/*
 *    Copyright [2011] [wisemapping]
 *
 *   Licensed under WiseMapping Public License, Version 1.0 (the "License").
 *   It is basically the Apache License, Version 2.0 (the "License") plus the
 *   "powered by wisemapping" text requirement on every single page;
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the license at
 *
 *       http://www.wisemapping.org/license
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */

web2d.peer.svg.GroupPeer = new Class({
    Extends: web2d.peer.svg.ElementPeer,
    initialize : function() {
        var svgElement = window.document.createElementNS(this.svgNamespace, 'g');
        this.parent(svgElement);
        this._native.setAttribute("preserveAspectRatio", "none");
        this._coordSize = {width:1,height:1};
        this._native.setAttribute("focusable", "true");
        this._position = {x:0,y:0};
        this._coordOrigin = {x:0,y:0};
    },

    setCoordSize : function(width, height) {
        var change = this._coordSize.width != width || this._coordSize.height != height;
        this._coordSize.width = width;
        this._coordSize.height = height;

        if (change)
            this.updateTransform();
        web2d.peer.utils.EventUtils.broadcastChangeEvent(this, "strokeStyle");
    },

    getCoordSize : function() {
        return {width:this._coordSize.width,height:this._coordSize.height};
    },

    /**
     * http://www.w3.org/TR/SVG/coords.html#TransformAttribute
     * 7.6 The transform  attribute
     *
     * The value of the transform attribute is a <transform-list>, which is defined as a list of transform definitions, which are applied in the order provided. The individual transform definitions are separated by whitespace and/or a comma. The available types of transform definitions include:
     *
     *    * matrix(<a> <b> <c> <d> <e> <f>), which specifies a transformation in the form of a transformation matrix of six values. matrix(a,b,c,d,e,f) is equivalent to applying the transformation matrix [a b c d e f].
     *
     *    * translate(<tx> [<ty>]), which specifies a translation by tx and ty. If <ty> is not provided, it is assumed to be zero.
     *
     *    * scale(<sx> [<sy>]), which specifies a scale operation by sx and sy. If <sy> is not provided, it is assumed to be equal to <sx>.
     *
     *    * rotate(<rotate-angle> [<cx> <cy>]), which specifies a rotation by <rotate-angle> degrees about a given point.
     *      If optional parameters <cx> and <cy> are not supplied, the rotate is about the origin of the current user coordinate system. The operation corresponds to the matrix [cos(a) sin(a) -sin(a) cos(a) 0 0].
     *      If optional parameters <cx> and <cy> are supplied, the rotate is about the point (<cx>, <cy>). The operation represents the equivalent of the following specification: translate(<cx>, <cy>) rotate(<rotate-angle>) translate(-<cx>, -<cy>).
     *
     *    * skewX(<skew-angle>), which specifies a skew transformation along the x-axis.
     *
     *    * skewY(<skew-angle>), which specifies a skew transformation along the y-axis.
     **/

    updateTransform : function() {
        var sx = this._size.width / this._coordSize.width;
        var sy = this._size.height / this._coordSize.height;

        var cx = this._position.x - this._coordOrigin.x * sx;
        var cy = this._position.y - this._coordOrigin.y * sy;

        this._native.setAttribute("transform", "translate(" + cx + "," + cy + ") scale(" + sx + "," + sy + ")");
    },

    setOpacity : function(value) {
        this._native.setAttribute("opacity", value);
    },

    setCoordOrigin : function(x, y) {
        var change = x != this._coordOrigin.x || y != this._coordOrigin.y;
        if ($defined(x)) {
            this._coordOrigin.x = x;
        }

        if ($defined(y)) {
            this._coordOrigin.y = y;
        }
        if (change)
            this.updateTransform();
    },

    setSize : function(width, height) {
        var change = width != this._size.width || height != this._size.height;
        this.parent(width, height);
        if (change)
            this.updateTransform();
    },

    setPosition : function(x, y) {
        var change = x != this._position.x || y != this._position.y;
        if ($defined(x)) {
            this._position.x = parseInt(x);
        }

        if ($defined(y)) {
            this._position.y = parseInt(y);
        }
        if (change)
            this.updateTransform();
    },

    getPosition : function() {
        return {x:this._position.x,y:this._position.y};
    },

    appendChild : function(child) {
        this.parent(child);
        web2d.peer.utils.EventUtils.broadcastChangeEvent(child, "onChangeCoordSize");
    },

    getCoordOrigin : function () {
        return {x:this._coordOrigin.x, y:this._coordOrigin.y};
    }
});