Search for nearest ancestor widget when scrolling with mousewheel

bin/Tk/FIJIUtils.pm

@@ -189,27 +189,31 @@ sub _wheel_handler {
 
     my ($event_widget, $val, $mw) = @_;
 
-    for (my $index = 0; $index < @{$mw->{'scrollable_widgets'}}; $index++) {
-        my $widget_to_scroll = @{$mw->{'scrollable_widgets'}}[$index];
-        # remove already deleted widgets from list
-        unless (Tk::Exists($widget_to_scroll)) {
-            delete @{$mw->{'scrollable_widgets'}}[$index];
-            next;
-        }
-        # only scroll if visible
-        next if (!$widget_to_scroll->ismapped());
-        my $scrolled = $widget_to_scroll->Subwidget('scrolled');
-        my $container;
-        for ($container = $event_widget; 
-             defined $container && $container != $widget_to_scroll;
-             $container = $container->parent) {}
-        next if (!defined $container);
-        if ($^O eq "MSWin32") {
-            $scrolled->yview(scroll=>(-$val/120)*SCROLL,'units');
-        } else {
-            $scrolled->yview(scroll=>$val*SCROLL,'units');
+    my $container;
+
+    # search through hierarchy of widget causing the event
+    # for the nearest ancestor in the list of widgets to be scrolled
+    for ($container = $event_widget; defined $container; $container = $container->parent) {
+        # search the list of the widgets to be scrolled
+        for (my $index = 0; $index < @{$mw->{'scrollable_widgets'}}; $index++) {
+            my $widget_to_scroll = @{$mw->{'scrollable_widgets'}}[$index];
+            # remove already deleted widgets from list
+            unless (Tk::Exists($widget_to_scroll)) {
+                delete @{$mw->{'scrollable_widgets'}}[$index];
+                next;
+            }
+            next if $container != @{$mw->{'scrollable_widgets'}}[$index];
+            my $scrolled = $widget_to_scroll->Subwidget('scrolled');
+            if ($^O eq "MSWin32") {
+                $scrolled->yview(scroll=>(-$val/120)*SCROLL,'units');
+            } else {
+                $scrolled->yview(scroll=>$val*SCROLL,'units');
+            }
+            goto END;
         }
     }
+END:
+    return;
 }
 
 1;