[squeak-dev] Help with UiPushButton>>#on:send:to: in Morphic Designer

David O'Toole deeteeoh1138 at gmail.com
Tue Jan 11 13:56:30 UTC 2022

Thank you Tom and Marcel for your assistance :) I had seen something
involving signals in the Explorer, but didn't realize it wasn't part of
stock Morphic.

On Tue, Jan 11, 2022 at 4:12 AM Marcel Taeumel <marcel.taeumel at hpi.de>

> Hi David --
> Yes, as Tom explained, UiPushButton is part of the Widgets project [1],
> which builds upon the Signals project [2].
> Use #connect:signal:toSelector: insteand of #on:send:to: See [2] for more
> information.
> Best,
> Marcel
> [1] https://github.com/hpi-swa/widgets
> [2] https://github.com/hpi-swa/signals
> Am 11.01.2022 08:12:50 schrieb Tom Beckmann <tomjonabc at gmail.com>:
> The widgets toolkit to which UiPushButton belongs uses a custom event
> mechanism called signals. You can find the place where #on:send:to is
> "disabled" here:
> https://github.com/hpi-swa/widgets/blob/master/repository/Widgets.package/UiButton.class/instance/initializeEventHandler.st
> This is the package that UiPushButton uses to dispatch messages instead:
> https://github.com/hpi-swa/signals I believe the signal you're looking
> for should be called #pressed then:
> https://github.com/hpi-swa/widgets/blob/master/repository/Widgets.package/UiButton.class/instance/pressed.st
> ---
> Maybe as a debugging strategy (that I haven't tried myself with this
> instance because I already the above suspicion), one way you *probably*
> could have found this out yourself would have been by overriding the
> mouseDown: method in UiPushButton, put a `self halt` at the top and have it
> call `super mouseDown:`. Admittedly, you would likely have wound up with
> quite a number of indirections (which may not be entirely clear unless
> you're deep in Morphic event lingo) until you would have eventually found
> that the events are being delegated to this Event Handler object that calls
> methods from the "signals" package.
> How would you have known to override mouseDown:? Since UiPushButton is a
> Morph, it must still follow the Morphic event dispatching rules. Searching
> for "mouse" in the Morph methods should give you a couple that seem
> promising, and eventually you'd probably have hit the one that triggers a
> halt at the right moment :)
> Not sure if this was actually helpful but I often find it quite
> interesting what sort of strategies people follow when debugging things, so
> I thought I'd give it a try :D
> On Tue, Jan 11, 2022 at 4:52 AM David O'Toole <deeteeoh1138 at gmail.com>
> wrote:
>> I cannot get UiPushButton>>#on:send:to: working; using on: #click it
>> gives no error, but events are never sent. When I substitute an SBButton
>> from Sandblocks, it works. Am I using the wrong selector with UiPushButton?
>> Or perhaps I am missing something else? I would greatly appreciate any help
>> you could offer in troubleshooting.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.squeakfoundation.org/pipermail/squeak-dev/attachments/20220111/4985d565/attachment.html>

More information about the Squeak-dev mailing list