1 files changed, 52 insertions, 7 deletions

diff --git a/src/main.rs b/src/main.rs
index 35a3ca3..ad81cea 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -19,7 +19,7 @@ mod wasm;
 
 use library::NodeIndex;
 use node::{AnyNode, ConcreteNode};
-use snarl_ext::{Compilable, WithSignatures};
+use snarl_ext::{Compilable, GraphError, WithSignatures};
 use types::{Dimension, FloatPrecision, ScalarType, Type};
 
 impl Into<PinInfo> for Type {
@@ -41,12 +41,30 @@ impl Into<PinInfo> for Type {
     }
 }
 
+static ERROR_COLOR: Color32 = Color32::from_rgb(0xc0, 0x00, 0x00);
+
 pub struct Viewer {
     dirty: bool,
     filename: Option<PathBuf>,
+    error: Option<GraphError>,
+
+    #[cfg(target_arch = "wasm32")]
     save_as_dialog: Option<String>,
 }
 
+impl Default for Viewer {
+    fn default() -> Self {
+        Self {
+            dirty: true,
+            filename: None,
+            error: None,
+
+            #[cfg(target_arch = "wasm32")]
+            save_as_dialog: None,
+        }
+    }
+}
+
 impl SnarlViewer<AnyNode> for Viewer {
     #[inline]
     fn connect(&mut self, from: &OutPin, to: &InPin, snarl: &mut Snarl<AnyNode>) {
@@ -126,6 +144,23 @@ impl SnarlViewer<AnyNode> for Viewer {
         }
     }
 
+    fn node_frame(
+        &mut self,
+        mut default: egui::Frame,
+        node: NodeId,
+        _inputs: &[InPin],
+        _outputs: &[OutPin],
+        _snarl: &Snarl<AnyNode>,
+    ) -> egui::Frame {
+        if Some(node) == self.error.and_then(|e| e.1) {
+            default.stroke = egui::Stroke {
+                width: 2.0,
+                color: ERROR_COLOR,
+            };
+        }
+
+        default
+    }
     fn has_graph_menu(&mut self, _pos: egui::Pos2, _snarl: &mut Snarl<AnyNode>) -> bool {
         true
     }
@@ -133,6 +168,7 @@ impl SnarlViewer<AnyNode> for Viewer {
     fn show_graph_menu(&mut self, pos: egui::Pos2, ui: &mut Ui, snarl: &mut Snarl<AnyNode>) {
         if let Some(node) = AnyNode::pick_node(ui) {
             snarl.insert_node(pos, node);
+            self.dirty = true;
             ui.close();
         }
     }
@@ -152,6 +188,7 @@ impl SnarlViewer<AnyNode> for Viewer {
         ui.label("Node menu");
         if ui.button("Remove").clicked() {
             snarl.remove_node(node);
+            self.dirty = true;
             ui.close();
         }
     }
@@ -221,11 +258,7 @@ impl App {
 
         App {
             snarl,
-            viewer: Viewer {
-                dirty: true,
-                filename: None,
-                save_as_dialog: None,
-            },
+            viewer: Default::default(),
             preview: preview::Preview::new(cx).expect("Failed to init preview"),
         }
     }
@@ -371,10 +404,13 @@ impl eframe::App for App {
             match self.snarl.compile(&mut buf) {
                 Ok(()) => {
                     info!("{}", buf);
+                    self.viewer.error = None;
                     Some(buf)
                 }
                 Err(x) => {
-                    error!("Error compiling: {}", x);
+                    error!("Error compiling: {:?}", x);
+                    self.viewer.dirty = false;
+                    self.viewer.error = Some(x);
                     None
                 }
             }
@@ -388,6 +424,15 @@ impl eframe::App for App {
                     self.viewer.dirty = false;
                 }
             });
+
+            if let Some(err) = &self.viewer.error {
+                let message = if let Some(node) = err.1 {
+                    format!("Error in node {}: {:?}", node.0, err.0)
+                } else {
+                    format!("Error while compiling: {:?}", err.0)
+                };
+                ui.colored_label(Color32::from_rgb(0xff, 0, 0), message);
+            }
         });
 
         egui::CentralPanel::default().show(ctx, |ui| {