private void SetFocusEngagement()
{
var pFocusManager = VisualTree.GetFocusManagerForElement(this);
if (pFocusManager != null)
{
if (IsFocusEngaged)
{
bool hasFocusedElement = FocusProperties.HasFocusedElement(this);
//Check to see if the element or any of it's descendants has focus
if (!hasFocusedElement)
{
IsFocusEngaged = false;
throw new InvalidOperationException("Can't engage focus when the control nor any of its descendants has focus.");
}
if (!IsFocusEngagementEnabled)
{
IsFocusEngaged = false;
throw new InvalidOperationException("Can't engage focus when IsFocusEngagementEnabled is false on the control.");
}
//Control is focused and has IsFocusEngagementEnabled set to true
pFocusManager.EngagedControl = this;
UpdateEngagementState(true /*engaging*/);
}
else if (pFocusManager.EngagedControl != null) //prevents re-entrancy because we set the property to false above in error cases.
{
pFocusManager.EngagedControl = null; /*No control is now engaged*/;
UpdateEngagementState(false /*Disengage*/);
var popupRoot = VisualTree.GetPopupRootForElement(this);
popupRoot?.ClearWasOpenedDuringEngagementOnAllOpenPopups();
}
}
}
protected virtual IEnumerable <DependencyObject>?GetChildrenInTabFocusOrder()
{
var children = FocusProperties.GetFocusChildren(this);
if (children != null && /*!children->IsLeaving() && */ children.Length > 0)
{
return(children);
}
return(Array.Empty <DependencyObject>());
}
internal static void ProcessControlFocused(Control control)
{
if (_log.Value.IsEnabled(LogLevel.Debug))
{
_log.Value.LogDebug($"{nameof(ProcessControlFocused)}() focusedElement={GetFocusedElement()}, control={control}");
}
if (FocusProperties.IsFocusable(control))
{
var focusManager = VisualTree.GetFocusManagerForElement(control);
focusManager?.UpdateFocus(new FocusMovement(control, FocusNavigationDirection.None, FocusState.Pointer));
}
}
private protected override void OnLoaded()
{
base.OnLoaded();
var spCurrentFocusedElement = this.GetFocusedElement();
var focusManager = VisualTree.GetFocusManagerForElement(this);
bool setDefaultFocus = focusManager?.IsPluginFocused() == true;
if (setDefaultFocus && spCurrentFocusedElement == null)
{
// Uno specific: If the page is focusable itself, we want to
// give it focus instead of the first element.
if (FocusProperties.IsFocusable(this))
{
this.SetFocusedElement(
this,
FocusState.Programmatic,
animateIfBringIntoView: false);
return;
}
// Set the focus on the first focusable control
var spFirstFocusableElementCDO = focusManager?.GetFirstFocusableElement(this);
if (spFirstFocusableElementCDO != null && focusManager != null)
{
var spFirstFocusableElementDO = spFirstFocusableElementCDO;
focusManager.InitialFocus = true;
TrySetFocusedElement(spFirstFocusableElementDO);
focusManager.InitialFocus = false;
}
if (spFirstFocusableElementCDO == null)
{
// Narrator listens for focus changed events to determine when the UI Automation tree needs refreshed. If we don't set default focus (on Phone) or if we fail to find a focusable element,
// we will need notify the narror of the UIA tree change when page is loaded.
var bAutomationListener = AutomationPeer.ListenerExistsHelper(AutomationEvents.AutomationFocusChanged);
if (bAutomationListener)
{
Uno.UI.Xaml.Core.CoreServices.Instance.UIARaiseFocusChangedEventOnUIAWindow(this);
}
}
}
}
private static IAsyncOperation <FocusMovementResult> TryFocusAsyncImpl(
DependencyObject pElement,
FocusState focusState)
{
FocusManager?focusManager = VisualTree.GetFocusManagerForElement(pElement);
if (focusManager == null)
{
throw new InvalidOperationException("Element is not part of the visual tree.");
}
FocusMovement movement = new FocusMovement(pElement, FocusNavigationDirection.None, focusState);
var spFocusAsyncOperation = new FocusAsyncOperation(movement.CorrelationId);
var asyncOperation = spFocusAsyncOperation.CreateAsyncOperation();
if (FocusProperties.IsFocusable(pElement) == false)
{
// We need to start and complete the async operation since this is a no-op
spFocusAsyncOperation.CoreSetResults(new FocusMovementResult());
spFocusAsyncOperation.CoreFireCompletion();
return(asyncOperation);
}
// TODO Uno specific: Do not use async operations, only simulated
//movement.ShouldCompleteAsyncOperation = focusManager.TrySetAsyncOperation(spFocusAsyncOperation);
if (movement.ShouldCompleteAsyncOperation)
{
//spFocusAsyncOperation.StartOperation();
}
var result = focusManager.SetFocusedElement(movement);
// TODO Uno specific: Simulate async completion.
spFocusAsyncOperation?.CoreSetResults(result);
spFocusAsyncOperation?.CoreFireCompletion();
// Async operation is not guaranteed to be released synchronously.
// Therefore, we let UpdateFocus to handle the responsibility of releasing it.
//spFocusAsyncOperation.Detach();
return(asyncOperation);
}
