Hi Marcel, all,

Regarding the behavior of Browsers (etc.) becoming active when other tool-type windows are dragged over them and Fast Window Dragging is turned off:  why does this happen even when "drop in" (this used to be called "accept drops"*) is disabled?  

I recall the argument being made that the window can't know if any of its submorphs want the drop.  But doesn't the parent morph's "accept drops" setting take precedence over child morphs?  Or am I mistakenly applying non-Morphic logic to Morphic?  Not super clear from reading http://wiki.squeak.org/squeak/6194 .  (The practical implications of this are interesting to think about... and probably have been for years.  :) )



There was a message posted to another thread on this list around the time I brought this up in which I detected (perhaps incorrectly) a sort-of "eye-rolling" tone (e.g. "ha ha, who would want to drop Workspaces into Browsers, amiright? ha ha [they don't know what they're missing!]").  This suggests to me that there must be other projects in Squeak which find it useful to have this behavior in the default configuration of the shipping image.  But what are those use cases?  Certainly it's not about "teleportation"-style morphs or any other custom windows which could have "accept drops" turned on and are not Browsers or Workspaces.  There must be some reason it's useful to have this behavior in the default shipping image even though (1) it slows down performance/introduces visible lag, (2) it seems (to me) to be a minority use case that e.g. a Workspace would be dropped onto a Browser, and (3) the morphs in question are not accepting drops...?

Thanks,
Tim J

* I don't want to get into the semantics wars, but in US English, "drop in" typically is used to describe an office or medical facility that does not require reservations, e.g. a "drop-in clinic."  I guess someone made the decision that "accept drops" was no longer acceptable...?  It is still referred to as such in various documentation:   http://wiki.squeak.org/squeak/6511 https://wiki.squeak.org/squeak/6194 

'Accept' is such common terminology w/r/t Morphs, it is a verb in the 'accept' / 'repel' protocol... 
https://github.com/hpi-swa-lab/SqueakByExample-english/blob/8287133e110d49c218e0a2ad6d6dc913adfe9b43/Morphic/Morphic.tex



> On Apr 4, 2022, at 12:18 AM, Marcel Taeumel <marcel.taeumel at hpi.de> wrote:
> 
> Hi Tim --
> 
> Yes, thanks for the pointer. The question is whether we can know that not a single element in a window would like to accept the drop. I don't think we can. Windows can host all kinds of stuff, even other worlds (or instances of PasteUpMorph). Hmm... 
> 
> Best,
> Marcel
>> Am 02.04.2022 19:32:41 schrieb tim Rowledge <tim at rowledge.org>:
>> 
>> It's a very long time since I played in this part of the sandpit but this seems like it might be amenable to the Morph>>#wantsDroppedMorph:event:/wantsToBeDroppedInto: protocol. And maybe the Morph>>#repelsMorph:event:/#rejectDropEvent: stuff too?
>> 
>> Surely the logic ought the include testing to see if the SystemWindow would ever be interested in accepting the drop?
>> 
>> > On 2022-04-02, at 10:11 AM, Tim Johnson wrote:
>> > 
>> > Hi,
>> > 
>> > I've been surprised about how SystemWindows become active when dragging other SystemWindows, Inspectors, PluggableXYZ windows (or morphs in general?) on top of (or over) them. It produces a noticable lag in the UI. This is only evident when the preference 'Fast window drag for Morphic' is turned OFF and whole windows are being dragged. (Having Soft shadows enabled slows it down further, I think.)
>> > 
>> > IMHO these windows would not accept the drop, so they should not become active.
>> > 
>> > I did some spying on the UI process and found that all code panes are being redrawn (?) when dragging morphs over SystemWindows. This is easily and quickly defeated/remedied by commenting out 'self activate' in the following method, as follows:
>> > 
>> > SystemWindow>>#mouseEnterDragging: evt
>> > "unlock children for drop operations"
>> > 
>> > self flag: #performance. "mt: There may be no need to change appearance if no widget wants the drop."
>> > self isActive ifTrue: [self lookFocused].
>> > 
>> > (self isActive not and: [evt hand hasSubmorphs]) ifTrue: [
>> > "self activate." "unlock contents for drop"
>> > evt hand addMouseListener: self. "for drop completion on submorph"
>> > ].
>> > 
>> > 
>> > My question: could the drag-and-drop "#wantsXYZ" protocol be followed here to optimize this? Or perhaps there is some other way to /not/ make the window active (and thus redraw all its panes, I think?) when a morph /it does not want/ is dragged over it?
>> > 
>> > Thanks
>> > Tim
>> > 
>> > 
>> > 
>> 
>> 
>> tim
>> --
>> tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
>> Strange OpCodes: DCVP: Destroy another Computer Via Phone-link
>> 
>> 
>> 
> 

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