如何停止使用Fabric.js繪圖

Question

我復制了一個代碼，使用fabric.js繪制了隨鼠標移動的矩形。 但是我需要當用戶選擇該選項時，繪圖停止。

我用了這個小提琴http://jsfiddle.net/a7mad24/aPLq5/

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

var rect, isDown, origX, origY;

canvas.on('mouse:down', function (o) {
    isDown = true;
    var pointer = canvas.getPointer(o.e);
    origX = pointer.x;
    origY = pointer.y;
    var pointer = canvas.getPointer(o.e);
    rect = new fabric.Rect({
        left: origX,
        top: origY,
        originX: 'left',
        originY: 'top',
        width: pointer.x - origX,
        height: pointer.y - origY,
        angle: 0,
        fill: 'rgba(255,0,0,0.5)',
        transparentCorners: false
    });
    canvas.add(rect);
});

canvas.on('mouse:move', function (o) {
    if (!isDown) return;
    var pointer = canvas.getPointer(o.e);

    if (origX > pointer.x) {
        rect.set({ left: Math.abs(pointer.x) });
    }
    if (origY > pointer.y) {
        rect.set({ top: Math.abs(pointer.y) });
    }

    rect.set({ width: Math.abs(origX - pointer.x) });
    rect.set({ height: Math.abs(origY - pointer.y) });


    canvas.renderAll();
});

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

Answer 1

您是說要啟用/禁用用戶輸入的復選框？ 請嘗試下面的代碼片段，以了解我的意思。

 var canvas = new fabric.Canvas('c', { selection: false }); var rect, isDown, origX, origY; canvas.on('mouse:down', function(o) { isDown = true; var pointer = canvas.getPointer(oe); origX = pointer.x; origY = pointer.y; var pointer = canvas.getPointer(oe); rect = new fabric.Rect({ left: origX, top: origY, originX: 'left', originY: 'top', width: pointer.x-origX, height: pointer.y-origY, angle: 0, fill: 'rgba(255,0,0,0.5)', transparentCorners: false }); canvas.add(rect); }); canvas.on('mouse:move', function(o){ if (!isDown) return; var pointer = canvas.getPointer(oe); if(origX>pointer.x){ rect.set({ left: Math.abs(pointer.x) }); } if(origY>pointer.y){ rect.set({ top: Math.abs(pointer.y) }); } rect.set({ width: Math.abs(origX - pointer.x) }); rect.set({ height: Math.abs(origY - pointer.y) }); canvas.renderAll(); }); canvas.on('mouse:up', function(o){ isDown = false; }); 

 .container { position: relative; pointer-events: auto; } #checkBox:checked ~ .container { pointer-events: none; } 

 <script src="https://rawgit.com/kangax/fabric.js/master/dist/fabric.js"></script> Disable: <input id="checkBox" type="checkbox"> <div class="container disabled"> <canvas id="c" width="500" height="500" style="border:1px solid #ccc"></canvas> </div> 

Answer 2

您可以使用canvas.on()和canvas.off()添加事件偵聽器。

這是更新的jsFiddle 。