Initial commit, layout mockup

addons/dockable_container/drag_n_drop_panel.gd

@@ -0,0 +1,82 @@
+@tool
+extends Control
+
+enum { MARGIN_LEFT, MARGIN_RIGHT, MARGIN_TOP, MARGIN_BOTTOM, MARGIN_CENTER }
+
+const DRAW_NOTHING := -1
+const DRAW_CENTERED := -2
+const MARGIN_NONE := -1
+
+var _draw_margin := DRAW_NOTHING
+var _should_split := false
+
+
+func _notification(what: int) -> void:
+	if what == NOTIFICATION_MOUSE_EXIT:
+		_draw_margin = DRAW_NOTHING
+		queue_redraw()
+	elif what == NOTIFICATION_MOUSE_ENTER and not _should_split:
+		_draw_margin = DRAW_CENTERED
+		queue_redraw()
+
+
+func _gui_input(event: InputEvent) -> void:
+	if _should_split and event is InputEventMouseMotion:
+		_draw_margin = _find_hover_margin(event.position)
+		queue_redraw()
+
+
+func _draw() -> void:
+	var rect: Rect2
+	if _draw_margin == DRAW_NOTHING:
+		return
+	elif _draw_margin == DRAW_CENTERED:
+		rect = Rect2(Vector2.ZERO, size)
+	elif _draw_margin == MARGIN_LEFT:
+		rect = Rect2(0, 0, size.x * 0.5, size.y)
+	elif _draw_margin == MARGIN_TOP:
+		rect = Rect2(0, 0, size.x, size.y * 0.5)
+	elif _draw_margin == MARGIN_RIGHT:
+		var half_width = size.x * 0.5
+		rect = Rect2(half_width, 0, half_width, size.y)
+	elif _draw_margin == MARGIN_BOTTOM:
+		var half_height = size.y * 0.5
+		rect = Rect2(0, half_height, size.x, half_height)
+	var stylebox := get_theme_stylebox("panel", "TooltipPanel")
+	draw_style_box(stylebox, rect)
+
+
+func set_enabled(enabled: bool, should_split: bool = true) -> void:
+	visible = enabled
+	_should_split = should_split
+	if enabled:
+		_draw_margin = DRAW_NOTHING
+		queue_redraw()
+
+
+func get_hover_margin() -> int:
+	return _draw_margin
+
+
+func _find_hover_margin(point: Vector2) -> int:
+	var half_size := size * 0.5
+
+	var left := point.distance_squared_to(Vector2(0, half_size.y))
+	var lesser := left
+	var lesser_margin := MARGIN_LEFT
+
+	var top := point.distance_squared_to(Vector2(half_size.x, 0))
+	if lesser > top:
+		lesser = top
+		lesser_margin = MARGIN_TOP
+
+	var right := point.distance_squared_to(Vector2(size.x, half_size.y))
+	if lesser > right:
+		lesser = right
+		lesser_margin = MARGIN_RIGHT
+
+	var bottom := point.distance_squared_to(Vector2(half_size.x, size.y))
+	if lesser > bottom:
+		#lesser = bottom  # unused result
+		lesser_margin = MARGIN_BOTTOM
+	return lesser_margin