boot/src/main/java/org/apidesign/html/boot/spi/Fn.java
changeset 838 bdc3d696dd4a
parent 837 892b0a823f46
child 839 7b0f9b77670a
     1.1 --- a/boot/src/main/java/org/apidesign/html/boot/spi/Fn.java	Tue Aug 26 17:43:37 2014 +0200
     1.2 +++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.3 @@ -1,332 +0,0 @@
     1.4 -/**
     1.5 - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
     1.6 - *
     1.7 - * Copyright 2013-2014 Oracle and/or its affiliates. All rights reserved.
     1.8 - *
     1.9 - * Oracle and Java are registered trademarks of Oracle and/or its affiliates.
    1.10 - * Other names may be trademarks of their respective owners.
    1.11 - *
    1.12 - * The contents of this file are subject to the terms of either the GNU
    1.13 - * General Public License Version 2 only ("GPL") or the Common
    1.14 - * Development and Distribution License("CDDL") (collectively, the
    1.15 - * "License"). You may not use this file except in compliance with the
    1.16 - * License. You can obtain a copy of the License at
    1.17 - * http://www.netbeans.org/cddl-gplv2.html
    1.18 - * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
    1.19 - * specific language governing permissions and limitations under the
    1.20 - * License.  When distributing the software, include this License Header
    1.21 - * Notice in each file and include the License file at
    1.22 - * nbbuild/licenses/CDDL-GPL-2-CP.  Oracle designates this
    1.23 - * particular file as subject to the "Classpath" exception as provided
    1.24 - * by Oracle in the GPL Version 2 section of the License file that
    1.25 - * accompanied this code. If applicable, add the following below the
    1.26 - * License Header, with the fields enclosed by brackets [] replaced by
    1.27 - * your own identifying information:
    1.28 - * "Portions Copyrighted [year] [name of copyright owner]"
    1.29 - *
    1.30 - * Contributor(s):
    1.31 - *
    1.32 - * The Original Software is NetBeans. The Initial Developer of the Original
    1.33 - * Software is Oracle. Portions Copyright 2013-2014 Oracle. All Rights Reserved.
    1.34 - *
    1.35 - * If you wish your version of this file to be governed by only the CDDL
    1.36 - * or only the GPL Version 2, indicate your decision by adding
    1.37 - * "[Contributor] elects to include this software in this distribution
    1.38 - * under the [CDDL or GPL Version 2] license." If you do not indicate a
    1.39 - * single choice of license, a recipient has the option to distribute
    1.40 - * your version of this file under either the CDDL, the GPL Version 2 or
    1.41 - * to extend the choice of license to its licensees as provided above.
    1.42 - * However, if you add GPL Version 2 code and therefore, elected the GPL
    1.43 - * Version 2 license, then the option applies only if the new code is
    1.44 - * made subject to such option by the copyright holder.
    1.45 - */
    1.46 -package org.apidesign.html.boot.spi;
    1.47 -
    1.48 -import java.io.Closeable;
    1.49 -import java.io.IOException;
    1.50 -import java.io.InputStream;
    1.51 -import java.io.InputStreamReader;
    1.52 -import java.io.Reader;
    1.53 -import java.net.URL;
    1.54 -import java.util.HashMap;
    1.55 -import java.util.HashSet;
    1.56 -import java.util.Map;
    1.57 -import java.util.Set;
    1.58 -import java.util.concurrent.Executor;
    1.59 -import net.java.html.js.JavaScriptBody;
    1.60 -import org.netbeans.html.boot.impl.FnContext;
    1.61 -
    1.62 -/** Represents single JavaScript function that can be invoked. 
    1.63 - * Created via {@link Presenter#defineFn(java.lang.String, java.lang.String...)}.
    1.64 - *
    1.65 - * @author Jaroslav Tulach
    1.66 - */
    1.67 -public abstract class Fn {
    1.68 -    private final Presenter presenter;
    1.69 -    
    1.70 -    /**
    1.71 -     * @deprecated Ineffective as of 0.6. 
    1.72 -     * Provide a presenter via {@link #Fn(org.apidesign.html.boot.spi.Fn.Presenter)}
    1.73 -     * constructor
    1.74 -     */
    1.75 -    @Deprecated
    1.76 -    protected Fn() {
    1.77 -        this(null);
    1.78 -    }
    1.79 -    
    1.80 -    /** Creates new function object and associates it with given presenter.
    1.81 -     * 
    1.82 -     * @param presenter the browser presenter associated with this function
    1.83 -     * @since 0.6 
    1.84 -     */
    1.85 -    protected Fn(Presenter presenter) {
    1.86 -        this.presenter = presenter;
    1.87 -    }
    1.88 -
    1.89 -    /** True, if currently active presenter is the same as presenter this
    1.90 -     * function has been created for via {@link #Fn(org.apidesign.html.boot.spi.Fn.Presenter)}.
    1.91 -     * 
    1.92 -     * @return true, if proper presenter is used
    1.93 -     */
    1.94 -    public final boolean isValid() {
    1.95 -        return presenter != null && FnContext.currentPresenter(false) == presenter;
    1.96 -    }
    1.97 -    
    1.98 -    /** Helper method to check if the provided instance is valid function.
    1.99 -     * Checks if the parameter is non-null and if so, does {@link #isValid()}
   1.100 -     * check.
   1.101 -     * 
   1.102 -     * @param fnOrNull function or <code>null</code>
   1.103 -     * @return true if the parameter is non-null and valid
   1.104 -     * @since 0.7
   1.105 -     */
   1.106 -    public static boolean isValid(Fn fnOrNull) {
   1.107 -        return fnOrNull != null && fnOrNull.isValid();
   1.108 -    }
   1.109 -
   1.110 -    /** Helper method to find current presenter and ask it to define new
   1.111 -     * function by calling {@link Presenter#defineFn(java.lang.String, java.lang.String...)}.
   1.112 -     * 
   1.113 -     * @param caller the class who wishes to define the function
   1.114 -     * @param code the body of the function (can reference <code>this</code> and <code>names</code> variables)
   1.115 -     * @param names names of individual parameters
   1.116 -     * @return the function object that can be {@link Fn#invoke(java.lang.Object, java.lang.Object...) invoked}
   1.117 -     *    - can return <code>null</code> if there is {@link #activePresenter() no presenter}
   1.118 -     * @since 0.7
   1.119 -     */
   1.120 -    public static Fn define(Class<?> caller, String code, String... names) {
   1.121 -        final Presenter p = FnContext.currentPresenter(false);
   1.122 -        return p == null ? null : p.defineFn(code, names);
   1.123 -    }
   1.124 -    
   1.125 -    private static final Map<String,Set<Presenter>> LOADED = new HashMap<String, Set<Presenter>>();
   1.126 -    
   1.127 -    /** Wraps function to ensure that the script represented by <code>resource</code>
   1.128 -     * gets loaded into the browser environment before the function <code>fn</code>
   1.129 -     * is executed.
   1.130 -     * 
   1.131 -     * @param fn original function to call (if <code>null</code> returns <code>null</code>)
   1.132 -     * @param caller the class who wishes to define/call the function
   1.133 -     * @param resource resources (accessible via {@link ClassLoader#getResource(java.lang.String)}) 
   1.134 -     *   with a <em>JavaScript</em> that is supposed to loaded into the browser
   1.135 -     *   environment
   1.136 -     * @return function that ensures the script is loaded and then delegates
   1.137 -     *   to <code>fn</code>. Returns <code>null</code> if the input <code>fn</code> is null
   1.138 -     * @since 0.7
   1.139 -     */
   1.140 -    public static Fn preload(final Fn fn, final Class<?> caller, final String resource) {
   1.141 -        if (fn == null) {
   1.142 -            return null;
   1.143 -        }
   1.144 -        return new Fn(fn.presenter()) {
   1.145 -            @Override
   1.146 -            public Object invoke(Object thiz, Object... args) throws Exception {
   1.147 -                loadResource();
   1.148 -                return fn.invoke(thiz, args);
   1.149 -            }
   1.150 -
   1.151 -            @Override
   1.152 -            public void invokeLater(Object thiz, Object... args) throws Exception {
   1.153 -                loadResource();
   1.154 -                fn.invokeLater(thiz, args);
   1.155 -            }
   1.156 -            
   1.157 -            private void loadResource() throws Exception {
   1.158 -                Presenter p = presenter();
   1.159 -                if (p == null) {
   1.160 -                    p = FnContext.currentPresenter(false);
   1.161 -                }
   1.162 -                if (p != null) {
   1.163 -                    Set<Presenter> there = LOADED.get(resource);
   1.164 -                    if (there == null) {
   1.165 -                        there = new HashSet<Presenter>();
   1.166 -                        LOADED.put(resource, there);
   1.167 -                    }
   1.168 -                    if (there.add(p)) {
   1.169 -                        final ClassLoader l = caller.getClassLoader();
   1.170 -                        InputStream is = l.getResourceAsStream(resource);
   1.171 -                        if (is == null && resource.startsWith("/")) {
   1.172 -                            is = l.getResourceAsStream(resource.substring(1));
   1.173 -                        }
   1.174 -                        if (is == null) {
   1.175 -                            throw new IOException("Cannot find " + resource + " in " + l);
   1.176 -                        }
   1.177 -                        try {
   1.178 -                            InputStreamReader r = new InputStreamReader(is, "UTF-8");
   1.179 -                            p.loadScript(r);
   1.180 -                        } finally {
   1.181 -                            is.close();
   1.182 -                        }
   1.183 -                    }
   1.184 -                }
   1.185 -            }
   1.186 -        };
   1.187 -    }
   1.188 -
   1.189 -    
   1.190 -    /** The currently active presenter.
   1.191 -     * 
   1.192 -     * @return the currently active presenter or <code>null</code>
   1.193 -     * @since 0.7
   1.194 -     */
   1.195 -    public static Presenter activePresenter() {
   1.196 -        return FnContext.currentPresenter(false);
   1.197 -    }
   1.198 -    
   1.199 -    /** Activates given presenter. Used to associate the native 
   1.200 -     * JavaScript code specified by 
   1.201 -     * {@link JavaScriptBody} annotation with certain presenter:
   1.202 -     * <pre>
   1.203 -     * try ({@link Closeable} c = Fn.activate(presenter)) {
   1.204 -     *   doCallsInPresenterContext();
   1.205 -     * }
   1.206 -     * </pre>
   1.207 -     * 
   1.208 -     * @param p the presenter that should be active until closable is closed
   1.209 -     * @return the closable to close
   1.210 -     * @since 0.7
   1.211 -     */
   1.212 -    public static Closeable activate(Presenter p) {
   1.213 -        return FnContext.activate(p);
   1.214 -    }
   1.215 -    
   1.216 -    /** Invokes the defined function with specified <code>this</code> and
   1.217 -     * appropriate arguments.
   1.218 -     * 
   1.219 -     * @param thiz the meaning of <code>this</code> inside of the JavaScript
   1.220 -     *   function - can be <code>null</code>
   1.221 -     * @param args arguments for the function
   1.222 -     * @return return value from the function
   1.223 -     * @throws Exception if something goes wrong, as exception may be thrown
   1.224 -     */
   1.225 -    public abstract Object invoke(Object thiz, Object... args) throws Exception;
   1.226 -
   1.227 -    /** Invokes the defined function with specified <code>this</code> and
   1.228 -     * appropriate arguments asynchronously. The invocation may be 
   1.229 -     * happen <em>"later"</em>.
   1.230 -     * 
   1.231 -     * @param thiz the meaning of <code>this</code> inside of the JavaScript
   1.232 -     *   function - can be <code>null</code>
   1.233 -     * @param args arguments for the function
   1.234 -     * @throws Exception if something goes wrong, as exception may be thrown
   1.235 -     * @since 0.7.6
   1.236 -     */
   1.237 -    public void invokeLater(Object thiz, Object... args) throws Exception {
   1.238 -        invoke(this, args);
   1.239 -    }
   1.240 -    
   1.241 -    /** Provides the function implementation access to the presenter provided
   1.242 -     * in {@link #Fn(org.apidesign.html.boot.spi.Fn.Presenter) the constructor}.
   1.243 -     * 
   1.244 -     * @return presenter passed in the constructor (may be, but should not be <code>null</code>)
   1.245 -     * @since 0.7
   1.246 -     */
   1.247 -    protected final Presenter presenter() {
   1.248 -        return presenter;
   1.249 -    }
   1.250 -
   1.251 -    /** The representation of a <em>presenter</em> - usually a browser window.
   1.252 -     * Should be provided by a library included in the application and registered
   1.253 -     * in <code>META-INF/services</code>, for example with
   1.254 -     * <code>@ServiceProvider(service = Fn.Presenter.class)</code> annotation.
   1.255 -     * <p>
   1.256 -     * Since 0.7 a presenter may implement {@link Executor} interface, in case
   1.257 -     * it supports single threaded execution environment. The executor's
   1.258 -     * {@link Executor#execute(java.lang.Runnable)} method is then supposed
   1.259 -     * to invoke the runnable immediately (in case we are on the right thread
   1.260 -     * already) or return and asynchronously invoke the runnable later on the
   1.261 -     * right thread (if we are on wrong thread).
   1.262 -     */
   1.263 -    public interface Presenter {
   1.264 -        /** Creates new function with given parameter names and provided body.
   1.265 -         * 
   1.266 -         * @param code the body of the function. Can refer to variables named
   1.267 -         *   as <code>names</code>
   1.268 -         * @param names names of parameters of the function - these will be 
   1.269 -         *   available when the <code>code</code> body executes
   1.270 -         * 
   1.271 -         * @return function that can be later invoked
   1.272 -         */
   1.273 -        public Fn defineFn(String code, String... names);
   1.274 -        
   1.275 -        /** Opens the browser, loads provided page and when the
   1.276 -         * page is ready, it calls back to the provider runnable.
   1.277 -         * 
   1.278 -         * @param page the URL for the page to display
   1.279 -         * @param onPageLoad callback when the page is ready
   1.280 -         */
   1.281 -        public void displayPage(URL page, Runnable onPageLoad);
   1.282 -        
   1.283 -        /** Loads a script into the browser JavaScript interpreter and 
   1.284 -         * executes it.
   1.285 -         * @param code the script to execute
   1.286 -         * @throws Exception if something goes wrong, throw an exception
   1.287 -         */
   1.288 -        public void loadScript(Reader code) throws Exception;
   1.289 -    }
   1.290 -    
   1.291 -    /** Additional interface to be implemented by {@link Presenter}s that
   1.292 -     * wish to control what objects are passed into the JavaScript virtual 
   1.293 -     * machine.
   1.294 -     * <p>
   1.295 -     * If a JavaScript engine makes callback to Java method that returns 
   1.296 -     * a value, the {@link #toJavaScript(java.lang.Object)} method is
   1.297 -     * consulted to convert the Java value to something reasonable inside
   1.298 -     * JavaScript VM.
   1.299 -     * <p>
   1.300 -     * <em>Note:</em> The implementation based on <em>JavaFX</em> <code>WebView</code>
   1.301 -     * uses this interface to convert Java arrays to JavaScript ones.
   1.302 -     * 
   1.303 -     * @see Presenter
   1.304 -     * @since 0.7
   1.305 -     */
   1.306 -    public interface ToJavaScript {
   1.307 -        /** Convert a Java return value into some object suitable for
   1.308 -         * JavaScript virtual machine.
   1.309 -         * 
   1.310 -         * @param toReturn the Java object to be returned
   1.311 -         * @return the replacement value to return instead
   1.312 -         */
   1.313 -        public Object toJavaScript(Object toReturn);
   1.314 -    }
   1.315 -    
   1.316 -    /** Additional interface to be implemented by {@link Presenter}s that
   1.317 -     * need to convert JavaScript object (usually array) to Java object 
   1.318 -     * when calling back from JavaScript to Java.
   1.319 -     * <p>
   1.320 -     * <em>Note:</em> The implementation based on <em>JavaFX</em>
   1.321 -     * <code>WebView</code> uses this interface to convert JavaScript arrays to
   1.322 -     * Java ones.
   1.323 -      * 
   1.324 -     * @since 0.7
   1.325 -     */
   1.326 -    public interface FromJavaScript {
   1.327 -        /** Convert a JavaScript object into suitable Java representation
   1.328 -         * before a Java method is called with this object as an argument.
   1.329 -         * 
   1.330 -         * @param js the JavaScript object
   1.331 -         * @return replacement object for 
   1.332 -         */
   1.333 -        public Object toJava(Object js);
   1.334 -    }
   1.335 -}