sysprof: fixed row height and text labels

This makes things look a bit more like flamegraphs.pl in the sense that we
have some labels and separation between rows. Also, use a ScrolledWindow so
that we can have much taller graphs to accommodate deep stack traces.

We might want to jump to the bottom at some point, but this gets things in
place for now. Icicle graphs are another option (invert).

src/sysprof/style.css

@@ -91,3 +91,7 @@ timescrubber timecode {
   font-feature-settings: 'tnum';
   font-size: .8em;
 }
+
+flamegraph {
+  font-size: 10px;
+}

src/sysprof/sysprof-flame-graph.c

@@ -28,6 +28,8 @@
 
 #include "sysprof-flame-graph.h"
 
+#define ROW_HEIGHT 14
+
 struct _SysprofFlameGraph
 {
   GtkWidget         parent_instance;
@@ -59,9 +61,9 @@ static void
 sysprof_flame_graph_snapshot_node (GtkSnapshot           *snapshot,
                                    SysprofCallgraphNode  *node,
                                    const graphene_rect_t *area,
-                                   double                 row_height,
                                    double                 min_width,
                                    const GdkRGBA         *default_color,
+                                   PangoLayout           *layout,
                                    int                    depth)
 {
   SysprofCallgraphCategory category;
@@ -84,9 +86,20 @@ sysprof_flame_graph_snapshot_node (GtkSnapshot           *snapshot,
   gtk_snapshot_append_color (snapshot,
                              color,
                              &GRAPHENE_RECT_INIT (area->origin.x,
-                                                  area->origin.y + area->size.height - row_height,
+                                                  area->origin.y + area->size.height - ROW_HEIGHT - 1,
                                                   area->size.width,
-                                                  row_height));
+                                                  ROW_HEIGHT));
+
+  if (area->size.width > ROW_HEIGHT)
+    {
+      pango_layout_set_text (layout, node->summary->symbol->name, -1);
+      pango_layout_set_width (layout, PANGO_SCALE * area->size.width);
+
+      gtk_snapshot_save (snapshot);
+      gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (round (area->origin.x), round (area->origin.y) + area->size.height - ROW_HEIGHT));
+      gtk_snapshot_append_layout (snapshot, layout, &(GdkRGBA) {1,1,1,1});
+      gtk_snapshot_restore (snapshot);
+    }
 
   if (node->children != NULL)
     {
@@ -98,7 +111,7 @@ sysprof_flame_graph_snapshot_node (GtkSnapshot           *snapshot,
 
       child_area.origin.x = area->origin.x;
       child_area.origin.y = area->origin.y;
-      child_area.size.height = area->size.height - row_height;
+      child_area.size.height = area->size.height - ROW_HEIGHT - 1;
 
       for (SysprofCallgraphNode *child = node->children; child; child = child->next)
         {
@@ -128,9 +141,9 @@ sysprof_flame_graph_snapshot_node (GtkSnapshot           *snapshot,
           sysprof_flame_graph_snapshot_node (snapshot,
                                              child,
                                              &child_area,
-                                             row_height,
                                              min_width,
                                              default_color,
+                                             layout,
                                              depth + 1);
 
           child_area.origin.x += width;
@@ -144,7 +157,7 @@ sysprof_flame_graph_snapshot (GtkWidget   *widget,
 {
   SysprofFlameGraph *self = (SysprofFlameGraph *)widget;
   SysprofColorIter iter;
-  double row_height;
+  PangoLayout *layout;
 
   g_assert (SYSPROF_IS_FLAME_GRAPH (self));
   g_assert (GTK_IS_SNAPSHOT (snapshot));
@@ -153,17 +166,48 @@ sysprof_flame_graph_snapshot (GtkWidget   *widget,
     return;
 
   sysprof_color_iter_init (&iter);
-  row_height = gtk_widget_get_height (widget) / (double)self->callgraph->height;
-
+  layout = gtk_widget_create_pango_layout (widget, NULL);
+  pango_layout_set_ellipsize (layout, PANGO_ELLIPSIZE_END);
   sysprof_flame_graph_snapshot_node (snapshot,
                                      &self->callgraph->root,
                                      &GRAPHENE_RECT_INIT (0, 0,
                                                           gtk_widget_get_width (widget),
                                                           gtk_widget_get_height (widget)),
-                                     row_height,
                                      1. / (double)gtk_widget_get_scale_factor (widget),
                                      sysprof_color_iter_next (&iter),
+                                     layout,
                                      0);
+  g_object_unref (layout);
+}
+
+static void
+sysprof_flame_graph_measure (GtkWidget      *widget,
+                             GtkOrientation  orientation,
+                             int             for_size,
+                             int            *minimum,
+                             int            *natural,
+                             int            *minimum_baseline,
+                             int            *natural_baseline)
+{
+  SysprofFlameGraph *self = (SysprofFlameGraph *)widget;
+
+  g_assert (SYSPROF_IS_FLAME_GRAPH (self));
+
+  *minimum_baseline = -1;
+  *natural_baseline = -1;
+
+  if (orientation == GTK_ORIENTATION_VERTICAL)
+    {
+      if (self->callgraph != NULL)
+        *minimum = ROW_HEIGHT * self->callgraph->height + self->callgraph->height + 1;
+
+      *natural = *minimum;
+    }
+  else
+    {
+      *minimum = 1;
+      *natural = 500;
+    }
 }
 
 static void
@@ -225,6 +269,7 @@ sysprof_flame_graph_class_init (SysprofFlameGraphClass *klass)
   object_class->set_property = sysprof_flame_graph_set_property;
 
   widget_class->snapshot = sysprof_flame_graph_snapshot;
+  widget_class->measure = sysprof_flame_graph_measure;
 
   properties[PROP_CALLGRAPH] =
     g_param_spec_object ("callgraph", NULL, NULL,
@@ -232,11 +277,14 @@ sysprof_flame_graph_class_init (SysprofFlameGraphClass *klass)
                          (G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS));
 
   g_object_class_install_properties (object_class, N_PROPS, properties);
+
+  gtk_widget_class_set_css_name (widget_class, "flamegraph");
 }
 
 static void
 sysprof_flame_graph_init (SysprofFlameGraph *self)
 {
+  gtk_widget_add_css_class (GTK_WIDGET (self), "view");
 }
 
 GtkWidget *
@@ -263,6 +311,6 @@ sysprof_flame_graph_set_callgraph (SysprofFlameGraph *self,
   if (g_set_object (&self->callgraph, callgraph))
     {
       g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_CALLGRAPH]);
-      gtk_widget_queue_draw (GTK_WIDGET (self));
+      gtk_widget_queue_resize (GTK_WIDGET (self));
     }
 }

src/sysprof/sysprof-samples-section.ui

@@ -154,10 +154,15 @@
                 <property name="icon-name">flamegraph-symbolic</property>
                 <property name="title" translatable="yes">Flamegraph</property>
                 <property name="child">
-                  <object class="SysprofFlameGraph">
-                    <binding name="callgraph">
-                      <lookup name="callgraph">callgraph_view</lookup>
-                    </binding>
+                  <object class="GtkScrolledWindow">
+                    <property name="hscrollbar-policy">never</property>
+                    <property name="child">
+                      <object class="SysprofFlameGraph">
+                        <binding name="callgraph">
+                          <lookup name="callgraph">callgraph_view</lookup>
+                        </binding>
+                      </object>
+                    </property>
                   </object>
                 </property>
               </object>