[gnome-shell/wip/carlosg/appgrid-navigation: 15/24] st/scrollview: Add ::content-padding property to StScrollView

[Marge Bot <marge-bot src gnome org>]

commit 0d62dadfbc4532953668a976a2585369d753ae01
Author: Carlos Garnacho <carlosg gnome org>
Date:   Fri Feb 19 16:42:34 2021 +0100

    st/scrollview: Add ::content-padding property to StScrollView
    
    This will be needed for fine tuning of the visible area for appGrid
    navigation purposes. We most nominally can let it happen via CSS as
    the size calculations happen on size allocate, so we want to avoid
    triggering relayouts while adapting to the given size.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1630>

 src/st/st-scroll-view-fade.c |  8 ++++++++
 src/st/st-scroll-view.c      | 21 +++++++++++++++++++++
 2 files changed, 29 insertions(+)
---
diff --git a/src/st/st-scroll-view-fade.c b/src/st/st-scroll-view-fade.c
index 38d40ed651..3ca7313372 100644
--- a/src/st/st-scroll-view-fade.c
+++ b/src/st/st-scroll-view-fade.c
@@ -97,6 +97,7 @@ st_scroll_view_fade_paint_target (ClutterOffscreenEffect *effect,
   gboolean h_scroll_visible, v_scroll_visible;
 
   ClutterActorBox allocation, content_box, paint_box;
+  ClutterMargin *content_padding;
 
   float fade_area_topleft[2];
   float fade_area_bottomright[2];
@@ -108,6 +109,13 @@ st_scroll_view_fade_paint_target (ClutterOffscreenEffect *effect,
   clutter_actor_get_allocation_box (self->actor, &allocation);
   st_theme_node_get_content_box (st_widget_get_theme_node (ST_WIDGET (self->actor)),
                                 (const ClutterActorBox *)&allocation, &content_box);
+  g_object_get (self->actor, "content-padding", &content_padding, NULL);
+
+  content_box.x1 += content_padding->left;
+  content_box.x2 -= content_padding->right;
+  content_box.y1 += content_padding->top;
+  content_box.y2 -= content_padding->bottom;
+  clutter_margin_free (content_padding);
 
   /*
    * The FBO is based on the paint_volume's size which can be larger then the actual
diff --git a/src/st/st-scroll-view.c b/src/st/st-scroll-view.c
index 3b9711ea21..606701565d 100644
--- a/src/st/st-scroll-view.c
+++ b/src/st/st-scroll-view.c
@@ -84,6 +84,8 @@ struct _StScrollViewPrivate
   StAdjustment *vadjustment;
   ClutterActor *vscroll;
 
+  ClutterMargin content_padding;
+
   StPolicyType hscrollbar_policy;
   StPolicyType vscrollbar_policy;
 
@@ -116,6 +118,7 @@ enum {
   PROP_VSCROLLBAR_VISIBLE,
   PROP_MOUSE_SCROLL,
   PROP_OVERLAY_SCROLLBARS,
+  PROP_CONTENT_PADDING,
 
   N_PROPS
 };
@@ -156,6 +159,9 @@ st_scroll_view_get_property (GObject    *object,
     case PROP_OVERLAY_SCROLLBARS:
       g_value_set_boolean (value, priv->overlay_scrollbars);
       break;
+    case PROP_CONTENT_PADDING:
+      g_value_set_boxed (value, &priv->content_padding);
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
     }
@@ -233,6 +239,9 @@ st_scroll_view_set_property (GObject      *object,
                                  priv->hscrollbar_policy,
                                  g_value_get_enum (value));
       break;
+    case PROP_CONTENT_PADDING:
+      priv->content_padding = * (ClutterMargin *) g_value_get_boxed (value);
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
     }
@@ -545,6 +554,11 @@ st_scroll_view_allocate (ClutterActor          *actor,
 
   st_theme_node_get_content_box (theme_node, box, &content_box);
 
+  content_box.x1 += priv->content_padding.left;
+  content_box.x2 -= priv->content_padding.right;
+  content_box.y1 += priv->content_padding.top;
+  content_box.y2 += priv->content_padding.bottom;
+
   avail_width = content_box.x2 - content_box.x1;
   avail_height = content_box.y2 - content_box.y1;
 
@@ -933,6 +947,13 @@ st_scroll_view_class_init (StScrollViewClass *klass)
                           FALSE,
                           ST_PARAM_READWRITE);
 
+  props[PROP_CONTENT_PADDING] =
+    g_param_spec_boxed ("content-padding",
+                        "Content padding",
+                        "Content padding",
+                        CLUTTER_TYPE_MARGIN,
+                        ST_PARAM_READWRITE);
+
   g_object_class_install_properties (object_class, N_PROPS, props);
 }