public int CreateComponent(Component toAdd)
{
int freeHandle = components.IndexOf(null);
if (freeHandle == -1)
{
toAdd.Handle = components.Count;
components.Add(toAdd);
return components.Count - 1;
}
else
{
toAdd.Handle = freeHandle;
components.Add(toAdd);
return freeHandle;
}
}
/// <summary>
/// Updates which control the mouse is hovering over.
/// </summary>
/// <param name="mouseState">The current mouse state.</param>
private void UpdateHoveredComponent(MouseState mouseState)
{
// TODO: Refactor this
Rectangle cursorBounds = new Rectangle(mouseState.X, mouseState.Y, 1, 1);
if (currentHoveringComponent != null && currentHoveringComponent is IMouseResponder &&
!currentHoveringComponent.Style.Bounds.Intersects(cursorBounds))
{
(currentHoveringComponent as IMouseResponder).InvokeMouseLeave(mouseState);
currentHoveringComponent = null;
}
for (int i = components.Count - 1; i >= 0; i--)
{
if (!components[i].Style.Bounds.Intersects(cursorBounds))
continue;
if (mouseState.LeftButton == ButtonState.Pressed ||
mouseState.RightButton == ButtonState.Pressed)
ComponentToFront(components[i].Handle);
var hoveringComponent = GetHoveredChild(cursorBounds, components[i]);
if (!(hoveringComponent is IMouseResponder))
continue;
if (currentHoveringComponent != null && currentHoveringComponent != hoveringComponent)
{
(currentHoveringComponent as IMouseResponder).InvokeMouseLeave(mouseState);
currentHoveringComponent = null;
}
if (currentHoveringComponent != hoveringComponent)
(hoveringComponent as IMouseResponder).InvokeMouseEnter(mouseState);
currentHoveringComponent = hoveringComponent;
break;
}
}
/// <summary>
/// Gets the child of the initialComponent that is under the cursor. Returns the initial
/// component if no child is under the cursor.
/// </summary>
/// <param name="cursorBounds">The location and size of the cursor.</param>
/// <param name="initialOwner">The component whose children are being checked.</param>
private Component GetHoveredChild(Rectangle cursorBounds, Component initialOwner)
{
// Replacement for a nasty recursive algorithm to find the component under the cursor.
var currentComponent = initialOwner;
bool childIntersects = true;
while (childIntersects)
{
childIntersects = false;
for (int i = currentComponent.Children.Count - 1; i >= 0; i--)
{
if (currentComponent.Children[i].Style.Bounds.Intersects(cursorBounds))
{
currentComponent = currentComponent.Children[i];
childIntersects = true;
break;
}
}
}
return currentComponent;
}