diff options
| author | Romain Pokrzywka <romain.pokrzywka@bluescape.com> | 2018-08-22 22:43:29 -0500 |
|---|---|---|
| committer | Romain Pokrzywka <romain.pokrzywka@gmail.com> | 2018-09-14 15:41:28 +0000 |
| commit | 5728a9d8a7f8b64099cf369d9d307a00b5fce29c (patch) | |
| tree | a7d1580ae766d438846dd262a753e0b65e4263e5 /src/corelib | |
| parent | a62bab95d3adfcd6aab1f32d41750f0c1a5adfe3 (diff) | |
Windows QPA: Dispatch skipped touch/pen events if compression is off
If the hardware produces events faster than the app can consume between
two updates, Windows automatically coalesces them into a single message
with the latest touch/pen pointer state and coordinates, effectively
compressing those events. But the pointer API also supports querying
and retrieving the skipped individual touch and pen frames.
There are cases where keeping all the events generated by the hardware
is desired, especially for pen events where having the most sampled
points available is critical to precisely rendering curves.
Qt already defines application attributes to control event compression
for general high frequency events and for tablet events in particular.
Use them on Windows also to control whether to retrieve skipped frames.
[ChangeLog][Windows] The application attributes AA_CompressTabletEvents
and AA_CompressHighFrequencyEvents are now supported on Windows 8 and
above for touch/pen input, with the same defaults as on X11 (compress
touch events, don't compress tablet events)
Task-number: QTBUG-44964
Task-number: QTBUG-60437
Change-Id: I1b11a043e2d71ee502895971fafb3a46306a89d8
Reviewed-by: Andre de la Rocha <andre.rocha@qt.io>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Diffstat (limited to 'src/corelib')
| -rw-r--r-- | src/corelib/global/qnamespace.qdoc | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/src/corelib/global/qnamespace.qdoc b/src/corelib/global/qnamespace.qdoc index 37144dcf17..42009e0b5e 100644 --- a/src/corelib/global/qnamespace.qdoc +++ b/src/corelib/global/qnamespace.qdoc @@ -245,7 +245,10 @@ QEvent::MouseMove, QEvent::TouchUpdate, and changes in window size and position will be combined whenever they occur more frequently than the application handles them, so that they don't accumulate and overwhelm the - application later. On other platforms, the default is false. + application later. + On Windows 8 and above the default value is also true, but it only applies + to touch events. Mouse and window events remain unaffected by this flag. + On other platforms, the default is false. (In the future, the compression feature may be implemented across platforms.) You can test the attribute to see whether compression is enabled. If your application needs to handle all events with no compression, @@ -256,8 +259,9 @@ \value AA_CompressTabletEvents Enables compression of input events from tablet devices. Notice that AA_CompressHighFrequencyEvents must be true for events compression - to be enabled, and that this flag extends the former to tablet events. Its default - value is false. + to be enabled, and that this flag extends the former to tablet events. + Currently supported on the X11 windowing system, Windows 8 and above. + The default value is false. This value was added in Qt 5.10. \value AA_DontCheckOpenGLContextThreadAffinity When making a context |