Add Brush tool warning; move font list loading to document creation time

editor/src/messages/tool/tool_messages/brush_tool.rs

@@ -29,6 +29,7 @@ pub struct BrushTool {
 }
 
 pub struct BrushOptions {
+	legacy_warning_was_shown: bool,
 	diameter: f64,
 	hardness: f64,
 	flow: f64,
@@ -41,6 +42,7 @@ pub struct BrushOptions {
 impl Default for BrushOptions {
 	fn default() -> Self {
 		Self {
+			legacy_warning_was_shown: false,
 			diameter: DEFAULT_BRUSH_SIZE,
 			hardness: 0.,
 			flow: 100.,
@@ -78,6 +80,7 @@ pub enum BrushToolMessageOptionsUpdate {
 	Hardness(f64),
 	Spacing(f64),
 	WorkingColors(Option<Color>, Option<Color>),
+	NoDisplayLegacyWarning,
 }
 
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
@@ -217,6 +220,7 @@ impl<'a> MessageHandler<ToolMessage, &mut ToolActionHandlerData<'a>> for BrushTo
 				self.options.color.primary_working_color = primary;
 				self.options.color.secondary_working_color = secondary;
 			}
+			BrushToolMessageOptionsUpdate::NoDisplayLegacyWarning => self.options.legacy_warning_was_shown = true,
 		}
 
 		self.send_layout(responses, LayoutTarget::ToolOptions);
@@ -308,6 +312,20 @@ impl Fsm for BrushToolFsmState {
 			document, global_tool_data, input, ..
 		} = tool_action_data;
 
+		if !tool_options.legacy_warning_was_shown {
+			responses.add(DialogMessage::DisplayDialogError {
+				title: "Unsupported tool".into(),
+				description: "
+					The current Brush tool is a legacy feature with\n\
+					significant quality and performance limitations.\n\
+					It will be replaced soon by a new implementation.\n\
+					"
+				.trim()
+				.into(),
+			});
+			responses.add(BrushToolMessage::UpdateOptions(BrushToolMessageOptionsUpdate::NoDisplayLegacyWarning));
+		}
+
 		let ToolMessage::Brush(event) = event else {
 			return self;
 		};