[gtk+/wip/watson/progress-tracker: 50/60] progressbar: port to progress tracker

[Matthew Watson <watson src gnome org>]

commit 5779779a6cc4496fe37a460a394803d21020c214
Author: Matt Watson <mattdangerw gmail com>
Date:   Mon Mar 28 01:09:02 2016 -0700

    progressbar: port to progress tracker

 gtk/gtkprogressbar.c |   36 ++++++++++++++++++++++--------------
 1 files changed, 22 insertions(+), 14 deletions(-)
---
diff --git a/gtk/gtkprogressbar.c b/gtk/gtkprogressbar.c
index 0942234..91dc693 100644
--- a/gtk/gtkprogressbar.c
+++ b/gtk/gtkprogressbar.c
@@ -38,6 +38,7 @@
 #include "gtkcssstylepropertyprivate.h"
 #include "gtkcsscustomgadgetprivate.h"
 #include "gtkcssnumbervalueprivate.h"
+#include "gtkprogresstrackerprivate.h"
 
 #include "a11y/gtkprogressbaraccessible.h"
 
@@ -92,6 +93,7 @@
 #define MIN_VERTICAL_BAR_WIDTH     7
 #define MIN_VERTICAL_BAR_HEIGHT    80
 
+#define DEFAULT_PULSE_DURATION     250000000
 
 struct _GtkProgressBarPrivate
 {
@@ -111,9 +113,10 @@ struct _GtkProgressBarPrivate
   GtkOrientation orientation;
 
   guint          tick_id;
+  GtkProgressTracker tracker;
   gint64         pulse1;
   gint64         pulse2;
-  gint64         frame1;
+  gdouble        last_iteration;
 
   guint          activity_dir  : 1;
   guint          activity_mode : 1;
@@ -1142,25 +1145,29 @@ tick_cb (GtkWidget     *widget,
 {
   GtkProgressBar *pbar = GTK_PROGRESS_BAR (widget);
   GtkProgressBarPrivate *priv = pbar->priv;
-  gint64 frame2;
-  gdouble fraction;
+  guint64 frame_time;
+  gdouble iteration, pulse_iterations, fraction;
 
-  frame2 = gdk_frame_clock_get_frame_time (frame_clock);
-  if (priv->frame1 == 0)
-    priv->frame1 = frame2 - 16667;
-  if (priv->pulse1 == 0)
-    priv->pulse1 = priv->pulse2 - 250 * 1000000;
+  frame_time = gdk_frame_clock_get_frame_time (frame_clock);
 
-  g_assert (priv->pulse2 > priv->pulse1);
-  g_assert (frame2 > priv->frame1);
+  gtk_progress_tracker_next_frame (&priv->tracker, frame_time);
 
+  /* Tracker will complete an iteration every DEFAULT_PULSE_DURATION. If we don't have any
+   * pulses yet, we'll take that long to move our progress by pulse_fraction.
+   */
+  pulse_iterations = 1.0;
+  if (priv->pulse2 != 0 && priv->pulse1 != 0)
+    pulse_iterations = (priv->pulse2 - priv->pulse1) / (gdouble) DEFAULT_PULSE_DURATION;
+  if (priv->pulse2 != 0)
+    pulse_iterations = MAX ((frame_time - priv->pulse2) / (gdouble) DEFAULT_PULSE_DURATION, 
pulse_iterations);
+
+  iteration = gtk_progress_tracker_get_iteration (&priv->tracker);
   /* Determine the fraction to move the block from one frame
    * to the next when pulse_fraction is how far the block should
    * move between two calls to gtk_progress_bar_pulse().
    */
-  fraction = priv->pulse_fraction * (frame2 - priv->frame1) / MAX (frame2 - priv->pulse2, priv->pulse2 - 
priv->pulse1);
-
-  priv->frame1 = frame2;
+  fraction = priv->pulse_fraction * (iteration - priv->last_iteration) / pulse_iterations;
+  priv->last_iteration = iteration;
 
   /* advance the block */
   if (priv->activity_dir == 0)
@@ -1237,10 +1244,11 @@ gtk_progress_bar_act_mode_enter (GtkProgressBar *pbar)
     }
 
   update_node_classes (pbar);
+  gtk_progress_tracker_start (&priv->tracker, DEFAULT_PULSE_DURATION, 0, INFINITY);
   priv->tick_id = gtk_widget_add_tick_callback (widget, tick_cb, NULL, NULL);
   priv->pulse2 = 0;
   priv->pulse1 = 0;
-  priv->frame1 = 0;
+  priv->last_iteration = 0;
 }
 
 static void