general: Allow DnD a texture to nautiluswip/corey/dnd-texture

We generally accept drops for types GDK_TYPE_FILE_LIST and G_TYPE_STRING.
Sometimes, an image (commonly from a web browser) will offer a
GDK_TYPE_FILE_LIST and a GDK_TYPE_TEXT.  Simply using a file list
to save an image has several potential disadvantages including:

1) Inconsistent / unexpected file names
2) Inconsistent behavior (i.e. a link to the image, rather than the
image itself may be saved)
3) Portal issues

Although, not clearly documented, the gtk_drop_target_set_gtypes,
creates a priority order for the type to be presented in ::drop.
Put GDK_TYPE_TEXTURE before GDK_TYPE_FILE_LIST since, typically if
both are available, we prefer a texture.

Fixes: https://gitlab.gnome.org/GNOME/nautilus/-/issues/2889

6 files changed, 30 insertions, 6 deletions

diff --git a/src/nautilus-dnd.c b/src/nautilus-dnd.c
index 5e6cfead0..8d1ef0f4d 100644
--- a/src/nautilus-dnd.c
+++ b/src/nautilus-dnd.c
@@ -11,6 +11,7 @@
 #include "nautilus-directory.h"
 #include "nautilus-dnd.h"
 #include "nautilus-file-utilities.h"
+#include "nautilus-files-view.h"
 #include "nautilus-files-view-dnd.h"
 #include "nautilus-tag-manager.h"
 
@@ -256,6 +257,12 @@ nautilus_dnd_perform_drop (NautilusFilesView *view,
                                               target_uri, action);
         return TRUE;
     }
+    else if (G_VALUE_HOLDS (value, GDK_TYPE_TEXTURE))
+    {
+        g_autofree char *dest_uri = g_file_get_uri (target_location);
+
+        nautilus_file_view_save_image (view, value, dest_uri);
+    }
     else if (G_VALUE_HOLDS (value, GDK_TYPE_FILE_LIST))
     {
         GSList *source_file_list = g_value_get_boxed (value);
diff --git a/src/nautilus-files-view.c b/src/nautilus-files-view.c
index abc9a39b7..3e263f75f 100644
--- a/src/nautilus-files-view.c
+++ b/src/nautilus-files-view.c
@@ -9046,6 +9046,16 @@ nautilus_files_view_get_uri (NautilusFilesView *view)
     return nautilus_directory_get_uri (priv->model);
 }
 
+void nautilus_file_view_save_image (NautilusFilesView *view,
+                                    const GValue      *value,
+                                    const char        *dest_uri)
+{
+    nautilus_file_operations_save_image_from_texture (GTK_WIDGET (view), NULL,
+                                                      dest_uri,
+                                                      g_value_get_object (value),
+                                                      copy_move_done_callback, pre_copy_move (view));
+}
+
 void
 nautilus_files_view_move_copy_items (NautilusFilesView *view,
                                      const GList       *item_uris,
diff --git a/src/nautilus-files-view.h b/src/nautilus-files-view.h
index 536c613f6..3d8d5c07f 100644
--- a/src/nautilus-files-view.h
+++ b/src/nautilus-files-view.h
@@ -274,6 +274,9 @@ void              nautilus_files_view_move_copy_items            (NautilusFilesV
                                                                   const GList            *item_uris,
                                                                   const char             *target_uri,
                                                                   int                     copy_action);
+void              nautilus_file_view_save_image                  (NautilusFilesView      *view,
+                                                                 const GValue            *value,
+                                                                 const char              *target_uri);
 void              nautilus_files_view_new_file_with_initial_contents (NautilusFilesView  *view,
                                                                       const char         *parent_uri,
                                                                       const char         *filename,
diff --git a/src/nautilus-list-base.c b/src/nautilus-list-base.c
index 8d16c682e..82f6f9ae3 100644
--- a/src/nautilus-list-base.c
+++ b/src/nautilus-list-base.c
@@ -678,7 +678,7 @@ get_preferred_action (NautilusFile *target_file,
             action = nautilus_dnd_get_preferred_action (target_file, NULL);
         }
     }
-    else if (G_VALUE_HOLDS (value, G_TYPE_STRING))
+    else if (G_VALUE_HOLDS (value, G_TYPE_STRING) || G_VALUE_HOLDS (value, GDK_TYPE_TEXTURE))
     {
         action = GDK_ACTION_COPY;
     }
@@ -944,7 +944,7 @@ setup_cell_common (GtkListItem      *listitem,
     drop_target = gtk_drop_target_new (G_TYPE_INVALID, GDK_ACTION_ALL);
     gtk_drop_target_set_preload (drop_target, TRUE);
     /* TODO: Implement GDK_TYPE_STRING */
-    gtk_drop_target_set_gtypes (drop_target, (GType[2]) { GDK_TYPE_FILE_LIST, G_TYPE_STRING }, 2);
+    gtk_drop_target_set_gtypes (drop_target, (GType[3]) { GDK_TYPE_TEXTURE, GDK_TYPE_FILE_LIST, G_TYPE_STRING }, 3);
     g_signal_connect (drop_target, "enter", G_CALLBACK (on_item_drag_enter), cell);
     g_signal_connect (drop_target, "notify::value", G_CALLBACK (on_item_drag_value_notify), cell);
     g_signal_connect (drop_target, "leave", G_CALLBACK (on_item_drag_leave), cell);
@@ -1892,7 +1892,7 @@ nautilus_list_base_setup_gestures (NautilusListBase *self)
     drop_target = gtk_drop_target_new (G_TYPE_INVALID, GDK_ACTION_ALL);
     gtk_drop_target_set_preload (drop_target, TRUE);
     /* TODO: Implement GDK_TYPE_STRING */
-    gtk_drop_target_set_gtypes (drop_target, (GType[2]) { GDK_TYPE_FILE_LIST, G_TYPE_STRING }, 2);
+    gtk_drop_target_set_gtypes (drop_target, (GType[3]) { GDK_TYPE_TEXTURE, GDK_TYPE_FILE_LIST, G_TYPE_STRING }, 3);
     g_signal_connect (drop_target, "enter", G_CALLBACK (on_view_drag_enter), self);
     g_signal_connect (drop_target, "notify::value", G_CALLBACK (on_view_drag_value_notify), self);
     g_signal_connect (drop_target, "motion", G_CALLBACK (on_view_drag_motion), self);
diff --git a/src/nautilus-pathbar.c b/src/nautilus-pathbar.c
index 83d8994c0..76676df32 100644
--- a/src/nautilus-pathbar.c
+++ b/src/nautilus-pathbar.c
@@ -771,6 +771,10 @@ on_drag_motion (GtkDropTarget *target,
             action = nautilus_dnd_get_preferred_action (button_data->file, items->data);
         }
     }
+    else if (G_VALUE_HOLDS (value, GDK_TYPE_TEXTURE))
+    {
+        action = GDK_ACTION_COPY;
+    }
 
     start = button_data->hover_start_point;
     if (gtk_drag_check_threshold (button_data->button, start.x, start.y, x, y))
@@ -1288,7 +1292,7 @@ make_button_data (NautilusPathBar *self,
 
     gtk_drop_target_set_preload (target, TRUE);
     /* TODO: Implement GDK_TYPE_STRING */
-    gtk_drop_target_set_gtypes (target, (GType[1]) { GDK_TYPE_FILE_LIST }, 1);
+    gtk_drop_target_set_gtypes (target, (GType[2]) { GDK_TYPE_TEXTURE, GDK_TYPE_FILE_LIST }, 2);
     g_signal_connect (target, "enter", G_CALLBACK (on_drag_motion), button_data);
     g_signal_connect (target, "motion", G_CALLBACK (on_drag_motion), button_data);
     g_signal_connect (target, "drop", G_CALLBACK (on_drag_drop), button_data);
diff --git a/src/nautilus-window.c b/src/nautilus-window.c
index 9424f154d..3ba24d661 100644
--- a/src/nautilus-window.c
+++ b/src/nautilus-window.c
@@ -1488,7 +1488,7 @@ extra_drag_value_cb (AdwTabBar    *self,
                 action = nautilus_dnd_get_preferred_action (file, G_FILE (file_list->data));
             }
         }
-        else if (G_VALUE_HOLDS (value, G_TYPE_STRING))
+        else if (G_VALUE_HOLDS (value, G_TYPE_STRING) || G_VALUE_HOLDS (value, GDK_TYPE_TEXTURE))
         {
             action = GDK_ACTION_COPY;
         }
@@ -1636,7 +1636,7 @@ nautilus_window_constructed (GObject *self)
      */
     adw_tab_bar_setup_extra_drop_target (window->tab_bar,
                                          GDK_ACTION_COPY | GDK_ACTION_MOVE,
-                                         (GType [2]) {GDK_TYPE_FILE_LIST, G_TYPE_STRING}, 2);
+                                         (GType [3]) {GDK_TYPE_TEXTURE, GDK_TYPE_FILE_LIST, G_TYPE_STRING}, 3);
     adw_tab_bar_set_extra_drag_preload (window->tab_bar, TRUE);
     g_signal_connect (window->tab_bar, "extra-drag-value", G_CALLBACK (extra_drag_value_cb), NULL);
     g_signal_connect (window->tab_bar, "extra-drag-drop", G_CALLBACK (extra_drag_drop_cb), NULL);