I believe https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1060580 is related to this bug, since that bug report describes lag during the panel fade event. I've noticed it in 13.10 and 14.04, that there's a skip in an icon's position during dragging while the Unity panel initiates its fade animation. I'm almost tempted to link these bugs as duplicates, as I believe they're very closely related. At the time an icon skips in its path, in the same moment a drop event would be lost.. actually I will link them, pretty confident and I think it'd be fairly trivial for one of the Compiz/Unity guys to fix, seeing as it happens at such a specific time, and is very easily reproduced.
Drew Snellgrove's video in comment #17 is an extremely good demonstration (thanks Drew!) -- You received this bug notification because you are a member of DX Packages, which is subscribed to unity in Ubuntu. Matching subscriptions: dx-packages https://bugs.launchpad.net/bugs/1018215 Title: Unity launcher appearing interrupts GTK drag and drop operation (that's nowhere near the launcher) Status in Unity: Triaged Status in “unity” package in Ubuntu: Confirmed Bug description: I am a developer for an app that uses Gtk's "drag-motion" and "drag- leave" signals. It is important that "drag-leave" not be fired until the mouse actually leaves the widget. However, when running unit, "drag-leave" will be fired ~1 second after a drag begins. Here is a test project (in Vala) that reproduces the issue. Select a file on your desktop, and drag it to the window that this test project creates. You must drag it to the window within ~1 second to reproduce the bug. You should see "in on_drag_leave" appear in stderr, despite the mouse remaining within the Window. void main(string[] args) { Gtk.init(ref args); new MainWindow(); Gtk.main(); } public class MainWindow : Gtk.Window { private const string URI_LIST_MIME_TYPE = "text/uri-list"; public MainWindow() { destroy.connect(Gtk.main_quit); set_size_request(450, 50); title = "Main Window"; Gtk.Widget destination = new Gtk.Label("Drag a file here"); const Gtk.TargetEntry[] target_entries = { { URI_LIST_MIME_TYPE, 0, 0 } }; Gtk.drag_dest_set(destination, Gtk.DestDefaults.MOTION | Gtk.DestDefaults.HIGHLIGHT, target_entries, Gdk.DragAction.COPY); destination.drag_data_received.connect(on_drag_data_received); destination.drag_drop.connect(on_drag_drop); destination.drag_leave.connect(on_drag_leave); add(destination); show_all(); } private void on_drag_data_received(Gtk.Widget sender, Gdk.DragContext context, int x, int y, Gtk.SelectionData selection_data, uint info, uint time_) { bool dnd_success = false; if (selection_data.get_length() >= 0) { string string_data = (string)selection_data.get_data(); stderr.printf("Received %s: '%s'\n", URI_LIST_MIME_TYPE, string_data); dnd_success = true; } Gtk.drag_finish(context, dnd_success, false, time_); } private bool on_drag_drop(Gtk.Widget sender, Gdk.DragContext context, int x, int y, uint time_) { if (context.list_targets() == null) return false; uint length = context.list_targets().length(); Gdk.Atom? target_type = null; for (uint i = 0; i < length; i++) { Gdk.Atom target = context.list_targets().nth_data(i); if (target.name() == URI_LIST_MIME_TYPE) target_type = target; } if (target_type == null) return false; Gtk.drag_get_data(sender, context, target_type, time_); return true; } private void on_drag_leave() { stderr.printf("in on_drag_leave\n"); } } ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: unity 5.12-0ubuntu1.1 ProcVersionSignature: Ubuntu 3.2.0-25.40-generic 3.2.18 Uname: Linux 3.2.0-25-generic x86_64 ApportVersion: 2.0.1-0ubuntu8 Architecture: amd64 CompizPlugins: [core,composite,opengl,compiztoolbox,decor,vpswitch,snap,mousepoll,resize,place,move,wall,grid,regex,imgpng,session,gnomecompat,animation,fade,unitymtgrabhandles,workarounds,scale,expo,ezoom,unityshell] Date: Tue Jun 26 18:06:07 2012 InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425) SourcePackage: unity UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/unity/+bug/1018215/+subscriptions -- Mailing list: https://launchpad.net/~dx-packages Post to : dx-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~dx-packages More help : https://help.launchpad.net/ListHelp