[sysprof] line-visualizer: teach draw code how to fill in lines

[Christian Hergert <chergert src gnome org>]

commit cad87dee4950141db863026342582f8a6af5b3bc
Author: Christian Hergert <chergert redhat com>
Date:   Thu Sep 28 13:24:58 2017 -0700

    line-visualizer: teach draw code how to fill in lines
    
    We don't expose this via API yet, but it's handy to have it here so we can
    build upon it for doing stacked drawings (as useful for things like memory
    usage graphs by type).

 lib/sp-line-visualizer-row.c |   32 ++++++++++++++++++++++++++++----
 1 files changed, 28 insertions(+), 4 deletions(-)
---
diff --git a/lib/sp-line-visualizer-row.c b/lib/sp-line-visualizer-row.c
index 0a92e5a..5340f61 100644
--- a/lib/sp-line-visualizer-row.c
+++ b/lib/sp-line-visualizer-row.c
@@ -72,6 +72,7 @@ typedef struct
   GdkRGBA background;
   GdkRGBA foreground;
   guint use_default_style : 1;
+  guint fill : 1;
 } LineInfo;
 
 typedef struct
@@ -139,12 +140,15 @@ sp_line_visualizer_row_draw (GtkWidget *widget,
   SpLineVisualizerRowPrivate *priv = sp_line_visualizer_row_get_instance_private (self);
   GtkStyleContext *style_context;
   GtkStateFlags flags;
+  GtkAllocation alloc;
   GdkRGBA foreground;
   gboolean ret;
 
   g_assert (SP_IS_LINE_VISUALIZER_ROW (widget));
   g_assert (cr != NULL);
 
+  gtk_widget_get_allocation (widget, &alloc);
+
   ret = GTK_WIDGET_CLASS (sp_line_visualizer_row_parent_class)->draw (widget, cr);
 
   if (priv->cache == NULL)
@@ -160,6 +164,7 @@ sp_line_visualizer_row_draw (GtkWidget *widget,
       const LineInfo *line_info = &g_array_index (priv->lines, LineInfo, line);
       const Point *fpoints;
       guint n_fpoints = 0;
+      GdkRGBA color;
 
       fpoints = point_cache_get_points (priv->cache, line_info->id, &n_fpoints);
 
@@ -179,7 +184,15 @@ sp_line_visualizer_row_draw (GtkWidget *widget,
           last_x = points[0].x;
           last_y = points[0].y;
 
-          cairo_move_to (cr, last_x, last_y);
+          if (line_info->fill)
+            {
+              cairo_move_to (cr, last_x, alloc.height);
+              cairo_line_to (cr, last_x, last_y);
+            }
+          else
+            {
+              cairo_move_to (cr, last_x, last_y);
+            }
 
           for (guint i = 1; i < n_fpoints; i++)
             {
@@ -194,14 +207,25 @@ sp_line_visualizer_row_draw (GtkWidget *widget,
               last_y = points[i].y;
             }
 
+          if (line_info->fill)
+            {
+              cairo_line_to (cr, last_x, alloc.height);
+              cairo_close_path (cr);
+            }
+
           cairo_set_line_width (cr, line_info->line_width);
 
           if (line_info->use_default_style)
-            gdk_cairo_set_source_rgba (cr, &foreground);
+            color = foreground;
           else
-            gdk_cairo_set_source_rgba (cr, &line_info->foreground);
+            color = line_info->foreground;
 
-          cairo_stroke (cr);
+          gdk_cairo_set_source_rgba (cr, &color);
+
+          if (line_info->fill)
+            cairo_fill (cr);
+          else
+            cairo_stroke (cr);
         }
     }