Fix path popup command disabling (#958)

src/autoload/Indications.gd

@@ -565,10 +565,12 @@ func get_selection_context(popup_method: Callable, context: Context) -> ContextP
 							TranslationServer.translate("Insert After"),
 							popup_insert_command_after_context.bind(popup_method), false,
 							load("res://visual/icons/Plus.svg")))
-					btn_arr.append(ContextPopup.create_button(
-							TranslationServer.translate("Convert To"),
-							popup_convert_to_context.bind(popup_method), false,
-							load("res://visual/icons/Reload.svg")))
+					if inner_selections[0] != 0 or\
+					element_ref.get_attribute("d").get_command(0).command_char != "M":
+						btn_arr.append(ContextPopup.create_button(
+								TranslationServer.translate("Convert To"),
+								popup_convert_to_context.bind(popup_method), false,
+								load("res://visual/icons/Reload.svg")))
 			"polygon", "polyline":
 				if inner_selections.size() == 1:
 					btn_arr.append(ContextPopup.create_button(
@@ -606,27 +608,54 @@ func popup_convert_to_context(popup_method: Callable) -> void:
 		context_popup.setup(btn_arr, true)
 		popup_method.call(context_popup)
 	elif not inner_selections.is_empty() and not semi_selected_xid.is_empty():
-		var cmd_char: String = SVG.root_element.get_xnode(semi_selected_xid).\
-				get_attribute("d").get_command(inner_selections[0]).command_char
+		var path_attrib: AttributePathdata =\
+				SVG.root_element.get_xnode(semi_selected_xid).get_attribute("d")
+		var selection_idx: int = inner_selections.max()
+		var cmd_char := path_attrib.get_command(selection_idx).command_char
+
 		var command_picker = PathCommandPopup.instantiate()
 		popup_method.call(command_picker)
 		command_picker.force_relativity(Utils.is_string_lower(cmd_char))
-		command_picker.disable_invalid([cmd_char.to_upper()])
+
+		var cmd_char_upper := cmd_char.to_upper()
+		var disabled_commands := PackedStringArray()
+		if selection_idx == 0:
+			disabled_commands = PackedStringArray(["L", "H", "V", "A", "Z", "Q", "T", "C", "S"])
+		else:
+			disabled_commands = PackedStringArray([cmd_char.to_upper()])
+			if cmd_char_upper != "Z" and\
+			path_attrib.get_command_count() > selection_idx + 1 and\
+			path_attrib.get_command(selection_idx + 1).command_char.to_upper() == "Z":
+				disabled_commands.append("Z")
+
+		command_picker.mark_invalid(PackedStringArray(), disabled_commands)
 		command_picker.path_command_picked.connect(convert_selected_command_to)
 
 func popup_insert_command_after_context(popup_method: Callable) -> void:
-	var cmd_char: String = SVG.root_element.get_xnode(semi_selected_xid).\
-			get_attribute("d").get_command(inner_selections.max()).command_char
+	var path_attrib: AttributePathdata =\
+			SVG.root_element.get_xnode(semi_selected_xid).get_attribute("d")
+	var selection_idx: int = inner_selections.max()
+	var cmd_char := path_attrib.get_command(selection_idx).command_char
 
 	var command_picker = PathCommandPopup.instantiate()
 	popup_method.call(command_picker)
 	command_picker.path_command_picked.connect(insert_path_command_after_selection)
+	# Disable invalid commands. Z is syntactically invalid, so disallow it even harder.
+	var warned_commands := PackedStringArray()
+	var disabled_commands := PackedStringArray()
+	var disable_z := false
 	match cmd_char.to_upper():
-		"M": command_picker.disable_invalid(["M", "Z", "T"])
-		"Z": command_picker.disable_invalid(["Z"])
-		"L", "H", "V", "A": command_picker.disable_invalid(["S", "T"])
-		"C", "S": command_picker.disable_invalid(["T"])
-		"Q", "T": command_picker.disable_invalid(["S"])
+		"M": warned_commands = PackedStringArray(["M", "Z", "T"])
+		"Z": disable_z = true
+		"L", "H", "V", "A": warned_commands = PackedStringArray(["S", "T"])
+		"C", "S": warned_commands = PackedStringArray(["T"])
+		"Q", "T": warned_commands = PackedStringArray(["S"])
+
+	if disable_z or (path_attrib.get_command_count() > selection_idx and\
+	path_attrib.get_command(selection_idx + 1).command_char.to_upper() == "Z"):
+		disabled_commands = PackedStringArray(["Z"])
+
+	command_picker.mark_invalid(warned_commands, disabled_commands)
 
 func convert_selected_element_to(element_name: String) -> void:
 	var xid := selected_xids[0]

src/ui_widgets/path_command_button.gd

@@ -1,6 +1,8 @@
 # A button for a path command picker.
 extends Button
 
+var warned := false
+
 signal pressed_custom(cmd_char: String)
 
 @export var command_char := ""
@@ -17,10 +19,18 @@ func set_invalid(new_state := true) -> void:
 	disabled = new_state
 	mouse_default_cursor_shape = CURSOR_ARROW if new_state else CURSOR_POINTING_HAND
 
+func set_warning(new_state := true) -> void:
+	warned = true
+
 # Couldn't think of any way to get RichTextLabel to autoresize its font on one line.
 func _draw() -> void:
 	var text_obj := TextLine.new()
-	var text_color := Color(0.5, 0.5, 0.5) if disabled else Color(1, 1, 1)
+	var text_color := Color(1, 1, 1)
+	if disabled:
+		text_color = Color(0.5, 0.5, 0.5)
+	elif warned:
+		text_color = GlobalSettings.savedata.basic_color_warning
+
 	var left_margin := get_theme_stylebox("normal").content_margin_left
 	var right_margin := get_theme_stylebox("normal").content_margin_right
 	var max_size := size.x - left_margin - right_margin

src/ui_widgets/path_popup.gd

@@ -25,10 +25,11 @@ func _on_relative_toggle_toggled(toggled_on: bool) -> void:
 				else command_button.command_char.to_upper()
 		command_button.queue_redraw()
 
-func disable_invalid(cmd_chars: Array) -> void:
-	for cmd_char in cmd_chars:
-		var cmd_char_upper: String = cmd_char.to_upper()
-		command_container.get_node(cmd_char_upper).set_invalid()
+func mark_invalid(warned: PackedStringArray, disabled: PackedStringArray) -> void:
+	for cmd_char in warned:
+		command_container.get_node(cmd_char.to_upper()).set_warning()
+	for cmd_char in disabled:
+		command_container.get_node(cmd_char.to_upper()).set_invalid()
 
 func force_relativity(relative: bool) -> void:
 	relative_toggle.hide()