gtkrevealer: support minimum size of childmin-size-revealer

GtkRevealer always allocates the natural size of the child so the
bin_window can take care of the animation with the full allocation of
the child.

However when GtkRevealer allocates the child doesn't take into
account the minimum size of the child. On the other hand it does take
into account the minimum size of the child when reporting the preferred
size to the parent of the GtkRevealer.
This behaviour clips the child of the GtkRevealer if the parent
allocates less than the natural size.

To fix this inconsistency, the patch makes the child adapt the
allocation of the GtkRevealer as long as it's not under the minimum
size of the child.

Closes https://gitlab.gnome.org/GNOME/gtk/issues/635

1 files changed, 37 insertions, 13 deletions

diff --git a/gtk/gtkrevealer.c b/gtk/gtkrevealer.c
index 84cb1ca851..a7f7cbc437 100644
--- a/gtk/gtkrevealer.c
+++ b/gtk/gtkrevealer.c
@@ -307,9 +307,11 @@ gtk_revealer_get_child_allocation (GtkRevealer   *revealer,
                                    GtkAllocation *allocation,
                                    GtkAllocation *child_allocation)
 {
+  GtkRevealerPrivate *priv = gtk_revealer_get_instance_private (revealer);
   GtkWidget *child;
   GtkRevealerTransitionType transition;
   GtkBorder padding;
+  gint minimum_width, minimum_height;
   gint vertical_padding, horizontal_padding;
 
   g_return_if_fail (revealer != NULL);
@@ -322,24 +324,46 @@ gtk_revealer_get_child_allocation (GtkRevealer   *revealer,
 
   child_allocation->x = 0;
   child_allocation->y = 0;
-  child_allocation->width = 0;
-  child_allocation->height = 0;
-
+  child_allocation->width = allocation->width - horizontal_padding;
+  child_allocation->height = allocation->height - vertical_padding;
   child = gtk_bin_get_child (GTK_BIN (revealer));
   if (child != NULL && gtk_widget_get_visible (child))
     {
       transition = effective_transition (revealer);
-      if (transition == GTK_REVEALER_TRANSITION_TYPE_SLIDE_LEFT ||
-          transition == GTK_REVEALER_TRANSITION_TYPE_SLIDE_RIGHT)
-        gtk_widget_get_preferred_width_for_height (child, MAX (0, allocation->height - vertical_padding), NULL,
-                                                   &child_allocation->width);
-      else
-        gtk_widget_get_preferred_height_for_width (child, MAX (0, allocation->width - horizontal_padding), NULL,
-                                                   &child_allocation->height);
+      switch (transition)
+        {
+        case GTK_REVEALER_TRANSITION_TYPE_SLIDE_LEFT:
+          gtk_widget_get_preferred_width_for_height (child, child_allocation->height,
+                                                     &minimum_width, NULL);
+          child_allocation->width = MAX (minimum_width,
+                                         child_allocation->width * priv->current_pos);
+          child_allocation->x = (allocation->width - horizontal_padding) - child_allocation->width;
+          break;
+        case GTK_REVEALER_TRANSITION_TYPE_SLIDE_RIGHT:
+          gtk_widget_get_preferred_width_for_height (child, child_allocation->height,
+                                                     &minimum_width, NULL);
+          child_allocation->width = MAX (minimum_width,
+                                         child_allocation->width * priv->current_pos);
+          break;
+        case GTK_REVEALER_TRANSITION_TYPE_SLIDE_DOWN:
+          gtk_widget_get_preferred_height_for_width (child, child_allocation->width,
+                                                     &minimum_height, NULL);
+          child_allocation->height = MAX (minimum_height,
+                                          child_allocation->height * priv->current_pos);
+          child_allocation->y = (allocation->height - vertical_padding) - child_allocation->height;
+        case GTK_REVEALER_TRANSITION_TYPE_SLIDE_UP:
+          gtk_widget_get_preferred_height_for_width (child, child_allocation->width,
+                                                     &minimum_height, NULL);
+          child_allocation->height = MAX (minimum_height,
+                                          child_allocation->height * priv->current_pos);
+          break;
+
+        case GTK_REVEALER_TRANSITION_TYPE_NONE:
+        case GTK_REVEALER_TRANSITION_TYPE_CROSSFADE:
+        default:
+          break;
+        }
     }
-
-  child_allocation->width = MAX (child_allocation->width, allocation->width - horizontal_padding);
-  child_allocation->height = MAX (child_allocation->height, allocation->height - vertical_padding);
 }
 
 static void