[nautilus] Revert "pathbar: Remove dnd handling"

[Carlos Soriano <csoriano src gnome org>]

commit 715a28cd3e318e553727a8cc00dd5f0c0326659e
Author: António Fernandes <AntonioJPFernandes gmail com>
Date:   Thu Aug 17 11:02:15 2017 +0100

    Revert "pathbar: Remove dnd handling"
    
    This reverts commit d379767851ac3dc28b1108d87b60ac0cad6c4c4a, which removed
    drag-and-drop interaction involving the pathbar, because it interfered with
    dragging to move the window from the headerbar.
    
    This made it impossible to drop files into a parent directory. But acting as
    a drop target would not interfere with dragging to move.
    
    We are removing again the problematic drag-source parts in the next commit.
    
    Fixes: https://bugzilla.gnome.org/show_bug.cgi?id=785619

 src/nautilus-pathbar.c |  177 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 177 insertions(+), 0 deletions(-)
---
diff --git a/src/nautilus-pathbar.c b/src/nautilus-pathbar.c
index 60817b4..b750ffd 100644
--- a/src/nautilus-pathbar.c
+++ b/src/nautilus-pathbar.c
@@ -94,6 +94,9 @@ struct _NautilusPathBarDetails
     guint need_timer : 1;
     guint ignore_click : 1;
 
+    unsigned int drag_slider_timeout;
+    gboolean drag_slider_timeout_for_up_button;
+
     GActionGroup *action_group;
 
     GMenu *context_menu;
@@ -226,6 +229,76 @@ get_slider_button (NautilusPathBar *path_bar,
     return button;
 }
 
+static gboolean
+slider_timeout (gpointer user_data)
+{
+    NautilusPathBar *path_bar;
+
+    path_bar = NAUTILUS_PATH_BAR (user_data);
+
+    path_bar->priv->drag_slider_timeout = 0;
+
+    if (gtk_widget_get_visible (GTK_WIDGET (path_bar)))
+    {
+        if (path_bar->priv->drag_slider_timeout_for_up_button)
+        {
+            nautilus_path_bar_scroll_up (path_bar);
+        }
+        else
+        {
+            nautilus_path_bar_scroll_down (path_bar);
+        }
+    }
+
+    return FALSE;
+}
+
+static void
+nautilus_path_bar_slider_drag_motion (GtkWidget      *widget,
+                                      GdkDragContext *context,
+                                      int             x,
+                                      int             y,
+                                      unsigned int    time,
+                                      gpointer        user_data)
+{
+    NautilusPathBar *path_bar;
+    GtkSettings *settings;
+    unsigned int timeout;
+
+    path_bar = NAUTILUS_PATH_BAR (user_data);
+
+    if (path_bar->priv->drag_slider_timeout == 0)
+    {
+        settings = gtk_widget_get_settings (widget);
+
+        g_object_get (settings, "gtk-timeout-expand", &timeout, NULL);
+        path_bar->priv->drag_slider_timeout =
+            g_timeout_add (timeout,
+                           slider_timeout,
+                           path_bar);
+
+        path_bar->priv->drag_slider_timeout_for_up_button =
+            widget == path_bar->priv->up_slider_button;
+    }
+}
+
+static void
+nautilus_path_bar_slider_drag_leave (GtkWidget      *widget,
+                                     GdkDragContext *context,
+                                     unsigned int    time,
+                                     gpointer        user_data)
+{
+    NautilusPathBar *path_bar;
+
+    path_bar = NAUTILUS_PATH_BAR (user_data);
+
+    if (path_bar->priv->drag_slider_timeout != 0)
+    {
+        g_source_remove (path_bar->priv->drag_slider_timeout);
+        path_bar->priv->drag_slider_timeout = 0;
+    }
+}
+
 static void
 nautilus_path_bar_init (NautilusPathBar *path_bar)
 {
@@ -266,6 +339,30 @@ nautilus_path_bar_init (NautilusPathBar *path_bar)
     g_signal_connect (path_bar->priv->down_slider_button, "button-press-event", G_CALLBACK 
(nautilus_path_bar_slider_button_press), path_bar);
     g_signal_connect (path_bar->priv->down_slider_button, "button-release-event", G_CALLBACK 
(nautilus_path_bar_slider_button_release), path_bar);
 
+    gtk_drag_dest_set (GTK_WIDGET (path_bar->priv->up_slider_button),
+                       0, NULL, 0, 0);
+    gtk_drag_dest_set_track_motion (GTK_WIDGET (path_bar->priv->up_slider_button), TRUE);
+    g_signal_connect (path_bar->priv->up_slider_button,
+                      "drag-motion",
+                      G_CALLBACK (nautilus_path_bar_slider_drag_motion),
+                      path_bar);
+    g_signal_connect (path_bar->priv->up_slider_button,
+                      "drag-leave",
+                      G_CALLBACK (nautilus_path_bar_slider_drag_leave),
+                      path_bar);
+
+    gtk_drag_dest_set (GTK_WIDGET (path_bar->priv->down_slider_button),
+                       0, NULL, 0, 0);
+    gtk_drag_dest_set_track_motion (GTK_WIDGET (path_bar->priv->down_slider_button), TRUE);
+    g_signal_connect (path_bar->priv->down_slider_button,
+                      "drag-motion",
+                      G_CALLBACK (nautilus_path_bar_slider_drag_motion),
+                      path_bar);
+    g_signal_connect (path_bar->priv->down_slider_button,
+                      "drag-leave",
+                      G_CALLBACK (nautilus_path_bar_slider_drag_leave),
+                      path_bar);
+
     gtk_style_context_add_class (gtk_widget_get_style_context (GTK_WIDGET (path_bar)),
                                  GTK_STYLE_CLASS_LINKED);
     gtk_style_context_add_class (gtk_widget_get_style_context (GTK_WIDGET (path_bar)),
@@ -281,6 +378,12 @@ nautilus_path_bar_finalize (GObject *object)
 
     nautilus_path_bar_stop_scrolling (path_bar);
 
+    if (path_bar->priv->drag_slider_timeout != 0)
+    {
+        g_source_remove (path_bar->priv->drag_slider_timeout);
+        path_bar->priv->drag_slider_timeout = 0;
+    }
+
     g_list_free (path_bar->priv->button_list);
 
     unschedule_pop_up_context_menu (NAUTILUS_PATH_BAR (object));
@@ -1568,6 +1671,15 @@ button_event_cb (GtkWidget      *button,
     return GDK_EVENT_PROPAGATE;
 }
 
+static void
+button_drag_begin_cb (GtkWidget      *widget,
+                      GdkDragContext *drag_context,
+                      gpointer        user_data)
+{
+    g_object_set_data (G_OBJECT (widget), "handle-button-release",
+                       GINT_TO_POINTER (FALSE));
+}
+
 static GIcon *
 get_gicon_for_mount (ButtonData *button_data)
 {
@@ -1732,6 +1844,66 @@ setup_button_type (ButtonData      *button_data,
 }
 
 static void
+button_drag_data_get_cb (GtkWidget        *widget,
+                         GdkDragContext   *context,
+                         GtkSelectionData *selection_data,
+                         guint             info,
+                         guint             time_,
+                         gpointer          user_data)
+{
+    ButtonData *button_data;
+    char *uri_list[2];
+    char *tmp;
+
+    button_data = user_data;
+
+    uri_list[0] = g_file_get_uri (button_data->path);
+    uri_list[1] = NULL;
+
+    if (info == NAUTILUS_ICON_DND_GNOME_ICON_LIST)
+    {
+        tmp = g_strdup_printf ("%s\r\n", uri_list[0]);
+        gtk_selection_data_set (selection_data, gtk_selection_data_get_target (selection_data),
+                                8, (const guchar *) tmp, strlen (tmp));
+        g_free (tmp);
+    }
+    else if (info == NAUTILUS_ICON_DND_URI_LIST)
+    {
+        gtk_selection_data_set_uris (selection_data, uri_list);
+    }
+
+    g_free (uri_list[0]);
+}
+
+static void
+setup_button_drag_source (ButtonData *button_data)
+{
+    GtkTargetList *target_list;
+    const GtkTargetEntry targets[] =
+    {
+        { NAUTILUS_ICON_DND_GNOME_ICON_LIST_TYPE, 0, NAUTILUS_ICON_DND_GNOME_ICON_LIST }
+    };
+
+    gtk_drag_source_set (button_data->button,
+                         GDK_BUTTON1_MASK |
+                         GDK_BUTTON2_MASK,
+                         NULL, 0,
+                         GDK_ACTION_MOVE |
+                         GDK_ACTION_COPY |
+                         GDK_ACTION_LINK |
+                         GDK_ACTION_ASK);
+
+    target_list = gtk_target_list_new (targets, G_N_ELEMENTS (targets));
+    gtk_target_list_add_uri_targets (target_list, NAUTILUS_ICON_DND_URI_LIST);
+    gtk_drag_source_set_target_list (button_data->button, target_list);
+    gtk_target_list_unref (target_list);
+
+    g_signal_connect (button_data->button, "drag-data-get",
+                      G_CALLBACK (button_drag_data_get_cb),
+                      button_data);
+}
+
+static void
 button_data_file_changed (NautilusFile *file,
                           ButtonData   *button_data)
 {
@@ -1942,8 +2114,13 @@ make_button_data (NautilusPathBar *path_bar,
     g_signal_connect (button_data->button, "clicked", G_CALLBACK (button_clicked_cb), button_data);
     g_signal_connect (button_data->button, "button-press-event", G_CALLBACK (button_event_cb), button_data);
     g_signal_connect (button_data->button, "button-release-event", G_CALLBACK (button_event_cb), 
button_data);
+    g_signal_connect (button_data->button, "drag-begin", G_CALLBACK (button_drag_begin_cb), button_data);
     g_object_weak_ref (G_OBJECT (button_data->button), (GWeakNotify) button_data_free, button_data);
 
+    setup_button_drag_source (button_data);
+
+    nautilus_drag_slot_proxy_init (button_data->button, button_data->file, NULL);
+
     g_object_unref (path);
 
     return button_data;