[gnome-builder] symbol-tree: avoid jumping between files when movin to symbol

[Christian Hergert <chergert src gnome org>]

commit fbc91acfd1bc41d71196d2c753933ae6199123f0
Author: Christian Hergert <chergert redhat com>
Date:   Fri Mar 6 10:34:13 2020 -0800

    symbol-tree: avoid jumping between files when movin to symbol
    
    We do not want to rely on the IdeEditorSurface to jump to a location here
    because it means that we might not activate the same IdePage that we are
    currently viewing.
    
    Instead, this tries to jump usin the local frame, and then falls back to
    the editor surface (just in case we raced to complete the operation with
    a page switch).
    
    Related: #723

 src/plugins/symbol-tree/gbp-symbol-tree-builder.c | 47 ++++++++++++++++++++++-
 1 file changed, 46 insertions(+), 1 deletion(-)
---
diff --git a/src/plugins/symbol-tree/gbp-symbol-tree-builder.c 
b/src/plugins/symbol-tree/gbp-symbol-tree-builder.c
index 5f6c3900e..e724f7f39 100644
--- a/src/plugins/symbol-tree/gbp-symbol-tree-builder.c
+++ b/src/plugins/symbol-tree/gbp-symbol-tree-builder.c
@@ -89,6 +89,27 @@ gbp_symbol_tree_builder_build_children (DzlTreeBuilder *builder,
     }
 }
 
+static gboolean
+page_contains_location (IdePage     *page,
+                        IdeLocation *location)
+{
+  IdeBuffer *buffer;
+  GFile *file;
+  GFile *loc_file;
+
+  if (location == NULL || !IDE_IS_EDITOR_PAGE (page))
+    return FALSE;
+
+  buffer = ide_editor_page_get_buffer (IDE_EDITOR_PAGE (page));
+  file = ide_buffer_get_file (buffer);
+  loc_file = ide_location_get_file (location);
+
+  if (file == NULL || loc_file == NULL)
+    return FALSE;
+
+  return g_file_equal (file, loc_file);
+}
+
 static void
 gbp_symbol_tree_builder_get_location_cb (GObject      *object,
                                          GAsyncResult *result,
@@ -98,9 +119,13 @@ gbp_symbol_tree_builder_get_location_cb (GObject      *object,
   g_autoptr(GbpSymbolTreeBuilder) self = user_data;
   g_autoptr(IdeLocation) location = NULL;
   g_autoptr(GError) error = NULL;
-  IdeSurface *editor;
   IdeWorkspace *workspace;
+  IdeSurface *editor;
+  IdeFrame *frame;
+  IdePage *page;
   DzlTree *tree;
+  gint line;
+  gint line_offset;
 
   IDE_ENTRY;
 
@@ -120,6 +145,26 @@ gbp_symbol_tree_builder_get_location_cb (GObject      *object,
   tree = dzl_tree_builder_get_tree (DZL_TREE_BUILDER (self));
   workspace = ide_widget_get_workspace (GTK_WIDGET (tree));
   editor = ide_workspace_get_surface_by_name (workspace, "editor");
+  frame = IDE_FRAME (dzl_gtk_widget_get_relative (GTK_WIDGET (tree), IDE_TYPE_FRAME));
+  page = ide_frame_get_visible_child (frame);
+  line = ide_location_get_line (location);
+  line_offset = ide_location_get_line_offset (location);
+
+  /* Because we activated from within the document, we can ignore
+   * using ide_editor_surface_focus_location() and instead just jump
+   * to the resulting line and column.
+   */
+  if (page_contains_location (page, location))
+    {
+      if (line > 0 || line_offset > 0)
+        ide_editor_page_scroll_to_line_offset (IDE_EDITOR_PAGE (page),
+                                               MAX (0, line),
+                                               MAX (0, line_offset));
+      else
+        gtk_widget_grab_focus (GTK_WIDGET (page));
+
+      IDE_EXIT;
+    }
 
   ide_editor_surface_focus_location (IDE_EDITOR_SURFACE (editor), location);