[libhandy/tabs: 62/62] dnd

[Alexander Mikhaylenko <alexm src gnome org>]

commit c8766d72f96598096cde40e9963d3b15cee39b3e
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Sat Sep 12 23:56:54 2020 +0500

    dnd

 src/hdy-tab-box.c          | 159 ++++++++++++++++++++++++++++-----------------
 src/hdy-tab-view-private.h |   2 +
 src/hdy-tab-view.c         |  12 ++++
 3 files changed, 113 insertions(+), 60 deletions(-)
---
diff --git a/src/hdy-tab-box.c b/src/hdy-tab-box.c
index d24bec76..d8ed168a 100644
--- a/src/hdy-tab-box.c
+++ b/src/hdy-tab-box.c
@@ -151,6 +151,8 @@ struct _HdyTabBox
   TabInfo *drop_target_tab;
   guint drop_switch_timeout_id;
   guint reset_drop_target_tab_id;
+  gboolean can_accept_drop;
+  int drop_target_x;
 
   HdyAnimation *scroll_animation;
   gboolean scroll_animation_done;
@@ -714,6 +716,46 @@ get_scroll_animation_value (HdyTabBox *self)
   return round (hdy_lerp (self->scroll_animation_from, to, value));
 }
 
+static gboolean
+drop_switch_timeout_cb (HdyTabBox *self)
+{
+  self->drop_switch_timeout_id = 0;
+  hdy_tab_view_set_selected_page (self->view,
+                                  self->drop_target_tab->page);
+
+  return G_SOURCE_REMOVE;
+}
+
+static void
+set_drop_target_tab (HdyTabBox *self,
+                     TabInfo   *info,
+                     gboolean   highlight)
+{
+  if (self->drop_target_tab == info)
+    return;
+
+  if (self->drop_target_tab) {
+    g_clear_handle_id (&self->drop_switch_timeout_id, g_source_remove);
+
+    gtk_drag_unhighlight (GTK_WIDGET (self->drop_target_tab->tab));
+    hdy_tab_set_hovering (self->drop_target_tab->tab, FALSE);
+  }
+
+  self->drop_target_tab = info;
+
+  if (self->drop_target_tab) {
+    hdy_tab_set_hovering (info->tab, TRUE);
+
+    if (highlight)
+      gtk_drag_highlight (GTK_WIDGET (info->tab));
+
+    self->drop_switch_timeout_id =
+      g_timeout_add (DROP_SWITCH_TIMEOUT,
+                     (GSourceFunc) drop_switch_timeout_cb,
+                     self);
+  }
+}
+
 static void
 adjustment_value_changed_cb (HdyTabBox *self)
 {
@@ -724,6 +766,11 @@ adjustment_value_changed_cb (HdyTabBox *self)
   update_hover (self);
   update_needs_attention (self);
 
+  if (self->drop_target_tab) {
+    self->drop_target_x += (value - self->adjustment_prev_value);
+    set_drop_target_tab (self, find_tab_info_at (self, self->drop_target_x), self->can_accept_drop);
+  }
+
   self->adjustment_prev_value = value;
 
   if (self->block_scrolling)
@@ -1221,6 +1268,7 @@ drag_autoscroll_cb (GtkWidget     *widget,
   gdouble x, delta_ms, start_threshold, end_threshold, autoscroll_factor;
   gint64 time;
   gint offset = 0;
+  gint tab_width = 0;
 
   g_object_get (self->adjustment,
                 "value", &value,
@@ -1229,15 +1277,23 @@ drag_autoscroll_cb (GtkWidget     *widget,
                 "page-size", &page_size,
                 NULL);
 
-  x = CLAMP ((gdouble) self->reorder_x,
+  if (self->reordered_tab) {
+    tab_width = self->reordered_tab->width;
+    x = (gdouble) self->reorder_x;
+  } else {
+    tab_width = self->drop_target_tab->width;
+    x = (gdouble) self->drop_target_x - tab_width / 2;
+  }
+
+  x = CLAMP (x,
              lower + AUTOSCROLL_AREA_WIDTH,
-             upper - self->reordered_tab->width - AUTOSCROLL_AREA_WIDTH);
+             upper - tab_width - AUTOSCROLL_AREA_WIDTH);
 
   time = gdk_frame_clock_get_frame_time (frame_clock);
   delta_ms = (time - self->drag_autoscroll_prev_time) / 1000.0;
 
   start_threshold = value + AUTOSCROLL_AREA_WIDTH;
-  end_threshold = value + page_size - self->reordered_tab->width - AUTOSCROLL_AREA_WIDTH;
+  end_threshold = value + page_size - tab_width - AUTOSCROLL_AREA_WIDTH;
   autoscroll_factor = 0;
 
   if (x < start_threshold)
@@ -1264,6 +1320,36 @@ drag_autoscroll_cb (GtkWidget     *widget,
   return G_SOURCE_CONTINUE;
 }
 
+static void
+start_autoscroll (HdyTabBox *self)
+{
+  GdkFrameClock *frame_clock;
+
+  if (!self->adjustment)
+    return;
+
+  if (self->drag_autoscroll_cb_id)
+    return;
+
+  frame_clock = gtk_widget_get_frame_clock (GTK_WIDGET (self));
+
+  self->drag_autoscroll_prev_time = gdk_frame_clock_get_frame_time (frame_clock);
+  self->drag_autoscroll_cb_id =
+    gtk_widget_add_tick_callback (GTK_WIDGET (self),
+                                  (GtkTickCallback) drag_autoscroll_cb,
+                                  self, NULL);
+}
+
+static void
+end_autoscroll (HdyTabBox *self)
+{
+  if (self->drag_autoscroll_cb_id) {
+    gtk_widget_remove_tick_callback (GTK_WIDGET (self),
+                                     self->drag_autoscroll_cb_id);
+    self->drag_autoscroll_cb_id = 0;
+  }
+}
+
 static void
 start_dragging (HdyTabBox *self,
                 GdkEvent  *event,
@@ -1288,16 +1374,7 @@ start_dragging (HdyTabBox *self,
   } else
     force_end_reordering (self);
 
-  if (self->adjustment) {
-    GdkFrameClock *frame_clock = gtk_widget_get_frame_clock (GTK_WIDGET (self));
-
-    self->drag_autoscroll_prev_time = gdk_frame_clock_get_frame_time (frame_clock);
-    self->drag_autoscroll_cb_id =
-      gtk_widget_add_tick_callback (GTK_WIDGET (self),
-                                    (GtkTickCallback) drag_autoscroll_cb,
-                                    self, NULL);
-  }
-
+  start_autoscroll (self);
   self->dragging = TRUE;
 
   if (!self->continue_reorder)
@@ -1328,11 +1405,7 @@ end_dragging (HdyTabBox *self)
 
   self->dragging = FALSE;
 
-  if (self->drag_autoscroll_cb_id) {
-    gtk_widget_remove_tick_callback (GTK_WIDGET (self),
-                                     self->drag_autoscroll_cb_id);
-    self->drag_autoscroll_cb_id = 0;
-  }
+  end_autoscroll (self);
 
   dest_tab = g_list_nth_data (self->tabs, self->reorder_index);
 
@@ -1891,7 +1964,7 @@ detach_into_new_window (HdyTabBox      *self,
 
   page = source_tab_box->detached_page;
 
-  g_signal_emit_by_name (source_tab_box->view, "create-window", &new_view);
+  new_view = hdy_tab_view_create_window (source_tab_box->view);
 
   if (!HDY_IS_TAB_VIEW (new_view))
     g_error ("Cannot detach into new window");
@@ -2839,46 +2912,6 @@ hdy_tab_box_drag_end (GtkWidget      *widget,
   g_clear_pointer (&self->drag_icon, g_free);
 }
 
-static gboolean
-drop_switch_timeout_cb (HdyTabBox *self)
-{
-  self->drop_switch_timeout_id = 0;
-  hdy_tab_view_set_selected_page (self->view,
-                                  self->drop_target_tab->page);
-
-  return G_SOURCE_REMOVE;
-}
-
-static void
-set_drop_target_tab (HdyTabBox *self,
-                     TabInfo   *info,
-                     gboolean   highlight)
-{
-  if (self->drop_target_tab == info)
-    return;
-
-  if (self->drop_target_tab) {
-    g_clear_handle_id (&self->drop_switch_timeout_id, g_source_remove);
-
-    gtk_drag_unhighlight (GTK_WIDGET (self->drop_target_tab->tab));
-    hdy_tab_set_hovering (self->drop_target_tab->tab, FALSE);
-  }
-
-  self->drop_target_tab = info;
-
-  if (self->drop_target_tab) {
-    hdy_tab_set_hovering (info->tab, TRUE);
-
-    if (highlight)
-      gtk_drag_highlight (GTK_WIDGET (info->tab));
-
-    self->drop_switch_timeout_id =
-      g_timeout_add (DROP_SWITCH_TIMEOUT,
-                     (GSourceFunc) drop_switch_timeout_cb,
-                     self);
-  }
-}
-
 static gboolean
 hdy_tab_box_drag_motion (GtkWidget      *widget,
                          GdkDragContext *context,
@@ -2897,7 +2930,11 @@ hdy_tab_box_drag_motion (GtkWidget      *widget,
   if (target != tab_target) {
     GdkAtom none_target = gdk_atom_intern_static_string ("NONE");
 
-    set_drop_target_tab (self, find_tab_info_at (self, x), target != none_target);
+    self->drop_target_x = x;
+    self->can_accept_drop = target != none_target;
+    set_drop_target_tab (self, find_tab_info_at (self, x), self->can_accept_drop);
+
+    start_autoscroll (self);
 
     return GDK_EVENT_STOP;
   }
@@ -2975,6 +3012,8 @@ hdy_tab_box_drag_leave (GtkWidget      *widget,
       self->reset_drop_target_tab_id =
         g_idle_add ((GSourceFunc) reset_drop_target_tab_cb, self);
 
+    end_autoscroll (self);
+
     return;
   }
 
diff --git a/src/hdy-tab-view-private.h b/src/hdy-tab-view-private.h
index f6e570fb..f7f541db 100644
--- a/src/hdy-tab-view-private.h
+++ b/src/hdy-tab-view-private.h
@@ -20,4 +20,6 @@ void hdy_tab_view_attach_page   (HdyTabView *self,
                                  HdyTabPage *page,
                                  gint        position);
 
+HdyTabView *hdy_tab_view_create_window (HdyTabView *self);
+
 G_END_DECLS
diff --git a/src/hdy-tab-view.c b/src/hdy-tab-view.c
index 94848862..893b9410 100644
--- a/src/hdy-tab-view.c
+++ b/src/hdy-tab-view.c
@@ -2701,3 +2701,15 @@ hdy_tab_view_get_pages (HdyTabView *self)
 
   return G_LIST_MODEL (self->pages);
 }
+
+HdyTabView *
+hdy_tab_view_create_window (HdyTabView *self)
+{
+  HdyTabView *new_view;
+
+  g_signal_emit (self, signals[SIGNAL_CREATE_WINDOW], 0, &new_view);
+
+  new_view->tab_transfer_count = self->tab_transfer_count;
+
+  return new_view;
+}