[gtksourceview/gtksourceview-4-2] gtksourceview: add GIMP style color formats

[Christian Hergert <chergert src gnome org>]

commit 08185ae4fc90670d6d489704344a89776124807a
Author: Christian Hergert <chergert redhat com>
Date:   Mon Sep 2 17:52:36 2019 -0700

    gtksourceview: add GIMP style color formats
    
    This implements an alternate format so that we can have DnD coming from
    the GIMP color picker. With this patch, we can drag from the color picker
    into the GtkSourceView.

 gtksourceview/gtksourceview.c | 40 +++++++++++++++++++++++++++++++---------
 1 file changed, 31 insertions(+), 9 deletions(-)
---
diff --git a/gtksourceview/gtksourceview.c b/gtksourceview/gtksourceview.c
index 6e0852f7..e60034d3 100644
--- a/gtksourceview/gtksourceview.c
+++ b/gtksourceview/gtksourceview.c
@@ -4259,30 +4259,52 @@ view_dnd_drop (GtkTextView      *view,
 
        if (info == TARGET_COLOR)
        {
-               guint16 *vals;
+               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;
                }
 
-               if (gtk_selection_data_get_format (selection_data) != 16 || length != 8)
+               format = gtk_selection_data_get_format (selection_data);
+
+               if (format == 8 && length == 4)
                {
-                       g_warning ("Received invalid color data\n");
-                       return;
+                       guint8 *vals;
+
+                       vals = (gpointer) gtk_selection_data_get_data (selection_data);
+
+                       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;
 
-               vals = (gpointer) gtk_selection_data_get_data (selection_data);
+                       vals = (gpointer) gtk_selection_data_get_data (selection_data);
 
-               vals[0] /= 256;
-               vals[1] /= 256;
-               vals[2] /= 256;
+                       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;
+               }
 
-               g_snprintf (string, sizeof (string), "#%02X%02X%02X", vals[0], vals[1], vals[2]);
+               g_snprintf (string, sizeof string, "#%02X%02X%02X",
+                           (gint)(rgba.red * 256),
+                           (gint)(rgba.green * 256),
+                           (gint)(rgba.blue * 256));
 
                gtk_text_view_window_to_buffer_coords (view,
                                                       GTK_TEXT_WINDOW_TEXT,