private TabStopProcessingResult ProcessTabStopInternal(
DependencyObject?pCandidateTabStop,
bool isBackward,
bool didCycleFocusAtRootVisualScope)
{
var spCurrent = this;
var result = new TabStopProcessingResult();
while (spCurrent != null && !(result.IsOverriden))
{
result = spCurrent.ProcessTabStopOverride(
this,
pCandidateTabStop,
isBackward,
didCycleFocusAtRootVisualScope);
var spParent = VisualTreeHelper.GetParent(spCurrent);
spCurrent = spParent as UIElement;
}
return(result);
}
private TabStopProcessingResult ProcessCandidateTabStopInternal(
DependencyObject?pCurrentTabStop,
DependencyObject?pOverriddenCandidateTabStop,
bool isBackward)
{
var spCurrent = this;
var result = new TabStopProcessingResult();
while (spCurrent != null && !(result.IsOverriden))
{
result = spCurrent.ProcessCandidateTabStopOverride(
pCurrentTabStop,
this,
pOverriddenCandidateTabStop,
isBackward);
var spParent = VisualTreeHelper.GetParent(spCurrent);
spCurrent = spParent as UIElement;
}
return(result);
}
internal TabStopProcessingResult ProcessTabStop(
DependencyObject?pFocusedElement,
DependencyObject?pCandidateTabStopElement,
bool isBackward,
bool didCycleFocusAtRootVisualScope)
{
DependencyObject?spFocusedTarget = null;
DependencyObject?spCandidateTarget = null;
DependencyObject?spFocusedTargetParent = null;
DependencyObject?spCandidateTargetParent = null;
UIElement? spFocusedTargetAsUIE = null;
UIElement? spCandidateTargetAsUIE = null;
UIElement? spNewCandidateTargetAsUIE = null;
var tabStopProcessingResult = new TabStopProcessingResult();
var candidateTabStopProcessingResult = new TabStopProcessingResult();
if (pFocusedElement != null)
{
spFocusedTarget = pFocusedElement;
spFocusedTargetAsUIE = spFocusedTarget as UIElement;
// Get the parent if it is not a UIElement. (E.g. Hyperlink)
if (spFocusedTargetAsUIE == null)
{
spFocusedTargetParent = VisualTreeHelper.GetParent(spFocusedTarget);
spFocusedTargetAsUIE = spFocusedTargetParent as UIElement;
}
}
if (pCandidateTabStopElement != null)
{
spCandidateTarget = pCandidateTabStopElement;
spCandidateTargetAsUIE = spCandidateTarget as UIElement;
// Get the parent if it is not a UIElement. (E.g. Hyperlink)
if (spCandidateTargetAsUIE == null)
{
spCandidateTargetParent = VisualTreeHelper.GetParent(spCandidateTarget);
spCandidateTargetAsUIE = spCandidateTargetParent as UIElement;
}
}
MUX_ASSERT(tabStopProcessingResult.NewTabStop == null);
if (spFocusedTargetAsUIE != null)
{
tabStopProcessingResult = spFocusedTargetAsUIE.ProcessTabStopInternal(spCandidateTarget, isBackward, didCycleFocusAtRootVisualScope);
}
if (!tabStopProcessingResult.IsOverriden && spCandidateTargetAsUIE != null)
{
MUX_ASSERT(tabStopProcessingResult.NewTabStop == null);
var candidateResult = spCandidateTargetAsUIE.ProcessCandidateTabStopInternal(
spFocusedTarget,
null,
isBackward);
tabStopProcessingResult.NewTabStop = candidateResult.NewTabStop;
tabStopProcessingResult.IsOverriden = candidateResult.IsOverriden;
}
else if (tabStopProcessingResult.IsOverriden && tabStopProcessingResult.NewTabStop != null)
{
spNewCandidateTargetAsUIE = tabStopProcessingResult.NewTabStop as UIElement;
if (spNewCandidateTargetAsUIE != null)
{
candidateTabStopProcessingResult = spNewCandidateTargetAsUIE.ProcessCandidateTabStopInternal(
spFocusedTarget,
tabStopProcessingResult.NewTabStop,
isBackward);
}
}
if (!tabStopProcessingResult.IsOverriden && !candidateTabStopProcessingResult.IsOverriden)
{
// Process TabStop if the application bar service is available.
var spApplicationBarService = DXamlCore.Current.TryGetApplicationBarService();
if (spApplicationBarService != null)
{
var appBarResult = spApplicationBarService.ProcessTabStopOverride(
spFocusedTarget,
spCandidateTarget,
isBackward);
tabStopProcessingResult.NewTabStop = appBarResult.NewTabStop;
tabStopProcessingResult.IsOverriden = appBarResult.IsOverriden;
if (tabStopProcessingResult.IsOverriden && tabStopProcessingResult.NewTabStop != null)
{
spNewCandidateTargetAsUIE = tabStopProcessingResult.NewTabStop as UIElement;
if (spNewCandidateTargetAsUIE != null)
{
candidateTabStopProcessingResult = spNewCandidateTargetAsUIE.ProcessCandidateTabStopInternal(
spFocusedTarget,
tabStopProcessingResult.NewTabStop,
isBackward);
}
}
}
}
var result = new TabStopProcessingResult();
if (candidateTabStopProcessingResult.IsOverriden)
{
if (candidateTabStopProcessingResult.NewTabStop != null)
{
result.NewTabStop = candidateTabStopProcessingResult.NewTabStop;
}
result.IsOverriden = true;
}
else if (tabStopProcessingResult.IsOverriden)
{
if (tabStopProcessingResult.NewTabStop != null)
{
result.NewTabStop = tabStopProcessingResult.NewTabStop;
}
result.IsOverriden = true;
}
return(result);
}