<Swing Dev> Fw: review request for 6899434: Add affine transformsupport to JLayer

[Alexander Potochkin]

Hello Artem

> I haven't mentioned JLayer at all. When we make some of our API
> public/protected, developers will be able to implement their own
> components with transformations of any kind - this is what I wrote about.

Aga, okay

It would be quite difficult to support any other transforms
then AffineTransform without having them implemented by 2D team

Anyway, I just can't wait to have this fix in JDK
:-)

Thank you guys for your time!
alexp

>
> Thanks,
>
> Artem
>
>> Thanks
>> alexp
>>
>>>
>>> Thanks,
>>>
>>> Artem
>>>
>>> On 2/8/2010 2:27 PM, Piet Blok wrote:
>>>> Hi Artem,
>>>>
>>>> To demonstrate the implemention via the AWTAccessor pattern, I
>>>> created a
>>>> version 2 implementation:
>>>>
>>>> http://www.pbjar.org/OpenJDK/6899434/version-2/webrev/
>>>>
>>>> This implementation is much cleaner than the original one.
>>>>
>>>> Looking forward for yout comments,
>>>> Piet
>>>>
>>>>
>>>>
>>>>> Hi Artem,
>>>>>
>>>>> The problem with making existing methods public is that it solves only
>>>>> half of the problem at hand:
>>>>>
>>>>> 1) Locate the correct component (can be solved)
>>>>>
>>>>> 2) Recalculating the mouse point from rendered space to layout space
>>>>> is not solved because the locating methods only return a component.
>>>>> Recalculation is needed to correctly set a mouse point in the new
>>>>> events, relative to the target component.
>>>>>
>>>>> In my proposed implementation the shift caused by transformations is
>>>>> stored when looking up the target (for future use: creating new events
>>>>> from the original event). This future is quite an immediate future
>>>>> because creating a new event from an existing event will always be
>>>>> directly preceded by looking up that target event.
>>>>>
>>>>> An alternative would be to again iterate through the hierarchy and do
>>>>> the transformations. This must be done in LightweightDispatcher in the
>>>>> methods:
>>>>>
>>>>> 1) retargetMouseEvent (an inverse transform is needed, so the new
>>>>> Container method getConvertedPoint can be used)
>>>>>
>>>>> 2) eventDispatched. Unfortunately here an ordinary transform is
>>>>> needed, so a second new Container method must be defined that does an
>>>>> ordinary transform.
>>>>>
>>>>> But.... a completely different approach is also possible. I did this
>>>>> in an earlier version, so I know that it works. With this approach no
>>>>> new public or protected methods need to be introduced and no existing
>>>>> methods need to go public or protected. All remains private or package
>>>>> private.
>>>>>
>>>>> That approach is as follows:
>>>>>
>>>>> 1) Define the AffineTransform as a private field in Component.
>>>>>
>>>>> 2) Use the AWTAccessor pattern to make the transform available in
>>>>> Container and LightweightDispatcher and in swing classes.
>>>>>
>>>>> 3) In Container and LightweightDispatcher, get the transform and do
>>>>> transformations when needed.
>>>>>
>>>>> In my opinion, the solution with the AWTAccessor pattern is the
>>>>> cleanest. However, it requires Component and AWTAccessor to be
>>>>> touched.
>>>>>
>>>>> Please let me know what you think.
>>>>>
>>>>> Piet
>>>>>
>>>>>
>>>>>
>>>>>> Hi, Piet,
>>>>>>
>>>>>> I haven't looked through the entire webrev and inspected mostly an
>>>>>> AWT part of the fix. A question is whether it's possible to get rid
>>>>>> of the new "conversionShift" field in Container, to make
>>>>>> transformations support really stateless?
>>>>>>
>>>>>> Another option to consider is to make some of the existing methods
>>>>>> (e.g. getMouseEventTargetImpl()) public instead of introducing new
>>>>>> ones.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Artem
>>>>>>
>>>>>> On 1/28/2010 8:21 PM, Piet Blok wrote:
>>>>>>> Hello all,
>>>>>>>
>>>>>>> review request for 6899434: Add affine transform support to JLayer
>>>>>>>
>>>>>>> The webrev: http://www.pbjar.org/OpenJDK/6899434/webrev/
>>>>>>>
>>>>>>> The patch covers all the requested functionality. It is
>>>>>>> concentrated in
>>>>>>> JLayer class, keeping in mind to affect the library as little as
>>>>>>> possible.
>>>>>>>
>>>>>>> 1) A setter and getter for the transform in JLayer
>>>>>>>
>>>>>>> 2) The paint method in JLayer has been adapted to use the transform
>>>>>>>
>>>>>>> 3) RepaintManager has been adapted to propagate repaint requests
>>>>>>> from
>>>>>>> the view or any of its children to the top level JLayer and have the
>>>>>>> dirty region transformed.
>>>>>>>
>>>>>>> 4) java.awt.Container and java.awt.LightweightDispatcher (both in
>>>>>>> the
>>>>>>> same source) have been adapted to redispatch MouseEvents to the
>>>>>>> intended
>>>>>>> target component. The lookup for the component that provides a
>>>>>>> custon
>>>>>>> cursor has also been adapted.
>>>>>>>
>>>>>>> 5) To enable Container to do necessary reculculations, a protected
>>>>>>> method has been introduced that will be overridden by JLayer:
>>>>>>> protected Point getConvertedPoint(Point point).
>>>>>>> (If someone can suggest a better name for this method I'm glad to
>>>>>>> hear)
>>>>>>>
>>>>>>> 6) A package private method in SwingUtilities has been added that
>>>>>>> helps
>>>>>>> JPopupMenu and ToolTipManager to find the correct popup location.
>>>>>>> JPopupMenu and ToolTipManager have been changed to use this new
>>>>>>> method
>>>>>>> in their calculations.
>>>>>>>
>>>>>>> 7) Two jtreg tests have been added.
>>>>>>>
>>>>>>> Looking forward for comments.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Piet
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>