On Sun, 2 Jun 2019 at 00:18, Markus Stumptner <m...@cs.unisa.edu.au> wrote: > > I have been trying to replicate the behaviour of an existing (non-Pharo, > non-Smalltalk) application with Morphic. This provides grouping images > in a workspace, and then switching between laying them out separately or > "stacked" by double clicking on the group (or an image in it). When the > group is stacked, it can be moved around as a single drag and drop > operation. When the group is separated, dragging an image out of it > removes it from the group. > > On the surface this looked like a perfect fit to the submorph tree. > Unfortunately, as both the Morphic chapter in Pharo by Example and the > intro document by Maloney make clear, if you enable double clicking (by > answering true to #handlesMouseDown:), you are interfering with what > Maloney calls the "default behaviour" of being able to drag a Morph around. > > How do I reinstate that behaviour if a group is clicked on and the > double click does not happen? Neither document helps in explaining where > that "default" can be found in the code.
Have you put a `self haltOnce` in #handlesMouseDown: ? I am far from an expert here, but the following may help: Three alternate ways of handling mouse events https://wiki.squeak.org/squeak/2477 http://squeak.preeminent.org/tut2007/html/078.html Check the Dragging section here... https://wiki.squeak.org/squeak/6194 Search for doubleclick here... https://course.ccs.neu.edu/com3230/squeak/SqueakMorphClassGuide.pdf a few more #handlesXXX methods... https://course.ccs.neu.edu/com3230/squeak/SqueakMouseControls.html cheers -ben
