[gtksourceview/gnome-3-24] gtksourceview: add GIMP style color formats

[Christian Hergert <chergert src gnome org>]

commit 9868a4b970e696549ad8658d228ee509c6e3e180
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 78f6857e..0c3a007b 100644
--- a/gtksourceview/gtksourceview.c
+++ b/gtksourceview/gtksourceview.c
@@ -4309,30 +4309,52 @@ 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,