[gtk/matthiasc/for-master: 2/2] columnview: Fix some issues with column resizing

[Matthias Clasen <matthiasc src gnome org>]

commit 62d62cd6a0064c4a82a8af37eaa1564bfc98707d
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Oct 18 21:29:08 2020 -0400

    columnview: Fix some issues with column resizing
    
    Ensure that we place the resize rectangle at the visible
    right edge of the column, not where the allocation ends
    (we clip the header drawing, after all).
    
    Make it so that for overlapping resize rectangles (with
    very narrow columns), we prefer the narrow column, so you
    can regrow a column after shrinking it all the way.
    
    Finally, ensure that the column resize cursor stays in
    place for the duration of the resize drag (the implicit
    grab was interfering with this).
    
    Related: #3274

 gtk/gtkcolumnview.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)
---
diff --git a/gtk/gtkcolumnview.c b/gtk/gtkcolumnview.c
index d2b73fe105..ae7ffd82aa 100644
--- a/gtk/gtkcolumnview.c
+++ b/gtk/gtkcolumnview.c
@@ -862,12 +862,16 @@ gtk_column_view_in_resize_rect (GtkColumnView       *self,
 {
   GtkWidget *header;
   graphene_rect_t rect;
+  int width;
 
   header = gtk_column_view_column_get_header (column);
 
   if (!gtk_widget_compute_bounds (header, self->header, &rect))
     return FALSE;
 
+  gtk_column_view_column_get_allocation (column, NULL, &width);
+  rect.size.width = width;
+
   rect.origin.x += rect.size.width - DRAG_WIDTH / 2;
   rect.size.width = DRAG_WIDTH;
 
@@ -902,7 +906,7 @@ header_drag_begin (GtkGestureDrag *gesture,
   self->drag_pos = -1;
 
   n = g_list_model_get_n_items (G_LIST_MODEL (self->columns));
-  for (i = 0; !self->in_column_resize && i < n; i++)
+  for (i = n - 1; !self->in_column_resize && i >= 0; i--)
     {
       GtkColumnViewColumn *column = g_list_model_get_item (G_LIST_MODEL (self->columns), i);
 
@@ -929,9 +933,22 @@ header_drag_begin (GtkGestureDrag *gesture,
           self->drag_x = start_x - size;
           self->in_column_resize = TRUE;
 
+          gtk_widget_set_cursor_from_name (gtk_column_view_column_get_header (column), "col-resize");
+
           g_object_unref (column);
           break;
         }
+    }
+
+  for (i = 0; !self->in_column_resize && i < n; i++)
+    {
+      GtkColumnViewColumn *column = g_list_model_get_item (G_LIST_MODEL (self->columns), i);
+
+      if (!gtk_column_view_column_get_visible (column))
+        {
+          g_object_unref (column);
+          continue;
+        }
 
       if (gtk_column_view_get_reorderable (self) &&
           gtk_column_view_in_header (self, column, start_x, start_y))
@@ -966,6 +983,12 @@ header_drag_end (GtkGestureDrag *gesture,
 
   if (self->in_column_resize)
     {
+      GtkColumnViewColumn *column;
+
+      column = g_list_model_get_item (G_LIST_MODEL (self->columns), self->drag_pos);
+      gtk_widget_set_cursor (gtk_column_view_column_get_header (column), NULL);
+      g_object_unref (column);
+
       self->in_column_resize = FALSE;
     }
   else if (self->in_column_reorder)
@@ -1102,6 +1125,9 @@ header_motion (GtkEventControllerMotion *controller,
   gboolean cursor_set = FALSE;
   int i, n;
 
+  if (self->in_column_resize)
+    return;
+
   n = g_list_model_get_n_items (G_LIST_MODEL (self->columns));
   for (i = 0; i < n; i++)
     {