/**

  * Back 2 Browser Bytecode Translator

  * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

  *

  * 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, version 2 of the License.

  *

  * 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. Look for COPYING file in the top folder.

  * If not, see http://opensource.org/licenses/GPL-2.0.

  */

 package org.apidesign.bck2brwsr.htmlpage.api;

 import javafx.scene.web.WebEngine;

 import netscape.javascript.JSObject;

 import org.apidesign.bck2brwsr.core.JavaScriptBody;

 /** Represents a generic HTML element.

  *

  * @author Jaroslav Tulach <jtulach@netbeans.org>

  */

 public abstract class Element {

     private final String id;

     public Element(String id) {

         this.id = id;

     }

     /** Id of the element in the document.

      * @return the id for this element

      */

     public String getId() {

         return id;

     }

     abstract void dontSubclass();

     @JavaScriptBody(

         args={"el", "property", "value"},

         body="var e = window.document.getElementById(el._id());\n"

            + "e[property] = value;\n"

     )

     static native void setAttribute(Element el, String property, Object value);

     @JavaScriptBody(

         args={"el", "property"},

         body="var e = window.document.getElementById(el._id());\n"

            + "return e[property];\n"

     )

     static native Object getAttribute(Element el, String property);

     @JavaScriptBody(

         args={"el"},

         body="return window.document.getElementById(el._id());"

     )

     static native Object getElementById(Element el);

     /** Executes given runnable when user performs a "click" on the given

      * element.

      * @param data an array of one element to fill with event parameter (if any)

      * @param r the runnable to execute, never null

      */

     @JavaScriptBody(

         args={ "ev", "r" },

         body="var e = window.document.getElementById(this._id());\n"

            + "e[ev._id()] = function(ev) {\n"

         + "  var d = ev ? ev : null;\n"

         + "  r.onEvent__VLjava_lang_Object_2(d);\n"

         + "};\n"

     )

     final void on(OnEvent ev, OnHandler r) {

         WebEngine e = web();

         JSObject add = (JSObject)e.executeScript(

               "var x = {}; x.add = new Function('e','attr','r', "

             + "  'window.document.getElementById(e)[attr] = function(ev) { var d = ev ? ev : null; try { r.onEvent(d); } catch (x) { alert(\"OK\" + r[\"onEvent\"] + \"e\" + d + x); } };'"

             + "); x;");

         add.call("add", id, ev.id, r);

     }

     private static WebEngine web() {

         return (WebEngine) System.getProperties().get("webEngine");

     }

     /** Shows alert message dialog in a browser.

      * @param msg the message to show

      */

     @JavaScriptBody(args = "msg", body = "alert(msg);")

     public static void alert(String msg) {

         JSObject obj = (JSObject) web().executeScript("window");

         obj.call("alert", msg);

     }

     /** Generic way to query any attribute of this element.

      * @param property name of the attribute

      */

     public final Object getAttribute(String property) {

         return getAttribute(this, property);

     }

     /** Generic way to change an attribute of this element.

      * 

      * @param property name of the attribute

      * @param value value to associate with the attribute

      */

     public final void setAttribute(String property, Object value) {

         setAttribute(this, property, value);

     }

 }