[gnome-shell/gbsneto/viewport: 2/2] st/box-layout: Reimplement as a StViewport subclass

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 8b14c24ba9e6a1528b5089d2957e964ea005b1a0
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Wed Dec 11 12:35:29 2019 -0300

    st/box-layout: Reimplement as a StViewport subclass
    
    With StViewport doing most of the heavy-lifting, StBoxLayout
    can be cleaned up as a StViewport subclass.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/929

 src/st/st-box-layout.c | 464 +------------------------------------------------
 src/st/st-box-layout.h |   5 +-
 2 files changed, 5 insertions(+), 464 deletions(-)
---
diff --git a/src/st/st-box-layout.c b/src/st/st-box-layout.c
index 019aebd76a..57705d3200 100644
--- a/src/st/st-box-layout.c
+++ b/src/st/st-box-layout.c
@@ -57,16 +57,12 @@
 
 
 static void st_box_container_iface_init (ClutterContainerIface *iface);
-static void st_box_scrollable_interface_init (StScrollableInterface *iface);
 
 enum {
   PROP_0,
 
   PROP_VERTICAL,
   PROP_PACK_START,
-
-  PROP_HADJUST,
-  PROP_VADJUST
 };
 
 struct _StBoxLayoutPrivate
@@ -75,104 +71,10 @@ struct _StBoxLayoutPrivate
   StAdjustment *vadjustment;
 };
 
-G_DEFINE_TYPE_WITH_CODE (StBoxLayout, st_box_layout, ST_TYPE_WIDGET,
+G_DEFINE_TYPE_WITH_CODE (StBoxLayout, st_box_layout, ST_TYPE_VIEWPORT,
                          G_ADD_PRIVATE (StBoxLayout)
                          G_IMPLEMENT_INTERFACE (CLUTTER_TYPE_CONTAINER,
-                                                st_box_container_iface_init)
-                         G_IMPLEMENT_INTERFACE (ST_TYPE_SCROLLABLE,
-                                                st_box_scrollable_interface_init));
-
-/*
- * StScrollable Interface Implementation
- */
-static void
-adjustment_value_notify_cb (StAdjustment *adjustment,
-                            GParamSpec   *pspec,
-                            StBoxLayout  *box)
-{
-  clutter_actor_queue_relayout (CLUTTER_ACTOR (box));
-}
-
-static void
-scrollable_set_adjustments (StScrollable *scrollable,
-                            StAdjustment *hadjustment,
-                            StAdjustment *vadjustment)
-{
-  StBoxLayoutPrivate *priv = ST_BOX_LAYOUT (scrollable)->priv;
-
-  g_object_freeze_notify (G_OBJECT (scrollable));
-
-  if (hadjustment != priv->hadjustment)
-    {
-      if (priv->hadjustment)
-        {
-          g_signal_handlers_disconnect_by_func (priv->hadjustment,
-                                                adjustment_value_notify_cb,
-                                                scrollable);
-          g_object_unref (priv->hadjustment);
-        }
-
-      if (hadjustment)
-        {
-          g_object_ref (hadjustment);
-          g_signal_connect (hadjustment, "notify::value",
-                            G_CALLBACK (adjustment_value_notify_cb),
-                            scrollable);
-        }
-
-      priv->hadjustment = hadjustment;
-      g_object_notify (G_OBJECT (scrollable), "hadjustment");
-    }
-
-  if (vadjustment != priv->vadjustment)
-    {
-      if (priv->vadjustment)
-        {
-          g_signal_handlers_disconnect_by_func (priv->vadjustment,
-                                                adjustment_value_notify_cb,
-                                                scrollable);
-          g_object_unref (priv->vadjustment);
-        }
-
-      if (vadjustment)
-        {
-          g_object_ref (vadjustment);
-          g_signal_connect (vadjustment, "notify::value",
-                            G_CALLBACK (adjustment_value_notify_cb),
-                            scrollable);
-        }
-
-      priv->vadjustment = vadjustment;
-      g_object_notify (G_OBJECT (scrollable), "vadjustment");
-    }
-
-  g_object_thaw_notify (G_OBJECT (scrollable));
-}
-
-static void
-scrollable_get_adjustments (StScrollable  *scrollable,
-                            StAdjustment **hadjustment,
-                            StAdjustment **vadjustment)
-{
-  StBoxLayoutPrivate *priv;
-
-  priv = (ST_BOX_LAYOUT (scrollable))->priv;
-
-  if (hadjustment)
-    *hadjustment = priv->hadjustment;
-
-  if (vadjustment)
-    *vadjustment = priv->vadjustment;
-}
-
-
-
-static void
-st_box_scrollable_interface_init (StScrollableInterface *iface)
-{
-  iface->set_adjustments = scrollable_set_adjustments;
-  iface->get_adjustments = scrollable_get_adjustments;
-}
+                                                st_box_container_iface_init));
 
 static void
 st_box_container_iface_init (ClutterContainerIface *iface)
@@ -188,7 +90,6 @@ st_box_layout_get_property (GObject    *object,
                             GParamSpec *pspec)
 {
   ClutterLayoutManager *layout;
-  StAdjustment *adjustment;
   ClutterOrientation orientation;
 
   switch (property_id)
@@ -204,16 +105,6 @@ st_box_layout_get_property (GObject    *object,
       g_value_set_boolean (value, clutter_box_layout_get_pack_start (CLUTTER_BOX_LAYOUT (layout)));
       break;
 
-    case PROP_HADJUST:
-      scrollable_get_adjustments (ST_SCROLLABLE (object), &adjustment, NULL);
-      g_value_set_object (value, adjustment);
-      break;
-
-    case PROP_VADJUST:
-      scrollable_get_adjustments (ST_SCROLLABLE (object), NULL, &adjustment);
-      g_value_set_object (value, adjustment);
-      break;
-
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
     }
@@ -237,343 +128,11 @@ st_box_layout_set_property (GObject      *object,
       st_box_layout_set_pack_start (box, g_value_get_boolean (value));
       break;
 
-    case PROP_HADJUST:
-      scrollable_set_adjustments (ST_SCROLLABLE (object),
-                                  g_value_get_object (value),
-                                  box->priv->vadjustment);
-      break;
-
-    case PROP_VADJUST:
-      scrollable_set_adjustments (ST_SCROLLABLE (object),
-                                  box->priv->hadjustment,
-                                  g_value_get_object (value));
-      break;
-
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
     }
 }
 
-static void
-st_box_layout_dispose (GObject *object)
-{
-  StBoxLayoutPrivate *priv = ST_BOX_LAYOUT (object)->priv;
-
-  if (priv->hadjustment)
-    {
-      g_object_unref (priv->hadjustment);
-      priv->hadjustment = NULL;
-    }
-
-  if (priv->vadjustment)
-    {
-      g_object_unref (priv->vadjustment);
-      priv->vadjustment = NULL;
-    }
-
-  G_OBJECT_CLASS (st_box_layout_parent_class)->dispose (object);
-}
-
-static void
-st_box_layout_allocate (ClutterActor          *actor,
-                        const ClutterActorBox *box,
-                        ClutterAllocationFlags flags)
-{
-  StBoxLayoutPrivate *priv = ST_BOX_LAYOUT (actor)->priv;
-  StThemeNode *theme_node = st_widget_get_theme_node (ST_WIDGET (actor));
-  ClutterLayoutManager *layout = clutter_actor_get_layout_manager (actor);
-  ClutterActorBox viewport_content_box;
-  ClutterActorBox content_box;
-  gfloat avail_width, avail_height, min_width, natural_width, min_height, natural_height;
-
-  st_theme_node_get_content_box (theme_node, box, &viewport_content_box);
-  clutter_actor_box_get_size (&viewport_content_box, &avail_width, &avail_height);
-
-  clutter_layout_manager_get_preferred_width (layout, CLUTTER_CONTAINER (actor),
-                                              avail_height,
-                                              &min_width, &natural_width);
-  clutter_layout_manager_get_preferred_height (layout, CLUTTER_CONTAINER (actor),
-                                               MAX (avail_width, min_width),
-                                               &min_height, &natural_height);
-
-  /* Because StBoxLayout implements StScrollable, the allocation box passed here
-   * may not match the minimum sizes reported by the layout manager. When that
-   * happens, the content box needs to be adjusted to match the reported minimum
-   * sizes before being passed to clutter_layout_manager_allocate() */
-  clutter_actor_set_allocation (actor, box, flags);
-
-  content_box = viewport_content_box;
-  content_box.x2 += MAX (0, min_width - avail_width);
-  content_box.y2 += MAX (0, min_height - avail_height);
-
-  clutter_layout_manager_allocate (layout, CLUTTER_CONTAINER (actor),
-                                   &content_box, flags);
-
-  /* update adjustments for scrolling */
-  if (priv->vadjustment)
-    {
-      gdouble prev_value;
-
-      g_object_set (G_OBJECT (priv->vadjustment),
-                    "lower", 0.0,
-                    "upper", MAX (min_height, avail_height),
-                    "page-size", avail_height,
-                    "step-increment", avail_height / 6,
-                    "page-increment", avail_height - avail_height / 6,
-                    NULL);
-
-      prev_value = st_adjustment_get_value (priv->vadjustment);
-      st_adjustment_set_value (priv->vadjustment, prev_value);
-    }
-
-  if (priv->hadjustment)
-    {
-      gdouble prev_value;
-
-      g_object_set (G_OBJECT (priv->hadjustment),
-                    "lower", 0.0,
-                    "upper", MAX (min_width, avail_width),
-                    "page-size", avail_width,
-                    "step-increment", avail_width / 6,
-                    "page-increment", avail_width - avail_width / 6,
-                    NULL);
-
-      prev_value = st_adjustment_get_value (priv->hadjustment);
-      st_adjustment_set_value (priv->hadjustment, prev_value);
-    }
-}
-
-static void
-st_box_layout_apply_transform (ClutterActor *a,
-                               CoglMatrix   *m)
-{
-  StBoxLayoutPrivate *priv = ST_BOX_LAYOUT (a)->priv;
-  gdouble x, y;
-
-  CLUTTER_ACTOR_CLASS (st_box_layout_parent_class)->apply_transform (a, m);
-
-  if (priv->hadjustment)
-    x = st_adjustment_get_value (priv->hadjustment);
-  else
-    x = 0;
-
-  if (priv->vadjustment)
-    y = st_adjustment_get_value (priv->vadjustment);
-  else
-    y = 0;
-
-  cogl_matrix_translate (m, (int) -x, (int) -y, 0);
-}
-
-/* If we are translated, then we need to translate back before chaining
- * up or the background and borders will be drawn in the wrong place */
-static void
-get_border_paint_offsets (StBoxLayout *self,
-                          double      *x,
-                          double      *y)
-{
-  StBoxLayoutPrivate *priv = self->priv;
-
-  if (priv->hadjustment)
-    *x = st_adjustment_get_value (priv->hadjustment);
-  else
-    *x = 0;
-
-  if (priv->vadjustment)
-    *y = st_adjustment_get_value (priv->vadjustment);
-  else
-    *y = 0;
-}
-
-
-static void
-st_box_layout_paint (ClutterActor        *actor,
-                     ClutterPaintContext *paint_context)
-{
-  StBoxLayout *self = ST_BOX_LAYOUT (actor);
-  StBoxLayoutPrivate *priv = self->priv;
-  StThemeNode *theme_node = st_widget_get_theme_node (ST_WIDGET (actor));
-  gdouble x, y;
-  ClutterActorBox allocation_box;
-  ClutterActorBox content_box;
-  ClutterActor *child;
-  CoglFramebuffer *fb = clutter_paint_context_get_framebuffer (paint_context);
-
-  get_border_paint_offsets (self, &x, &y);
-  if (x != 0 || y != 0)
-    {
-      cogl_framebuffer_push_matrix (fb);
-      cogl_framebuffer_translate (fb, (int)x, (int)y, 0);
-    }
-
-  st_widget_paint_background (ST_WIDGET (actor), paint_context);
-
-  if (x != 0 || y != 0)
-    {
-      cogl_framebuffer_pop_matrix (fb);
-    }
-
-  if (clutter_actor_get_n_children (actor) == 0)
-    return;
-
-  clutter_actor_get_allocation_box (actor, &allocation_box);
-  st_theme_node_get_content_box (theme_node, &allocation_box, &content_box);
-
-  content_box.x1 += x;
-  content_box.y1 += y;
-  content_box.x2 += x;
-  content_box.y2 += y;
-
-  /* The content area forms the viewport into the scrolled contents, while
-   * the borders and background stay in place; after drawing the borders and
-   * background, we clip to the content area */
-  if (priv->hadjustment || priv->vadjustment)
-    cogl_framebuffer_push_rectangle_clip (fb,
-                                          (int)content_box.x1,
-                                          (int)content_box.y1,
-                                          (int)content_box.x2,
-                                          (int)content_box.y2);
-
-  for (child = clutter_actor_get_first_child (actor);
-       child != NULL;
-       child = clutter_actor_get_next_sibling (child))
-    clutter_actor_paint (child, paint_context);
-
-  if (priv->hadjustment || priv->vadjustment)
-    cogl_framebuffer_pop_clip (fb);
-}
-
-static void
-st_box_layout_pick (ClutterActor       *actor,
-                    ClutterPickContext *pick_context)
-{
-  StBoxLayout *self = ST_BOX_LAYOUT (actor);
-  StBoxLayoutPrivate *priv = self->priv;
-  StThemeNode *theme_node = st_widget_get_theme_node (ST_WIDGET (actor));
-  gdouble x, y;
-  ClutterActorBox allocation_box;
-  ClutterActorBox content_box;
-  ClutterActor *child;
-  CoglFramebuffer *fb = clutter_pick_context_get_framebuffer (pick_context);
-
-  get_border_paint_offsets (self, &x, &y);
-  if (x != 0 || y != 0)
-    {
-      cogl_framebuffer_push_matrix (fb);
-      cogl_framebuffer_translate (fb, (int)x, (int)y, 0);
-    }
-
-  CLUTTER_ACTOR_CLASS (st_box_layout_parent_class)->pick (actor, pick_context);
-
-  if (x != 0 || y != 0)
-    {
-      cogl_framebuffer_pop_matrix (fb);
-    }
-
-  if (clutter_actor_get_n_children (actor) == 0)
-    return;
-
-  clutter_actor_get_allocation_box (actor, &allocation_box);
-  st_theme_node_get_content_box (theme_node, &allocation_box, &content_box);
-
-  content_box.x1 += x;
-  content_box.y1 += y;
-  content_box.x2 += x;
-  content_box.y2 += y;
-
-  if (priv->hadjustment || priv->vadjustment)
-    cogl_framebuffer_push_rectangle_clip (fb,
-                                          (int)content_box.x1,
-                                          (int)content_box.y1,
-                                          (int)content_box.x2,
-                                          (int)content_box.y2);
-
-  for (child = clutter_actor_get_first_child (actor);
-       child != NULL;
-       child = clutter_actor_get_next_sibling (child))
-    clutter_actor_pick (child, pick_context);
-
-  if (priv->hadjustment || priv->vadjustment)
-    cogl_framebuffer_pop_clip (fb);
-}
-
-static gboolean
-st_box_layout_get_paint_volume (ClutterActor       *actor,
-                                ClutterPaintVolume *volume)
-{
-  StBoxLayout *self = ST_BOX_LAYOUT (actor);
-  gdouble x, y, lower, upper;
-  StBoxLayoutPrivate *priv = self->priv;
-  StThemeNode *theme_node = st_widget_get_theme_node (ST_WIDGET (actor));
-  ClutterActorBox allocation_box;
-  ClutterActorBox content_box;
-  graphene_point3d_t origin;
-
-  /* Setting the paint volume does not make sense when we don't have any allocation */
-  if (!clutter_actor_has_allocation (actor))
-    return FALSE;
-
-  /* When have an adjustment we are clipped to the content box, so base
-   * our paint volume on that. */
-  if (priv->hadjustment || priv->vadjustment)
-    {
-      gdouble width, height;
-
-      clutter_actor_get_allocation_box (actor, &allocation_box);
-      st_theme_node_get_content_box (theme_node, &allocation_box, &content_box);
-      origin.x = content_box.x1 - allocation_box.x1;
-      origin.y = content_box.y1 - allocation_box.y2;
-      origin.z = 0.f;
-
-      if (priv->hadjustment)
-        {
-          g_object_get (priv->hadjustment,
-                        "lower", &lower,
-                        "upper", &upper,
-                        NULL);
-          width = upper - lower;
-        }
-      else
-        {
-          width = content_box.x2 - content_box.x1;
-        }
-
-      if (priv->vadjustment)
-        {
-          g_object_get (priv->vadjustment,
-                        "lower", &lower,
-                        "upper", &upper,
-                        NULL);
-          height = upper - lower;
-        }
-      else
-        {
-          height = content_box.y2 - content_box.y1;
-        }
-
-      clutter_paint_volume_set_width (volume, width);
-      clutter_paint_volume_set_height (volume, height);
-    }
-  else if (!CLUTTER_ACTOR_CLASS (st_box_layout_parent_class)->get_paint_volume (actor, volume))
-    return FALSE;
-
-  /* When scrolled, st_box_layout_apply_transform() includes the scroll offset
-   * and affects paint volumes. This is right for our children, but our paint volume
-   * is determined by our allocation and borders and doesn't scroll, so we need
-   * to reverse-compensate here, the same as we do when painting.
-   */
-  get_border_paint_offsets (self, &x, &y);
-  if (x != 0 || y != 0)
-    {
-      clutter_paint_volume_get_origin (volume, &origin);
-      origin.x += x;
-      origin.y += y;
-      clutter_paint_volume_set_origin (volume, &origin);
-    }
-
-  return TRUE;
-}
-
 static void
 st_box_layout_style_changed (StWidget *self)
 {
@@ -623,20 +182,11 @@ static void
 st_box_layout_class_init (StBoxLayoutClass *klass)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
-  ClutterActorClass *actor_class = CLUTTER_ACTOR_CLASS (klass);
   StWidgetClass *widget_class = ST_WIDGET_CLASS (klass);
   GParamSpec *pspec;
 
   object_class->get_property = st_box_layout_get_property;
   object_class->set_property = st_box_layout_set_property;
-  object_class->dispose = st_box_layout_dispose;
-
-  actor_class->allocate = st_box_layout_allocate;
-  actor_class->apply_transform = st_box_layout_apply_transform;
-
-  actor_class->paint = st_box_layout_paint;
-  actor_class->get_paint_volume = st_box_layout_get_paint_volume;
-  actor_class->pick = st_box_layout_pick;
 
   widget_class->style_changed = st_box_layout_style_changed;
 
@@ -654,16 +204,6 @@ st_box_layout_class_init (StBoxLayoutClass *klass)
                                 FALSE,
                                 ST_PARAM_READWRITE);
   g_object_class_install_property (object_class, PROP_PACK_START, pspec);
-
-  /* StScrollable properties */
-  g_object_class_override_property (object_class,
-                                    PROP_HADJUST,
-                                    "hadjustment");
-
-  g_object_class_override_property (object_class,
-                                    PROP_VADJUST,
-                                    "vadjustment");
-
 }
 
 static void
diff --git a/src/st/st-box-layout.h b/src/st/st-box-layout.h
index 3e127b942b..82f5a70457 100644
--- a/src/st/st-box-layout.h
+++ b/src/st/st-box-layout.h
@@ -26,11 +26,12 @@
 #define _ST_BOX_LAYOUT_H
 
 #include <st/st-widget.h>
+#include <st/st-viewport.h>
 
 G_BEGIN_DECLS
 
 #define ST_TYPE_BOX_LAYOUT st_box_layout_get_type()
-G_DECLARE_FINAL_TYPE (StBoxLayout, st_box_layout, ST, BOX_LAYOUT, StWidget)
+G_DECLARE_FINAL_TYPE (StBoxLayout, st_box_layout, ST, BOX_LAYOUT, StViewport)
 
 typedef struct _StBoxLayout StBoxLayout;
 typedef struct _StBoxLayoutPrivate StBoxLayoutPrivate;
@@ -44,7 +45,7 @@ typedef struct _StBoxLayoutPrivate StBoxLayoutPrivate;
 struct _StBoxLayout
 {
   /*< private >*/
-  StWidget parent;
+  StViewport parent;
 
   StBoxLayoutPrivate *priv;
 };