Method _highLight

src/openlayers/overlay/Graphic.js:517–566

* @function Graphic.prototype._highLight * @description 高亮显示选中要素。 * @param {Array. } center - 中心点。 * @param {ol.style.Style} image - 点样式。 * @param {OverlayGraphic} selectGraphic - 高效率点图层点要素。 * @param {ol.Pixel} evtPixel - 当前选中的屏幕像素坐标。 * @private

(center, image, selectGraphic, evtPixel)

     * @private
     */
    _highLight(center, image, selectGraphic, evtPixel) {
        if (selectGraphic.getStyle() instanceof CloverShape) {
            if (this.hitGraphicLayer) {
                this.map.removeLayer(this.hitGraphicLayer);
                this.hitGraphicLayer = null;
            }
            var pixel = this.map.getPixelFromCoordinate([center[0], center[1]]);
            //点击点与中心点的角度
            evtPixel = evtPixel || [0, 0];
            var angle = (Math.atan2(evtPixel[1] - pixel[1], evtPixel[0] - pixel[0]) / Math.PI) * 180;
            angle = angle > 0 ? angle : 360 + angle;
            //确定扇叶
            var index = Math.ceil(angle / (image.getAngle() + image.getSpaceAngle()));
            //扇叶的起始角度
            var sAngle = (index - 1) * (image.getAngle() + image.getSpaceAngle());
            //渲染参数
            var opts = {
                stroke: new StrokeStyle({
                    color: '#ff0000',
                    width: 1
                }),
                fill: new FillStyle({
                    color: '#0099ff'
                }),
                radius: image.getRadius(),
                angle: image.getAngle(),
                eAngle: sAngle + image.getAngle(),
                sAngle: sAngle,
                rotation: image.getRotation()
            };
            if (this.highLightStyle && this.highLightStyle instanceof HitCloverShape) {
                opts.stroke = this.highLightStyle.getStroke();
                opts.fill = this.highLightStyle.getFill();
                opts.radius = this.highLightStyle.getRadius();
                opts.angle = this.highLightStyle.getAngle();
            }
            var hitGraphic = new OverlayGraphic(new Point(center));
            hitGraphic.setStyle(new HitCloverShape(opts));
            this.hitGraphicLayer = new ImageLayer({
                source: new Graphic({
                    map: this.map,
                    graphics: [hitGraphic]
                })
            });
            this.map.addLayer(this.hitGraphicLayer);
        } else {
            this.selected = selectGraphic;
            this.changed();
        }
    }

    /**
     * @function Graphic.prototype.getGraphicsInExtent