Merge branch 'wip/exalm/overshoot-changes-gtk3' into 'gtk-3-24'

scrolledwindow: Cancel overshoot on dimension changes

See merge request GNOME/gtk!3333

3 files changed, 79 insertions, 0 deletions

diff --git a/gtk/gtkkineticscrolling.c b/gtk/gtkkineticscrolling.c
index 9036e158dc..497627000b 100644
--- a/gtk/gtkkineticscrolling.c
+++ b/gtk/gtkkineticscrolling.c
@@ -124,6 +124,35 @@ gtk_kinetic_scrolling_new (gdouble lower,
   return data;
 }
 
+GtkKineticScrollingChange
+gtk_kinetic_scrolling_update_size (GtkKineticScrolling *data,
+                                   gdouble              lower,
+                                   gdouble              upper)
+{
+  GtkKineticScrollingChange change = GTK_KINETIC_SCROLLING_CHANGE_NONE;
+
+  if (lower != data->lower)
+    {
+      if (data->position <= lower)
+        change |= GTK_KINETIC_SCROLLING_CHANGE_LOWER;
+
+      data->lower = lower;
+    }
+
+  if (upper != data->upper)
+    {
+      if (data->position >= data->upper)
+        change |= GTK_KINETIC_SCROLLING_CHANGE_UPPER;
+
+      data->upper = upper;
+    }
+
+  if (data->phase == GTK_KINETIC_SCROLLING_PHASE_OVERSHOOTING)
+    change |= GTK_KINETIC_SCROLLING_CHANGE_IN_OVERSHOOT;
+
+  return change;
+}
+
 void
 gtk_kinetic_scrolling_free (GtkKineticScrolling *kinetic)
 {
diff --git a/gtk/gtkkineticscrolling.h b/gtk/gtkkineticscrolling.h
index d00f1d05f6..8155d57687 100644
--- a/gtk/gtkkineticscrolling.h
+++ b/gtk/gtkkineticscrolling.h
@@ -23,6 +23,13 @@
 
 G_BEGIN_DECLS
 
+typedef enum {
+  GTK_KINETIC_SCROLLING_CHANGE_NONE = 0,
+  GTK_KINETIC_SCROLLING_CHANGE_LOWER = 1 << 0,
+  GTK_KINETIC_SCROLLING_CHANGE_UPPER = 1 << 1,
+  GTK_KINETIC_SCROLLING_CHANGE_IN_OVERSHOOT = 1 << 2,
+} GtkKineticScrollingChange;
+
 typedef struct _GtkKineticScrolling GtkKineticScrolling;
 
 GtkKineticScrolling *    gtk_kinetic_scrolling_new  (gdouble               lower,
@@ -34,6 +41,10 @@ GtkKineticScrolling *    gtk_kinetic_scrolling_new  (gdouble               lower
                                                      gdouble               initial_velocity);
 void                     gtk_kinetic_scrolling_free (GtkKineticScrolling  *kinetic);
 
+GtkKineticScrollingChange gtk_kinetic_scrolling_update_size (GtkKineticScrolling *data,
+                                                             gdouble              lower,
+                                                             gdouble              upper);
+
 gboolean                 gtk_kinetic_scrolling_tick (GtkKineticScrolling  *data,
                                                      gdouble               time_delta,
                                                      gdouble              *position,
diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index bea7339f39..1909077220 100644
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -3900,6 +3900,24 @@ gtk_scrolled_window_adjustment_changed (GtkAdjustment *adjustment,
 
 	  if (priv->hscrollbar_visible != visible)
 	    gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
+
+          if (priv->hscrolling)
+            {
+              GtkKineticScrollingChange change;
+              gdouble lower = gtk_adjustment_get_lower (adjustment);
+              gdouble upper = gtk_adjustment_get_upper (adjustment);
+              upper -= gtk_adjustment_get_page_size (adjustment);
+
+              change = gtk_kinetic_scrolling_update_size (priv->hscrolling, lower, upper);
+
+              if ((change & GTK_KINETIC_SCROLLING_CHANGE_IN_OVERSHOOT) &&
+                  (change & (GTK_KINETIC_SCROLLING_CHANGE_UPPER | GTK_KINETIC_SCROLLING_CHANGE_LOWER)))
+                {
+                  g_clear_pointer (&priv->hscrolling, gtk_kinetic_scrolling_free);
+                  priv->unclamped_hadj_value = gtk_adjustment_get_value (adjustment);
+                  gtk_scrolled_window_invalidate_overshoot (scrolled_window);
+                }
+            }
 	}
     }
   else if (adjustment == gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar)))
@@ -3914,8 +3932,29 @@ gtk_scrolled_window_adjustment_changed (GtkAdjustment *adjustment,
 
 	  if (priv->vscrollbar_visible != visible)
 	    gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
+
+          if (priv->vscrolling)
+            {
+              GtkKineticScrollingChange change;
+              gdouble lower = gtk_adjustment_get_lower (adjustment);
+              gdouble upper = gtk_adjustment_get_upper (adjustment);
+              upper -= gtk_adjustment_get_page_size (adjustment);
+
+              change = gtk_kinetic_scrolling_update_size (priv->vscrolling, lower, upper);
+
+              if ((change & GTK_KINETIC_SCROLLING_CHANGE_IN_OVERSHOOT) &&
+                  (change & (GTK_KINETIC_SCROLLING_CHANGE_UPPER | GTK_KINETIC_SCROLLING_CHANGE_LOWER)))
+                {
+                  g_clear_pointer (&priv->vscrolling, gtk_kinetic_scrolling_free);
+                  priv->unclamped_vadj_value = gtk_adjustment_get_value (adjustment);
+                  gtk_scrolled_window_invalidate_overshoot (scrolled_window);
+                }
+            }
 	}
     }
+
+  if (!priv->hscrolling && !priv->vscrolling)
+    gtk_scrolled_window_cancel_deceleration (scrolled_window);
 }
 
 static void