[gtk/columnview-reordering: 3/8] columnviewcolumn: Add reordering helpers

[Matthias Clasen <matthiasc src gnome org>]

commit ecb47457bfde4c1a8f52ca09045b3a0b7e778d9a
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Dec 20 17:19:55 2019 -0500

    columnviewcolumn: Add reordering helpers
    
    Add helper functions that let us temporarily give
    a different allocation to headers. These will be
    used to implement interactive column reordering
    in GtkColumnView.

 gtk/gtkcolumnviewcolumn.c        | 21 +++++++++++++++++++++
 gtk/gtkcolumnviewcolumnprivate.h |  6 ++++++
 2 files changed, 27 insertions(+)
---
diff --git a/gtk/gtkcolumnviewcolumn.c b/gtk/gtkcolumnviewcolumn.c
index cd4f9821d5..41a20b3762 100644
--- a/gtk/gtkcolumnviewcolumn.c
+++ b/gtk/gtkcolumnviewcolumn.c
@@ -60,6 +60,7 @@ struct _GtkColumnViewColumn
   int natural_size_request;
   int allocation_offset;
   int allocation_size;
+  int header_position;
 
   int fixed_width;
 
@@ -453,6 +454,7 @@ gtk_column_view_column_allocate (GtkColumnViewColumn *self,
 {
   self->allocation_offset = offset;
   self->allocation_size = size;
+  self->header_position = offset;
 }
 
 void
@@ -880,3 +882,22 @@ gtk_column_view_column_get_header (GtkColumnViewColumn *self)
 {
   return self->header;
 }
+
+void
+gtk_column_view_column_set_header_position (GtkColumnViewColumn *self,
+                                            int                  offset)
+{
+  self->header_position = offset;
+}
+
+void
+gtk_column_view_column_get_header_allocation (GtkColumnViewColumn *self,
+                                              int                 *offset,
+                                              int                 *size)
+{
+  if (offset)
+    *offset = self->header_position;
+
+  if (size)
+    *size = self->allocation_size;
+}
diff --git a/gtk/gtkcolumnviewcolumnprivate.h b/gtk/gtkcolumnviewcolumnprivate.h
index 925343f998..2fa9afa989 100644
--- a/gtk/gtkcolumnviewcolumnprivate.h
+++ b/gtk/gtkcolumnviewcolumnprivate.h
@@ -48,4 +48,10 @@ void                    gtk_column_view_column_get_allocation           (GtkColu
 
 void                    gtk_column_view_column_notify_sort              (GtkColumnViewColumn    *self);
 
+void                    gtk_column_view_column_set_header_position      (GtkColumnViewColumn    *self,
+                                                                         int                     offset);
+void                    gtk_column_view_column_get_header_allocation    (GtkColumnViewColumn    *self,
+                                                                         int                    *offset,
+                                                                         int                    *size);
+
 #endif  /* __GTK_COLUMN_VIEW_COLUMN_PRIVATE_H__ */