如何在fabric.js中選擇和拖動對象

Question

我以這個jsfiddle為例，在這里我使用fabric.js，當我們單擊按鈕時，它將創建線條。我的問題是如何在fabric.js中的畫布中選擇或移動對象？

var canvas = new fabric.Canvas('c', { selection: false });

var line, isDown;

canvas.on('mouse:down', function(o){
  isDown = true;
  var pointer = canvas.getPointer(o.e);
  var points = [ pointer.x, pointer.y, pointer.x, pointer.y ];
  line = new fabric.Line(points, {
    strokeWidth: 5,
    fill: 'red',
    stroke: 'red',
    originX: 'center',
    originY: 'center'
  });
  canvas.add(line);
});

canvas.on('mouse:move', function(o){
  if (!isDown) return;
  var pointer = canvas.getPointer(o.e);
  line.set({ x2: pointer.x, y2: pointer.y });
  canvas.renderAll();
});

canvas.on('mouse:up', function(o){
  isDown = false;
});

如果我將第一行作為var canvas = new fabric.Canvas('c', { selection: true }); 我可以獲得邊界框，但我無法拖動

Answer 1

我解決了這個問題。

var canvas = new fabric.Canvas('c', { selection: false });

var line, isDown;

canvas.on('mouse:down', function(o){
    if(canvas.findTarget(o.e))return;
  isDown = true;
  var pointer = canvas.getPointer(o.e);
  var points = [ pointer.x, pointer.y, pointer.x, pointer.y ];
  line = new fabric.Line(points, {
    strokeWidth: 5,
    fill: 'red',
    stroke: 'red',
    originX: 'center',
    originY: 'center'
  });
  canvas.add(line);
});

canvas.on('mouse:move', function(o){
  if (!isDown) return;
  var pointer = canvas.getPointer(o.e);
  line.set({ x2: pointer.x, y2: pointer.y });
  line.setCoords();
  canvas.renderAll();
});

canvas.on('mouse:up', function(o){
  isDown = false;
});