e3cf47d7d7
The setter is complicated, because it reads the values of four
properties (loopCount, totalCurrentTime, currentLoop, and direction)
and modifies the values of two properties (totalCurrentTime and
currentLoop).
For the read-only properties, inroduce local variables, so that the
binding evaluation is done only once, and re-use the local variables
afterwards.
For the read-write properties, use {set}ValueBypassingBindings()
methods, because we are anyway explicitly calling notify() afterwards.
Intorduce a newCurrentLoop local variable to calculate the new value
of currentLoop, and update the actual property only once.
Use the newCurrentLoop and msecs variables instead of accessing the
actual properties when determining if we need to notify about
property changes.
The other complexity is that the setter calls a virtual
updateCurrentTime() method in the middle of the calculation.
Subclasses can override the default implementation and modify the
properties there (at least QSequentialAnimationGroup updates
totalCurrentTime property under certain conditions). Keep it in
mind and re-read the property values after the call to the virtual
method.
As a drive-by, make some pre-existing variables const.
Task-number: QTBUG-116346
Change-Id: I0a48bcabde15333e80ea2d54e308cb9438b310e7
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
(cherry picked from commit bfc2d69c613d9431f00ac303aed3076e0d1d4dae)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>