Fabricjs一个简单强大的Canvas绘图库快速入门：

https://blog.csdn.net/BADAO_LIUMANG_QIZHI/article/details/122850075

在上面的基础上，怎样监听画布上鼠标按下、移动、抬起时的事件，以及画布上对象

被选中、被移动、被旋转、被加入和被移除的事件。

博客：
https://blog.csdn.net/badao_liumang_qizhi
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1、画布的事件监听

      //鼠标按下时事件
      canvas.on('mouse:down', function(options) {
        console.log("mouse:down"+options.e.clientX, options.e.clientY)
      //鼠标移动时事件
      canvas.on('mouse:move', function(options) {
        console.log("mouse:move"+options.e.clientX, options.e.clientY)
      //鼠标抬起时事件
      canvas.on('mouse:up', function(options) {
        console.log("mouse:up"+options.e.clientX, options.e.clientY)
2、对象的事件监听
      //绘制不规则图形
      var path = new fabric.Path('M 0 0 L 200 100 L 170 200 z');
      path.set({ left: 120, top: 120,fill:'red' });
      //选中监听事件
      path.on('selected', function() {
        console.log('selected');
      //对象移动监听事件
      path.on('moving', function() {
        console.log('moving');
      //对象被旋转监听事件
      path.on('rotating', function() {
        console.log('rotating');
      //对象被加入监听事件
      path.on('added', function() {
        console.log('added');
      //对象被移除监听事件
      path.on('removed', function() {
        console.log('removed');
      // create a wrapper around native canvas element (with id="c")
      // 声明画布
      var canvas = new fabric.Canvas("c");
      //鼠标按下时事件
      canvas.on('mouse:down', function(options) {
        console.log("mouse:down"+options.e.clientX, options.e.clientY)
      //鼠标移动时事件
      canvas.on('mouse:move', function(options) {
        console.log("mouse:move"+options.e.clientX, options.e.clientY)
      //鼠标抬起时事件
      canvas.on('mouse:up', function(options) {
        console.log("mouse:up"+options.e.clientX, options.e.clientY)
      // create a rectangle object
      // 绘制图形
      var rect = new fabric.Rect({
        left: 80, //距离画布左侧的距离，单位是像素
        top: 80, //距离画布上边的距离
        fill: "red", //填充的颜色
        width: 20, //方形的宽度
        height: 20, //方形的高度
      // "add" rectangle onto canvas
      //添加图形至画布
      canvas.add(rect);
      //添加图片
      fabric.Image.fromURL('images/light.png', function(oImg) {
        // scale image down, and flip it, before adding it onto canvas
        //缩小图像并翻转它
        oImg.scale(0.5).set('flipX', true);
        canvas.add(oImg);
      //绘制不规则图形
      var path = new fabric.Path('M 0 0 L 200 100 L 170 200 z');
      path.set({ left: 120, top: 120,fill:'red' });
      //选中监听事件
      path.on('selected', function() {
        console.log('selected');
      //对象移动监听事件
      path.on('moving', function() {
        console.log('moving');
      //对象被旋转监听事件
      path.on('rotating', function() {
        console.log('rotating');
      //对象被加入监听事件
      path.on('added', function() {
        console.log('added');
      //对象被移除监听事件
      path.on('removed', function() {
        console.log('removed');
      canvas.add(path);
</script>