Bug 567386

Summary: Expanding/collapsing of tree nodes feels sluggish when using the mouse in some trees
Product: [Eclipse Project] Platform Reporter: Holger Voormann <eclipse>
Component: UIAssignee: Platform-UI-Inbox <Platform-UI-Inbox>
Status: NEW --- QA Contact:
Severity: normal    
Priority: P3    
Version: 4.17   
Target Milestone: ---   
Hardware: PC   
OS: Windows 10   
Whiteboard:

Description Holger Voormann CLA 2020-09-26 06:58:39 EDT 
See https://twitter.com/dashorst/status/1309075183098122240

In the Project Explorer and the Package Explorer when clicking on a tree handle (or double-click a tree item) to expand or to collapse it, further mouse clicks are ignored until expanding/collapsing is completed and that is what feels sluggish.

In contrast, when using the keyboard (right/left), the same tree node can be collapsed/expanded before the previous opposite expanding/collapsing procedure is completed and that feels super fast.

The same behavior (sluggish when using the mouse vs. not sluggish when using the keyboard) can be seen in the Search view for search results as a tree, but not in the Preferences dialog in the tree on the left for navigation (not sluggish even when using the mouse).