private void UpdateMouseOver(UIComponentProcessor.UIComponentState state)
{
if (input == null || !input.HasMouse)
{
return;
}
var intersectionPoint = Vector3.Zero;
var mousePosition = input.MousePosition;
var rootElement = state.UIComponent.RootElement;
var lastOveredElement = state.LastOveredElement;
var overredElement = lastOveredElement;
// determine currently overred element.
if (mousePosition != lastMousePosition)
{
overredElement = GetElementAtScreenPosition(rootElement, mousePosition, ref intersectionPoint);
}
// find the common parent between current and last overred elements
var commonElement = FindCommonParent(overredElement, lastOveredElement);
// disable mouse over state to previously overred hierarchy
var parent = lastOveredElement;
while (parent != commonElement && parent != null)
{
parent.MouseOverState = MouseOverState.MouseOverNone;
parent = parent.VisualParent;
}
// enable mouse over state to currently overred hierarchy
if (overredElement != null)
{
// the element itself
overredElement.MouseOverState = MouseOverState.MouseOverElement;
// its hierarchy
parent = overredElement.VisualParent;
while (parent != null)
{
if (parent.IsHierarchyEnabled)
{
parent.MouseOverState = MouseOverState.MouseOverChild;
}
parent = parent.VisualParent;
}
}
// update cached values
state.LastOveredElement = overredElement;
lastMousePosition = mousePosition;
}
private void UpdateTouchEvents(UIComponentProcessor.UIComponentState state, GameTime gameTime)
{
var rootElement = state.UIComponent.RootElement;
var intersectionPoint = Vector3.Zero;
var lastTouchPosition = new Vector2(float.NegativeInfinity);
// analyze pointer event input and trigger UI touch events depending on hit Tests
foreach (var pointerEvent in compactedPointerEvents)
{
// performance optimization: skip all the events that started outside of the UI
var lastTouchedElement = state.LastTouchedElement;
if (lastTouchedElement == null && pointerEvent.State != PointerState.Down)
{
continue;
}
var time = gameTime.Total;
var currentTouchPosition = pointerEvent.Position;
var currentTouchedElement = lastTouchedElement;
// re-calculate the element under cursor if click position changed.
if (lastTouchPosition != currentTouchPosition)
{
currentTouchedElement = GetElementAtScreenPosition(rootElement, pointerEvent.Position, ref intersectionPoint);
}
if (pointerEvent.State == PointerState.Down || pointerEvent.State == PointerState.Up)
{
state.LastIntersectionPoint = intersectionPoint;
}
var touchEvent = new TouchEventArgs
{
Action = TouchAction.Down,
Timestamp = time,
ScreenPosition = currentTouchPosition,
ScreenTranslation = pointerEvent.DeltaPosition,
WorldPosition = intersectionPoint,
WorldTranslation = intersectionPoint - state.LastIntersectionPoint
};
switch (pointerEvent.State)
{
case PointerState.Down:
touchEvent.Action = TouchAction.Down;
if (currentTouchedElement != null)
{
currentTouchedElement.RaiseTouchDownEvent(touchEvent);
}
break;
case PointerState.Up:
touchEvent.Action = TouchAction.Up;
// generate enter/leave events if we passed from an element to another without move events
if (currentTouchedElement != lastTouchedElement)
{
ThrowEnterAndLeaveTouchEvents(currentTouchedElement, lastTouchedElement, touchEvent);
}
// trigger the up event
if (currentTouchedElement != null)
{
currentTouchedElement.RaiseTouchUpEvent(touchEvent);
}
break;
case PointerState.Move:
touchEvent.Action = TouchAction.Move;
// first notify the move event (even if the touched element changed in between it is still coherent in one of its parents)
if (currentTouchedElement != null)
{
currentTouchedElement.RaiseTouchMoveEvent(touchEvent);
}
// then generate enter/leave events if we passed from an element to another
if (currentTouchedElement != lastTouchedElement)
{
ThrowEnterAndLeaveTouchEvents(currentTouchedElement, lastTouchedElement, touchEvent);
}
break;
case PointerState.Out:
case PointerState.Cancel:
touchEvent.Action = TouchAction.Move;
// generate enter/leave events if we passed from an element to another without move events
if (currentTouchedElement != lastTouchedElement)
{
ThrowEnterAndLeaveTouchEvents(currentTouchedElement, lastTouchedElement, touchEvent);
}
// then raise leave event to all the hierarchy of the previously selected element.
var element = currentTouchedElement;
while (element != null)
{
if (element.IsTouched)
{
element.RaiseTouchLeaveEvent(touchEvent);
}
element = element.VisualParent;
}
break;
default:
throw new ArgumentOutOfRangeException();
}
lastTouchPosition = currentTouchPosition;
state.LastTouchedElement = currentTouchedElement;
state.LastIntersectionPoint = intersectionPoint;
}
}
