绘画板 08——删除与清屏

删除

GlobalStatus增加isRecycle()方法,用来判断删除按钮是否被点击

isRecycle: function(){
    return $("#tool_delete").hasClass("active");
},

在Element扩展的click方法中,增加删除判断,执行remove()方法。并在mouseover时修改鼠标图标显示

(function() {

    SVG.extend(SVG.Doc, {
        transformPoint: function(event) {
            event = event || window.event;
            var touches = event.changedTouches && event.changedTouches[0] || event;
            var node = this.node;
            var point = node.createSVGPoint();
            point.x = touches.pageX - window.scrollX;
            point.y = touches.pageY - window.scrollY;
            var matrix = node.getScreenCTM().inverse();
            return point.matrixTransform(matrix);
        }
    });

    SVG.extend(SVG.Element, {
        pickable: function(enabled) {
            var _ele = this;
            GlobalStatus.pushElements(_ele);
            var color = _ele._stroke;
            var width = _ele.attr("stroke-width");
            _ele.on("mouseover", function() {
                if (GlobalStatus.isPicked()) {
                    _ele.stroke({
                        width: width * 2,
                        color: 'red'
                    });
                    $("#svgPanel").css("cursor", "pointer");
                } else if (GlobalStatus.isPreFilled()) {
                    $("#svgPanel").css("cursor", "url(style/img/cur/tool_fill.cur), auto");
                } else if (GlobalStatus.isRecycle()) {
                    $("#svgPanel").css("cursor", "url(style/img/cur/tool_delete.cur), auto");
                }


            });
            _ele.on("mouseout", function() {
                if (GlobalStatus.isPicked()) {
                    _ele.stroke({
                        width: width,
                        color: color
                    });
                    $("#svgPanel").css("cursor", "default");
                } else if (GlobalStatus.isPreFilled()) {
                    $("#svgPanel").css("cursor", "default");
                } else if (GlobalStatus.isRecycle()) {
                    $("#svgPanel").css("cursor", "default");
                }

            });
            _ele.on("click", function() {
                if (GlobalStatus.isPreFilled()) {
                    if ($("#fill_color").hasClass("active")) {
                        _ele.fill(GlobalStatus.getFillColor());
                        _ele.style("fill-opacity", GlobalStatus.getFillOpacity());
                    } else {
                        _ele.style("stroke", GlobalStatus.getFontColor());
                    }

                } else if (GlobalStatus.isPicked()) {
                    if (!_ele.attr("picked")) {
                        _ele.attr("picked", true);
                        _ele.handleBorder = _ele.handleBorder || new HandleBorder(svgDoc);
                        _ele.handleBorder.showShade(_ele);
                        GlobalStatus.pushPicked(_ele);
                    } else {
                        _ele.attr("picked", null);
                        _ele.handleBorder && _ele.handleBorder.hideShade(_ele);
                        GlobalStatus.removePicked(_ele);
                    }
                } else if (GlobalStatus.isRecycle()) {
                    _ele.remove();
                }
            });
            return this;
        }

    });
})();

清屏

单击清屏按钮时,清空所有的element元素,不需要按钮被点击状态。

此时有一个思考,是遍历所有的元素执行删除操作,还是重新设置svg doc。

先用遍历方法执行。

将elementList抽象到GlobalStatus方法中管理,并在元素完成后执行添加操作。

elementList : [],
pushElements: function(o){
    return this.elementList.push(o);
},
removeElements: function(o) {
    return this.elementList.remove(o);
},
getAllElements: function(){
    return this.elementList;
}

监听清屏按钮,遍历删除element

$("#clear_all").on("click", function() {
    $(GlobalStatus.getAllElements()).each(function(){
        this.remove();
    });
});

github地址: https://github.com/wangyuheng/painter

DEMO地址: http://painter.crick.wang/