Ellipse radiuses, width, height problems

[Ifko]

If ellipse exists and rx or ry is set, the width and height is not set. On the opposite side, if width and height is set, the rx and ry stay on their same values. I think it is a bug. These properties should influence each other otherwise the object does not carry the proper information (either bounding box or radiuses are badly set) I fixed it in the class derived from ellipse, but I think I am not alone with this problem. This discussion addresse the problem as well: https://groups.google.com/forum/#!topic/fabricjs/lt6p-936Ko4

[asturur]

in the ellipse class we can add something like that:

    _set: function(key, value) {
      this.callSuper('_set', key, value);

      switch (key) {
        case 'rx':
          this.rx = value;
          this.width = value * 2;
          break;

        case 'ry':
          this.ry = value;
          this.height = value * 2;
          break;

        case 'width':
          this.rx = value / 2;
          this.width = value;
          break;
      }

      return this;
    },

Pluse the getRx and getRy methods to behave like circle more or less.

[asturur]

PR #1699 if we need this, circle has it, so it may have even ellipse.
I don't think it should be both way, rx should update width , but width should not update rx. at least in Circle they implemented in this way.
just my two cents.
If we do not need this let's close issue and PR.

[Ifko]

if think the problem is that rx should be only 'get' accessor. If there is width, why we need to set rx? Or width 'setter' should update rx and rx 'setter' should update width. The same for ry and height

[asturur]

@Ifko Sorry a typo in my first comment made my comment meaningless.
Before modify the ellipse tests, i wait to see if kangax agree with this functionality.

[asturur]

@kangax what do you think about this?
the PR #1699 ( to be completed with tests ) has been done copying from circle structure.
Do you think is good to implement like that?
Do you think it should work even set width -> update rx ?
To do so we should not call the set method but update the proerties directly otherways width will trigger rx that will trigger width and so on.