[gimp] app: GimpHistogramBox: map the range to 0..1 for != 8 bit histograms

[Michael Natterer <mitch src gnome org>]

commit 945e57af1d6bbde502aceb1b34b0ab6b98f67272
Author: Michael Natterer <mitch gimp org>
Date:   Wed Jun 12 11:18:07 2013 +0200

    app: GimpHistogramBox: map the range to 0..1 for != 8 bit histograms

 app/widgets/gimphistogrambox.c |   88 +++++++++++++++++++++++++++-------------
 app/widgets/gimphistogrambox.h |    5 ++
 2 files changed, 65 insertions(+), 28 deletions(-)
---
diff --git a/app/widgets/gimphistogrambox.c b/app/widgets/gimphistogrambox.c
index 5519560..1346e88 100644
--- a/app/widgets/gimphistogrambox.c
+++ b/app/widgets/gimphistogrambox.c
@@ -75,12 +75,13 @@ gimp_histogram_box_init (GimpHistogramBox *box)
   GtkWidget *hbox;
   GtkWidget *vbox;
   GtkWidget *vbox2;
-  GtkWidget *spinbutton;
   GtkObject *adjustment;
   GtkWidget *frame;
   GtkWidget *view;
   GtkWidget *bar;
 
+  box->n_bins = 256;
+
   gtk_orientable_set_orientation (GTK_ORIENTABLE (box),
                                   GTK_ORIENTATION_VERTICAL);
 
@@ -150,12 +151,12 @@ gimp_histogram_box_init (GimpHistogramBox *box)
   gtk_widget_show (hbox);
 
   /*  low spinbutton  */
-  spinbutton = gimp_spin_button_new (&adjustment,
-                                     0.0, 0.0, 255.0, 1.0, 16.0, 0.0,
-                                     1.0, 0);
+  box->low_spinbutton = gimp_spin_button_new (&adjustment,
+                                              0.0, 0.0, 255.0, 1.0, 16.0, 0.0,
+                                              1.0, 0);
   box->low_adj = GTK_ADJUSTMENT (adjustment);
-  gtk_box_pack_start (GTK_BOX (hbox), spinbutton, FALSE, FALSE, 0);
-  gtk_widget_show (spinbutton);
+  gtk_box_pack_start (GTK_BOX (hbox), box->low_spinbutton, FALSE, FALSE, 0);
+  gtk_widget_show (box->low_spinbutton);
 
   g_signal_connect (adjustment, "value-changed",
                     G_CALLBACK (gimp_histogram_box_low_adj_update),
@@ -165,12 +166,12 @@ gimp_histogram_box_init (GimpHistogramBox *box)
                                   GTK_ADJUSTMENT (adjustment));
 
   /*  high spinbutton  */
-  spinbutton = gimp_spin_button_new (&adjustment,
-                                     255.0, 0.0, 255.0, 1.0, 16.0, 0.0,
-                                     1.0, 0);
+  box->high_spinbutton = gimp_spin_button_new (&adjustment,
+                                               255.0, 0.0, 255.0, 1.0, 16.0, 0.0,
+                                               1.0, 0);
   box->high_adj = GTK_ADJUSTMENT (adjustment);
-  gtk_box_pack_end (GTK_BOX (hbox), spinbutton, FALSE, FALSE, 0);
-  gtk_widget_show (spinbutton);
+  gtk_box_pack_end (GTK_BOX (hbox), box->high_spinbutton, FALSE, FALSE, 0);
+  gtk_widget_show (box->high_spinbutton);
 
   g_signal_connect (adjustment, "value-changed",
                     G_CALLBACK (gimp_histogram_box_high_adj_update),
@@ -196,28 +197,34 @@ static void
 gimp_histogram_box_low_adj_update (GtkAdjustment    *adjustment,
                                    GimpHistogramBox *box)
 {
-  gint value = ROUND (gtk_adjustment_get_value (adjustment));
+  gdouble value = gtk_adjustment_get_value (adjustment);
 
-  if (box->view->start != value)
-    {
-      gtk_adjustment_set_lower (box->high_adj, value);
+  gtk_adjustment_set_lower (box->high_adj, value);
 
-      gimp_histogram_view_set_range (box->view, value, box->view->end);
-    }
+  if (box->n_bins != 256)
+    value *= box->n_bins - 1;
+
+  value = ROUND (value);
+
+  if (box->view->start != value)
+    gimp_histogram_view_set_range (box->view, value, box->view->end);
 }
 
 static void
 gimp_histogram_box_high_adj_update (GtkAdjustment    *adjustment,
                                     GimpHistogramBox *box)
 {
-  gint value = ROUND (gtk_adjustment_get_value (adjustment));
+  gdouble value = gtk_adjustment_get_value (adjustment);
 
-  if (box->view->end != value)
-    {
-      gtk_adjustment_set_upper (box->low_adj, value);
+  gtk_adjustment_set_upper (box->low_adj, value);
 
-      gimp_histogram_view_set_range (box->view, box->view->start, value);
-    }
+  if (box->n_bins != 256)
+    value *= box->n_bins - 1;
+
+  value = ROUND (value);
+
+  if (box->view->end != value)
+    gimp_histogram_view_set_range (box->view, box->view->start, value);
 }
 
 static void
@@ -226,13 +233,38 @@ gimp_histogram_box_histogram_range (GimpHistogramView *view,
                                     gint               end,
                                     GimpHistogramBox  *box)
 {
-  gtk_adjustment_set_lower (box->high_adj, start);
-  gtk_adjustment_set_upper (box->high_adj, view->n_bins - 1);
+  gdouble s = start;
+  gdouble e = end;
+
+  if (box->n_bins != view->n_bins)
+    {
+      box->n_bins = view->n_bins;
+
+      if (box->n_bins == 256)
+        {
+          gtk_adjustment_set_upper (box->high_adj, 255);
+          gtk_spin_button_set_digits (GTK_SPIN_BUTTON (box->low_spinbutton), 0);
+          gtk_spin_button_set_digits (GTK_SPIN_BUTTON (box->high_spinbutton), 0);
+        }
+      else
+        {
+          gtk_adjustment_set_upper (box->high_adj, 1.0);
+          gtk_spin_button_set_digits (GTK_SPIN_BUTTON (box->low_spinbutton), 3);
+          gtk_spin_button_set_digits (GTK_SPIN_BUTTON (box->high_spinbutton), 3);
+        }
+    }
+
+  if (box->n_bins != 256)
+    {
+      s /= box->n_bins - 1;
+      e /= box->n_bins - 1;
+    }
 
-  gtk_adjustment_set_upper (box->low_adj,  end);
+  gtk_adjustment_set_lower (box->high_adj, s);
+  gtk_adjustment_set_upper (box->low_adj,  e);
 
-  gtk_adjustment_set_value (box->low_adj,  start);
-  gtk_adjustment_set_value (box->high_adj, end);
+  gtk_adjustment_set_value (box->low_adj,  s);
+  gtk_adjustment_set_value (box->high_adj, e);
 }
 
 static void
diff --git a/app/widgets/gimphistogrambox.h b/app/widgets/gimphistogrambox.h
index f84383e..a6a8b2b 100644
--- a/app/widgets/gimphistogrambox.h
+++ b/app/widgets/gimphistogrambox.h
@@ -37,8 +37,13 @@ struct _GimpHistogramBox
   GtkWidget         *color_bar;
   GtkWidget         *slider_bar;
 
+  gint               n_bins;
+
   GtkAdjustment     *low_adj;
   GtkAdjustment     *high_adj;
+
+  GtkWidget         *low_spinbutton;
+  GtkWidget         *high_spinbutton;
 };
 
 struct _GimpHistogramBoxClass