private void UpdateCommonStatesWithoutNeedsLayout(ManipulationUpdateKind manipulationUpdate = ManipulationUpdateKind.None)
{
using (InterceptSetNeedsLayout())
{
UpdateCommonStates(manipulationUpdate);
}
}
private void UpdateCommonStates(ManipulationUpdateKind manipulationUpdate = ManipulationUpdateKind.None)
{
var state = GetState(IsSelected, IsPointerOver, HasPointerCapture);
// On Windows, the pressed state appears only after a few, and won't appear at all if you quickly start to scroll with the finger.
// So here we make sure to delay the beginning of a manipulation to match this behavior (and avoid flickering when scrolling)
// We also make sure that when user taps (Enter->Pressed->Move*->Release->Exit) on the item, he is able to see the pressed (selected) state.
var request = ++_goToStateRequest;
TimeSpan delay; // delay to apply the 'state'
bool pause; // should we force a pause after applying the 'state'
if (manipulationUpdate == ManipulationUpdateKind.Clicked &&
_currentState != CommonStates.PressedSelected &&
_currentState != CommonStates.Pressed)
{
// When clicked (i.e. pointer released), but not yet in pressed state, we force to go immediately in pressed state
// Then we let the standard go to state process (i.e. with delay handling) reach the final expected state.
var pressedState = GetState(IsSelected, IsPointerOver, isPressed: true);
_currentState = pressedState;
VisualStateManager.GoToState(this, pressedState, true);
_pauseStateUpdateUntil = DateTime.Now + MinTimeBetweenPressStates;
delay = MinTimeBetweenPressStates;
pause = false;
}
else if (manipulationUpdate == ManipulationUpdateKind.Begin)
{
// We delay the beginning of a manipulation to avoid flickers, but not for "exact" devices which has hover states
// (i.e. mouse and pen when not on iOS)
delay = MinTimeBetweenPressStates;
pause = true;
}
else
{
delay = _pauseStateUpdateUntil - DateTime.Now;
pause = false;
}
if (delay < TimeSpan.Zero)
{
_currentState = state;
VisualStateManager.GoToState(this, state, true);
}
else
{
CoreDispatcher.Main.RunAsync(CoreDispatcherPriority.Normal, async() =>
{
await Task.Delay(delay);
if (_goToStateRequest != request)
{
return;
}
_currentState = state;
VisualStateManager.GoToState(this, state, true);
if (pause)
{
_pauseStateUpdateUntil = DateTime.Now + MinTimeBetweenPressStates;
}
});
}
}
private void UpdateCommonStates(ManipulationUpdateKind manipulationUpdate = ManipulationUpdateKind.None)
{
// On Windows, the pressed state appears only after a few, and won't appear at all if you quickly start to scroll with the finger.
// So here we make sure to delay the beginning of a manipulation to match this behavior (and avoid flickering when scrolling)
// We also make sure that when user taps (Enter->Pressed->Move*->Release->Exit) on the item, he is able to see the pressed (selected) state.
var state = GetState(IsEnabled, IsSelected, IsPointerOver, _canRaiseClickOnPointerRelease);
var requestId = ++_goToStateRequest; // Request ID is use to ensure to apply only the last requested state.
TimeSpan delay; // delay to apply the 'state'
bool pause; // should we force a pause after applying the 'state'
if (manipulationUpdate == ManipulationUpdateKind.Clicked &&
_currentState != CommonStates.PressedSelected &&
_currentState != CommonStates.Pressed)
{
// When clicked (i.e. pointer released), but not yet in pressed state, we force to go immediately in pressed state
// Then we let the standard go to state process (i.e. with delay handling) reach the final expected state.
var pressedState = GetState(IsEnabled, IsSelected, IsPointerOver, isPressed: true);
_currentState = pressedState;
VisualStateManager.GoToState(this, pressedState, true);
_pauseStateUpdateUntil = _chronometer.Elapsed + MinTimeBetweenPressStates;
delay = MinTimeBetweenPressStates;
pause = false;
}
else if (manipulationUpdate == ManipulationUpdateKind.Begin)
{
// We delay the beginning of a manipulation to avoid flickers, but not for "exact" devices which has hover states
// (i.e. mouse and pen when not on iOS)
delay = MinTimeBetweenPressStates;
pause = true;
}
else
{
delay = _pauseStateUpdateUntil - _chronometer.Elapsed;
pause = false;
}
if (delay < TimeSpan.Zero)
{
_currentState = state;
VisualStateManager.GoToState(this, state, true);
}
else
{
CoreDispatcher.Main.RunAsync(CoreDispatcherPriority.Normal, async() =>
{
await Task.Delay(delay);
if (_goToStateRequest != requestId
// If element has been unloaded (e.g. click on a ComboBoxItem) native animations of the target state won't run.
// Then even if on next load we request UpdateCommonStates,
// the VSM will determine that state didn't changed and will just ignore the request.
// Note: The issue is probably in the VSM to allow a GoToState while not in visual tree,
// but this is the most common case and teh safest place to patch.
|| !IsLoaded)
{
return;
}
_currentState = state;
VisualStateManager.GoToState(this, state, true);
if (pause)
{
_pauseStateUpdateUntil = _chronometer.Elapsed + MinTimeBetweenPressStates;
}
});
}
}
