[gtk+] GtkLabel: better treatment for ellipsized links

[Matthias Clasen <matthiasc src gnome org>]

commit 1cddd14ab4f9d420b92ea091f247561697f67458
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Sep 3 20:49:44 2014 -0400

    GtkLabel: better treatment for ellipsized links
    
    When links are entirely hidden in an ellipsis, don't let
    them be activated by clicking and skip them when moving
    the focus around.
    
    This commit depends on enhancements in pango 1.36.7 which
    make it possible to find the ellipsed runs in a PangoLayout.
    With older pango, things will work the same way as before.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=668258

 gtk/gtklabel.c |  111 ++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 files changed, 95 insertions(+), 16 deletions(-)
---
diff --git a/gtk/gtklabel.c b/gtk/gtklabel.c
index cf60cf3..d5377ae 100644
--- a/gtk/gtklabel.c
+++ b/gtk/gtklabel.c
@@ -4561,6 +4561,53 @@ get_layout_index (GtkLabel *label,
   return inside;
 }
 
+static gboolean
+range_is_in_ellipsis (GtkLabel *label,
+                      gint      start,
+                      gint      end)
+{
+  GtkLabelPrivate *priv = label->priv;
+  PangoLayoutIter *iter;
+  gboolean in_ellipsis;
+
+  if (!priv->ellipsize)
+    return FALSE;
+
+  gtk_label_ensure_layout (label);
+
+  if (!pango_layout_is_ellipsized (priv->layout))
+    return FALSE;
+
+  iter = pango_layout_get_iter (priv->layout);
+
+  in_ellipsis = FALSE;
+
+  do {
+    PangoLayoutRun *run;
+
+    run = pango_layout_iter_get_run_readonly (iter);
+    if (run)
+      {
+        PangoItem *item;
+
+        item = ((PangoGlyphItem*)run)->item;
+
+        if (item->offset <= start && end <= item->offset + item->length)
+          {
+            if (item->analysis.flags & PANGO_ANALYSIS_FLAG_IS_ELLIPSIS)
+              in_ellipsis = TRUE;
+            break;
+          }
+        else if (item->offset + item->length >= end)
+          break;
+      }
+  } while (pango_layout_iter_next_run (iter));
+
+  pango_layout_iter_free (iter);
+
+  return in_ellipsis;
+}
+
 static void
 gtk_label_select_word (GtkLabel *label)
 {
@@ -4588,6 +4635,7 @@ gtk_label_grab_focus (GtkWidget *widget)
   GtkLabelPrivate *priv = label->priv;
   gboolean select_on_focus;
   GtkLabelLink *link;
+  GList *l;
 
   if (priv->select_info == NULL)
     return;
@@ -4608,10 +4656,17 @@ gtk_label_grab_focus (GtkWidget *widget)
     {
       if (priv->select_info->links && !priv->in_click)
         {
-          link = priv->select_info->links->data;
-          priv->select_info->selection_anchor = link->start;
-          priv->select_info->selection_end = link->start;
-          _gtk_label_accessible_focus_link_changed (label);
+          for (l = priv->select_info->links; l; l = l->next)
+            {
+              link = l->data;
+              if (!range_is_in_ellipsis (label, link->start, link->end))
+                {
+                  priv->select_info->selection_anchor = link->start;
+                  priv->select_info->selection_end = link->start;
+                  _gtk_label_accessible_focus_link_changed (label);
+                  break;
+                }
+            }
         }
     }
 }
@@ -4634,11 +4689,16 @@ gtk_label_focus (GtkWidget        *widget,
           focus_link = gtk_label_get_focus_link (label);
           if (focus_link && direction == GTK_DIR_TAB_BACKWARD)
             {
-              l = g_list_last (info->links);
-              focus_link = l->data;
-              info->selection_anchor = focus_link->start;
-              info->selection_end = focus_link->start;
-              _gtk_label_accessible_focus_link_changed (label);
+              for (l = g_list_last (info->links); l; l = l->prev)
+                {
+                  focus_link = l->data;
+                  if (!range_is_in_ellipsis (label, focus_link->start, focus_link->end))
+                    {
+                      info->selection_anchor = focus_link->start;
+                      info->selection_end = focus_link->start;
+                      _gtk_label_accessible_focus_link_changed (label);
+                    }
+                }
             }
         }
 
@@ -4664,9 +4724,12 @@ gtk_label_focus (GtkWidget        *widget,
 
             if (link->start > index)
               {
-                gtk_label_select_region_index (label, link->start, link->start);
-                _gtk_label_accessible_focus_link_changed (label);
-                return TRUE;
+                if (!range_is_in_ellipsis (label, link->start, link->end))
+                  {
+                    gtk_label_select_region_index (label, link->start, link->start);
+                    _gtk_label_accessible_focus_link_changed (label);
+                    return TRUE;
+                  }
               }
           }
       else if (direction == GTK_DIR_TAB_BACKWARD)
@@ -4676,9 +4739,12 @@ gtk_label_focus (GtkWidget        *widget,
 
             if (link->end < index)
               {
-                gtk_label_select_region_index (label, link->start, link->start);
-                _gtk_label_accessible_focus_link_changed (label);
-                return TRUE;
+                if (!range_is_in_ellipsis (label, link->start, link->end))
+                  {
+                    gtk_label_select_region_index (label, link->start, link->start);
+                    _gtk_label_accessible_focus_link_changed (label);
+                    return TRUE;
+                  }
               }
           }
 
@@ -4697,6 +4763,12 @@ gtk_label_focus (GtkWidget        *widget,
             }
           else
             l = info->links;
+          for (; l; l = l->next)
+            {
+              GtkLabelLink *link = l->data;
+              if (!range_is_in_ellipsis (label, link->start, link->end))
+                break;
+            }
           break;
 
         case GTK_DIR_TAB_BACKWARD:
@@ -4707,6 +4779,12 @@ gtk_label_focus (GtkWidget        *widget,
             }
           else
             l = g_list_last (info->links);
+          for (; l; l = l->prev)
+            {
+              GtkLabelLink *link = l->data;
+              if (!range_is_in_ellipsis (label, link->start, link->end))
+                break;
+            }
           break;
 
         default:
@@ -5114,7 +5192,8 @@ gtk_label_motion (GtkWidget      *widget,
                   link = l->data;
                   if (index >= link->start && index <= link->end)
                     {
-                      found = TRUE;
+                      if (!range_is_in_ellipsis (label, link->start, link->end))
+                        found = TRUE;
                       break;
                     }
                 }