public void _pushPolicyData(TraversalDirection direction, FocusScopeNode nearestScope, FocusNode focusedChild)
{
_DirectionalPolicyData policyData = _policyData[nearestScope];
if (policyData != null && !(policyData is _DirectionalPolicyData))
{
return;
}
_DirectionalPolicyDataEntry newEntry = new _DirectionalPolicyDataEntry(node: focusedChild, direction: direction);
if (policyData != null)
{
policyData.history.Add(newEntry);
}
else
{
_policyData[nearestScope] = new _DirectionalPolicyData(history: new List <_DirectionalPolicyDataEntry>()
{
newEntry
});
}
}
public bool _popPolicyDataIfNeeded(TraversalDirection direction, FocusScopeNode nearestScope, FocusNode focusedChild)
{
_DirectionalPolicyData policyData = _policyData[nearestScope];
if (policyData != null && policyData.history.isNotEmpty() && policyData.history.First().direction != direction)
{
if (policyData.history.Last().node.parent == null)
{
invalidateScopeData(nearestScope);
return(false);
}
bool popOrInvalidate(TraversalDirection _direction)
{
FocusNode lastNode = policyData.history.removeLast().node;
if (Scrollable.of(lastNode.context) != Scrollable.of(FocusManagerUtils.primaryFocus.context))
{
invalidateScopeData(nearestScope);
return(false);
}
ScrollPositionAlignmentPolicy alignmentPolicy = ScrollPositionAlignmentPolicy.explicitPolicy;
switch (_direction)
{
case TraversalDirection.up:
case TraversalDirection.left:
alignmentPolicy = ScrollPositionAlignmentPolicy.keepVisibleAtStart;
break;
case TraversalDirection.right:
case TraversalDirection.down:
alignmentPolicy = ScrollPositionAlignmentPolicy.keepVisibleAtEnd;
break;
}
FocusTravesalUtils._focusAndEnsureVisible(
lastNode,
alignmentPolicy: alignmentPolicy
);
return(true);
}
switch (direction)
{
case TraversalDirection.down:
case TraversalDirection.up:
switch (policyData.history.First().direction)
{
case TraversalDirection.left:
case TraversalDirection.right:
invalidateScopeData(nearestScope);
break;
case TraversalDirection.up:
case TraversalDirection.down:
if (popOrInvalidate(direction))
{
return(true);
}
break;
}
break;
case TraversalDirection.left:
case TraversalDirection.right:
switch (policyData.history.First().direction)
{
case TraversalDirection.left:
case TraversalDirection.right:
if (popOrInvalidate(direction))
{
return(true);
}
break;
case TraversalDirection.up:
case TraversalDirection.down:
invalidateScopeData(nearestScope);
break;
}
break;
}
}
if (policyData != null && policyData.history.isEmpty())
{
invalidateScopeData(nearestScope);
}
return(false);
}
