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, 52 insertions, 0 deletions

diff --git a/tikzit/src/gtk/PropertyListEditor.m b/tikzit/src/gtk/PropertyListEditor.m
index ba909da..72b7441 100644
--- a/tikzit/src/gtk/PropertyListEditor.m
+++ b/tikzit/src/gtk/PropertyListEditor.m
@@ -16,6 +16,7 @@
  */
 
 #import "PropertyListEditor.h"
+#import "gtkhelpers.h"
 
 // {{{ Constants
 
@@ -45,6 +46,12 @@ static void add_atom_clicked_cb (GtkButton *button,
                                  PropertyListEditor  *editor);
 static void remove_clicked_cb (GtkButton *button,
                                PropertyListEditor  *editor);
+static void text_editing_started (GtkCellRenderer     *cell,
+                                  GtkCellEditable     *editable,
+                                  const gchar         *path,
+                                  PropertyListEditor  *editor);
+static void text_changed_cb (GtkEditable *editable,
+                             PropertyListEditor *pane);
 
 // }}}
 // {{{ Private
@@ -95,6 +102,10 @@ static void remove_clicked_cb (GtkButton *button,
                                                            NULL);
         gtk_tree_view_append_column (GTK_TREE_VIEW (view), column);
         g_signal_connect (G_OBJECT (renderer),
+            "editing-started",
+            G_CALLBACK (text_editing_started),
+            self);
+        g_signal_connect (G_OBJECT (renderer),
             "edited",
             G_CALLBACK (name_edited_cb),
             self);
@@ -237,6 +248,9 @@ static void remove_clicked_cb (GtkButton *button,
 
 @implementation PropertyListEditor (Private)
 - (void) updatePath:(gchar*)pathStr withValue:(NSString*)newText {
+    if (![newText isValidTikz])
+        return;
+
     GtkTreeIter iter;
     GtkTreePath *path = gtk_tree_path_new_from_string (pathStr);
 
@@ -265,6 +279,9 @@ static void remove_clicked_cb (GtkButton *button,
 }
 
 - (void) updatePath:(gchar*)pathStr withName:(NSString*)newText {
+    if (![newText isValidTikz])
+        return;
+
     GtkTreeIter iter;
     GtkTreePath *path = gtk_tree_path_new_from_string (pathStr);
 
@@ -420,6 +437,41 @@ static void remove_clicked_cb (GtkButton *button,
     [pool drain];
 }
 
+static void text_editing_started (GtkCellRenderer    *cell,
+                                  GtkCellEditable    *editable,
+                                  const gchar        *path,
+                                  PropertyListEditor *editor)
+{
+    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+
+    if (GTK_IS_EDITABLE (editable) && GTK_IS_WIDGET (editable)) {
+        g_signal_handlers_disconnect_by_func (G_OBJECT (editable),
+            G_CALLBACK (text_changed_cb),
+            editor);
+        widget_clear_error (GTK_WIDGET (editable));
+        g_signal_connect (G_OBJECT (editable),
+            "changed",
+            G_CALLBACK (text_changed_cb),
+            editor);
+    }
+
+    [pool drain];
+}
+
+static void text_changed_cb (GtkEditable *editable, PropertyListEditor *pane)
+{
+    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+
+    NSString *newValue = gtk_editable_get_string (editable, 0, -1);
+    if (![newValue isValidTikz]) {
+        widget_set_error (GTK_WIDGET (editable));
+    } else {
+        widget_clear_error (GTK_WIDGET (editable));
+    }
+
+    [pool drain];
+}
+
 // }}}
 
 // vim:ft=objc:ts=8:et:sts=4:sw=4:foldmethod=marker