Improve handle syncing (#873)

src/ui_parts/PathHandle.gd

@@ -6,21 +6,22 @@ var command_index: int
 var x_param: String
 var y_param: String
 
-func _init(new_element: Element, command_idx: int, x_name := "x", y_name := "y") -> void:
+
+func _init(new_element: Element, command_idx: int, x_name: String, y_name: String) -> void:
 	element = new_element
 	command_index = command_idx
 	x_param = x_name
 	y_param = y_name
 	sync()
 
 func set_pos(new_pos: Vector2) -> void:
-	var path_attribute: AttributePathdata = element.get_attribute(pathdata_name)
-	var command := path_attribute.get_command(command_index)
-	var new_coords := new_pos - command.start if command.relative else new_pos
 	if pos != new_pos:
-		pos = new_pos
+		var path_attribute: AttributePathdata = element.get_attribute(pathdata_name)
+		var command := path_attribute.get_command(command_index)
+		var new_coords := new_pos - command.start if command.relative else new_pos
 		path_attribute.set_command_property(command_index, x_param, new_coords.x)
 		path_attribute.set_command_property(command_index, y_param, new_coords.y)
+		sync()
 
 
 func sync() -> void:

src/ui_parts/XYHandle.gd

@@ -3,19 +3,24 @@ class_name XYHandle extends Handle
 
 var x_name: String
 var y_name: String
+var attached_handles: Array[Handle]
 
-func _init(new_element: Element, xref: String, yref: String) -> void:
+func _init(new_element: Element, xref: String, yref: String,
+new_attached_handles: Array[Handle] = []) -> void:
 	element = new_element
 	x_name = xref
 	y_name = yref
+	attached_handles = new_attached_handles
 	sync()
 
 func set_pos(new_pos: Vector2) -> void:
 	if pos != new_pos:
-		pos = new_pos
 		element.set_attribute(x_name, new_pos.x)
 		element.set_attribute(y_name, new_pos.y)
+		sync()
 
 func sync() -> void:
 	pos = Vector2(element.get_attribute_num(x_name), element.get_attribute_num(y_name))
+	for handle in attached_handles:
+		handle.sync()
 	super()

src/ui_parts/handles_manager.gd

@@ -92,8 +92,7 @@ func _ready() -> void:
 	c.material = stroke_material
 	add_child(c, false, InternalMode.INTERNAL_MODE_BACK)
 
-	SVG.any_attribute_changed.connect(queue_redraw.unbind(1))
-	SVG.any_attribute_changed.connect(sync_handles.unbind(1))
+	SVG.any_attribute_changed.connect(sync_handles)
 	SVG.elements_layout_changed.connect(queue_update)
 	SVG.changed_unknown.connect(queue_update)
 	Indications.selection_changed.connect(queue_redraw)
@@ -111,22 +110,29 @@ func _process(_delta: float) -> void:
 		update_handles()
 		update_pending = false
 
-
 func update_handles() -> void:
 	handles.clear()
 	for element in SVG.root_element.get_all_elements():
 		match element.name:
 			"circle":
-				handles.append(XYHandle.new(element, "cx", "cy"))
-				handles.append(DeltaHandle.new(element, "cx", "cy", "r", true))
+				var delta_handle := DeltaHandle.new(element, "cx", "cy", "r", true)
+				var delta_handle_arr: Array[Handle] = [delta_handle]
+				handles.append(XYHandle.new(element, "cx", "cy", delta_handle_arr))
+				handles.append(delta_handle)
 			"ellipse":
-				handles.append(XYHandle.new(element, "cx", "cy"))
-				handles.append(DeltaHandle.new(element, "cx", "cy", "rx", true))
-				handles.append(DeltaHandle.new(element, "cx", "cy", "ry", false))
+				var delta_handle_1 := DeltaHandle.new(element, "cx", "cy", "rx", true)
+				var delta_handle_2 := DeltaHandle.new(element, "cx", "cy", "ry", false)
+				var delta_handle_arr: Array[Handle] = [delta_handle_1, delta_handle_2]
+				handles.append(XYHandle.new(element, "cx", "cy", delta_handle_arr))
+				handles.append(delta_handle_1)
+				handles.append(delta_handle_2)
 			"rect":
-				handles.append(XYHandle.new(element, "x", "y"))
-				handles.append(DeltaHandle.new(element, "x", "y", "width", true))
-				handles.append(DeltaHandle.new(element, "x", "y", "height", false))
+				var delta_handle_1 := DeltaHandle.new(element, "x", "y", "width", true)
+				var delta_handle_2 := DeltaHandle.new(element, "x", "y", "height", false)
+				var delta_handle_arr: Array[Handle] = [delta_handle_1, delta_handle_2]
+				handles.append(XYHandle.new(element, "x", "y", delta_handle_arr))
+				handles.append(delta_handle_1)
+				handles.append(delta_handle_2)
 			"line":
 				handles.append(XYHandle.new(element, "x1", "y1"))
 				handles.append(XYHandle.new(element, "x2", "y2"))
@@ -136,38 +142,36 @@ func update_handles() -> void:
 	Utils.throw_mouse_motion_event()
 	queue_redraw()
 
-
-func sync_handles() -> void:
-	# For XYHandles, sync them. For PathHandles, they can be added and removed as an
-	# attribute changes, so remove them and re-add them except for the dragged one.
-	for handle_idx in range(handles.size() - 1, -1, -1):
-		var handle := handles[handle_idx]
-		if handle is PathHandle:
-			if dragged_handle != handle:
-				handles.remove_at(handle_idx)
-		else:
-			handle.sync()
+func sync_handles(xid: PackedInt32Array) -> void:
+	var element := SVG.root_element.get_element(xid)
+	if not element is ElementPath:
+		return
 
-	for element in SVG.root_element.get_all_elements():
-		if element.name == "path":
-			handles += generate_path_handles(element)
+	var new_handles: Array[Handle] = []
+	for handle in handles:
+		if handle.element != element:
+			new_handles.append(handle)
+	handles = new_handles
+	handles += generate_path_handles(element)
 	queue_redraw()
 
 func generate_path_handles(element: Element) -> Array[Handle]:
-	var path_handles: Array[Handle] = []
 	var data_attrib: AttributePathdata = element.get_attribute("d")
-	for idx in data_attrib.get_command_count():
+	var path_handles: Array[Handle] = []
+	for idx in range(data_attrib.get_command_count() - 1, -1, -1):
 		var path_command := data_attrib.get_command(idx)
-		if not path_command.command_char in "Zz":
-			path_handles.append(PathHandle.new(element, idx))
-			if path_command.command_char in "CcQq":
-				var tangent := PathHandle.new(element, idx, "x1", "y1")
-				tangent.display_mode = Handle.Display.SMALL
-				path_handles.append(tangent)
-			if path_command.command_char in "CcSs":
-				var tangent := PathHandle.new(element, idx, "x2", "y2")
-				tangent.display_mode = Handle.Display.SMALL
-				path_handles.append(tangent)
+		if path_command.command_char in "Zz":
+			continue
+
+		if path_command.command_char in "CcQq":
+			var tangent := PathHandle.new(element, idx, "x1", "y1")
+			tangent.display_mode = Handle.Display.SMALL
+			path_handles.append(tangent)
+		if path_command.command_char in "CcSs":
+			var tangent := PathHandle.new(element, idx, "x2", "y2")
+			tangent.display_mode = Handle.Display.SMALL
+			path_handles.append(tangent)
+		path_handles.append(PathHandle.new(element, idx, "x", "y"))
 	return path_handles