PIKApp/pdb/groups/image_undo.pdb

# PIKA - Photo and Image Kooker Application
# Copyright (C) 1995 Spencer Kimball and Peter Mattis

# 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/>.

# "Perlized" from C source by Manish Singh <yosh@gimp.org>

sub image_undo_group_start {
    $blurb = 'Starts a group undo.';

    $help = <<'HELP';
This function is used to start a group undo--necessary for logically combining
two or more undo operations into a single operation. This call must be used in
conjunction with a pika_image_undo_group_end() call.
HELP

    &std_pdb_misc;
    $date = '1997';

    @inargs = (
	{ name => 'image', type => 'image',
	  desc => 'The ID of the image in which to open an undo group' }
    );

    %invoke = (
	code => <<'CODE'
{
  PikaPlugIn  *plug_in   = pika->plug_in_manager->current_plug_in;
  const gchar *undo_desc = NULL;

  if (plug_in)
    {
      success = pika_plug_in_cleanup_undo_group_start (plug_in, image);

      if (success)
        undo_desc = pika_plug_in_get_undo_desc (plug_in);
    }

  if (success)
    pika_image_undo_group_start (image, PIKA_UNDO_GROUP_MISC, undo_desc);
}
CODE
    );
}

sub image_undo_group_end {
    $blurb = 'Finish a group undo.';

    $help = <<'HELP';
This function must be called once for each pika_image_undo_group_start() call
that is made.
HELP

    &std_pdb_misc;
    $date = '1997';

    @inargs = (
	{ name => 'image', type => 'image',
	  desc => 'The ID of the image in which to close an undo group' }
    );

    %invoke = (
	code => <<'CODE'
{
  PikaPlugIn *plug_in = pika->plug_in_manager->current_plug_in;

  if (plug_in)
    success = pika_plug_in_cleanup_undo_group_end (plug_in, image);

  if (success)
    pika_image_undo_group_end (image);
}
CODE
    );
}

sub image_undo_is_enabled {
    $blurb = "Check if the image's undo stack is enabled.";

    $help = <<'HELP';
This procedure checks if the image's undo stack is currently enabled or
disabled.  This is useful when several plug-ins or scripts call each other
and want to check if their caller has already used pika_image_undo_disable()
or pika_image_undo_freeze().
HELP

    &raphael_pdb_misc('1999');

    @inargs = (
	{ name => 'image', type => 'image',
	  desc  => 'The image' }
    );

    @outargs = (
	{ name => 'enabled', type => 'boolean',
	  desc => 'TRUE if undo is enabled for this image' }
    );

    %invoke = (
	code => <<'CODE'
{
  enabled = pika_image_undo_is_enabled (image);
}
CODE
    );
}

sub image_undo_disable {
    $blurb = "Disable the image's undo stack.";

    $help = <<'HELP';
This procedure disables the image's undo stack, allowing subsequent operations
to ignore their undo steps. This is generally called in conjunction with
pika_image_undo_enable() to temporarily disable an image undo stack. This is
advantageous because saving undo steps can be time and memory intensive.
HELP

    &std_pdb_misc;

    @inargs = (
	{ name => 'image', type => 'image',
	  desc => 'The image' }
    );

    @outargs = (
	{ name => 'disabled', type => 'boolean',
	  desc => 'TRUE if the image undo has been disabled' }
    );

    %invoke = (
	code => <<'CODE'
{
#if 0
  PikaPlugIn *plug_in = pika->plug_in_manager->current_plug_in;

  if (plug_in)
    success = pika_plug_in_cleanup_undo_disable (plug_in, image);
#endif

  if (success)
    disabled = pika_image_undo_disable (image);
}
CODE
    );
}

sub image_undo_enable {
    $blurb = "Enable the image's undo stack.";

    $help = <<'HELP';
This procedure enables the image's undo stack, allowing subsequent operations
to store their undo steps. This is generally called in conjunction with
pika_image_undo_disable() to temporarily disable an image undo stack.
HELP

    &std_pdb_misc;

    @inargs = (
	{ name => 'image', type => 'image',
	  desc => 'The image' }
    );

    @outargs = (
	{ name => 'enabled', type => 'boolean',
	  desc => 'TRUE if the image undo has been enabled' }
    );

    %invoke = (
	code => <<'CODE'
{
#if 0
  PikaPlugIn *plug_in = pika->plug_in_manager->current_plug_in;

  if (plug_in)
    success = pika_plug_in_cleanup_undo_enable (plug_in, image);
#endif

  if (success)
    enabled = pika_image_undo_enable (image);
}
CODE
    );
}

sub image_undo_freeze {
    $blurb = "Freeze the image's undo stack.";

    &adam_pdb_misc('1999');

    $help = <<'HELP';
This procedure freezes the image's undo stack, allowing subsequent
operations to ignore their undo steps.  This is generally called in
conjunction with pika_image_undo_thaw() to temporarily disable an
image undo stack.  This is advantageous because saving undo steps can
be time and memory intensive.  pika_image_undo_freeze() /
pika_image_undo_thaw() and pika_image_undo_disable() /
pika_image_undo_enable() differ in that the former does not free up
all undo steps when undo is thawed, so is more suited to interactive
in-situ previews.  It is important in this case that the image is back
to the same state it was frozen in before thawing, else 'undo'
behavior is undefined.
HELP

    @inargs = (
	{ name => 'image', type => 'image',
	  desc => 'The image' }
    );

    @outargs = (
	{ name => 'frozen', type => 'boolean',
	  desc => 'TRUE if the image undo has been frozen' }
    );

    %invoke = (
	code => <<'CODE'
{
#if 0
  PikaPlugIn *plug_in = pika->plug_in_manager->current_plug_in;

  if (plug_in)
    success = pika_plug_in_cleanup_undo_freeze (plug_in, image);
#endif

  if (success)
    frozen = pika_image_undo_freeze (image);
}
CODE
    );
}

sub image_undo_thaw {
    $blurb = "Thaw the image's undo stack.";

    &adam_pdb_misc('1999');

    $help = <<'HELP';
This procedure thaws the image's undo stack, allowing subsequent
operations to store their undo steps. This is generally called in
conjunction with pika_image_undo_freeze() to temporarily freeze an
image undo stack.  pika_image_undo_thaw() does NOT free the undo stack
as pika_image_undo_enable() does, so is suited for situations where
one wishes to leave the undo stack in the same state in which one
found it despite non-destructively playing with the image in the
meantime.  An example would be in-situ plug-in previews.  Balancing
freezes and thaws and ensuring image consistency is the responsibility
of the caller.
HELP

    @inargs = (
	{ name => 'image', type => 'image',
	  desc => 'The image' }
    );

    @outargs = (
	{ name => 'thawed', type => 'boolean',
	  desc => 'TRUE if the image undo has been thawed' }
    );

    %invoke = (
	code => <<'CODE'
{
#if 0
  PikaPlugIn *plug_in = pika->plug_in_manager->current_plug_in;

  if (plug_in)
    success = pika_plug_in_cleanup_undo_thaw (plug_in, image);
#endif

  if (success)
    thawed = pika_image_undo_thaw (image);
}
CODE
    );
}


@headers = qw("core/pika.h"
              "core/pikaimage-undo.h"
              "plug-in/pikaplugin.h"
              "plug-in/pikaplugin-cleanup.h"
              "plug-in/pikapluginmanager.h");

@procs = qw(image_undo_group_start image_undo_group_end
            image_undo_is_enabled
            image_undo_disable image_undo_enable
            image_undo_freeze image_undo_thaw);

%exports = (app => [@procs], lib => [@procs]);

$desc = 'Image Undo';
$doc_title = 'pikaimageundo';
$doc_short_desc = 'Control of image undo/redo.';
$doc_long_desc = 'Control of image undo/redo.';

1;