improve portal edit UX

ability to cancel adding a portal as well as removing existing portal
closes #94.

CHANGELOG.md

@@ -8,6 +8,7 @@
 ### Added
 
 - Added "disable train" setting for blocks. Any train in a block with this setting enabled will not be connected via bluetooth. Layout Controllers will only need to connect when a device is assigned to one of it's ports. (https://github.com/Novakasa/brickrail/issues/161)
+- Improved Portal UX. Made add portal process cancellable, added option to remove the Portal again (https://github.com/Novakasa/brickrail/issues/94).
 
 ### Fixed
 

brickrail-gui/layout/track/directed_layout_track.gd

@@ -519,6 +519,13 @@ func has_portal():
 		if not is_continuous_to(connections[turn], turn):
 			return true
 	return false
+
+func remove_portal(first_call=true):
+	for turn in connections:
+		if not is_continuous_to(connections[turn], turn):
+			if first_call:
+				connections[turn].get_opposite().remove_portal(false)
+			disconnect_turn(turn)
 
 func get_shader_state(turn):
 	var state = 0

brickrail-gui/layout/track/layout_section_inspector.gd

@@ -7,6 +7,9 @@ func _enter_tree():
 	var _err = LayoutInfo.connect("layout_mode_changed", self, "_on_layout_mode_changed")
 
 func _on_layout_mode_changed(mode):
+	if mode == "edit":
+		# if portal is added
+		_on_section_track_added(null)
 	if mode == "control":
 		section.unselect()
 
@@ -38,6 +41,10 @@ func _on_section_track_added(_track):
 			update_speed_select()
 		if dirtrack.get_next() == null:
 			$AddPortal.visible=true
+			$AddPortal.text = "Add portal"
+		elif dirtrack.has_portal():
+			$AddPortal.visible=true
+			$AddPortal.text = "Remove portal"
 		else:
 			$AddPortal.visible=false
 		$FacingFilterSelector.visible=true
@@ -140,8 +147,16 @@ func _on_OneWayCheckbox_toggled(button_pressed):
 	section.tracks[0].set_one_way(button_pressed)
 
 func _on_AddPortal_pressed():
-	LayoutInfo.set_portal_dirtrack(dirtrack)
-	LayoutInfo.set_layout_mode("portal")
+	if section.tracks[0].has_portal():
+		section.tracks[0].remove_portal()
+		_on_section_track_added(null)
+	elif LayoutInfo.layout_mode != "portal":
+		LayoutInfo.set_portal_dirtrack(dirtrack)
+		LayoutInfo.set_layout_mode("portal")
+		$AddPortal.text = "Cancel portal"
+	else:
+		LayoutInfo.set_layout_mode("edit")
+		$AddPortal.text = "Add portal"
 
 func _on_FacingFilterSelector_meta_selected(meta):
 	section.tracks[0].set_facing_filter(meta)