From: Carlos Garnacho <carlosg@gnome.org>
Date: Fri, 29 Jul 2022 18:34:55 +0000 (+0200)
Subject: gtk/scrolledwindow: Check for overshoot setting up kinetic scroll helpers
X-Git-Tag: archive/raspbian/4.8.3+ds-2+rpi1~3^2~20^2~4^2~13^2
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=0e5a97ae58c26b48a75f3a186dc171a5a6e93d98;p=gtk4.git

gtk/scrolledwindow: Check for overshoot setting up kinetic scroll helpers

We may have situations where velocity is 0/0, but are overshooting. Places where
this happens are mouse wheels, and continuous scroll that ended up still before
finish. In this situation we also want to run the animation for overshoot, so
check for the corresponding axes to also set up the kinetic scroll helper.

Closes: https://gitlab.gnome.org/GNOME/gtk/-/issues/4784
---

diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index 518e0a4412..116fc9645a 100644
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -3337,6 +3337,7 @@ gtk_scrolled_window_start_deceleration (GtkScrolledWindow *scrolled_window)
   GdkFrameClock *frame_clock;
   gint64 current_time;
   double elapsed;
+  int overshoot_x, overshoot_y;
 
   g_return_if_fail (priv->deceleration_id == 0);
 
@@ -3346,6 +3347,8 @@ gtk_scrolled_window_start_deceleration (GtkScrolledWindow *scrolled_window)
   elapsed = (current_time - priv->last_deceleration_time) / (double)G_TIME_SPAN_SECOND;
   priv->last_deceleration_time = current_time;
 
+  _gtk_scrolled_window_get_overshoot (scrolled_window, &overshoot_x, &overshoot_y);
+
   if (may_hscroll (scrolled_window))
     {
       double lower,upper;
@@ -3354,7 +3357,7 @@ gtk_scrolled_window_start_deceleration (GtkScrolledWindow *scrolled_window)
       gtk_scrolled_window_accumulate_velocity (&priv->hscrolling, elapsed, &priv->x_velocity);
       g_clear_pointer (&priv->hscrolling, gtk_kinetic_scrolling_free);
 
-      if (priv->x_velocity != 0)
+      if (priv->x_velocity != 0 || overshoot_x != 0)
         {
           hadjustment = gtk_scrollbar_get_adjustment (GTK_SCROLLBAR (priv->hscrollbar));
           lower = gtk_adjustment_get_lower (hadjustment);
@@ -3381,7 +3384,7 @@ gtk_scrolled_window_start_deceleration (GtkScrolledWindow *scrolled_window)
       gtk_scrolled_window_accumulate_velocity (&priv->vscrolling, elapsed, &priv->y_velocity);
       g_clear_pointer (&priv->vscrolling, gtk_kinetic_scrolling_free);
 
-      if (priv->y_velocity != 0)
+      if (priv->y_velocity != 0 || overshoot_y != 0)
         {
           vadjustment = gtk_scrollbar_get_adjustment (GTK_SCROLLBAR (priv->vscrollbar));
           lower = gtk_adjustment_get_lower(vadjustment);