[squeak-dev] Drag and drop to reorder items in a single list

Marcel Taeumel marcel.taeumel at hpi.de
Tue Nov 26 16:33:05 UTC 2019

Hi Jakob,

I just merged your fix into Trunk. Thanks! :-)


(#handlesMouseOverDragging: could stay as is. Your example works fine.)


Am 25.11.2019 14:52:15 schrieb David T. Lewis <lewis at mail.msen.com>:
The changes work as advertised, and it seems like a good thing to
include in trunk. I cannot really say if there would be side effects,
but it is a small number of changed methods and I see nothing bad
happening so far. I'll keep it in my image.


On Sun, Nov 24, 2019 at 03:50:42PM +0100, Jakob Reschke wrote:
> Is anyone interested in reviewing this? I still have it in my image, making
> Morphic dirty, hampering Monticello backports in that package.
> The attachments are still here:
> http://forum.world.st/Drag-and-drop-to-reorder-items-in-a-single-list-td5082943.html
> On 2018-08-14T14:50+02:00 Jakob Reschke wrote:
> > Hello everyone,
> >
> > tl;dr: the current PluggableTextMorph/Plus does not support the
> > reordering of items in a single list via drag and drop. Attached you
> > find a change set that fixes this, but it might also break in other
> > places. Thus, I kindly ask for a review.
> >
> > Today I found myself implementing a ToolBuilder-built list in which
> > the items should be reorderable via drag and drop. Unfortunately, the
> > current implementation of PluggableTextMorph/Plus does not allow this:
> > you first have to drag the item out of the list before you can drop it
> > in again.
> >
> > Seems like the list morph needs the mouse focus to be able to accept
> > the drop. However, the current implementation explicitly releases the
> > focus from the list upon grabbing the item.
> >
> > Then I changed the PluggableTextMorphPlus to not drop the focus, but
> > keep it, when starting to drag an item. Now the focus would not even
> > be released anymore when the item was indeed dragged out of a list if
> > that list itself does not accept any drops (such as the method list in
> > the system browser: it does not accept drops, but the methods can be
> > dragged from it to the message categories list). So I have changed
> > further methods to make the list morphs always handle dragging events,
> > even if they are not interested in drops.
> >
> > But I do not know what else that might have broken. So, please have a
> > look at the attached change sets. The one without "all" in the file
> > name contains only the actual changes. The one with "all" also
> > contains other relevant (unchanged) methods that I touched during my
> > investigation. Eventually, I would like to put this or a revised
> > edition of it in the inbox because list reordering via drag and drop
> > should not be impossible.
> >
> > The third file contains a simple Model subclass with a list whose
> > items should be reorderable via drag and drop, so you do not have to
> > write it yourself. Grab a sample instance and open it with the
> > ToolBuilder:
> >
> > ToolBuilder open: DragDropInSingleList new.
> >
> > In case I simply got it wrong and there is no need to change Morphic
> > lists to achieve what I want, please tell me how to do it right. ;-)
> >
> > Best regards,
> > Jakob
> >


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.squeakfoundation.org/pipermail/squeak-dev/attachments/20191126/48631c12/attachment.html>

More information about the Squeak-dev mailing list