It assumes exactly one of pagedef and richlet is not null.
	 */
	public void execNewPage0(final Execution exec, final PageDefinition pagedef,
	final Richlet richlet, final Page page, final Writer out) throws IOException {
		//Update the client type first. If this is the second page and not
		//belonging to the same client type, an exception is thrown
		final Desktop desktop = exec.getDesktop();
		final LanguageDefinition langdef = //default page
			pagedef != null ? pagedef.getLanguageDefinition():
			richlet != null ? richlet.getLanguageDefinition(): null;
		if (langdef != null)
			desktop.setClientType(langdef.getClientType()); //set and check!

		//It is possible this method is invoked when processing other exec
		final Execution oldexec = Executions.getCurrent();
		final ExecutionCtrl oldexecCtrl = (ExecutionCtrl)oldexec;
		final UiVisualizer olduv =
			oldexecCtrl != null ? (UiVisualizer)oldexecCtrl.getVisualizer(): null;

		final UiVisualizer uv;
		if (olduv != null) uv = doReactivate(exec, olduv);
		else uv = doActivate(exec, null);

		final ExecutionCtrl execCtrl = (ExecutionCtrl)exec;
		final Page old = execCtrl.getCurrentPage();
		final PageDefinition olddef = execCtrl.getCurrentPageDefinition();
		execCtrl.setCurrentPage(page);
		execCtrl.setCurrentPageDefinition(pagedef);

		final Configuration config = desktop.getWebApp().getConfiguration();
		boolean cleaned = false;
		try {
			config.invokeExecutionInits(exec, oldexec);

			if (olduv != null) olduv.setOwner(page);

			//Cycle 1: Creates all components

			//Note:
			//1) stylesheet, tablib are inited in Page's contructor
			//2) we add variable resolvers before init because
			//init's zscirpt might depend on it.
			if (pagedef != null) {
				page.addFunctionMapper(pagedef.getFunctionMapper());
				initVariableResolvers(pagedef, page);

				final Initiators inits = Initiators.doInit(pagedef, page);
				try {
					//Request 1472813: sendRedirect in init; test: sendRedirectNow.zul
					pagedef.init(page,
						!uv.isEverAsyncUpdate() && !uv.isAborting(), !uv.isAborting());
					if (!uv.isAborting())
						execCreate(exec, page, pagedef, null);
					inits.doAfterCompose(page);
				} catch(Throwable ex) {
					inits.doCatch(ex);
					throw UiException.Aide.wrap(ex);
				} finally {
					inits.doFinally();
				}
			} else {
				//FUTURE: a way to allow richlet to set page ID
				((PageCtrl)page).init(null, null, null, null);
				richlet.service(page);
			}

			//Cycle 2: process pending events
			Event event = nextEvent(uv);
			do {
				for (; event != null; event = nextEvent(uv)) {
					process(desktop, event);
					//Unlike execUpdate, we don't cache exception here
				}

				//Cycle 2a: processing resumed event processing
				resumeAll(desktop, uv, null);
			} while ((event = nextEvent(uv)) != null);

			//Cycle 3: Redraw the page (and responses)
			List responses = uv.getResponses();

			final AbortingReason aborting = uv.getAbortingReason();
			if (aborting != null) {
				final AuResponse abtresp = aborting.getResponse();
				if (abtresp != null)
					responses.add(0, abtresp);
			}

			if (olduv != null && olduv.addToFirstAsyncUpdate(responses))
				responses = null;
				//A new ZK page might be included by an async update
				//(example: ZUL's include).
				//If so, we cannot generate the responses in the page.
				//Rather, we shall add them to the async update.

			((PageCtrl)page).redraw(responses, out);
		} catch (Throwable ex) {
			cleaned = true;
			config.invokeExecutionCleanups(exec, oldexec, ex, null);
				//TODO: find a way to send back the error message, if any, returned

			if (ex instanceof IOException) throw (IOException)ex;
			throw UiException.Aide.wrap(ex);
		} finally {
			if (!cleaned) config.invokeExecutionCleanups(exec, oldexec, null, null);

			execCtrl.setCurrentPage(old); //restore it
			execCtrl.setCurrentPageDefinition(olddef); //restore it

			if (olduv != null) doDereactivate(exec, olduv);
			else doDeactivate(exec);
		}
	}

	private static final Event nextEvent(UiVisualizer uv) {
		final Event evt = ((ExecutionCtrl)uv.getExecution()).getNextEvent();
		return evt != null && !uv.isAborting() ? evt: null;
	}
	/** Cycle 1:
	 * Creates all child components defined in the specified definition.
	 * @return the first component being created.
	 */
	private static final Component execCreate(Execution exec, Page page,
	InstanceDefinition parentdef, Component parent)
	throws IOException {
		Component firstCreated = null;
		final PageDefinition pagedef = parentdef.getPageDefinition();
			//note: don't use page.getDefinition because createComponents
			//might be called from a page other than instance's
		for (Iterator it = parentdef.getChildren().iterator(); it.hasNext();) {
			final Object obj = it.next();
			if (obj instanceof InstanceDefinition) {
				final InstanceDefinition childdef = (InstanceDefinition)obj;
				final ForEach forEach = childdef.getForEach(page, parent);
				if (forEach == null) {
					if (isEffective(childdef, page, parent)) {
						final Component child =
							execCreateChild(exec, page, parent, childdef);
						if (firstCreated == null) firstCreated = child;
					}
				} else {
					while (forEach.next()) {
						if (isEffective(childdef, page, parent)) {
							final Component child =
								execCreateChild(exec, page, parent, childdef);
							if (firstCreated == null) firstCreated = child;
						}
					}
				}
			} else if (obj instanceof ZScript) {
				final ZScript script = (ZScript)obj;
				if (isEffective(script, page, parent)) {
					final Namespace ns = parent != null ?
						Namespaces.beforeInterpret(exec, parent):
						Namespaces.beforeInterpret(exec, page);
					try {
						page.interpret(script.getContent(page, parent), ns);
					} finally {
						Namespaces.afterInterpret(ns);
					}
				}
			} else {
				throw new IllegalStateException("Unknown object: "+obj);
			}
		}
		return firstCreated;