[gtksourceview/wip/chergert/snippets: 94/119] view: port DnD to GdkContentFormats

[Christian Hergert <chergert src gnome org>]

commit 14d8fec273082d9de31d10fc489d665b6dd9abc8
Author: Christian Hergert <chergert redhat com>
Date:   Wed Jan 15 15:13:28 2020 -0800

    view: port DnD to GdkContentFormats
    
    Largely based on GtkColorSwatch for conversion of RGBA content via the
    DnD drag contents.

 gtksourceview/gtksourceview.c | 198 ++++++++++++++++++++++--------------------
 1 file changed, 104 insertions(+), 94 deletions(-)
---
diff --git a/gtksourceview/gtksourceview.c b/gtksourceview/gtksourceview.c
index 61c25d47..f8de77b2 100644
--- a/gtksourceview/gtksourceview.c
+++ b/gtksourceview/gtksourceview.c
@@ -245,8 +245,8 @@ typedef enum _GtkSourceViewDropTypes {
        TARGET_COLOR = 200
 } GtkSourceViewDropTypes;
 
-static const GtkTargetEntry drop_types[] = {
-       {(gchar *)"application/x-color", 0, TARGET_COLOR}
+static const char *dnd_targets[] = {
+       "application/x-color"
 };
 
 static void           gtk_source_view_dispose              (GObject                 *object);
@@ -285,14 +285,6 @@ static void           gtk_source_view_move_words           (GtkSourceView
                                                             gint                     step);
 static gboolean       gtk_source_view_key_press_event      (GtkWidget               *widget,
                                                             GdkEventKey             *event);
-static void           view_dnd_drop                        (GtkTextView             *view,
-                                                            GdkDragContext          *context,
-                                                            gint                     x,
-                                                            gint                     y,
-                                                            GtkSelectionData        *selection_data,
-                                                            guint                    info,
-                                                            guint                    timestamp,
-                                                            gpointer                 data);
 static gint           calculate_real_tab_width             (GtkSourceView           *view,
                                                             guint                    tab_size,
                                                             gchar                    c);
@@ -312,6 +304,11 @@ static void           gtk_source_view_draw_layer           (GtkTextView
 static MarkCategory  *mark_category_new                    (GtkSourceMarkAttributes *attributes,
                                                             gint                     priority);
 static void           mark_category_free                   (MarkCategory            *category);
+static gboolean       gtk_source_view_drag_drop                          (GtkDropTarget           *dest,
+                                                                          GdkDrop                 *drop,
+                                                                          int                      x,
+                                                                          int                      y,
+                                                                          GtkSourceView           *view);
 
 static void
 gtk_source_view_constructed (GObject *object)
@@ -1264,8 +1261,8 @@ gtk_source_view_init (GtkSourceView *view)
 {
        GtkSourceViewPrivate *priv = gtk_source_view_get_instance_private (view);
        GtkStyleContext *context;
-       GtkTargetList *target_list;
-
+       GdkContentFormats *formats;
+       GtkDropTarget *dest;
 
        priv->tab_width = DEFAULT_TAB_WIDTH;
        priv->tabs_set = FALSE;
@@ -1293,18 +1290,14 @@ gtk_source_view_init (GtkSourceView *view)
                                                       (GDestroyNotify) g_free,
                                                       (GDestroyNotify) mark_category_free);
 
-       target_list = gtk_drag_dest_get_target_list (GTK_WIDGET (view));
-       g_return_if_fail (target_list != NULL);
-
-       gtk_target_list_add_table (target_list, drop_types, G_N_ELEMENTS (drop_types));
+       formats = gdk_content_formats_new (dnd_targets, G_N_ELEMENTS (dnd_targets));
+       dest = gtk_drop_target_new (formats, GDK_ACTION_COPY);
+       g_signal_connect (dest, "drag-drop", G_CALLBACK (gtk_source_view_drag_drop), view);
+       gtk_widget_add_controller (GTK_WIDGET (view), GTK_EVENT_CONTROLLER (dest));
+       gdk_content_formats_unref (formats);
 
        gtk_widget_set_has_tooltip (GTK_WIDGET (view), TRUE);
 
-       g_signal_connect (view,
-                         "drag_data_received",
-                         G_CALLBACK (view_dnd_drop),
-                         NULL);
-
        g_signal_connect (view,
                          "notify::buffer",
                          G_CALLBACK (notify_buffer_cb),
@@ -4279,93 +4272,110 @@ gtk_source_view_set_indent_on_tab (GtkSourceView *view,
 }
 
 static void
-view_dnd_drop (GtkTextView      *view,
-               GdkDragContext   *context,
-               gint              x,
-               gint              y,
-               GtkSelectionData *selection_data,
-               guint             info,
-               guint             timestamp,
-               gpointer          data)
+insert_rgba_at_mark (GtkSourceView *view,
+                     const GdkRGBA *rgba,
+                     GtkTextMark   *mark)
 {
-
+       GtkTextBuffer *buffer;
        GtkTextIter iter;
+       gchar *str;
 
-       if (info == TARGET_COLOR)
-       {
-               GdkRGBA rgba;
-               gchar string[] = "#000000";
-               gint buffer_x;
-               gint buffer_y;
-               gint length = gtk_selection_data_get_length (selection_data);
-               guint format;
-
-               if (length < 0)
-               {
-                       return;
-               }
-
-               format = gtk_selection_data_get_format (selection_data);
+       buffer = gtk_text_mark_get_buffer (mark);
+       gtk_text_buffer_get_iter_at_mark (buffer, &iter, mark);
 
-               if (format == 8 && length == 4)
-               {
-                       guint8 *vals;
+       if (rgba->alpha == 1.0)
+       {
+               str = g_strdup_printf ("#%02X%02X%02X",
+                                      (gint)(rgba->red * 256),
+                                      (gint)(rgba->green * 256),
+                                      (gint)(rgba->blue * 256));
+       }
+       else
+       {
+               str = gdk_rgba_to_string (rgba);
+       }
 
-                       vals = (gpointer) gtk_selection_data_get_data (selection_data);
+       gtk_text_buffer_insert (buffer, &iter, str, -1);
+       gtk_text_buffer_place_cursor (buffer, &iter);
 
-                       rgba.red = vals[0] / 256.0;
-                       rgba.green = vals[1] / 256.0;
-                       rgba.blue = vals[2] / 256.0;
-                       rgba.alpha = 1.0;
-               }
-               else if (format == 16 && length == 8)
-               {
-                       guint16 *vals;
+       /*
+        * FIXME: Check if the iter is inside a selection
+        * If it is, remove the selection and then insert at
+        * the cursor position - Paolo
+        */
 
-                       vals = (gpointer) gtk_selection_data_get_data (selection_data);
+       g_free (str);
+}
 
-                       rgba.red = vals[0] / 65535.0;
-                       rgba.green = vals[1] / 65535.0;
-                       rgba.blue = vals[2] / 65535.0;
-                       rgba.alpha = 1.0;
-               }
-               else
-               {
-                       g_warning ("Received invalid color data\n");
-                       return;
-               }
+static void
+got_color (GObject      *source,
+           GAsyncResult *result,
+           gpointer      data)
+{
+       GdkDrop *drop = GDK_DROP (source);
+       GtkSourceView *view = data;
+       const GValue *value;
+       GtkTextMark *mark;
 
-               g_snprintf (string, sizeof string, "#%02X%02X%02X",
-                           (gint)(rgba.red * 256),
-                           (gint)(rgba.green * 256),
-                           (gint)(rgba.blue * 256));
+       value = gdk_drop_read_value_finish (drop, result, NULL);
+       mark = g_object_get_data (G_OBJECT (drop), "GTK_SOURCE_VIEW_DND_MARK");
 
-               gtk_text_view_window_to_buffer_coords (view,
-                                                      GTK_TEXT_WINDOW_TEXT,
-                                                      x,
-                                                      y,
-                                                      &buffer_x,
-                                                      &buffer_y);
-               gtk_text_view_get_iter_at_location (view, &iter, buffer_x, buffer_y);
+       if (mark != NULL && value != NULL && G_VALUE_HOLDS (value, GDK_TYPE_RGBA))
+       {
+               const GdkRGBA *rgba = g_value_get_boxed (value);
+               insert_rgba_at_mark (view, rgba, mark);
+               gdk_drop_finish (drop, GDK_ACTION_COPY);
+       }
+       else
+       {
+               gdk_drop_finish (drop, 0);
+       }
 
-               if (gtk_text_view_get_editable (view))
-               {
-                       gtk_text_buffer_insert (gtk_text_view_get_buffer (view),
-                                               &iter,
-                                               string,
-                                               strlen (string));
-                       gtk_text_buffer_place_cursor (gtk_text_view_get_buffer (view),
-                                               &iter);
-               }
+       g_object_set_data (G_OBJECT (drop), "GTK_SOURCE_VIEW_DND_MARK", NULL);
+}
 
-               /*
-                * FIXME: Check if the iter is inside a selection
-                * If it is, remove the selection and then insert at
-                * the cursor position - Paolo
-                */
+static void
+release_drop_mark (GtkTextMark *mark)
+{
+       gtk_text_buffer_delete_mark (gtk_text_mark_get_buffer (mark), mark);
+       g_object_unref (mark);
+}
 
-               return;
+static gboolean
+gtk_source_view_drag_drop (GtkDropTarget *dest,
+                           GdkDrop       *drop,
+                           int            x,
+                           int            y,
+                           GtkSourceView *view)
+{
+       if (gdk_drop_has_value (drop, GDK_TYPE_RGBA))
+       {
+               GtkTextBuffer *buffer;
+               GtkTextMark *mark;
+               GtkTextIter pos;
+
+               buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
+               gtk_text_view_window_to_buffer_coords (GTK_TEXT_VIEW (view),
+                                                      GTK_TEXT_WINDOW_WIDGET,
+                                                      x, y, &x, &y);
+               gtk_text_view_get_iter_at_location (GTK_TEXT_VIEW (view), &pos, x, y);
+
+               mark = gtk_text_buffer_create_mark (buffer, NULL, &pos, TRUE);
+               g_object_set_data_full (G_OBJECT (drop),
+                                       "GTK_SOURCE_VIEW_DND_MARK",
+                                       g_object_ref (mark),
+                                       (GDestroyNotify) release_drop_mark);
+
+               gdk_drop_read_value_async (drop,
+                                          GDK_TYPE_RGBA,
+                                          G_PRIORITY_DEFAULT,
+                                          NULL,
+                                          got_color,
+                                          view);
+               return TRUE;
        }
+
+       return FALSE;
 }
 
 /**