[gimp] plug-ins: port palette-offset to new API.

[Jehan <jehanp src gnome org>]

commit dca353f8cd00e3eabc93b739bc9b5376b88b74cc
Author: Jehan <jehan girinstud io>
Date:   Tue Aug 6 00:31:50 2019 +0200

    plug-ins: port palette-offset to new API.
    
    This first version will just offset by 1 in interactive mode, by
    default. The GIMP 2 version used to have a GUI, but it was not created
    by the plug-in itself. I am guessing that maybe our Python wrapper used
    to create GUI by default.
    If so, this will have to change. Python plug-ins will be responsible of
    their own GUI, just like C plug-ins.

 plug-ins/pygimp/plug-ins/palette-offset.py |  61 ------------
 plug-ins/python/Makefile.am                |   4 +-
 plug-ins/python/palette-offset.py          | 148 +++++++++++++++++++++++++++++
 3 files changed, 150 insertions(+), 63 deletions(-)
---
diff --git a/plug-ins/python/Makefile.am b/plug-ins/python/Makefile.am
index f347e921ad..0785f66e3a 100644
--- a/plug-ins/python/Makefile.am
+++ b/plug-ins/python/Makefile.am
@@ -11,7 +11,7 @@ source_scripts = \
 ##     foggify.py                      \
 ##     gradients-save-as-css.py        \
 ##     histogram-export.py             \
-##     palette-offset.py               \
+       palette-offset.py               \
 ##     palette-sort.py                 \
        palette-to-gradient.py
 ##     py-slice.py                     \
@@ -30,7 +30,7 @@ scripts = \
 ##     foggify/foggify.py                              \
 ##     gradients-save-as-css/gradients-save-as-css.py  \
 ##     histogram-export/histogram-export.py            \
-##     palette-offset/palette-offset.py                \
+       palette-offset/palette-offset.py                \
 ##     palette-sort/palette-sort.py                    \
        palette-to-gradient/palette-to-gradient.py
 ##     py-slice/py-slice.py                            \
diff --git a/plug-ins/python/palette-offset.py b/plug-ins/python/palette-offset.py
new file mode 100644
index 0000000000..f5bba51b54
--- /dev/null
+++ b/plug-ins/python/palette-offset.py
@@ -0,0 +1,148 @@
+#!/usr/bin/env python2
+# -*- coding: utf-8 -*-
+#    This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation; either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+import gi
+gi.require_version('Gimp', '3.0')
+from gi.repository import Gimp
+from gi.repository import GObject
+from gi.repository import GLib
+from gi.repository import Gio
+import sys
+
+import gettext
+_ = gettext.gettext
+def N_(message): return message
+
+def run(procedure, args, data):
+    # Get the parameters
+    palette = None
+    if args.length() > 1:
+        palette = args.index(1)
+    if palette == '' or palette is None:
+        palette = Gimp.context_get_palette()
+    (exists, num_colors) = Gimp.palette_get_info(palette)
+    if not exists:
+        error = 'Unknown palette: {}'.format(palette)
+        return procedure.new_return_values(Gimp.PDBStatusType.CALLING_ERROR,
+                                           GLib.Error(error))
+    if args.length() > 2:
+        amount = args.index(2)
+    else:
+        amount = 1
+
+    #If palette is read only, work on a copy:
+    editable = Gimp.palette_is_editable(palette)
+    if not editable:
+        palette = Gimp.palette_duplicate (palette)
+
+    tmp_entry_array = []
+    for i in xrange (num_colors):
+        tmp_entry_array.append  ((Gimp.palette_entry_get_name (palette, i)[1],
+                                  Gimp.palette_entry_get_color (palette, i)[1]))
+    for i in xrange (num_colors):
+        target_index = i + amount
+        if target_index >= num_colors:
+            target_index -= num_colors
+        elif target_index < 0:
+            target_index += num_colors
+        Gimp.palette_entry_set_name (palette, target_index, tmp_entry_array[i][0])
+        Gimp.palette_entry_set_color (palette, target_index, tmp_entry_array[i][1])
+
+    retval = procedure.new_return_values(Gimp.PDBStatusType.SUCCESS, GLib.Error())
+    value = GObject.Value(GObject.TYPE_STRING, palette)
+    retval.remove(1)
+    retval.insert(1, value)
+    return retval
+
+class PaletteOffset (Gimp.PlugIn):
+    ## Parameter: run-mode ##
+    @GObject.Property(type=Gimp.RunMode,
+                      default=Gimp.RunMode.NONINTERACTIVE,
+                      nick="Run mode", blurb="The run mode")
+    def run_mode(self):
+        """Read-write integer property."""
+        return self.runmode
+
+    @run_mode.setter
+    def run_mode(self, runmode):
+        self.runmode = runmode
+
+    ## Parameter: palette ##
+    @GObject.Property(type=str,
+                      default="",
+                      nick= _("Palette"),
+                      blurb= _("Palette"))
+    def palette(self):
+        return self.palette
+
+    @palette.setter
+    def palette(self, palette):
+        self.palette = palette
+
+    ## Parameter: amount ##
+    @GObject.Property(type=int,
+                      default=1,
+                      nick= _("Off_set"),
+                      blurb= _("Offset"))
+    def amount(self):
+        return self.amount
+
+    @amount.setter
+    def amount(self, amount):
+        self.amount = amount
+
+    ## Return: new-palette ##
+    @GObject.Property(type=str,
+                      default=None,
+                      nick="Name of the edited palette",
+                      blurb="Name of the newly created palette if read-only or the input palette otherwise")
+    def new_palette(self):
+        return self.new_palette
+
+    @new_palette.setter
+    def new_palette(self, new_palette):
+        self.new_palette = new_palette
+
+    ## GimpPlugIn virtual methods ##
+    def do_query_procedures(self):
+        # Localization
+        self.set_translation_domain ("gimp30-python",
+                                     Gio.file_new_for_path(Gimp.locale_directory()))
+
+        return [ "python-fu-palette-offset" ]
+
+    def do_create_procedure(self, name):
+        procedure = Gimp.Procedure.new(self, name,
+                                       Gimp.PDBProcType.PLUGIN,
+                                       run, None)
+        if name == 'python-fu-palette-offset':
+            procedure.set_menu_label(N_("_Offset Palette..."))
+            procedure.set_documentation(N_("Offset the colors in a palette"),
+                                        "palette_offset (palette, amount) -> modified_palette",
+                                        "")
+            procedure.set_attribution("Joao S. O. Bueno Calligaris, Carol Spears",
+                                      "(c) Joao S. O. Bueno Calligaris",
+                                      "2004, 2006")
+            procedure.add_argument_from_property(self, "run-mode")
+            procedure.add_argument_from_property(self, "palette")
+            procedure.add_argument_from_property(self, "amount")
+            procedure.add_return_value_from_property(self, "new-palette")
+            procedure.add_menu_path ('<Palettes>')
+        else:
+            procedure = None
+
+        return procedure
+
+Gimp.main(PaletteOffset.__gtype__, sys.argv)