[gtk+/wip/cosimoc/range-gadget] range: add a gadget for the whole widget area

[Cosimo Cecchi <cosimoc src gnome org>]

commit 9584f904e0c96747e2c53867a272243992762a76
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Wed Feb 24 13:28:54 2016 -0800

    range: add a gadget for the whole widget area
    
    This commit introduces another node, called "contents", that holds the
    main contents of the range. This allows for the main gadget itself to
    span across the whole surface of the widget now.

 gtk/gtkrange.c |  148 +++++++++++++++++++++++++++++++++++++++++--------------
 1 files changed, 110 insertions(+), 38 deletions(-)
---
diff --git a/gtk/gtkrange.c b/gtk/gtkrange.c
index 8da9755..4eca2f6 100644
--- a/gtk/gtkrange.c
+++ b/gtk/gtkrange.c
@@ -103,6 +103,7 @@ struct _GtkRangePrivate
    *               a b      c d
    */
   GtkCssGadget *gadget;
+  GtkCssGadget *contents_gadget;
   GtkCssGadget *stepper_a_gadget;
   GtkCssGadget *stepper_b_gadget;
   GtkCssGadget *stepper_c_gadget;
@@ -296,7 +297,26 @@ static gboolean      gtk_range_render_trough            (GtkCssGadget *gadget,
                                                          int           width,
                                                          int           height,
                                                          gpointer      user_data);
-
+static void          gtk_range_measure                  (GtkCssGadget   *gadget,
+                                                         GtkOrientation  orientation,
+                                                         gint            for_size,
+                                                         gint           *minimum,
+                                                         gint           *natural,
+                                                         gint           *minimum_baseline,
+                                                         gint           *natural_baseline,
+                                                         gpointer        user_data);
+static void          gtk_range_allocate                 (GtkCssGadget        *gadget,
+                                                         const GtkAllocation *allocation,
+                                                         int                  baseline,
+                                                         GtkAllocation       *out_clip,
+                                                         gpointer             data);
+static gboolean      gtk_range_render                   (GtkCssGadget *gadget,
+                                                         cairo_t      *cr,
+                                                         int           x,
+                                                         int           y,
+                                                         int           width,
+                                                         int           height,
+                                                         gpointer      user_data);
 
 G_DEFINE_ABSTRACT_TYPE_WITH_CODE (GtkRange, gtk_range, GTK_TYPE_WIDGET,
                                   G_ADD_PRIVATE (GtkRange)
@@ -665,13 +685,13 @@ gtk_range_sync_orientation (GtkRange *range)
 
   orientation = gtk_orientable_get_orientation (GTK_ORIENTABLE (range));
   _gtk_orientable_set_style_classes (GTK_ORIENTABLE (range));
-  gtk_box_gadget_set_orientation (GTK_BOX_GADGET (priv->gadget), orientation);
+  gtk_box_gadget_set_orientation (GTK_BOX_GADGET (priv->contents_gadget), orientation);
 
   if (orientation == GTK_ORIENTATION_VERTICAL)
-    gtk_box_gadget_set_gadget_expand (GTK_BOX_GADGET (priv->gadget),
+    gtk_box_gadget_set_gadget_expand (GTK_BOX_GADGET (priv->contents_gadget),
                                       priv->trough_gadget, FALSE, TRUE);
   else
-    gtk_box_gadget_set_gadget_expand (GTK_BOX_GADGET (priv->gadget),
+    gtk_box_gadget_set_gadget_expand (GTK_BOX_GADGET (priv->contents_gadget),
                                       priv->trough_gadget, TRUE, FALSE);
 }
 
@@ -803,8 +823,15 @@ gtk_range_init (GtkRange *range)
   _gtk_orientable_set_style_classes (GTK_ORIENTABLE (range));
 
   widget_node = gtk_widget_get_css_node (GTK_WIDGET (range));
-  priv->gadget = gtk_box_gadget_new_for_node (widget_node, GTK_WIDGET (range));
-
+  priv->gadget = gtk_css_custom_gadget_new_for_node (widget_node,
+                                                     GTK_WIDGET (range),
+                                                     gtk_range_measure,
+                                                     gtk_range_allocate,
+                                                     gtk_range_render,
+                                                     NULL, NULL);
+  priv->contents_gadget = gtk_box_gadget_new ("contents",
+                                              GTK_WIDGET (range),
+                                              priv->gadget, NULL);
   priv->trough_gadget = gtk_css_custom_gadget_new ("trough",
                                                    GTK_WIDGET (range),
                                                    NULL, NULL,
@@ -814,7 +841,7 @@ gtk_range_init (GtkRange *range)
                                                    NULL, NULL);
   gtk_css_gadget_set_state (priv->trough_gadget,
                             gtk_css_node_get_state (widget_node));
-  gtk_box_gadget_insert_gadget (GTK_BOX_GADGET (priv->gadget), -1, priv->trough_gadget,
+  gtk_box_gadget_insert_gadget (GTK_BOX_GADGET (priv->contents_gadget), -1, priv->trough_gadget,
                                 TRUE, FALSE, GTK_ALIGN_CENTER);
 
   priv->slider_gadget = gtk_builtin_icon_new ("slider",
@@ -1246,7 +1273,7 @@ gtk_range_get_range_rect (GtkRange     *range,
 
   priv = range->priv;
 
-  measure_one_gadget_alloc (range, priv->gadget, FALSE, range_rect);
+  measure_one_gadget_alloc (range, priv->contents_gadget, FALSE, range_rect);
 }
 
 /**
@@ -1713,6 +1740,7 @@ gtk_range_destroy (GtkWidget *widget)
   g_clear_object (&priv->long_press_gesture);
 
   g_clear_object (&priv->gadget);
+  g_clear_object (&priv->contents_gadget);
   g_clear_object (&priv->trough_gadget);
   g_clear_object (&priv->fill_gadget);
   g_clear_object (&priv->highlight_gadget);
@@ -1788,17 +1816,22 @@ gtk_range_measure_trough (GtkCssGadget   *gadget,
 }
 
 static void
-gtk_range_size_request (GtkWidget      *widget,
-                        GtkOrientation  orientation,
-                        gint           *minimum,
-                        gint           *natural)
+gtk_range_measure (GtkCssGadget   *gadget,
+                   GtkOrientation  orientation,
+                   gint            for_size,
+                   gint           *minimum,
+                   gint           *natural,
+                   gint           *minimum_baseline,
+                   gint           *natural_baseline,
+                   gpointer        user_data)
 {
+  GtkWidget *widget = gtk_css_gadget_get_owner (gadget);
   GtkRange *range = GTK_RANGE (widget);
   GtkRangePrivate *priv = range->priv;
   GtkBorder border = { 0 };
 
   /* Measure the main box */
-  gtk_css_gadget_get_preferred_size (priv->gadget,
+  gtk_css_gadget_get_preferred_size (priv->contents_gadget,
                                      orientation,
                                      -1,
                                      minimum, natural,
@@ -1821,6 +1854,20 @@ gtk_range_size_request (GtkWidget      *widget,
 }
 
 static void
+gtk_range_size_request (GtkWidget      *widget,
+                        GtkOrientation  orientation,
+                        gint           *minimum,
+                        gint           *natural)
+{
+  GtkRange *range = GTK_RANGE (widget);
+  GtkRangePrivate *priv = range->priv;
+
+  gtk_css_gadget_get_preferred_size (priv->gadget, orientation, -1,
+                                     minimum, natural,
+                                     NULL, NULL);
+}
+
+static void
 gtk_range_get_preferred_width (GtkWidget *widget,
                                gint      *minimum,
                                gint      *natural)
@@ -1955,11 +2002,11 @@ gtk_range_allocate_trough (GtkCssGadget        *gadget,
  * give space to border over dimensions in one direction.
  */
 static void
-clamp_dimensions (GtkAllocation *allocation,
-                  int           *width,
-                  int           *height,
-                  GtkBorder     *border,
-                  gboolean       border_expands_horizontally)
+clamp_dimensions (const GtkAllocation *allocation,
+                  int                 *width,
+                  int                 *height,
+                  GtkBorder           *border,
+                  gboolean             border_expands_horizontally)
 {
   gint extra, shortage;
 
@@ -2038,41 +2085,43 @@ clamp_dimensions (GtkAllocation *allocation,
 }
 
 static void
-gtk_range_allocate_box (GtkRange      *range,
-                        GtkAllocation *out_clip)
+gtk_range_allocate (GtkCssGadget        *gadget,
+                    const GtkAllocation *allocation,
+                    int                  baseline,
+                    GtkAllocation       *out_clip,
+                    gpointer             data)
 {
+  GtkWidget *widget = gtk_css_gadget_get_owner (gadget);
+  GtkRange *range = GTK_RANGE (widget);
   GtkRangePrivate *priv = range->priv;
-  GtkWidget *widget = GTK_WIDGET (range);
   GtkBorder border = { 0 };
-  GtkAllocation box_alloc, widget_alloc;
+  GtkAllocation box_alloc;
   int box_min_width, box_min_height;
 
-  gtk_widget_get_allocation (widget, &widget_alloc);
-
   if (GTK_RANGE_GET_CLASS (range)->get_range_border)
     GTK_RANGE_GET_CLASS (range)->get_range_border (range, &border);
 
-  measure_one_gadget (priv->gadget, &box_min_width, &box_min_height);
+  measure_one_gadget (priv->contents_gadget, &box_min_width, &box_min_height);
 
   if (priv->orientation == GTK_ORIENTATION_VERTICAL)
-    clamp_dimensions (&widget_alloc, &box_min_width, &box_min_height, &border, TRUE);
+    clamp_dimensions (allocation, &box_min_width, &box_min_height, &border, TRUE);
   else
-    clamp_dimensions (&widget_alloc, &box_min_width, &box_min_height, &border, FALSE);
+    clamp_dimensions (allocation, &box_min_width, &box_min_height, &border, FALSE);
 
-  box_alloc.x = border.left + widget_alloc.x;
-  box_alloc.y = border.top + widget_alloc.y;
+  box_alloc.x = border.left + allocation->x;
+  box_alloc.y = border.top + allocation->y;
   box_alloc.width = box_min_width;
   box_alloc.height = box_min_height;
 
-  gtk_css_gadget_allocate (priv->gadget,
+  gtk_css_gadget_allocate (priv->contents_gadget,
                            &box_alloc,
-                           gtk_widget_get_allocated_baseline (widget),
+                           baseline,
                            out_clip);
 
   /* TODO: we should compute a proper clip from get_range_border(),
    * but this will at least give us outset shadows.
    */
-  gdk_rectangle_union (out_clip, &widget_alloc, out_clip);
+  gdk_rectangle_union (out_clip, allocation, out_clip);
 }
 
 static void
@@ -2090,8 +2139,10 @@ gtk_range_size_allocate (GtkWidget     *widget,
                             allocation->x, allocation->y,
                             allocation->width, allocation->height);
 
-  gtk_range_allocate_box (range, &clip);
-
+  gtk_css_gadget_allocate (priv->gadget,
+                           allocation,
+                           gtk_widget_get_allocated_baseline (widget),
+                           &clip);
   gtk_widget_set_clip (widget, &clip);
 }
 
@@ -2256,13 +2307,22 @@ gtk_range_render_trough (GtkCssGadget *gadget,
 }
 
 static gboolean
-gtk_range_draw (GtkWidget *widget,
-                cairo_t   *cr)
+gtk_range_render (GtkCssGadget *gadget,
+                  cairo_t      *cr,
+                  int           x,
+                  int           y,
+                  int           width,
+                  int           height,
+                  gpointer      user_data)
 {
+  GtkWidget *widget = gtk_css_gadget_get_owner (gadget);
   GtkRange *range = GTK_RANGE (widget);
   GtkRangePrivate *priv = range->priv;
   gboolean draw_trough = TRUE;
 
+  /* HACK: we can't render the contents box directly because
+   * GtkColorScale wants to omit the trough but still draw the slider...
+   */
   if (GTK_IS_COLOR_SCALE (widget))
       draw_trough = FALSE;
 
@@ -2281,6 +2341,18 @@ gtk_range_draw (GtkWidget *widget,
   if (priv->stepper_d_gadget)
     gtk_css_gadget_draw (priv->stepper_d_gadget, cr);
 
+  return FALSE;
+}
+
+static gboolean
+gtk_range_draw (GtkWidget *widget,
+                cairo_t   *cr)
+{
+  GtkRange *range = GTK_RANGE (widget);
+  GtkRangePrivate *priv = range->priv;
+
+  gtk_css_gadget_draw (priv->gadget, cr);
+
   return GDK_EVENT_PROPAGATE;
 }
 
@@ -3865,7 +3937,7 @@ sync_stepper_gadget (GtkRange                *range,
   if (!should_have_stepper)
     {
       if (*gadget_ptr != NULL)
-        gtk_box_gadget_remove_gadget (GTK_BOX_GADGET (priv->gadget), *gadget_ptr);
+        gtk_box_gadget_remove_gadget (GTK_BOX_GADGET (priv->contents_gadget), *gadget_ptr);
       g_clear_object (gadget_ptr);
       return;
     }
@@ -3879,7 +3951,7 @@ sync_stepper_gadget (GtkRange                *range,
   gtk_css_gadget_add_class (gadget, class);
   gtk_css_gadget_set_state (gadget, gtk_css_node_get_state (widget_node));
 
-  gtk_box_gadget_insert_gadget_after (GTK_BOX_GADGET (priv->gadget), prev_sibling,
+  gtk_box_gadget_insert_gadget_after (GTK_BOX_GADGET (priv->contents_gadget), prev_sibling,
                                       gadget, FALSE, FALSE, GTK_ALIGN_FILL);
   *gadget_ptr = gadget;
 }