[gtk+] gtkwindow: windows with a fixed size can shrink

[Matthias Clasen <matthiasc src gnome org>]

commit adcd1ce2d325c7b3bc0edc8c319bf4ab480d215b
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Fri Mar 4 10:34:12 2016 +0100

    gtkwindow: windows with a fixed size can shrink
    
    One important aspect of non-resizable windows that we need to preserve
    is that they shrink when their content requires less size.
    
    Previous changes to allow the default size to be applied to fixed size
    windows would have prevented all fixed size windows from shrinking when
    their content requires less size.
    
    Allow shrinking for fixed-size windows unless a default size was
    specified.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=762974

 gtk/gtkwindow.c |   61 +++++++++++++++++++++++++++++++++++++++++++++----------
 1 files changed, 50 insertions(+), 11 deletions(-)
---
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 8a3d749..563414d 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -479,6 +479,10 @@ static void     gtk_window_constrain_position        (GtkWindow    *window,
                                                       gint          new_height,
                                                       gint         *x,
                                                       gint         *y);
+static void     gtk_window_update_fixed_size         (GtkWindow    *window,
+                                                      GdkGeometry  *new_geometry,
+                                                      gint          new_width,
+                                                      gint          new_height);
 static void     gtk_window_compute_hints             (GtkWindow    *window,
                                                       GdkGeometry  *new_geometry,
                                                       guint        *new_flags);
@@ -9133,17 +9137,7 @@ gtk_window_compute_configure_request (GtkWindow    *window,
   gtk_window_compute_configure_request_size (window,
                                              &new_geometry, new_flags,
                                              &w, &h);
-  /* If not resizeable, set min/max to what we have */
-  if (!priv->resizable)
-    {
-      new_flags |= GDK_HINT_MAX_SIZE;
-
-      new_geometry.min_width = MAX (w, new_geometry.min_width);
-      new_geometry.max_width = new_geometry.min_width;
-      new_geometry.min_height = MAX (h, new_geometry.min_height);
-      new_geometry.max_height = new_geometry.min_height;
-    }
-
+  gtk_window_update_fixed_size (window, &new_geometry, w, h);
   gtk_window_constrain_size (window,
                              &new_geometry, new_flags,
                              w, h,
@@ -9773,6 +9767,44 @@ gtk_window_constrain_size (GtkWindow   *window,
                              new_width, new_height);
 }
 
+/* For non-resizable windows, make sure the given width/height fits
+ * in the geometry contrains and update the geometry hints to match
+ * the given width/height if not.
+ * This is to make sure that non-resizable windows get the default
+ * width/height if set, but can still grow if their content requires.
+ *
+ * Note: Fixed size windows with a default size set will not shrink
+ * when their content requires less size.
+ */
+static void
+gtk_window_update_fixed_size (GtkWindow   *window,
+                              GdkGeometry *new_geometry,
+                              gint         new_width,
+                              gint         new_height)
+{
+  GtkWindowPrivate *priv = window->priv;
+  gint default_width;
+  gint default_height;
+
+  /* Adjust the geometry hints for non-resizable windows only */
+  if (priv->resizable)
+    return;
+
+  /* if a default size is set, make sure the hints allow for the new size */
+  gtk_window_get_default_size (window, &default_width, &default_height);
+  if (default_width > -1)
+    {
+      new_geometry->min_width = MAX (new_width, new_geometry->min_width);
+      new_geometry->max_width = new_geometry->min_width;
+    }
+
+  if (default_height > -1)
+    {
+      new_geometry->min_height = MAX (new_height, new_geometry->min_height);
+      new_geometry->max_height = new_geometry->min_height;
+    }
+}
+
 /* Compute the set of geometry hints and flags for a window
  * based on the application set geometry, and requisition
  * of the window. gtk_widget_get_preferred_size() must have been
@@ -9872,6 +9904,13 @@ gtk_window_compute_hints (GtkWindow   *window,
 
       new_geometry->max_height = MAX (new_geometry->max_height, new_geometry->min_height);
     }
+  else if (!priv->resizable)
+    {
+      *new_flags |= GDK_HINT_MAX_SIZE;
+
+      new_geometry->max_width = new_geometry->min_width;
+      new_geometry->max_height = new_geometry->min_height;
+    }
 
   *new_flags |= GDK_HINT_WIN_GRAVITY;
   new_geometry->win_gravity = priv->gravity;