/**

 * 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);

    }

}