Version 4 breaking changes

Canvas.uniScaleTransform has been removed, Canvas.uniformScaling has been added. The property was poorly named, and its purpose was unclear. If uniformScaling is true, objects get scaled proportionally, if uniscaleKey is pressed, the behaviour get swapped. From true to false or from false to true. Canvas.uniscaleKey is the key that swaps the value of Canvas.uniformScaling.

Object.lockUniScaling has been removed. It was unclear how it should have interacted with the old Canvas.uniformScaling and the uniscaleKey.

Object.hasRotatingPoint has been removed. If you do not want an object to have the rotating control, set it to invisible or make a control set that does not have the control at all.

Object.rotatingPointOffset has been removed. You can now tweak the offsetY property of the mtr control of the standard control set, or of any other control.

The function Canvas.onBeforeScaleRotate has been removed. Please subscribe to Canvas.on('before:transform') and move your code to the callback.

Object.setShadow and BaseBrush.setShadow have been removed. Please use:

// before
Object.setShadow(options);

// after
Object.set('shadow', new fabric.Shadow(options));
// or
Object.shadow = new fabric.Shadow(options);

Similarly Object.setGradient has been removed. Please use:

// before
Object.setGradient(options);

// after
Object.set('fill', new fabric.Gradient(otherOptions));
Object.set('stroke', new fabric.Gradient(otherOptions));

// or
Object.fill = new fabric.Gradient(otherOptions));
Object.stroke = new fabric.Gradient(otherOptions));

// the old setGradient function had a different option format.
// as a recap, let's show the correct gradient options here:
{
  type: 'linear',
  gradientUnits: 'pixels', // or 'percentage'
  coords: { x1: 0, y1: 0, x2: 50, y2: 0 },
  colorStops:[
    { offset: 0, color: 'red' },
    { offset: 1, color: 'green'}
  ]
}

The options format is slightly different, but since the introduction of percentage values for gradients, writing a gradient for an object is easier and it does not make sense to maintain examples and code for 2 different way of doing the exact same thing.

For the same reason, the following methods have also been removed: Object.setPatternFill changes to Object.set('fill', new fabric.Pattern(options)); Object.setColor changes to Object.set('fill', color);

Although Object.transformMatrix was deprecated in version 2, the rendering of it was kept until now. It is now completely ignored.

Removed the object:selected event. Use selection:created. In the callback you will still find target in the options, but you will also find selected which contains all of the objects selected during that single event.

Gradient.forObject has been removed. The new Gradient with relative coordinates introduced in version 3 makes this method no longer useful.

Object.clipTo and Canvas.clipTo have been removed. While clipTo was a notch faster and sharper than clipPath, it was difficult to serialize and also nested clipTo were not possible at all. In future, clipPath will be improved to make it sharper.

Canvas.loadFromDatalessJSON has been removed. It was just an alias for loadFromJSON.

In the observable mixin, observe, stopObserving, trigger have been removed. You can keep using on, off, and fire since they are shorter and often referred to in our documentation.

Removed the ability for Object.set to take a function as a value. It was a rather unusual and non-standard use case.

Removed fabric.util.customTransformMatrix Use the replacement fabric.util.composeMatrix

Removed 2 utils members that were not used anywhere: fabric.util.getScript and fabric.util.getElementStyle

Removed private member Canvas._setImageSmoothing. Added fabric.util.setImageSmoothing(ctx, value) to replace it. Now it is used by fabric.Canvas and fabric.Image, but still considered private, so not useful for the developer.

Removed Image.setCrossOrigin. Having the property crossOrigin on the fabric.Image class was misleading and prone to errors. crossOrigin is for loading/reloading of image resources, and must be specified at each load.