[squeak-dev] mouse enter/move/leave event confusion

karl ramberg karlramberg at gmail.com
Wed Dec 2 07:59:10 UTC 2015


Do you have the code available so I can look at it?

Best,
Karl

On Wed, Dec 2, 2015 at 3:30 AM, tim Rowledge <tim at rowledge.org> wrote:

> I’m trying to provide the appearance of a cursor that is gridded in a
> paint program; the idea is that the tool cursor should jump only to
> positions on the grid and when the bitmap is scaled to say 4X that would be
> every 4th pixel position on the screen.
>
> Since making the actual HandMorph & real cursor do gridding seemed a bit
> of a heavyweight thing to impose on everything else, I’m attempting to do
> it by handling mousemove events within my painting canvas morph. It
> *almost* works but there is something very odd going on at far too frequent
> occasions.
>
> So far as I can currently tell the event handling code up in Morph &
> HandMorph is sometimes deciding that the mouse has left my morph and thus
> sends me a mouseleave event instead of a a move. Then as soon as the cursor
> moves, I get a new mouseenter and more moves until whatever it is upsets
> things again. There’s some unpleasantly complex code up at
> MouseOverHandler>processMouseOver: for example that appears to be in the
> middle of my problem - best I can tell is that ‘leftMorphs’ is somehow
> including my morph when the mouse is still right there in the middle of it.
>
> My basic scheme is to create a suitable ImageMorph on the mouseEnter,
> change its position with each mouseMove and then delete it on mouseLeave.
> I have implemented handlesMouseMove: to always return true, so I seem to
> get all the move events.
>
> Any idea about why I get the dud mouseLeave events? Has anyone else done a
> scaled-up-grid-cursor thingy?
>
> tim
> --
> tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
> "How many Pak Protectors does it take to change a lightbulb?”
> "Only one, but the lightbulb has to smell right."
>
>
>
>
>
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