fix(): stop transforming on discardActiveObject

[ShaMan123]

Motivation
closes #7953

[github-actions]

Code Coverage Summary

> fabric@5.1.0 coverage:report
> nyc report --reporter=lcov --reporter=text

-----------|---------|----------|---------|---------|-----------------------------------------------
File       | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s                             
-----------|---------|----------|---------|---------|-----------------------------------------------
All files  |   83.03 |    75.94 |   85.69 |   82.75 |                                               
 fabric.js |   83.03 |    75.94 |   85.69 |   82.75 | ...,30854,30928,30939-31004,31127,31226,31462 
-----------|---------|----------|---------|---------|-----------------------------------------------

[github-actions]

Code Coverage Summary

> fabric@5.1.0 coverage:report
> nyc report --reporter=lcov --reporter=text

-----------|---------|----------|---------|---------|-----------------------------------------------
File       | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s                             
-----------|---------|----------|---------|---------|-----------------------------------------------
All files  |   83.02 |    75.91 |   85.69 |   82.74 |                                               
 fabric.js |   83.02 |    75.91 |   85.69 |   82.74 | ...,30855,30929,30940-31005,31128,31227,31463 
-----------|---------|----------|---------|---------|-----------------------------------------------

[github-actions]

Code Coverage Summary

> fabric@5.1.0 coverage:report
> nyc report --reporter=lcov --reporter=text

-----------|---------|----------|---------|---------|-----------------------------------------------
File       | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s                             
-----------|---------|----------|---------|---------|-----------------------------------------------
All files  |   83.03 |    75.94 |   85.69 |   82.75 |                                               
 fabric.js |   83.03 |    75.94 |   85.69 |   82.75 | ...,30855,30929,30940-31005,31128,31227,31463 
-----------|---------|----------|---------|---------|-----------------------------------------------

[github-actions]

Code Coverage Summary

> fabric@5.1.0 coverage:report
> nyc report --reporter=lcov --reporter=text

-----------|---------|----------|---------|---------|-----------------------------------------------
File       | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s                             
-----------|---------|----------|---------|---------|-----------------------------------------------
All files  |   83.03 |    75.94 |   85.69 |   82.75 |                                               
 fabric.js |   83.03 |    75.94 |   85.69 |   82.75 | ...,30855,30929,30940-31005,31128,31227,31463 
-----------|---------|----------|---------|---------|-----------------------------------------------

[ShaMan123]

should we call this._resetTransformEventData();?

[ShaMan123]

@asturur this is not outdated
Thoughts?

[ShaMan123]

It's actually Canvas._target , I think it should be reset but I'm not sure

[ShaMan123]

I have encountered the case that demands to nullify _target
When an object is being moved by the user and discarded meanwhile.
Currently the object will continue moving and will be inactive only on mouseup.

[ShaMan123]

Note for future self

setting canvas._target on mousedown:before hijacks the event and fires it on the hijacker

[ShaMan123]

#8335

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[asturur]

I m ok with this PR but i would like there was a canvas method that says (cancel/stop/end)CurrentTransform and does what it needs to do to to cancel the current transform, and we use it on discardActiveObject

[github-actions]

Code Coverage Summary

> fabric@5.1.0 coverage:report
> nyc report --reporter=lcov --reporter=text

-----------|---------|----------|---------|---------|-----------------------------------------------
File       | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s                             
-----------|---------|----------|---------|---------|-----------------------------------------------
All files  |   83.18 |    76.14 |   85.86 |   82.91 |                                               
 fabric.js |   83.18 |    76.14 |   85.86 |   82.91 | ...,30869,30943,30954-31019,31142,31241,31477 
-----------|---------|----------|---------|---------|-----------------------------------------------

[asturur]

i grouped the 2 calls in a method. i m ok merginging this.
The only doubt i have left and we can solve whenever is if that the discard of active objects belong to _discardActiveObject or discardActiveObject.

for example on object removed calls _discardActiveObject, and it could call _discardActiveObject and endCurrentTransform, instead of relying on the inner part, focused on discardind, now also fires an object modified event ( eventually ).

Is not a big deal, can probably be changed later.
Too much automatic behaviours usually brought to issues in the past

[ShaMan123]

for example on object removed calls _discardActiveObject, and it could call _discardActiveObject and endCurrentTransform, instead of relying on the inner part, focused on discardind, now also fires an object modified event ( eventually ).

Sounds a good point to me.

I am not sure but I think I walked into a bug with this PR somewhere...
Well, I'll try reproduce and PR a fix is so.

[asturur]

is ok to merge this part as it is, is reasonably correct and help us moving forward

[asturur]

is small, is focused, has a test, has docs, can be merged imho.