Initial commit

Half-baked state. Most of the UI is mostly done, but the integration
with Grist (or any other data provider) is still missing.

gui.gd

@@ -0,0 +1,26 @@
+extends Container
+
+func _ready() -> void:
+	%DebugScaleSlider.value_changed.connect(Global.set_scale)
+	
+	%TaraButton.pressed.connect(_on_tara_button)
+	%OkayButton.pressed.connect(Global.confirm_entry)
+	%FinishButton.pressed.connect(_on_finish_button)
+	
+	Global.cart_updated.connect(_on_cart_updated)
+	
+	Global.weights_updated.emit() # Replace placeholder texts
+
+func _on_tara_button():
+	var popup = load("res://tara_popup.tscn").instantiate()
+	add_child(popup)
+	popup.popup_centered()
+	
+func _on_finish_button():
+	var popup = load("res://finish_popup.tscn").instantiate()
+	add_child(popup)
+	popup.popup_centered()
+	
+
+func _on_cart_updated():
+	%CartTotal.text = "Summe: %.2f€" % (Global.cart_total_cents / 100.0)