GTK: prevent the user from creating invalid tikz

The free-form entry fields (graph element properties and node labels)
are a potential source of invalid tikz code.  Since we quote any
dodgy-looking text with { and }, we just need to make sure there are no
unmatched curly braces entered in those fields.

This will turn the entry widgets red when there are unmatched braces,
and refuse to make use of any such values.

1 files changed, 19 insertions, 9 deletions

diff --git a/tikzit/src/gtk/PropertiesPane.m b/tikzit/src/gtk/PropertiesPane.m
index 990304e..36dd079 100644
--- a/tikzit/src/gtk/PropertiesPane.m
+++ b/tikzit/src/gtk/PropertiesPane.m
@@ -337,10 +337,14 @@ static void edge_node_toggled_cb (GtkToggleButton *widget, PropertiesPane *pane)
         return;
     }
 
-    Node *node = [sel anyObject];
-    [document startModifyNode:node];
-    [node setLabel:newValue];
-    [document endModifyNode];
+    if ([newValue isValidTikz]) {
+        Node *node = [sel anyObject];
+        [document startModifyNode:node];
+        [node setLabel:newValue];
+        [document endModifyNode];
+    } else {
+        widget_set_error (GTK_WIDGET (nodeLabelEntry));
+    }
 }
 
 - (void) edgeNodeLabelEdited:(NSString*)newValue {
@@ -359,9 +363,13 @@ static void edge_node_toggled_cb (GtkToggleButton *widget, PropertiesPane *pane)
         return;
     }
 
-    [document startModifyEdge:edge];
-    [[edge edgeNode] setLabel:newValue];
-    [document endModifyEdge];
+    if ([newValue isValidTikz]) {
+        [document startModifyEdge:edge];
+        [[edge edgeNode] setLabel:newValue];
+        [document endModifyEdge];
+    } else {
+        widget_set_error (GTK_WIDGET (edgeNodeLabelEntry));
+    }
 }
 
 - (void) edgeNodeToggled:(BOOL)newValue {
@@ -410,6 +418,7 @@ static void edge_node_toggled_cb (GtkToggleButton *widget, PropertiesPane *pane)
         [nodePropDelegate setNode:n];
         [nodeProps setData:[n data]];
         gtk_entry_set_text (nodeLabelEntry, [[n label] UTF8String]);
+        widget_clear_error (GTK_WIDGET (nodeLabelEntry));
         [self _setDisplayedWidget:nodePropsWidget];
         editGraphProps = NO;
     } else {
@@ -422,16 +431,17 @@ static void edge_node_toggled_cb (GtkToggleButton *widget, PropertiesPane *pane)
             Edge *e = [edgeSel anyObject];
             [edgePropDelegate setEdge:e];
             [edgeProps setData:[e data]];
+            widget_clear_error (GTK_WIDGET (edgeNodeLabelEntry));
             if ([e hasEdgeNode]) {
                 gtk_toggle_button_set_active (edgeNodeToggle, TRUE);
                 gtk_widget_show (edgeNodePropsWidget);
-                gtk_entry_set_text (GTK_ENTRY (edgeNodeLabelEntry), [[[e edgeNode] label] UTF8String]);
+                gtk_entry_set_text (edgeNodeLabelEntry, [[[e edgeNode] label] UTF8String]);
                 [edgeNodeProps setData:[[e edgeNode] data]];
                 gtk_widget_set_sensitive (edgeNodePropsWidget, TRUE);
             } else {
                 gtk_toggle_button_set_active (edgeNodeToggle, FALSE);
                 gtk_widget_hide (edgeNodePropsWidget);
-                gtk_entry_set_text (GTK_ENTRY (edgeNodeLabelEntry), "");
+                gtk_entry_set_text (edgeNodeLabelEntry, "");
                 [edgeNodeProps setData:nil];
                 gtk_widget_set_sensitive (edgeNodePropsWidget, FALSE);
             }