[goffice] fixed unicolor gradients brightness

[Jean Bréfort <jbrefort src gnome org>]

commit cc3480ed960d0d613a29e0c5c6e442e6543bb46a
Author: Jean Brefort <jean brefort normalesup org>
Date:   Sun Sep 27 08:41:05 2009 +0200

    fixed unicolor gradients brightness

 ChangeLog                       |    6 ++++++
 NEWS                            |    3 +++
 goffice/utils/go-style-prefs.ui |    6 +++++-
 goffice/utils/go-style.c        |   12 +++++++++---
 4 files changed, 23 insertions(+), 4 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 251f526..50666d0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2009-09-27  Jean Brefort  <jean brefort normalesup org>
+
+	* goffice/utils/go-style-prefs.ui: fixed unicolor gradients brightness.
+	* goffice/utils/go-style.c (fill_gradient_init),
+	(cb_fill_type_changed), (go_style_set_fill_brightness): ditto.
+
 2009-09-25  Jean Brefort  <jean brefort normalesup org>
 
 	* docs/reference/goffice-0.8-sections.txt: added a few more entries.
diff --git a/NEWS b/NEWS
index dd822a6..a965d8b 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,8 @@
 goffice 0.7.14:
 
+Jean:
+	* Fix unicolor gradient brightness.
+
 --------------------------------------------------------------------------
 goffice 0.7.13:
 
diff --git a/goffice/utils/go-style-prefs.ui b/goffice/utils/go-style-prefs.ui
index bbbaced..e41ba75 100644
--- a/goffice/utils/go-style-prefs.ui
+++ b/goffice/utils/go-style-prefs.ui
@@ -1,5 +1,6 @@
 <?xml version="1.0"?>
 <interface>
+  <!-- interface-requires gtk+ 2.12 -->
   <!-- interface-naming-policy toplevel-contextual -->
   <object class="GtkAdjustment" id="adjustment1">
     <property name="upper">30</property>
@@ -542,7 +543,10 @@
                                 <property name="visible">True</property>
                                 <property name="can_focus">True</property>
                                 <property name="adjustment">adjustment3</property>
-                                <property name="inverted">True</property>
+                                <property name="upper_stepper_sensitivity">off</property>
+                                <property name="show_fill_level">True</property>
+                                <property name="restrict_to_fill_level">False</property>
+                                <property name="fill_level">0</property>
                                 <property name="draw_value">False</property>
                               </object>
                               <packing>
diff --git a/goffice/utils/go-style.c b/goffice/utils/go-style.c
index 9ba7d91..5748f88 100644
--- a/goffice/utils/go-style.c
+++ b/goffice/utils/go-style.c
@@ -414,6 +414,7 @@ fill_gradient_init (StylePrefState *state)
 
 	state->fill.gradient.brightness = brightness =
 		go_gtk_builder_get_widget (state->gui, "fill_brightness_scale");
+	gtk_range_set_value (GTK_RANGE (brightness), state->style->fill.gradient.brightness);
 	label = go_gtk_builder_get_widget (state->gui, "fill_brightness_label");
 	gtk_size_group_add_widget (state->fill.size_group, label);
 	gtk_label_set_mnemonic_widget (GTK_LABEL (label), brightness);
@@ -595,6 +596,9 @@ cb_fill_type_changed (GtkWidget *menu, StylePrefState *state)
 
 	index = CLAMP (gtk_combo_box_get_active (GTK_COMBO_BOX (menu)), 0, (int) G_N_ELEMENTS (fill_infos) - 1);
 
+	if (state->style->fill.type == GO_STYLE_FILL_GRADIENT)
+	/* we need to set brightness to 0 because of unicolor gradients recognition */
+		gtk_range_set_value (GTK_RANGE (state->fill.gradient.brightness), 0.);
 	state->style->fill.type = fill_infos[index].type;
 	state->style->fill.auto_type = FALSE;
 	set_style (state);
@@ -1996,15 +2000,17 @@ go_style_set_font (GOStyle *style, GOFont const *font)
 void
 go_style_set_fill_brightness (GOStyle *style, float brightness)
 {
+	double limit;
 	g_return_if_fail (GO_IS_STYLE (style));
 	g_return_if_fail (style->fill.type == GO_STYLE_FILL_GRADIENT);
 
 	brightness = CLAMP (brightness, 0, 100.0);
+	limit = (GO_COLOR_UINT_R (style->fill.pattern.back) + GO_COLOR_UINT_G (style->fill.pattern.back) + GO_COLOR_UINT_B (style->fill.pattern.back)) / 7.65;
 
 	style->fill.gradient.brightness = brightness;
-	style->fill.pattern.fore = (brightness < 50.)
-		? GO_COLOR_INTERPOLATE(style->fill.pattern.back, GO_COLOR_WHITE, 1. - brightness / 50.)
-		: GO_COLOR_INTERPOLATE(style->fill.pattern.back, GO_COLOR_BLACK, brightness / 50. - 1.);
+	style->fill.pattern.fore = (brightness <= limit && limit > 0.)
+		? GO_COLOR_INTERPOLATE(style->fill.pattern.back, GO_COLOR_BLACK, 1. - brightness / limit)
+		: GO_COLOR_INTERPOLATE(style->fill.pattern.back, GO_COLOR_WHITE, (brightness - limit) / (100. - limit));
 }
 
 /**