[gtk/min-size-revealer] gtkrevealer: support minimum size of child

[Carlos Soriano <csoriano src gnome org>]

commit 6211541ff2fd931fa373450ded0ac19a45491a79
Author: Carlos Soriano <csoriano redhat com>
Date:   Fri Aug 3 17:28:01 2018 +0200

    gtkrevealer: support minimum size of child
    
    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

 gtk/gtkrevealer.c | 50 +++++++++++++++++++++++++++++++++++++-------------
 1 file 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