[shotwell] Really use a configurable scroll factor

[Jens Georg <jensgeorg src gnome org>]

commit f8e7f8f5201e76a7075da586e5046009ff6fed54
Author: Jens Georg <mail jensge org>
Date:   Sat Oct 8 06:32:00 2022 +0200

    Really use a configurable scroll factor

 src/Page.vala            | 11 +++++++----
 src/SinglePhotoPage.vala |  1 +
 2 files changed, 8 insertions(+), 4 deletions(-)
---
diff --git a/src/Page.vala b/src/Page.vala
index d21cfa33..0df56416 100644
--- a/src/Page.vala
+++ b/src/Page.vala
@@ -85,6 +85,9 @@ public abstract class Page : Gtk.ScrolledWindow {
     private int cursor_hide_time_cached = 0;
     private bool are_actions_attached = false;
     private OneShotScheduler? update_actions_scheduler = null;
+
+    protected double wheel_factor = 0.0;
+    protected double modified_wheel_factor = 1.0;
     
     protected Page(string page_name) {
         this.page_name = page_name;
@@ -989,13 +992,13 @@ public abstract class Page : Gtk.ScrolledWindow {
                     double dx, dy;
                     event.get_scroll_deltas(out dx, out dy);
 
-                    if (dy < 0)
+                    if (dy < -1.0 * this.wheel_factor)
                         return on_mousewheel_up(event);
-                    else if (dy > 0)
+                    else if (dy > this.wheel_factor)
                         return on_mousewheel_down(event);
-                    else if (dx < 0)
+                    else if (dx < -1.0 * this.wheel_factor)
                         return on_mousewheel_left(event);
-                    else if (dx > 0)
+                    else if (dx > this.wheel_factor)
                         return on_mousewheel_right(event);
                     else
                         return false;
diff --git a/src/SinglePhotoPage.vala b/src/SinglePhotoPage.vala
index d87b891c..d186318f 100644
--- a/src/SinglePhotoPage.vala
+++ b/src/SinglePhotoPage.vala
@@ -38,6 +38,7 @@ public abstract class SinglePhotoPage : Page {
 
     protected SinglePhotoPage(string page_name, bool scale_up_to_viewport) {
         base(page_name);
+        this.wheel_factor = 0.9999;
 
         this.scale_up_to_viewport = scale_up_to_viewport;