[gimp] app: add gimp_display_shell_scrollbars_update_steppers()

[Michael Natterer <mitch src gnome org>]

commit 73a9ac967caefa14175173e52e3ef750464d783c
Author: Michael Natterer <mitch gimp org>
Date:   Tue Jan 5 20:53:34 2016 +0100

    app: add gimp_display_shell_scrollbars_update_steppers()
    
    for the code from gimp_display_shell_scroll_clamp_and_update() that
    sets the scrollbar stepper sensitivity.

 app/display/gimpdisplayshell-scroll.c     |   33 +++++-----------------
 app/display/gimpdisplayshell-scrollbars.c |   41 +++++++++++++++++++++++++++++
 app/display/gimpdisplayshell-scrollbars.h |    6 ++++
 3 files changed, 55 insertions(+), 25 deletions(-)
---
diff --git a/app/display/gimpdisplayshell-scroll.c b/app/display/gimpdisplayshell-scroll.c
index 919264b..5345251 100644
--- a/app/display/gimpdisplayshell-scroll.c
+++ b/app/display/gimpdisplayshell-scroll.c
@@ -35,7 +35,6 @@
 #include "gimpdisplay-foreach.h"
 #include "gimpdisplayshell.h"
 #include "gimpdisplayshell-expose.h"
-#include "gimpdisplayshell-rotate.h"
 #include "gimpdisplayshell-rulers.h"
 #include "gimpdisplayshell-scale.h"
 #include "gimpdisplayshell-scroll.h"
@@ -198,34 +197,18 @@ gimp_display_shell_scroll_clamp_and_update (GimpDisplayShell *shell)
           max_offset_y = sh + overpan_amount - shell->disp_height;
         }
 
-
-      /* Handle scrollbar stepper sensitiity */
-
-      gtk_range_set_lower_stepper_sensitivity (GTK_RANGE (shell->hsb),
-                                               min_offset_x < shell->offset_x ?
-                                               GTK_SENSITIVITY_ON :
-                                               GTK_SENSITIVITY_OFF);
-
-      gtk_range_set_upper_stepper_sensitivity (GTK_RANGE (shell->hsb),
-                                               max_offset_x > shell->offset_x ?
-                                               GTK_SENSITIVITY_ON :
-                                               GTK_SENSITIVITY_OFF);
-
-      gtk_range_set_lower_stepper_sensitivity (GTK_RANGE (shell->vsb),
-                                               min_offset_y < shell->offset_y ?
-                                               GTK_SENSITIVITY_ON :
-                                               GTK_SENSITIVITY_OFF);
-
-      gtk_range_set_upper_stepper_sensitivity (GTK_RANGE (shell->vsb),
-                                               max_offset_y > shell->offset_y ?
-                                               GTK_SENSITIVITY_ON :
-                                               GTK_SENSITIVITY_OFF);
-
-
       /* Clamp */
 
       shell->offset_x = CLAMP (shell->offset_x, min_offset_x, max_offset_x);
       shell->offset_y = CLAMP (shell->offset_y, min_offset_y, max_offset_y);
+
+      /* Set scrollbar stepper sensitiity */
+
+      gimp_display_shell_scrollbars_update_steppers (shell,
+                                                     min_offset_x,
+                                                     max_offset_x,
+                                                     min_offset_y,
+                                                     max_offset_y);
     }
   else
     {
diff --git a/app/display/gimpdisplayshell-scrollbars.c b/app/display/gimpdisplayshell-scrollbars.c
index 152dcd9..ee998c6 100644
--- a/app/display/gimpdisplayshell-scrollbars.c
+++ b/app/display/gimpdisplayshell-scrollbars.c
@@ -161,3 +161,44 @@ gimp_display_shell_scrollbars_setup_vertical (GimpDisplayShell *shell,
                                                  MINIMUM_STEP_AMOUNT),
                 NULL);
 }
+
+/**
+ * gimp_display_shell_scrollbars_update_steppers:
+ * @shell:
+ * @min_offset_x:
+ * @max_offset_x:
+ * @min_offset_y:
+ * @max_offset_y:
+ *
+ * Sets the scrollbars' stepper sensitivity which is set differently
+ * from its adjustment limits because we support overscrolling.
+ **/
+void
+gimp_display_shell_scrollbars_update_steppers (GimpDisplayShell *shell,
+                                               gint              min_offset_x,
+                                               gint              max_offset_x,
+                                               gint              min_offset_y,
+                                               gint              max_offset_y)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  gtk_range_set_lower_stepper_sensitivity (GTK_RANGE (shell->hsb),
+                                           min_offset_x < shell->offset_x ?
+                                           GTK_SENSITIVITY_ON :
+                                           GTK_SENSITIVITY_OFF);
+
+  gtk_range_set_upper_stepper_sensitivity (GTK_RANGE (shell->hsb),
+                                           max_offset_x > shell->offset_x ?
+                                           GTK_SENSITIVITY_ON :
+                                           GTK_SENSITIVITY_OFF);
+
+  gtk_range_set_lower_stepper_sensitivity (GTK_RANGE (shell->vsb),
+                                           min_offset_y < shell->offset_y ?
+                                           GTK_SENSITIVITY_ON :
+                                           GTK_SENSITIVITY_OFF);
+
+  gtk_range_set_upper_stepper_sensitivity (GTK_RANGE (shell->vsb),
+                                           max_offset_y > shell->offset_y ?
+                                           GTK_SENSITIVITY_ON :
+                                           GTK_SENSITIVITY_OFF);
+}
diff --git a/app/display/gimpdisplayshell-scrollbars.h b/app/display/gimpdisplayshell-scrollbars.h
index 8a7dff1..954537d 100644
--- a/app/display/gimpdisplayshell-scrollbars.h
+++ b/app/display/gimpdisplayshell-scrollbars.h
@@ -26,5 +26,11 @@ void   gimp_display_shell_scrollbars_setup_horizontal (GimpDisplayShell *shell,
 void   gimp_display_shell_scrollbars_setup_vertical   (GimpDisplayShell *shell,
                                                        gdouble           value);
 
+void   gimp_display_shell_scrollbars_update_steppers  (GimpDisplayShell *shell,
+                                                       gint              min_offset_x,
+                                                       gint              max_offset_x,
+                                                       gint              min_offset_y,
+                                                       gint              max_offset_y);
+
 
 #endif  /*  __GIMP_DISPLAY_SHELL_SCROLLBARS_H__  */