/// <summary>Called when a button on the game pad has been released</summary>
/// <param name="button">Button that has been released</param>
internal void ProcessButtonRelease(Buttons button)
{
// If we're the top level control, we will receive button presses and their related
// releases even if nobody was interested in the button presses. Thus, we silently
// ignore those presses we didn't accept.
if (_heldButtonCount == 0)
{
return;
}
// If we receive a release, we must have a control on which the mouse
// was pressed (possibly even ourselves)
Debug.Assert(
_activatedControl != null,
"ProcessButtonRelease() had no control a button was pressed on; " +
"ProcessButtonRelease() was called on a control instance, but the control " +
"did not register a prior button press for itself or any of its child controls"
);
--_heldButtonCount;
if (_activatedControl != this)
{
_activatedControl.ProcessButtonRelease(button);
}
else
{
OnButtonReleased(button);
}
// If no more keys buttons are being held down, clear the activated control
if (!AnyKeysOrButtonsPressed)
{
_activatedControl = null;
}
}
/// <summary>Called when a mouse button has been pressed down</summary>
/// <param name="button">Index of the button that has been pressed</param>
/// <returns>Whether the control has processed the mouse press</returns>
internal bool ProcessMousePress(MouseButton button)
{
// We remember the control the mouse was pressed over and won't replace it for
// as long as the mouse is being held down. This ensures the mouse release
// notification is always delivered to a control, even if the mouse is released
// after moving it away from the control.
if (_activatedControl == null)
{
_activatedControl = _mouseOverControl;
// If we received an initial mouse press outside of our control area,
// someone is feeding us notifications we shouldn't be receiving. The best
// thing we can do is ignore this notification. This is a normal situation
// for the top level control which does the input filtering.
if (_activatedControl == null)
{
return(false);
}
// If we're a control that can appear on top of or below our siblings in
// the z order, bring us into foreground since the user just clicked on us.
if (_activatedControl != this)
{
if (_activatedControl._affectsOrdering)
{
_children.MoveToStart(_children.IndexOf(_activatedControl));
}
}
}
// Add the buttons to the list of mouse buttons being held down. This is used
// to track when we should clear the mouse-over control again.
_heldMouseButtons |= button;
// If the mouse is over another control, pass on the mouse press.
if (_activatedControl != this)
{
return(_activatedControl.ProcessMousePress(button));
}
// Otherwise, the mouse press applies to us
// If this control can take the input focus, make it the focused control
if (_screen != null)
{
var focusable = this as IFocusable;
if ((focusable != null) && focusable.CanGetFocus)
{
_screen.FocusedControl = this;
}
}
// Deliver the notification to the control deriving from us
OnMousePressed(button);
return(true);
}
/// <summary>Switches the mouse over control to a different control</summary>
/// <param name="newMouseOverControl">New control the mouse is hovering over</param>
private void SwitchMouseOverControl(GuiControl newMouseOverControl, float x, float y)
{
if (_mouseOverControl != newMouseOverControl)
{
// Tell the previous mouse-over control that the mouse is no longer
// hovering over it
if (_mouseOverControl != null)
{
_mouseOverControl.ProcessMouseLeave(x, y);
}
_mouseOverControl = newMouseOverControl;
// Inform the new mouse-over control that the mouse is now over it
newMouseOverControl.OnMouseEntered();
}
}
/// <summary>Assigns a new parent to the control</summary>
/// <param name="parent">New parent to assign to the control</param>
internal void SetParent(GuiControl parent)
{
_parent = parent;
// Have we been assigned to a parent?
if (_parent != null)
{
// If this ownership change transferred us to a different gui, we will
// have to migrate our visual and also the visuals of all our children.
if (!ReferenceEquals(_screen, parent._screen))
{
SetScreen(parent._screen);
}
}
else
{
// No parent, we're now officially an orphan ;)
// Orphans don't have screens!
SetScreen(null);
}
}
/// <summary>Called when a mouse button has been released again</summary>
/// <param name="button">Index of the button that has been released</param>
internal void ProcessMouseRelease(MouseButton button)
{
// When the mouse is clicked on game window's border and the user drags it
// into the GUI area, we will get a rogue mouse release message without
// the related mouse press. We ignore such rogue mouse release messages.
if ((_heldMouseButtons & button) != button)
{
return;
}
// If we receive a release, we must have a control on which the mouse
// was pressed (possibly even ourselves)
Debug.Assert(
_activatedControl != null,
"ProcessMouseRelease() had no control the mouse was pressed on; " +
"ProcessMouseRelease() was called on a control instance, but the control " +
"did not register a prior mouse press over itself or any of its child controls"
);
// Remove the button from the list of mouse buttons being held down. This
// allows us to see when we can clear the mouse-press control.
_heldMouseButtons &= ~button;
// If the mouse was held over one of our childs, pass on the notification
if (_activatedControl != this)
{
_activatedControl.ProcessMouseRelease(button);
}
else
{
OnMouseReleased(button);
}
// If no more mouse buttons are being held down, clear the mouse-press control
if (!AnyKeysOrButtonsPressed)
{
_activatedControl = null;
}
}
/// <summary>
/// Called when the mouse has left the control and is no longer hovering over it
/// </summary>
internal void ProcessMouseLeave(float x, float y)
{
// Because the mouse has left us, if we have a mouse-over control, it also
// cannot be over one of our children Children leaving the parent container
// are not supported by design and for consistency, the behavior is tweaked
// so the children are left when the parent is left - this avoids strange
// behavior like being able to select a control if entering it with the mouse
// from the container side but being unable to select it if entering from
// the outside.
if (_mouseOverControl != null)
{
if (_mouseOverControl != this)
{
_mouseOverControl.ProcessMouseLeave(x, y);
}
else
{
OnMouseLeft(x, y);
}
_mouseOverControl = null;
}
}
/// <summary>Called when a key on the keyboard has been released again</summary>
/// <param name="keyCode">Code of the key that was released</param>
internal void ProcessKeyRelease(Keys keyCode)
{
// Any key release should have an associated key press, otherwise, someone
// delivered notifications to us we should not have received.
Debug.Assert(
_heldKeyCount > 0,
"ProcessKeyRelease() called more often then ProcessKeyPress(); " +
"ProcessKeyRelease() was called more often the ProcessKeyPress() has been " +
"called with the repetition parameter set to false"
);
// If we receive a release, we must have a control on which the mouse
// was pressed (possibly even ourselves)
Debug.Assert(
_activatedControl != null,
"ProcessKeyRelease() had no control a key was pressed on; " +
"ProcessKeyRelease() was called on a control instance, but the control " +
"did not register a prior key press for itself or any of its child controls"
);
--_heldKeyCount;
if (_activatedControl != this)
{
_activatedControl.ProcessKeyRelease(keyCode);
}
else
{
OnKeyReleased(keyCode);
}
// If no more keys buttons are being held down, clear the activated control
if (!AnyKeysOrButtonsPressed)
{
_activatedControl = null;
}
}
/// <summary>Called when a key on the keyboard has been pressed down</summary>
/// <param name="keyCode">Code of the key that was pressed</param>
/// <param name="repetition">Whether the key press is due to the user holding down a key</param>
internal bool ProcessKeyPress(Keys keyCode, bool repetition)
{
// If there's an activated control (one being held down by the mouse or having
// accepted a previous key press), this control will get the key press delivered,
// whether it wants to or not. We don't want to track for each key which control
// is currently processing it. ;-)
if (_activatedControl != null)
{
if (!repetition)
{
++_heldKeyCount;
}
// If one of our children is the activated control, pass on the message
if (_activatedControl != this)
{
_activatedControl.ProcessKeyPress(keyCode, repetition);
}
else
{
OnKeyPressed(keyCode); // We're the activated control
}
return(true); // Ignore user code and always accept the key press
}
// A key has been pressed but no control is activated currently. This means we
// have to look for a control which feels responsible for the key press, starting
// with ourselves.
// Does the user code in our derived class feel responsible for this key?
// If so, we're the new activated control and the key has been handled.
if (OnKeyPressed(keyCode))
{
_activatedControl = this;
++_heldKeyCount;
return(true);
}
// Nope, we have to ask our children (and they, potentially recursively, theirs)
// to find a control that feels responsible.
var encounteredOrderingControl = false;
for (var index = 0; index < _children.Count; ++index)
{
var child = _children[index];
// We only process one child that has the affectsOrdering field set. This
// ensures that key presses will not be delivered to windows sitting behind
// another window. Other siblings that are not windows are asked still.
if (child._affectsOrdering)
{
if (encounteredOrderingControl)
{
continue;
}
else
{
encounteredOrderingControl = true;
}
}
// Does this child feel responsible for the key press?
if (child.ProcessKeyPress(keyCode, repetition))
{
_activatedControl = child;
++_heldKeyCount;
return(true);
}
}
// Neither we nor any of our children felt responsible for the key. Give up.
return(false);
}
/// <summary>Called when a button on the game pad has been pressed</summary>
/// <param name="button">Button that has been pressed</param>
/// <returns>
/// True if the button press was processed by the control and future game pad
/// input belongs to the control until all buttons are released again
/// </returns>
internal bool ProcessButtonPress(Buttons button)
{
// If there's an activated control (one being held down by the mouse or having
// accepted a previous button press), this control will get the button press
// delivered, whether it wants to or not.
if (_activatedControl != null)
{
++_heldButtonCount;
// If one of our children is the activated control, pass on the message
if (_activatedControl != this)
{
_activatedControl.ProcessButtonPress(button);
}
else
{
OnButtonPressed(button);
}
// We're already activated, so this button press is accepted in any case
return(true);
}
// A button has been pressed but no control is activated currently. This means we
// have to look for a control which feels responsible for the button press,
// starting with ourselves.
// Does the user code in our derived class feel responsible for this button?
// If so, we're the new activated control and the button has been handled.
if (OnButtonPressed(button))
{
_activatedControl = this;
++_heldButtonCount;
return(true);
}
// Nope, we have to ask our children to find a control that feels responsible.
var encounteredOrderingControl = false;
foreach (var child in _children)
{
// We only process one child that has the affectsOrdering field set. This
// ensures that key presses will not be delivered to windows sitting behind
// another window. Other siblings that are not windows are asked still, so
// a bunch of buttons on the desktop would be asked in addition to a window.
if (child._affectsOrdering)
{
if (encounteredOrderingControl)
{
continue;
}
encounteredOrderingControl = true;
}
// Does this child feel responsible for the button press?
if (child.ProcessButtonPress(button))
{
_activatedControl = child;
++_heldButtonCount;
return(true);
}
}
// Neither we nor any of our children felt responsible for the button. Give up.
return(false);
}
/// <summary>Initializes a new control event args instance</summary>
/// <param name="control">Control to provide to the subscribers of the event</param>
public ControlEventArgs(GuiControl control)
{
_control = control;
}
