WIP: implement sideboard with scrolling and capability to accept both card and sticky drops depending on context

src/logic-scenes/board/card-board.gd

@@ -20,20 +20,46 @@ var cards : Array[Card] = []
 
 var board_was_completed: bool = false
 
-var current_context : int = NAVIGATE
+var current_context : Context = Context.NAVIGATE
 var selection_state : SelectionState
 
+var last_card_selected: Card
+var last_note_selected: StickyNote
+var selection: Draggable = null:
+	set(value):
+		if selection == value: return
+		
+		if selection:
+			if selection is Card:
+				last_card_selected = selection
+			elif selection is StickyNote:
+				last_note_selected = selection
+		
+		# Select & highlight new
+		if selection: selection.highlighted = false
+		selection = value
+		if selection: selection.highlighted = true
+
+		# Are we selecting cards or stickies?
+		if selection is Card:
+			selection_state = SelectionState.CARDS
+			if current_context == Context.ASSIGN:
+				selection.preview_sticky_note(last_note_selected)
+
+		if selection is StickyNote:
+			selection_state = SelectionState.STICKIES
+
 #@onready var instructions := $instructions_panel/HBoxContainer/cards_remaining
 
 @onready var dropzone : Control = %CardZone
-@onready var notezone : Control = %NoteZone
+@onready var sideboard : SideBoard = %SideBoard
 
 enum SelectionState {FREE,STICKIES,CARDS}
-enum {NAVIGATE, ASSIGN, DRAG}
+enum Context {NAVIGATE, ASSIGN, DRAG}
 
 
 func _ready() -> void:
-	prints("card-board.gd:", "_ready()", self, "room:", State.room, owner)
+	prints("card-board.gd:", "_ready()", self, "room:", State.active_room, owner)
 	super._ready()
 
 	_delayed_ready.call_deferred()
@@ -42,9 +68,10 @@ func _ready() -> void:
 # We need to wait for our room further up our parent hierarchy to actually make itself known
 # for interactables to do things with it, e.g. CardBoard needs to register itself
 func _delayed_ready() ->void:
-	var board_room := State.room as RoomWithBoard
+	var board_room := State.active_room as RoomWithBoard
-	assert(board_room, "CardBoard spawned in room that's not a RoomWithboard.")
+	if not get_tree().root == get_parent():
-	board_room.card_board = self
+		assert(board_room, "CardBoard spawned in room that's not a RoomWithboard.")
+		board_room.card_board = self
 	is_memory_board = is_memory_board
 
 
@@ -75,23 +102,6 @@ var mementos_collected: int = 0:
 		mementos_collected = mementos
 
 
-var selection: Draggable = null:
-	set(value):
-		if selection == value: return
-
-		# Select & highlight new
-		if selection: selection.highlighted = false
-		selection = value
-		if selection: selection.highlighted = true
-
-		# Are we selecting cards or stickies?
-		if selection is Card:
-			selection_state = SelectionState.CARDS
-
-		if selection is StickyNote:
-			selection_state = SelectionState.STICKIES
-
-
 func _navigate_next():
 	var candidates := _selection_candidates
 	var index := maxi(0, candidates.find(selection))
@@ -111,34 +121,6 @@ func _smooth(current: Vector2, goal: Vector2, delta: float) -> Vector2:
 	return (k) * current + (1.0-k) * goal
 
 
-func _process(delta: float):
-	var zone_position := Vector2(notezone.get_screen_position().x + sticky_width / 3.0, sticky_height)
-
-	var dragging := notes.any(func (n : Draggable): return n.is_dragged)
-
-	if dragging:
-		# Y-sort the nodes, this lets us fill the gap more nicely.
-		notes.sort_custom(func (a:Draggable, b:Draggable): return a.global_position.y < b.global_position.y)
-
-	for note in notes:
-		# Skip all dragged and already attached notes
-		if note.is_attached: continue
-		if note.is_dragged: continue
-
-		# Magnetically move all notes to where they ought to be on screen
-		note.home = zone_position
-		zone_position.y += sticky_height
-
-		# Only if not already in transit / animated or user holding on to one
-		if not dragging and not note.tween:
-			note.animate_home()
-		else:
-			# do adjustment with FIR filter
-			note.position = _smooth(note.position, note.home, delta)
-			note.z_index = 0
-
-
-
 func _check_completion() -> void:
 	if is_board_complete():
 		board_was_completed = true
@@ -148,7 +130,7 @@ func _check_completion() -> void:
 ## Finalizes board state before closing (ends drags, cleans up transitions)
 func _finalize_board_state() -> void:
 	# End any active drag operations
-	if current_context == DRAG:
+	if current_context == Context.DRAG:
 		_end_drag(selection)
 	for item in notes:
 		item.is_dragged = false
@@ -157,7 +139,7 @@ func _finalize_board_state() -> void:
 		item.is_dragged = false
 
 	# Reset context to NAVIGATE
-	current_context = NAVIGATE
+	current_context = Context.NAVIGATE
 	print("CardBoard: Board state finalized")
 
 
@@ -181,8 +163,8 @@ func populate_board(names: Array[StringName]):
 	for new_card: Card in all_new["cards"]:
 		add_card(new_card)
 
-	for new_sticky_note: StickyNote in all_new["sticky_notes"]:
+
-		add_note(new_sticky_note)
+	notes += sideboard.populate(all_new["sticky_notes"])
 
 
 # FIXME: This can be made even simpler.
@@ -243,14 +225,14 @@ func add_note(note: StickyNote) -> void:
 	note.is_draggable = true
 
 func appear():
-	await Main.curtain.close()
+	#await Main.curtain.close()
 	show()
-	await Main.curtain.open()
+	#await Main.curtain.open()
 
 func vanish():
-	await Main.curtain.close()
+	#await Main.curtain.close()
 	hide()
-	await Main.curtain.open()
+	#await Main.curtain.open()
 
 
 # Called by notes when a mouse event needs handling
@@ -265,13 +247,15 @@ func handle_mouse_button(input: InputEventMouseButton, target: Draggable) -> voi
 		_end_drag(target)
 		return
 
-
+var parent_before_drag: Node
 ## Starts a drag operation for the given draggable
 func _start_drag(draggable: Draggable) -> void:
+	parent_before_drag = draggable.get_parent()
 	selection = draggable
-	current_context = DRAG
+	current_context = Context.DRAG
 	var mouse_offset := get_viewport().get_mouse_position() - draggable.global_position
 	draggable.start_drag(mouse_offset)
+	draggable.reparent(self)
 
 
 ## Ends a drag operation and handles the drop
@@ -279,26 +263,30 @@ func _end_drag(draggable: Draggable) -> void:
 	selection = draggable
 
 	# Cleanup and state update
-	current_context = NAVIGATE
+	current_context = Context.NAVIGATE
 
 	var destination := draggable.end_drag()
 	
-	# Handle sticky note drops
+	if destination:
-	if draggable is StickyNote:
+		if destination is Card:
-		var sticky := draggable as StickyNote
+			# If dropped on a card, attach it
+			if draggable is StickyNote:
+				destination.attach_or_exchange_note(draggable)
 		
-		# If dropped on a card, attach it
+		elif destination is SideBoundary:
-		if destination and destination is Card:
+			if not sideboard.accept_drop(draggable):
-			var target_card := destination as Card
+				#FIXME remove if handle_drop and can_accept_drop is properly implemented.
-			target_card.attach_or_exchange_note(sticky)
+				destination = null
 			
-		# If dropped on board (no destination), ensure it's a child of the board
+	# If dropped on board (no destination), ensure it's a child of the board
-		elif not destination:
+	if not destination:
-			if sticky.is_attached:
+		if draggable is StickyNote:
-				reclaim_sticky(sticky)
+			reclaim_sticky(draggable)
 
-		# Check win condition after any sticky movement
+	# Check win condition after any sticky movement
-		check_board_completion()
+	check_board_completion()
+
+	parent_before_drag = null
 
 
 func reclaim_sticky(note: StickyNote):
@@ -384,8 +372,6 @@ func _nearest_hovered(candidates: Array[Draggable]) -> Draggable:
 	return null
 
 
-
-
 func _by_spatial(a: Draggable, b: Draggable) -> bool:
 	return a.position.x + a.position.y * 10000 > b.position.x + b.position.y * 10000
 
@@ -408,6 +394,7 @@ func _sort_by_positions() -> void:
 func can_accept_drop(draggable: Draggable) -> bool:
 	return draggable is Card or draggable is StickyNote
 
+# FIXME: this function seems to not be used.
 ## Handles dropping a draggable onto the board (into the dropzone)
 func handle_drop(draggable: Draggable) -> int:
 	if not can_accept_drop(draggable):
@@ -423,12 +410,49 @@ func _perform(action : StringName) -> void:
 
 # Takes the inputs for control inputs
 func _input(event : InputEvent) -> void:
-	if selection and not selection.is_dragged and event is InputEventMouseMotion and not event.is_action_pressed("mouse_left"):
+	# trying to not do the double check on the line below.
+	var is_mouse_left:= false
+	if event is InputEventMouseButton:
+		is_mouse_left = event.button_index == MOUSE_BUTTON_LEFT
+	
+	if selection and not selection.is_dragged and event is InputEventMouseMotion and not is_mouse_left:
 		var candidate := _nearest_hovered(_sort_by_proximity_and_depth(notes))
 		if not candidate:
 			candidate = _nearest_hovered(_sort_by_proximity_and_depth(cards))
 		selection = candidate
+	if event.is_action_pressed("ui_left"):
+		_handle_direction_input(Vector2.LEFT)
+	if event.is_action_pressed("ui_right"):
+		_handle_direction_input(Vector2.RIGHT)
+	if event.is_action_pressed("ui_up"):
+		_handle_direction_input(Vector2.UP)
+	if event.is_action_pressed("ui_down"):
+		_handle_direction_input(Vector2.DOWN)
 	
+	#TODO: make this work with the prompter once more.
+	if event.is_action_pressed("ui_cancel"):
+		get_viewport().set_input_as_handled()
+		closed.emit()
+
+func _handle_direction_input(direction: Vector2):
+	
+	if current_context == Context.NAVIGATE and _assure_selection():
+		try_select_nearest_card(selection.global_position, direction, (current_context != Context.ASSIGN))
+
+func _assure_selection() -> bool:
+	if selection:
+		return true
+	else:
+		if selection_state == SelectionState.STICKIES or selection_state == SelectionState.FREE:
+			if dropzone.get_child_count() > 0:
+				selection = dropzone.get_child(0)
+				return true
+		## Attempting to still select a Card if no sticky could be found.
+		if sideboard.get_child_count() > 0:
+			selection = sideboard.get_child(0)
+			return true 
+	
+	return false	
 
 ## Saves board state directly to SaveGame resource
 func save_to_resource(savegame: SaveGame) -> void:
@@ -572,3 +596,65 @@ func _debug_mode() -> void:
 	populate_board(["c_out_of_world", 'c_confusion', "p_outer_conflict", "p_unique"])
 	await get_tree().process_frame
 	play()
+
+
+
+func try_select_nearest_card(from: Vector2, towards: Vector2, include_stickies: bool = false) -> bool:
+	var selection_transform = Transform2D(0, from).looking_at(from+towards)
+	
+	var scores: Dictionary[int, Area2D] = {-1: null}
+	for child:Area2D in dropzone.get_children():
+		if not (child is StickyNote and include_stickies):
+			scores[get_distance_score(child.global_position, selection_transform)] = child
+	scores.erase(-1)
+	scores.sort()
+	
+	if include_stickies:
+		var panel_scores: Dictionary[int, Control] = {-1: null}
+		for child:Control in sideboard.get_children():
+			if not child.is_empty():
+				panel_scores[get_distance_score(child.attached_sticky_note.global_position, selection_transform)] = child
+		panel_scores.erase(-1)
+		panel_scores.sort()
+		
+		if panel_scores != {}:
+			if scores != {}:
+				if panel_scores.keys()[0] < scores.keys()[0]:
+					if current_context == Context.ASSIGN: return false
+					selection = panel_scores.values()[0]
+					selection_state = SelectionState.STICKIES
+					return true
+			else:
+				if current_context == Context.ASSIGN: return false
+				selection = panel_scores.values()[0]
+				selection_state = SelectionState.STICKIES
+				return true
+	
+	
+	if scores != {}:
+		selection = scores.values()[0]
+		return true
+	return false
+
+func try_select_nearest_empty_card(from: Vector2) -> bool:
+	var scores: Dictionary[int, Area2D] = {}
+	
+	for card in dropzone.get_children():
+		if card is Card:
+			if not card.has_note_attached():
+				scores[int((from-card.global_position).length())] = card
+	
+	scores.sort()
+	
+	if scores != {}:
+		selection = scores.values()[0]
+		return true
+	return false
+
+func get_distance_score(from: Vector2, to: Transform2D) -> int:
+	var diff = from * to
+	var dir = diff.normalized()
+	if dir.x > 0.5 and diff.length() > 0:
+		return int((abs(dir.y) + 0.5) * diff.length())
+	else:
+		return -1

src/logic-scenes/board/card.gd

@@ -43,7 +43,7 @@ var transfor_arr: Array[Transform2D] = [
 @export_range(1, 2) var scale_bump: float = 1.05
 @export_range(1.0, 10.0) var bounce_speed: float = 5
 
-@export_color_no_alpha var highlight_color: Color = Color(1.4, 1.4, 1.4)
+@export_color_no_alpha var highlight_color: Color = Color(1.2, 1.2, 1.2)
 
 ## Override set_highlight to add visual feedback for cards
 func set_highlight(value: bool) -> void:
@@ -231,6 +231,10 @@ func get_attached_note() -> StickyNote:
 	return null
 
 
+func get_size() -> Vector2:
+	return $CollisionShape2D.shape.size
+
+
 func preview_sticky_note(sticky_note: StickyNote):
 	if not is_instance_valid(sticky_note):
 		return
@@ -252,7 +256,7 @@ func attach_or_exchange_note(note: StickyNote, instant: bool = false) -> void:
 		old.reparent(note.attached_to)
 		old.animate_home()
 	else:
-		remove_note_if_present() # just kick out our old note
+		return_old_child(note) # just kick out our old note
 
 	# ... in with the new
 	note.reparent(self)
@@ -268,13 +272,19 @@ func attach_or_exchange_note(note: StickyNote, instant: bool = false) -> void:
 		Steam.storeStats()
 
 
-func remove_note_if_present() -> void:
+func return_old_child(new_note: StickyNote = null) -> void:
 	var former_child: StickyNote = get_attached_note()
 	if not former_child: return
 	
-	former_child.reparent(get_parent())
 	former_child.tween = null # the positioning logic in card-board will pick that one up and calc a nice slot.
 	
+	if new_note:
+		former_child.reparent(new_note.last_parent)
+		former_child.animate_home(new_note.home)
+	else:
+		former_child.reparent(get_parent())
+		
+
 
 # === DROP TARGET PATTERN IMPLEMENTATION ===
 
@@ -282,6 +292,7 @@ func remove_note_if_present() -> void:
 func can_accept_drop(draggable: Draggable) -> bool:
 	return draggable is StickyNote
 
+# FIXME: this function seems to not be used.
 ## Handles dropping a sticky note onto this card
 ## Returns DropResult indicating success, rejection, or exchange
 func handle_drop(draggable: StickyNote) -> int:
@@ -292,6 +303,23 @@ func handle_drop(draggable: StickyNote) -> int:
 	draggable.z_index = 0
 	return Draggable.DropResult.ACCEPTED
 
+
+## End drag operation and return the node we were dropped on
+func end_drag() -> Node:
+	super.end_drag()
+	return _find_drop_target()
+
+
+## Find best drop target: Card > Panel > Board (in priority order)
+func _find_drop_target() -> Node:
+	print(get_overlapping_areas())
+	# Priority 1: Check for overlapping cards in dropzone
+	for area in get_overlapping_areas():
+		if area is SideBoundary:
+			return area
+
+	return null
+
 # === DRAG LIFECYCLE OVERRIDES ===
 
 ## Cards always drop back to board dropzone

src/logic-scenes/board/card.tscn

@@ -9,7 +9,7 @@ size = Vector2(277, 231)
 
 [node name="Card" type="Area2D" unique_id=5263467]
 collision_layer = 4
-collision_mask = 0
+collision_mask = 8
 priority = 50
 script = ExtResource("1_emip0")
 text = "card"
@@ -34,6 +34,7 @@ offset_right = 136.0
 offset_bottom = 77.95834
 grow_horizontal = 2
 grow_vertical = 2
+mouse_default_cursor_shape = 13
 theme = ExtResource("3_mdi7r")
 theme_type_variation = &"card_text"
 text = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. "

src/logic-scenes/board/draggable.gd

@@ -40,6 +40,7 @@ func set_highlight(value: bool) -> void:
 var _drag_start_position: Vector2
 var _mouse_drag_offset: Vector2
 var _drag_source: Node = null  # Where the drag started from
+var last_parent: Node = null  # Where they were last dragged from. Used by return_old_child() in Card
 
 ## === SETUP ###
 func _ready() -> void:
@@ -69,11 +70,15 @@ func _get_button_handler() -> Node:
 var tween : Tween = null
 
 
-func animate_home() -> void:
+func animate_home(target: Vector2 = home) -> void:
 	z_index = 100
 	if tween: tween.kill()
 	tween = create_tween().set_ease(Tween.EASE_IN_OUT).set_trans(Tween.TRANS_QUART)
-	tween.tween_property(self, "position", home, 0.5)
+	tween.tween_property(self, "position", target, 0.5)
+
+func get_size() -> Vector2:
+	assert(false, "This function needs to be overridden!")
+	return Vector2.ZERO
 
 func _on_mouse_entered() -> void:
 	#prints("Draggable[base]._on_mouse_entered", self, self.name)
@@ -110,6 +115,7 @@ func start_drag(mouse_offset: Vector2) -> void:
 	_drag_start_position = global_position
 	_mouse_drag_offset = mouse_offset
 	_drag_source = get_parent()
+	last_parent = _drag_source
 	z_index = 60
 	is_dragged = true
 
@@ -132,6 +138,11 @@ func end_drag() -> Node:
 	_drag_source = null
 	return null
 
+func _set_home() -> void:
+	var parent = get_parent()
+	if parent is Control:
+		confine_to_screen()
+		home = position
 
 ## Confines this draggable element to stay within screen or container bounds
 ## Skip this check if a sticky note is attached to a card

src/logic-scenes/board/physics-board.tscn

@@ -4,10 +4,12 @@
 [ext_resource type="Shader" uid="uid://kyd37e0s6fdu" path="res://logic-scenes/board/physics-board.gdshader" id="1_ggnth"]
 [ext_resource type="Script" uid="uid://cqsor57nvowni" path="res://logic-scenes/board/card-board.gd" id="3_8v4c4"]
 [ext_resource type="AudioStream" uid="uid://bywmf3patoe56" path="res://base-environments/youth_room/audio/board_completed.wav" id="5_qjqy3"]
+[ext_resource type="Script" uid="uid://cwc0k3mtj4k1f" path="res://logic-scenes/board/side_board.gd" id="6_kvxnu"]
 [ext_resource type="AudioStream" uid="uid://bgtohhyd8whbm" path="res://base-environments/youth_room/audio/board_completed_de.wav" id="6_ni75f"]
 [ext_resource type="AudioStream" uid="uid://dj8fpajqhj4k7" path="res://base-environments/youth_room/audio/board_incomplete.wav" id="6_vtvtf"]
 [ext_resource type="AudioStream" uid="uid://brolrc3lhaeid" path="res://base-environments/youth_room/audio/board_unfitting.wav" id="7_0phgc"]
 [ext_resource type="AudioStream" uid="uid://swlo6elqs4vx" path="res://base-environments/youth_room/audio/board_incomplete_de.wav" id="7_2qppy"]
+[ext_resource type="Script" uid="uid://c7gbr6rdk843f" path="res://logic-scenes/board/side_boundary.gd" id="7_k5h0q"]
 [ext_resource type="Script" uid="uid://c1oub0cs7cph6" path="res://dev-util/stereo-switch.gd" id="8_ni75f"]
 [ext_resource type="AudioStream" uid="uid://y8fg3wjscvci" path="res://base-environments/youth_room/audio/board_unfitting_de.wav" id="10_kvxnu"]
 [ext_resource type="Texture2D" uid="uid://diviesbhf6p77" path="res://logic-scenes/board/board-texture/cardbord-box.png" id="11_ni75f"]
@@ -20,6 +22,9 @@ shader_parameter/magic_scale_factor = 1500.0
 
 [sub_resource type="StyleBoxFlat" id="StyleBoxFlat_m1g7s"]
 
+[sub_resource type="WorldBoundaryShape2D" id="WorldBoundaryShape2D_htay1"]
+normal = Vector2(-1, 0)
+
 [sub_resource type="Animation" id="Animation_qjqy3"]
 length = 0.001
 
@@ -164,7 +169,6 @@ script = ExtResource("3_8v4c4")
 
 [node name="CardboardBox" type="TextureRect" parent="." unique_id=450836053]
 unique_name_in_owner = true
-visible = false
 clip_contents = true
 layout_direction = 3
 layout_mode = 2
@@ -173,8 +177,10 @@ expand_mode = 2
 
 [node name="Label" type="Label" parent="CardboardBox" unique_id=1585163137]
 layout_mode = 0
-offset_right = 274.0
+offset_left = 14.0
-offset_bottom = 99.416664
+offset_top = 13.0
+offset_right = 288.0
+offset_bottom = 112.416664
 size_flags_horizontal = 8
 size_flags_vertical = 0
 theme_override_colors/font_color = Color(0, 0, 0, 1)
@@ -192,11 +198,28 @@ layout_mode = 2
 size_flags_horizontal = 3
 mouse_filter = 2
 
-[node name="NoteZone" type="Control" parent="HBoxContainer" unique_id=92501430]
+[node name="SideBoard" type="ScrollContainer" parent="HBoxContainer" unique_id=738913213]
 unique_name_in_owner = true
+clip_contents = false
 custom_minimum_size = Vector2(400, 0)
 layout_mode = 2
-mouse_filter = 1
+horizontal_scroll_mode = 0
+vertical_scroll_mode = 3
+script = ExtResource("6_kvxnu")
+
+[node name="Panel" type="Control" parent="HBoxContainer/SideBoard" unique_id=1893108919]
+custom_minimum_size = Vector2(400, 1500)
+layout_mode = 2
+mouse_filter = 2
+
+[node name="SideBoundary" type="Area2D" parent="HBoxContainer/SideBoard" unique_id=1180680912]
+position = Vector2(155, 0)
+collision_layer = 8
+collision_mask = 0
+script = ExtResource("7_k5h0q")
+
+[node name="CollisionShape2D" type="CollisionShape2D" parent="HBoxContainer/SideBoard/SideBoundary" unique_id=1692634692]
+shape = SubResource("WorldBoundaryShape2D_htay1")
 
 [node name="Timer" type="Timer" parent="." unique_id=1859393351]
 

src/logic-scenes/board/side_board.gd

@@ -0,0 +1,136 @@
+class_name SideBoard extends ScrollContainer
+
+@export var h_margin: = 8
+
+# Panel is a bit easier to understand as a name, while Control is easier to use.
+var panel: Control
+var board: CardBoard
+
+func _ready() -> void:
+	panel = $Panel
+	panel.custom_minimum_size = Vector2(size.x, 0)
+	board = owner
+
+func _start_drag(draggable: Draggable) -> void:
+	assert(false)
+
+func get_nearest_legal_position(from: Vector2, target: Draggable) -> Vector2:
+	var children := get_children_sorted()
+	
+	var nearest_child_below: Draggable
+	var nearest_child_above: Draggable
+	var min_distance_above: float
+	var min_distance_below: float
+	
+	
+	for i in range(children.size()):
+		if children[i].home.y < from.y:
+			nearest_child_above = children[i]
+			min_distance_above = children[i].get_size().y/2 + h_margin + target.get_size().y/2
+			if i > 0:
+				nearest_child_below = children[i-1]
+				min_distance_below = children[i-1].get_size().y/2 + h_margin + target.get_size().y/2
+	
+	if nearest_child_above:
+		from.y = minf(from.y, nearest_child_above.home.y - min_distance_above)
+	if nearest_child_below:
+		from.y = maxf(from.y, nearest_child_below.home.y - min_distance_below)
+	
+	from.x = _get_x_pos(target)
+	
+	return from
+
+func can_accept_drop(draggable: Draggable) -> bool:
+	return (draggable is Card and board.is_memory_board) or draggable is StickyNote
+
+# FIXME: this function seems to not be used.
+func handle_drop(draggable: Draggable) -> int:
+	if not can_accept_drop(draggable):
+		return Draggable.DropResult.REJECTED
+	return Draggable.DropResult.ACCEPTED
+
+# FIXME: integrate this into functions mentioned above!
+func accept_drop(draggable: Draggable) -> bool:
+	if can_accept_drop(draggable):
+		draggable.home = get_nearest_legal_position(draggable.global_position, draggable)
+		draggable.reparent(panel)
+		_scoot_children()
+		return true
+	return false
+
+func populate(with_notes: Array) -> Array[StickyNote]:
+	var notes: Array[StickyNote] = []
+	
+	for note: StickyNote in with_notes:
+		notes.append(note)
+		panel.add_child(note)
+		
+	_scoot_children(true)
+	
+	return notes
+
+
+func _scoot_children(force_packing: bool = false):
+	#FIXME: the non-force-packing algorythm is borked right now
+	force_packing = true
+	var children := get_children_sorted()
+	
+	if children.size() < 2: return
+	
+	var min_size := h_margin
+	
+	for child in children:
+		min_size += child.get_size().y + h_margin
+	
+	# If space is too tight, children will be spaced optimally.
+	if maxf(min_size, children[-1].home.y + children[-1].get_size().y) > (size.y - h_margin) or force_packing:
+		var top :float = h_margin
+		
+		for child in children:
+			child.home = Vector2(_get_x_pos(child), top + child.get_size().y/2)
+			top += h_margin + child.get_size().y
+			child.animate_home()
+	
+	else:
+		children[1].home.y = maxf(children[0].get_size().y + h_margin, children[1].home.y)
+		var last_distance := 0.0
+		for i in range(1, children.size()-1):
+			var min_distance_bottom: float = children[i+1].get_size().y/2 + h_margin + children[i].get_size().y/2
+			
+			var bottom_distance: float = children[i+1].home.y - children[i].home.y
+			
+			if bottom_distance < min_distance_bottom:
+				children[i-1].home.y = children[i-1].home.y - min(last_distance, bottom_distance)
+				
+				children[i].home.y = children[i-1].home.y + min_distance_bottom
+				
+			last_distance = maxf(children[i].home.y - children[i-1].home.y - min_distance_bottom, 0)
+			
+		for child in children:
+			child.home.x = _get_x_pos(child)
+			child.animate_home()
+		
+		if children[-1]:
+			panel.custom_minimum_size.y = children[-1].home.y + children[-1].get_size().y
+			
+func get_children_sorted() -> Array[Draggable]:
+	var children: Array[Draggable] = []
+	for child in panel.get_children(true):
+		if child is Draggable:
+			children.append(child)
+	
+	children.sort_custom(_by_position)
+	
+	return children
+
+func _get_x_pos(target: Draggable) -> float:
+	if target is StickyNote:
+		return size.x - 256
+	if target is Card:
+		return size.x - 160
+	
+	return 42
+	
+	
+func _by_position(a: Draggable, b: Draggable) -> bool:
+	return a.position.y < b.position.y

src/logic-scenes/board/side_board.gd.uid

@@ -0,0 +1 @@
+uid://cwc0k3mtj4k1f

src/logic-scenes/board/side_boundary.gd

@@ -0,0 +1 @@
+class_name SideBoundary extends Area2D

src/logic-scenes/board/side_boundary.gd.uid

@@ -0,0 +1 @@
+uid://c7gbr6rdk843f

src/logic-scenes/board/sticky-note.gd

@@ -71,8 +71,7 @@ func init(sticky_name: String = "sticky_note", card_id: StringName = "-1") -> vo
 	parent_id = StringName(card_id.rsplit(".", false, 1)[0])
 	sticky_id = card_id
 	
-	# first digit of the card id is 0-3 for youth cards.
+	from_youth = int((card_id as String)[0]) < (Scenes.id.TRANSITION as int)
-	from_youth = (card_id as String)[0] as int < 4
 
 func _ready() -> void:
 	super._ready()
@@ -112,8 +111,9 @@ func end_drag() -> Node:
 
 ## Find best drop target: Card > Panel > Board (in priority order)
 func _find_drop_target() -> Node:
+
 	# Priority 1: Check for overlapping cards in dropzone
-	var closest : Card = null
+	var closest : Node = null
 	for area in get_overlapping_areas():
 		if area is StickyNote and not area.is_attached: continue # Can only drop on attached stickies
 
@@ -121,9 +121,17 @@ func _find_drop_target() -> Node:
 			if (not closest) or ((area.position - position).length() < (closest.position - position).length()):
 				closest = area
 				
+		if area is SideBoundary:
+			if not closest:
+				closest = area
+
 	return closest
 
 
 ## Sticky notes are exempt from confinement if stuck to a card
 func confine_to_screen() -> void:
 	if attached_to is not Card: super.confine_to_screen()
+
+
+func get_size() -> Vector2:
+	return Vector2($CollisionShape2D.shape.height, $CollisionShape2D.shape.radius*2)

src/logic-scenes/board/sticky-note.tscn

@@ -10,7 +10,7 @@ height = 312.0
 
 [node name="sticky-note" type="Area2D" unique_id=1136333559]
 collision_layer = 2
-collision_mask = 6
+collision_mask = 14
 priority = 100
 script = ExtResource("1_yvh5n")
 text = "card"
@@ -37,12 +37,13 @@ anchor_left = 0.5
 anchor_top = 0.5
 anchor_right = 0.5
 anchor_bottom = 0.5
-offset_left = -52.0
+offset_left = -43.0
-offset_top = -50.0
+offset_top = -46.0
 offset_right = 243.0
-offset_bottom = 47.0
+offset_bottom = 42.0
 grow_horizontal = 2
 grow_vertical = 2
+mouse_default_cursor_shape = 13
 theme = ExtResource("3_qmm0h")
 theme_type_variation = &"card_text"
 text = "sticksum ipsum dolor sit amet met post-it sulcum dulce est 3M, et tesa est."