Mouse

Mouse is the most common input device on desktop platforms. You can access the mouse state by using the MouseDispatcher.

MouseDispatcher

The MouseDispatcher is a class used to track mouse button events. It inherits from PointerDispatcher so it can be used to produce touch events using the mouse.

public abstract class MouseDispatcher : PointerDispatcher
{
    public MouseButtons State { get; }
    public Point ScrollDelta { get; }
    public Point PositionDelta { get; }
    public Point Position { get; }
    public abstract CursorTypes CursorType { get; }
    public bool IsMouseOver { get; }

    public event EventHandler<MouseButtonEventArgs> MouseButtonUp;
    public event EventHandler<MouseButtonEventArgs> MouseButtonDown;
    public event EventHandler<MouseEventArgs> MouseLeave;
    public event EventHandler<MouseEventArgs> MouseEnter;
    public event EventHandler<MouseEventArgs> MouseMove;
    public event EventHandler<MouseScrollEventArgs> MouseScroll;

    public bool IsButtonDown(MouseButtons button);
    public ButtonState ReadButtonState(MouseButtons button);
    public bool TrySetCursorPosition(Point position);
    public abstract bool TrySetCursorType(CursorTypes cursorType);
}

Properties

It gives you the following properties:

Properties	Description
State	Gets a flag enum that indicates which mouse buttons are pressed at the current frame.
Position	Gets the mouse absolute screen position at the current frame.
PositionDelta	property gets the mouse delta position since the last frame. In other words, it describes how much the mouse has.
ScrollDelta	Gets the mouse scroll increment since the last frame. The value X indicates a horizontal scroll increment. The value is positive if the mouse wheel is rotated to the right or negative if the mouse wheel is rotated to the left. The value Y indicates a vertical scroll increment. The value is positive if the mouse wheel is rotated in an upward direction (away from the user) or negative if the mouse wheel is rotated in a downward direction (toward the user).
CursorType	property gets the mouse active cursor type.
IsMouseOver	Indicates if the mouse is over the Surface.

Events

You can be subscribed to events to ve notified when mouse state change:

Events	Description
MouseMove and MouseScroll	This events track changes in mouse position and scroll.
MouseButtonDown and MouseButtonUp	This events are available to track mouse pressed buttons but it is recommended to use IsButtonDown and ReadButtonState methods: IsButtonDown: Gets a value indicating whether the current state of a mouse button is Pressing or Pressed. ReadButtonState: Gets the current state of a mouse button.
MouseLeave and MouseEnter	They indicate if the mouse enter or leave the Surface, so, they track changes in the IsMouseOver property.

Useful Methods

Events	Description
TrySetCursorPosition	Try to update the cursor position. When this method is supported by the patform, this method will return true.
TrySetCursorType	Try to update the cursor type. When this method is supported by the patform, this method will return true.

Using MouseDispatcher

The MouseDispatcher can be found within the Display or Surface objects. The following sample code can be used to access the mouse dispatcher from a Component or Service.

[BindService]
protected GraphicsPresenter graphicsPresenter;

protected override void Update(TimeSpan time)
{
    MouseDispatcher mouseDispatcher = this.graphicsPresenter.FocusedDisplay?.MouseDispatcher;

    if (mouseDispatcher?.ReadButtonState(MouseButtons.Left) == ButtonState.Pressing)
    {
        // Do something
    }
}