[epiphany/wip/exalm/fullscreen: 1/3] fullscreen-box: Hide header bar when touch is used

[Alexander Mikhaylenko <alexm src gnome org>]

commit 31a4a9fa84b0aa4ccc1c19177bd137e0b1dcd069
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Mon Mar 22 20:04:19 2021 +0500

    fullscreen-box: Hide header bar when touch is used

 src/ephy-fullscreen-box.c | 39 +++++++++++++++++++++++++++++++--------
 1 file changed, 31 insertions(+), 8 deletions(-)
---
diff --git a/src/ephy-fullscreen-box.c b/src/ephy-fullscreen-box.c
index c8e3fe9ce..591d2bf99 100644
--- a/src/ephy-fullscreen-box.c
+++ b/src/ephy-fullscreen-box.c
@@ -31,6 +31,7 @@ struct _EphyFullscreenBox {
 
   HdyFlap *flap;
   GtkEventController *controller;
+  GtkGesture *gesture;
 
   gboolean fullscreen;
   gboolean autohide;
@@ -39,6 +40,7 @@ struct _EphyFullscreenBox {
 
   GtkWidget *last_focus;
   gdouble last_y;
+  gboolean is_touch;
 };
 
 static void ephy_fullscreen_box_buildable_init (GtkBuildableIface *iface);
@@ -127,18 +129,20 @@ static void
 update (EphyFullscreenBox *self,
         gboolean           hide_immediately)
 {
-  gdouble height;
-
   if (!self->autohide || !self->fullscreen)
     return;
 
-  height = gtk_widget_get_allocated_height (hdy_flap_get_flap (self->flap));
-  height *= hdy_flap_get_reveal_progress (self->flap);
-  height = MAX (height, SHOW_HEADERBAR_DISTANCE_PX);
+  if (!self->is_touch) {
+    gdouble height;
 
-  if (self->last_y <= height) {
-    show_ui (self);
-    return;
+    height = gtk_widget_get_allocated_height (hdy_flap_get_flap (self->flap));
+    height *= hdy_flap_get_reveal_progress (self->flap);
+    height = MAX (height, SHOW_HEADERBAR_DISTANCE_PX);
+
+    if (self->last_y <= height) {
+      show_ui (self);
+      return;
+    }
   }
 
   if (self->last_focus && is_descendant_of (self->last_focus,
@@ -155,11 +159,22 @@ motion_cb (EphyFullscreenBox *self,
            gdouble            x,
            gdouble            y)
 {
+  self->is_touch = FALSE;
   self->last_y = y;
 
   update (self, FALSE);
 }
 
+static void
+press_cb (EphyFullscreenBox *self)
+{
+  gtk_gesture_set_state (self->gesture, GTK_EVENT_SEQUENCE_DENIED);
+
+  self->is_touch = TRUE;
+
+  update (self, TRUE);
+}
+
 static void
 set_focus_cb (EphyFullscreenBox *self,
               GtkWidget         *widget)
@@ -306,6 +321,7 @@ ephy_fullscreen_box_dispose (GObject *object)
   EphyFullscreenBox *self = EPHY_FULLSCREEN_BOX (object);
 
   g_clear_object (&self->controller);
+  g_clear_object (&self->gesture);
 
   G_OBJECT_CLASS (ephy_fullscreen_box_parent_class)->dispose (object);
 }
@@ -390,6 +406,13 @@ ephy_fullscreen_box_init (EphyFullscreenBox *self)
   gtk_event_controller_set_propagation_phase (self->controller, GTK_PHASE_CAPTURE);
   g_signal_connect_object (self->controller, "motion",
                            G_CALLBACK (motion_cb), self, G_CONNECT_SWAPPED);
+
+  self->gesture = gtk_gesture_multi_press_new (GTK_WIDGET (self));
+  gtk_event_controller_set_propagation_phase (GTK_EVENT_CONTROLLER (self->gesture),
+                                              GTK_PHASE_CAPTURE);
+  gtk_gesture_single_set_touch_only (GTK_GESTURE_SINGLE (self->gesture), TRUE);
+  g_signal_connect_object (self->gesture, "pressed",
+                           G_CALLBACK (press_cb), self, G_CONNECT_SWAPPED);
 }
 
 static void