Input

Pretty much everything input related is handled by the Input class.

Ref: InputEvent - InputEventMouse - InputEventMouseButton - InputEventMouseMotion

Mouse

Setting the mouse visibility is done via mouse_mode:

# Show mouse
Input.mouse_mode = Input.MOUSE_MODE_VISIBLE
# Hide mouse and capture
Input.mouse_mode = Input.MOUSE_MODE_CAPTURED

Mouse Position

Canvas items (which controls inherit from) can get the gobal mouse position aswell as the local mouse position.

GUI interaction

Mouseclicks on GUI controls register via Control._gui_input, which is a virtual method

func _gui_input(event):
    if event is InputEventMouseButton:
        if event.button_index == MOUSE_BUTTON_LEFT and event.pressed:
            print("I've been clicked D:")

Propagates through a control node tree.

Drag and Drop interaction

Drag and Drop uses a seperate mechanic from the control class and inherited classes.

• Control._get_drag_data: to get data that can be dragged and dropped onto controls that expect drop data.
• Control._can_drop_data: to test if data from a control's _get_drag_data() can be dropped.
• Control._drop_data: to pass you the data from a control's _get_drag_data() result.
• Control.set_drag_preview: Shows the given control at the mouse pointer. A good time to call this method is in _get_drag_data().

Drag and Drop example using a texture (Video Tutorial):

extends TextureRect
func _get_drag_data(at_position):
    var preview_texture = TextureRect.new() # Create a preview texture
    preview_texture.texture = texture
    preview_texture.expand_mode = 1
    preview_texture.size = Vector2(30,30)
    var preview = Control.new()
    preview.add_child(preview_texture)
    set_drag_preview(preview) # Shows the preview at the mouse pointer
    texture = null
    return preview_texture.texture

func _can_drop_data(_pos, data):
    return data is Texture2D

func _drop_data(_pos, data):
    texture = data

Info: The contol's own functionality can be overwritten with Control.set_drag_preview.

Keys

Keys trigger input events. These propagate up through the node tree calling until a node consumes it.

For gameplay input, _unhandled_input() and _unhandled_key_input() are usually a better fit as they allow the GUI to intercept the events first. How does it work?