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  1. Qt
  2. QTBUG-82701

Windows 7: Strange processing pause when QToolTip is first shown

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    • Icon: Bug Bug
    • Resolution: Done
    • Icon: P1: Critical P1: Critical
    • 5.15.0 Beta4
    • 5.14.1
    • Core: Event loop
    • None
    • Windows 7, MSVC 2017 and MinGw 7.3. Fast 8-core CPU (i7-7820X @3.6GHz), 64GB RAM, NVIDIA GTX970 GPU.
    • Windows
    • e0d80167c18b5a71acf4dac59f3e6f37292fa397 (qt/qtbase/5.14)

      At least some part of event processing seems to "pause" (or hang) when a tooltip is first shown.

      Please run attached example and hover over the first label. When the tooltip appears, the animation on the label below it should pause for a second or so.

      I used a QPropertyAnimation for the demo because that's when I first noticed the issue with my app. I first tried with a blinking cursor and then an animated GIF inside a QMovie (on a QLabel), but neither of those seem affected. So I'm not sure what exactly is affected by this issue (GUI events in general or something specific to animations).

      Qt 5.12.x doesn't do this (I haven't tried 5.13).

      Reproduced with MSVC 2017 and MinGW 7.3, in both Debug and Release modes.  

      No observed issues on Linux.

        1. qtbug82701.zip
          2 kB
        2. ttpause.cpp
          0.7 kB
        For Gerrit Dashboard: QTBUG-82701
        # Subject Branch Project Status CR V
        294403,5 QEventDispatcherWin32: fix posted events delivering 5.14 qt/qtbase Status: MERGED +2 0

            alex1973tr Alex Trotsenko
            mpaperno Maxim Paperno
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              Created:
              Updated:
              Resolved:

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