/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * 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 2
 * 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, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2008, Blender Foundation, Joshua Leung
 * This is a new part of Blender
 *
 * Contributor(s): Joshua Leung, Antonio Vazquez
 *
 * ***** END GPL LICENSE BLOCK *****
 *
 * Operators for dealing with GP datablocks and layers
 */

/** \file blender/editors/gpencil/gpencil_data.c
 *  \ingroup edgpencil
 */


#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include <math.h>

#include "MEM_guardedalloc.h"

#include "BLI_blenlib.h"
#include "BLI_utildefines.h"
#include "BLI_ghash.h"
#include "BLI_math.h"
#include "BLI_string_utils.h"

#include "BLT_translation.h"

#include "DNA_scene_types.h"
#include "DNA_screen_types.h"
#include "DNA_space_types.h"
#include "DNA_view3d_types.h"
#include "DNA_gpencil_types.h"

#include "BKE_context.h"
#include "BKE_global.h"
#include "BKE_gpencil.h"
#include "BKE_library.h"
#include "BKE_object.h"
#include "BKE_report.h"
#include "BKE_scene.h"
#include "BKE_screen.h"
#include "BKE_colortools.h"

#include "UI_interface.h"
#include "UI_resources.h"

#include "WM_api.h"
#include "WM_types.h"

#include "RNA_access.h"
#include "RNA_define.h"
#include "RNA_enum_types.h"

#include "ED_gpencil.h"

#include "gpencil_intern.h"

/* ************************************************ */
/* Datablock Operators */

/* ******************* Add New Data ************************ */

/* add new datablock - wrapper around API */
static int gp_data_add_exec(bContext *C, wmOperator *op)
{
	bGPdata **gpd_ptr = ED_gpencil_data_get_pointers(C, NULL);
	ToolSettings *ts = CTX_data_tool_settings(C);

	if (gpd_ptr == NULL) {
		BKE_report(op->reports, RPT_ERROR, "Nowhere for grease pencil data to go");
		return OPERATOR_CANCELLED;
	}
	else {
		/* decrement user count and add new datablock */
		bGPdata *gpd = (*gpd_ptr);
		
		id_us_min(&gpd->id);
		*gpd_ptr = BKE_gpencil_data_addnew(DATA_("GPencil"));

		/* if not exist brushes, create a new set */
		if (ts) {
			if (BLI_listbase_is_empty(&ts->gp_brushes)) {
				/* create new brushes */
				BKE_gpencil_brush_init_presets(ts);
			}
		}

	}
	
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
	
	return OPERATOR_FINISHED;
}

void GPENCIL_OT_data_add(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Grease Pencil Add New";
	ot->idname = "GPENCIL_OT_data_add";
	ot->description = "Add new Grease Pencil data-block";
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
	
	/* callbacks */
	ot->exec = gp_data_add_exec;
	ot->poll = gp_add_poll;
}

/* ******************* Unlink Data ************************ */

/* poll callback for adding data/layers - special */
static int gp_data_unlink_poll(bContext *C)
{
	bGPdata **gpd_ptr = ED_gpencil_data_get_pointers(C, NULL);
	
	/* if we have access to some active data, make sure there's a datablock before enabling this */
	return (gpd_ptr && *gpd_ptr);
}


/* unlink datablock - wrapper around API */
static int gp_data_unlink_exec(bContext *C, wmOperator *op)
{
	bGPdata **gpd_ptr = ED_gpencil_data_get_pointers(C, NULL);
	
	if (gpd_ptr == NULL) {
		BKE_report(op->reports, RPT_ERROR, "Nowhere for grease pencil data to go");
		return OPERATOR_CANCELLED;
	}
	else {
		/* just unlink datablock now, decreasing its user count */
		bGPdata *gpd = (*gpd_ptr);

		id_us_min(&gpd->id);
		*gpd_ptr = NULL;
	}
	
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
	
	return OPERATOR_FINISHED;
}

void GPENCIL_OT_data_unlink(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Grease Pencil Unlink";
	ot->idname = "GPENCIL_OT_data_unlink";
	ot->description = "Unlink active Grease Pencil data-block";
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
	
	/* callbacks */
	ot->exec = gp_data_unlink_exec;
	ot->poll = gp_data_unlink_poll;
}


/* ************************************************ */
/* Layer Operators */

/* ******************* Add New Layer ************************ */

/* add new layer - wrapper around API */
static int gp_layer_add_exec(bContext *C, wmOperator *op)
{
	bGPdata **gpd_ptr = ED_gpencil_data_get_pointers(C, NULL);
	ToolSettings *ts = CTX_data_tool_settings(C);

	/* if there's no existing Grease-Pencil data there, add some */
	if (gpd_ptr == NULL) {
		BKE_report(op->reports, RPT_ERROR, "Nowhere for grease pencil data to go");
		return OPERATOR_CANCELLED;
	}
	if (*gpd_ptr == NULL)
		*gpd_ptr = BKE_gpencil_data_addnew(DATA_("GPencil"));
	
	/* if not exist brushes, create a new set */
	if (ts) {
		if (BLI_listbase_is_empty(&ts->gp_brushes)) {
			/* create new brushes */
			BKE_gpencil_brush_init_presets(ts);
		}
	}

	/* add new layer now */
	BKE_gpencil_layer_addnew(*gpd_ptr, DATA_("GP_Layer"), true);
	
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
	
	return OPERATOR_FINISHED;
}

void GPENCIL_OT_layer_add(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Add New Layer";
	ot->idname = "GPENCIL_OT_layer_add";
	ot->description = "Add new Grease Pencil layer for the active Grease Pencil data-block";
	
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
	
	/* callbacks */
	ot->exec = gp_layer_add_exec;
	ot->poll = gp_add_poll;
}

/* ******************* Remove Active Layer ************************* */

static int gp_layer_remove_exec(bContext *C, wmOperator *op)
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDlayer *gpl = BKE_gpencil_layer_getactive(gpd);
	
	/* sanity checks */
	if (ELEM(NULL, gpd, gpl))
		return OPERATOR_CANCELLED;
	
	if (gpl->flag & GP_LAYER_LOCKED) {
		BKE_report(op->reports, RPT_ERROR, "Cannot delete locked layers");
		return OPERATOR_CANCELLED;
	}
	
	/* make the layer before this the new active layer
	 * - use the one after if this is the first
	 * - if this is the only layer, this naturally becomes NULL
	 */
	if (gpl->prev)
		BKE_gpencil_layer_setactive(gpd, gpl->prev);
	else
		BKE_gpencil_layer_setactive(gpd, gpl->next);
	
	/* delete the layer now... */
	BKE_gpencil_layer_delete(gpd, gpl);
	
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
	
	return OPERATOR_FINISHED;
}

void GPENCIL_OT_layer_remove(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Remove Layer";
	ot->idname = "GPENCIL_OT_layer_remove";
	ot->description = "Remove active Grease Pencil layer";
	
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
	
	/* callbacks */
	ot->exec = gp_layer_remove_exec;
	ot->poll = gp_active_layer_poll;
}

/* ******************* Move Layer Up/Down ************************** */

enum {
	GP_LAYER_MOVE_UP   = -1,
	GP_LAYER_MOVE_DOWN = 1
};

static int gp_layer_move_exec(bContext *C, wmOperator *op)
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDlayer *gpl = BKE_gpencil_layer_getactive(gpd);
	
	int direction = RNA_enum_get(op->ptr, "type");
	
	/* sanity checks */
	if (ELEM(NULL, gpd, gpl))
		return OPERATOR_CANCELLED;
	
	BLI_assert(ELEM(direction, -1, 0, 1)); /* we use value below */
	if (BLI_listbase_link_move(&gpd->layers, gpl, direction)) {
		WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
	}
	
	return OPERATOR_FINISHED;
}

void GPENCIL_OT_layer_move(wmOperatorType *ot)
{
	static EnumPropertyItem slot_move[] = {
		{GP_LAYER_MOVE_UP, "UP", 0, "Up", ""},
		{GP_LAYER_MOVE_DOWN, "DOWN", 0, "Down", ""},
		{0, NULL, 0, NULL, NULL}
	};
	
	/* identifiers */
	ot->name = "Move Grease Pencil Layer";
	ot->idname = "GPENCIL_OT_layer_move";
	ot->description = "Move the active Grease Pencil layer up/down in the list";
	
	/* api callbacks */
	ot->exec = gp_layer_move_exec;
	ot->poll = gp_active_layer_poll;
	
	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
	
	ot->prop = RNA_def_enum(ot->srna, "type", slot_move, 0, "Type", "");
}

/* ********************* Duplicate Layer ************************** */

static int gp_layer_copy_exec(bContext *C, wmOperator *UNUSED(op))
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDlayer *gpl = BKE_gpencil_layer_getactive(gpd);
	bGPDlayer *new_layer;
	
	/* sanity checks */
	if (ELEM(NULL, gpd, gpl))
		return OPERATOR_CANCELLED;
	
	/* make copy of layer, and add it immediately after the existing layer */
	new_layer = BKE_gpencil_layer_duplicate(gpl);
	BLI_insertlinkafter(&gpd->layers, gpl, new_layer);
	
	/* ensure new layer has a unique name, and is now the active layer */
	BLI_uniquename(&gpd->layers, new_layer, DATA_("GP_Layer"), '.', offsetof(bGPDlayer, info), sizeof(new_layer->info));
	BKE_gpencil_layer_setactive(gpd, new_layer);
	
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
	
	return OPERATOR_FINISHED;
}

void GPENCIL_OT_layer_duplicate(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Duplicate Layer";
	ot->idname = "GPENCIL_OT_layer_duplicate";
	ot->description = "Make a copy of the active Grease Pencil layer";
	
	/* callbacks */
	ot->exec = gp_layer_copy_exec;
	ot->poll = gp_active_layer_poll;
	
	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* *********************** Hide Layers ******************************** */

static int gp_hide_exec(bContext *C, wmOperator *op)
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDlayer *layer = BKE_gpencil_layer_getactive(gpd);
	bool unselected = RNA_boolean_get(op->ptr, "unselected");
	
	/* sanity checks */
	if (ELEM(NULL, gpd, layer))
		return OPERATOR_CANCELLED;
	
	if (unselected) {
		bGPDlayer *gpl;
		
		/* hide unselected */
		for (gpl = gpd->layers.first; gpl; gpl = gpl->next) {
			if (gpl != layer) {
				gpl->flag |= GP_LAYER_HIDE;
			}
		}
	}
	else {
		/* hide selected/active */
		layer->flag |= GP_LAYER_HIDE;
	}
	
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
	
	return OPERATOR_FINISHED;
}

void GPENCIL_OT_hide(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Hide Layer(s)";
	ot->idname = "GPENCIL_OT_hide";
	ot->description = "Hide selected/unselected Grease Pencil layers";
	
	/* callbacks */
	ot->exec = gp_hide_exec;
	ot->poll = gp_active_layer_poll; /* NOTE: we need an active layer to play with */
	
	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
	
	/* props */
	RNA_def_boolean(ot->srna, "unselected", 0, "Unselected", "Hide unselected rather than selected layers");
}

/* ********************** Show All Layers ***************************** */

/* poll callback for showing layers */
static int gp_reveal_poll(bContext *C)
{
	return ED_gpencil_data_get_active(C) != NULL;
}

static int gp_reveal_exec(bContext *C, wmOperator *UNUSED(op))
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDlayer *gpl;
	
	/* sanity checks */
	if (gpd == NULL)
		return OPERATOR_CANCELLED;
	
	/* make all layers visible */
	for (gpl = gpd->layers.first; gpl; gpl = gpl->next) {
		gpl->flag &= ~GP_LAYER_HIDE;
	}
	
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
	
	return OPERATOR_FINISHED;
}

void GPENCIL_OT_reveal(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Show All Layers";
	ot->idname = "GPENCIL_OT_reveal";
	ot->description = "Show all Grease Pencil layers";
	
	/* callbacks */
	ot->exec = gp_reveal_exec;
	ot->poll = gp_reveal_poll;
	
	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* ***************** Lock/Unlock All Layers ************************ */

static int gp_lock_all_exec(bContext *C, wmOperator *UNUSED(op))
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDlayer *gpl;
	
	/* sanity checks */
	if (gpd == NULL)
		return OPERATOR_CANCELLED;
	
	/* make all layers non-editable */
	for (gpl = gpd->layers.first; gpl; gpl = gpl->next) {
		gpl->flag |= GP_LAYER_LOCKED;
	}
	
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
	
	return OPERATOR_FINISHED;
}

void GPENCIL_OT_lock_all(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Lock All Layers";
	ot->idname = "GPENCIL_OT_lock_all";
	ot->description = "Lock all Grease Pencil layers to prevent them from being accidentally modified";
	
	/* callbacks */
	ot->exec = gp_lock_all_exec;
	ot->poll = gp_reveal_poll; /* XXX: could use dedicated poll later */
	
	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* -------------------------- */

static int gp_unlock_all_exec(bContext *C, wmOperator *UNUSED(op))
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDlayer *gpl;
	
	/* sanity checks */
	if (gpd == NULL)
		return OPERATOR_CANCELLED;
	
	/* make all layers editable again */
	for (gpl = gpd->layers.first; gpl; gpl = gpl->next) {
		gpl->flag &= ~GP_LAYER_LOCKED;
	}
	
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
	
	return OPERATOR_FINISHED;
}

void GPENCIL_OT_unlock_all(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Unlock All Layers";
	ot->idname = "GPENCIL_OT_unlock_all";
	ot->description = "Unlock all Grease Pencil layers so that they can be edited";
	
	/* callbacks */
	ot->exec = gp_unlock_all_exec;
	ot->poll = gp_reveal_poll; /* XXX: could use dedicated poll later */
	
	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* ********************** Isolate Layer **************************** */

static int gp_isolate_layer_exec(bContext *C, wmOperator *op)
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDlayer *layer = BKE_gpencil_layer_getactive(gpd);
	bGPDlayer *gpl;
	int flags = GP_LAYER_LOCKED;
	bool isolate = false;
	
	if (RNA_boolean_get(op->ptr, "affect_visibility"))
		flags |= GP_LAYER_HIDE;
		
	if (ELEM(NULL, gpd, layer)) {
		BKE_report(op->reports, RPT_ERROR, "No active layer to isolate");
		return OPERATOR_CANCELLED;
	}
	
	/* Test whether to isolate or clear all flags */
	for (gpl = gpd->layers.first; gpl; gpl = gpl->next) {
		/* Skip if this is the active layer */
		if (gpl == layer)
			continue;
		
		/* If the flags aren't set, that means that the layer is
		 * not alone, so we have some layers to isolate still
		 */
		if ((gpl->flag & flags) == 0) {
			isolate = true;
			break;
		}
	}
	
	/* Set/Clear flags as appropriate */
	/* TODO: Include onionskinning on this list? */
	if (isolate) {
		/* Set flags on all "other" layers */
		for (gpl = gpd->layers.first; gpl; gpl = gpl->next) {
			if (gpl == layer)
				continue;
			else
				gpl->flag |= flags;
		}
	}
	else {
		/* Clear flags - Restore everything else */
		for (gpl = gpd->layers.first; gpl; gpl = gpl->next) {
			gpl->flag &= ~flags;
		}
	}
	
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
	
	return OPERATOR_FINISHED;
}

void GPENCIL_OT_layer_isolate(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Isolate Layer";
	ot->idname = "GPENCIL_OT_layer_isolate";
	ot->description = "Toggle whether the active layer is the only one that can be edited and/or visible";
	
	/* callbacks */
	ot->exec = gp_isolate_layer_exec;
	ot->poll = gp_active_layer_poll;
	
	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
	
	/* properties */
	RNA_def_boolean(ot->srna, "affect_visibility", false, "Affect Visibility",
	                "In addition to toggling the editability, also affect the visibility");
}

/* ********************** Merge Layer with the next layer **************************** */

static int gp_merge_layer_exec(bContext *C, wmOperator *op)
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDlayer *gpl_current = BKE_gpencil_layer_getactive(gpd);
	bGPDlayer *gpl_next = gpl_current->next;

	if (ELEM(NULL, gpd, gpl_current, gpl_next)) {
		BKE_report(op->reports, RPT_ERROR, "No layers to merge");
		return OPERATOR_CANCELLED;
	}

	/* Collect frames of gpl_current in hash table to avoid O(n^2) lookups */
	GHash *gh_frames_cur = BLI_ghash_int_new_ex(__func__, 64);
	for (bGPDframe *gpf = gpl_current->frames.first; gpf; gpf = gpf->next) {
		BLI_ghash_insert(gh_frames_cur, SET_INT_IN_POINTER(gpf->framenum), gpf);
	}

	/* read all frames from next layer */
	for (bGPDframe *gpf = gpl_next->frames.first; gpf; gpf = gpf->next) {
		/* try to find frame in active layer */
		bGPDframe *frame = BLI_ghash_lookup(gh_frames_cur, SET_INT_IN_POINTER(gpf->framenum));
		if (!frame) {
			/* nothing found, create new */
			frame = BKE_gpencil_frame_addnew(gpl_current, gpf->framenum);
		}
		/* add to tail all strokes */
		BLI_movelisttolist(&frame->strokes, &gpf->strokes);
	}
	/* Now delete next layer */
	BKE_gpencil_layer_delete(gpd, gpl_next);
	BLI_ghash_free(gh_frames_cur, NULL, NULL);

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_layer_merge(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Merge Down";
	ot->idname = "GPENCIL_OT_layer_merge";
	ot->description = "Merge the current layer with the layer below";

	/* callbacks */
	ot->exec = gp_merge_layer_exec;
	ot->poll = gp_active_layer_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* ********************** Change Layer ***************************** */

static int gp_layer_change_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(evt))
{
	uiPopupMenu *pup;
	uiLayout *layout;
	
	/* call the menu, which will call this operator again, hence the canceled */
	pup = UI_popup_menu_begin(C, op->type->name, ICON_NONE);
	layout = UI_popup_menu_layout(pup);
	uiItemsEnumO(layout, "GPENCIL_OT_layer_change", "layer");
	UI_popup_menu_end(C, pup);
	
	return OPERATOR_INTERFACE;
}

static int gp_layer_change_exec(bContext *C, wmOperator *op)
{
	bGPdata *gpd = CTX_data_gpencil_data(C);
	bGPDlayer *gpl = NULL;
	int layer_num = RNA_enum_get(op->ptr, "layer");
	
	/* Get layer or create new one */
	if (layer_num == -1) {
		/* Create layer */
		gpl = BKE_gpencil_layer_addnew(gpd, DATA_("GP_Layer"), true);
	}
	else {
		/* Try to get layer */
		gpl = BLI_findlink(&gpd->layers, layer_num);
		
		if (gpl == NULL) {
			BKE_reportf(op->reports, RPT_ERROR, "Cannot change to non-existent layer (index = %d)", layer_num);
			return OPERATOR_CANCELLED;
		}
	}
	
	/* Set active layer */
	BKE_gpencil_layer_setactive(gpd, gpl);
	
	/* updates */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
	
	return OPERATOR_FINISHED;
}

void GPENCIL_OT_layer_change(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Change Layer";
	ot->idname = "GPENCIL_OT_layer_change";
	ot->description = "Change active Grease Pencil layer";
	
	/* callbacks */
	ot->invoke = gp_layer_change_invoke;
	ot->exec = gp_layer_change_exec;
	ot->poll = gp_active_layer_poll;
	
	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
	
	/* gp layer to use (dynamic enum) */
	ot->prop = RNA_def_enum(ot->srna, "layer", DummyRNA_DEFAULT_items, 0, "Grease Pencil Layer", "");
	RNA_def_enum_funcs(ot->prop, ED_gpencil_layers_with_new_enum_itemf);
}

/* ************************************************ */

/* ******************* Arrange Stroke Up/Down in drawing order ************************** */

enum {
	GP_STROKE_MOVE_UP = -1,
	GP_STROKE_MOVE_DOWN = 1,
	GP_STROKE_MOVE_TOP = 2,
	GP_STROKE_MOVE_BOTTOM = 3
};

static int gp_stroke_arrange_exec(bContext *C, wmOperator *op)
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDlayer *gpl = BKE_gpencil_layer_getactive(gpd);
	bGPDstroke *gps;

	/* sanity checks */
	if (ELEM(NULL, gpd, gpl, gpl->actframe)) {
		return OPERATOR_CANCELLED;
	}

	bGPDframe *gpf = gpl->actframe;
	/* temp listbase to store selected strokes */
	ListBase selected = {NULL};
	const int direction = RNA_enum_get(op->ptr, "direction");

	/* verify if any selected stroke is in the extreme of the stack and select to move */
	for (gps = gpf->strokes.first; gps; gps = gps->next) {
		/* only if selected */
		if (gps->flag & GP_STROKE_SELECT) {
			/* skip strokes that are invalid for current view */
			if (ED_gpencil_stroke_can_use(C, gps) == false) {
				continue;
			}
			/* check if the color is editable */
			if (ED_gpencil_stroke_color_use(gpl, gps) == false) {
				continue;
			}
			/* some stroke is already at front*/
			if ((direction == GP_STROKE_MOVE_TOP) || (direction == GP_STROKE_MOVE_UP)) {
				if (gps == gpf->strokes.last) {
					return OPERATOR_CANCELLED;
				}
			}
			/* some stroke is already at botom */
			if ((direction == GP_STROKE_MOVE_BOTTOM) || (direction == GP_STROKE_MOVE_DOWN)) {
				if (gps == gpf->strokes.first) {
					return OPERATOR_CANCELLED;
				}
			}
			/* add to list */
			BLI_addtail(&selected, BLI_genericNodeN(gps));
		}
	}

	/* Now do the movement of the stroke */
	switch (direction) {
		/* Bring to Front */
		case GP_STROKE_MOVE_TOP:
			for (LinkData *link = selected.first; link; link = link->next) {
				gps = link->data;
				BLI_remlink(&gpf->strokes, gps);
				BLI_addtail(&gpf->strokes, gps);
			}
			break;
		/* Bring Forward */
		case GP_STROKE_MOVE_UP:
			for (LinkData *link = selected.last; link; link = link->prev) {
				gps = link->data;
				BLI_listbase_link_move(&gpf->strokes, gps, 1);
			}
			break;
		/* Send Backward */
		case GP_STROKE_MOVE_DOWN:
			for (LinkData *link = selected.first; link; link = link->next) {
				gps = link->data;
				BLI_listbase_link_move(&gpf->strokes, gps, -1);
			}
			break;
		/* Send to Back */
		case GP_STROKE_MOVE_BOTTOM:
			for (LinkData *link = selected.last; link; link = link->prev) {
				gps = link->data;
				BLI_remlink(&gpf->strokes, gps);
				BLI_addhead(&gpf->strokes, gps);
			}
			break;
		default:
			BLI_assert(0);
			break;
	}
	BLI_freelistN(&selected);

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_stroke_arrange(wmOperatorType *ot)
{
	static EnumPropertyItem slot_move[] = {
		{GP_STROKE_MOVE_UP, "UP", 0, "Bring Forward", ""},
		{GP_STROKE_MOVE_DOWN, "DOWN", 0, "Send Backward", ""},
		{GP_STROKE_MOVE_TOP, "TOP", 0, "Bring to Front", ""},
		{GP_STROKE_MOVE_BOTTOM, "BOTTOM", 0, "Send to Back", ""},
		{0, NULL, 0, NULL, NULL }
	};

	/* identifiers */
	ot->name = "Arrange Stroke";
	ot->idname = "GPENCIL_OT_stroke_arrange";
	ot->description = "Arrange selected strokes up/down in the drawing order of the active layer";

	/* api callbacks */
	ot->exec = gp_stroke_arrange_exec;
	ot->poll = gp_active_layer_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	ot->prop = RNA_def_enum(ot->srna, "direction", slot_move, GP_STROKE_MOVE_UP, "Direction", "");
}
/* ******************* Move Stroke to new color ************************** */

static int gp_stroke_change_color_exec(bContext *C, wmOperator *UNUSED(op))
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDpalette *palette;
	bGPDpalettecolor *color;

	/* sanity checks */
	if (ELEM(NULL, gpd)) {
		return OPERATOR_CANCELLED;
	}

	palette = BKE_gpencil_palette_getactive(gpd);
	color = BKE_gpencil_palettecolor_getactive(palette);
	if (ELEM(NULL, palette, color)) {
		return OPERATOR_CANCELLED;
	}

	/* loop all strokes */
	for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
		/* only editable and visible layers are considered */
		if (gpencil_layer_is_editable(gpl) && (gpl->actframe != NULL)) {
			for (bGPDstroke *gps = gpl->actframe->strokes.last; gps; gps = gps->prev) {
				/* only if selected */
				if (gps->flag & GP_STROKE_SELECT) {
					/* skip strokes that are invalid for current view */
					if (ED_gpencil_stroke_can_use(C, gps) == false)
						continue;
					/* check if the color is editable */
					if (ED_gpencil_stroke_color_use(gpl, gps) == false)
						continue;

					/* asign new color (only if different) */
					if ((STREQ(gps->colorname, color->info) == false) || (gps->palcolor != color)) {
						BLI_strncpy(gps->colorname, color->info, sizeof(gps->colorname));
						gps->palcolor = color;
					}
				}
			}
		}
	}
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_stroke_change_color(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Change Stroke Color";
	ot->idname = "GPENCIL_OT_stroke_change_color";
	ot->description = "Move selected strokes to active color";

	/* api callbacks */
	ot->exec = gp_stroke_change_color_exec;
	ot->poll = gp_active_layer_poll;
}

/* ******************* Lock color of non selected Strokes colors ************************** */

static int gp_stroke_lock_color_exec(bContext *C, wmOperator *UNUSED(op))
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDpalette *palette;

	/* sanity checks */
	if (ELEM(NULL, gpd))
		return OPERATOR_CANCELLED;

	palette = BKE_gpencil_palette_getactive(gpd);
	if (ELEM(NULL, palette))
		return OPERATOR_CANCELLED;

	/* first lock all colors */
	for (bGPDpalettecolor *palcolor = palette->colors.first; palcolor; palcolor = palcolor->next) {
		palcolor->flag |= PC_COLOR_LOCKED;
	}

	/* loop all selected strokes and unlock any color */
	for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
		/* only editable and visible layers are considered */
		if (gpencil_layer_is_editable(gpl) && (gpl->actframe != NULL)) {
			for (bGPDstroke *gps = gpl->actframe->strokes.last; gps; gps = gps->prev) {
				/* only if selected */
				if (gps->flag & GP_STROKE_SELECT) {
					/* skip strokes that are invalid for current view */
					if (ED_gpencil_stroke_can_use(C, gps) == false) {
						continue;
					}
					/* unlock color */
					if (gps->palcolor != NULL) {
						gps->palcolor->flag &= ~PC_COLOR_LOCKED;
					}
				}
			}
		}
	}
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_stroke_lock_color(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Lock Unused Colors";
	ot->idname = "GPENCIL_OT_stroke_lock_color";
	ot->description = "Lock any color not used in any selected stroke";

	/* api callbacks */
	ot->exec = gp_stroke_lock_color_exec;
	ot->poll = gp_active_layer_poll;
}

/* ************************************************ */
/* Drawing Brushes Operators */

/* ******************* Add New Brush ************************ */

/* add new brush - wrapper around API */
static int gp_brush_add_exec(bContext *C, wmOperator *op)
{
	ToolSettings *ts = CTX_data_tool_settings(C);

	/* if there's no existing container */
	if (ts == NULL) {
		BKE_report(op->reports, RPT_ERROR, "Nowhere for brush data to go");
		return OPERATOR_CANCELLED;
	}
	/* add new brush now */
	BKE_gpencil_brush_addnew(ts, DATA_("GP_Brush"), true);

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_brush_add(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Add Brush";
	ot->idname = "GPENCIL_OT_brush_add";
	ot->description = "Add new Grease Pencil drawing brush for the active Grease Pencil data-block";

	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* callbacks */
	ot->exec = gp_brush_add_exec;
	ot->poll = gp_add_poll;
}

/* ******************* Remove Active Brush ************************* */

static int gp_brush_remove_exec(bContext *C, wmOperator *op)
{
	ToolSettings *ts = CTX_data_tool_settings(C);
	bGPDbrush *brush = BKE_gpencil_brush_getactive(ts);

	/* sanity checks */
	if (ELEM(NULL, ts, brush))
		return OPERATOR_CANCELLED;

	if (BLI_listbase_count_ex(&ts->gp_brushes, 2) < 2) {
		BKE_report(op->reports, RPT_ERROR, "Grease Pencil needs a brush, unable to delete the last one");
		return OPERATOR_CANCELLED;
	}


	/* make the brush before this the new active brush
	 * - use the one after if this is the first
	 * - if this is the only brush, this naturally becomes NULL
	 */
	if (brush->prev)
		BKE_gpencil_brush_setactive(ts, brush->prev);
	else
		BKE_gpencil_brush_setactive(ts, brush->next);

	/* delete the brush now... */
	BKE_gpencil_brush_delete(ts, brush);

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_brush_remove(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Remove Brush";
	ot->idname = "GPENCIL_OT_brush_remove";
	ot->description = "Remove active Grease Pencil drawing brush";

	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* callbacks */
	ot->exec = gp_brush_remove_exec;
	ot->poll = gp_active_brush_poll;
}

/* ********************** Change Brush ***************************** */

static int gp_brush_change_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(evt))
{
	uiPopupMenu *pup;
	uiLayout *layout;

	/* call the menu, which will call this operator again, hence the canceled */
	pup = UI_popup_menu_begin(C, op->type->name, ICON_NONE);
	layout = UI_popup_menu_layout(pup);
	uiItemsEnumO(layout, "GPENCIL_OT_brush_change", "brush");
	UI_popup_menu_end(C, pup);

	return OPERATOR_INTERFACE;
}

static int gp_brush_change_exec(bContext *C, wmOperator *op)
{
	ToolSettings *ts = CTX_data_tool_settings(C);
	bGPDbrush *brush = NULL;
	int brush_num = RNA_enum_get(op->ptr, "brush");

	/* Get brush or create new one */
	if (brush_num == -1) {
		/* Create brush */
		brush = BKE_gpencil_brush_addnew(ts, DATA_("GP_Brush"), true);
	}
	else {
		/* Try to get brush */
		brush = BLI_findlink(&ts->gp_brushes, brush_num);

		if (brush == NULL) {
			BKE_reportf(op->reports, RPT_ERROR, "Cannot change to non-existent brush (index = %d)", brush_num);
			return OPERATOR_CANCELLED;
		}
	}

	/* Set active brush */
	BKE_gpencil_brush_setactive(ts, brush);

	/* updates */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_brush_change(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Change Brush";
	ot->idname = "GPENCIL_OT_brush_change";
	ot->description = "Change active Grease Pencil drawing brush";

	/* callbacks */
	ot->invoke = gp_brush_change_invoke;
	ot->exec = gp_brush_change_exec;
	ot->poll = gp_active_brush_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* gp brush to use (dynamic enum) */
	ot->prop = RNA_def_enum(ot->srna, "brush", DummyRNA_DEFAULT_items, 0, "Grease Pencil Brush", "");
	RNA_def_enum_funcs(ot->prop, ED_gpencil_brushes_enum_itemf);
}

/* ******************* Move Brush Up/Down ************************** */

enum {
	GP_BRUSH_MOVE_UP = -1,
	GP_BRUSH_MOVE_DOWN = 1
};

static int gp_brush_move_exec(bContext *C, wmOperator *op)
{
	ToolSettings *ts = CTX_data_tool_settings(C);
	bGPDbrush *brush = BKE_gpencil_brush_getactive(ts);

	int direction = RNA_enum_get(op->ptr, "type");

	/* sanity checks */
	if (ELEM(NULL, ts, brush)) {
		return OPERATOR_CANCELLED;
	}

	/* up or down? */
	if (direction == GP_BRUSH_MOVE_UP) {
		/* up */
		BLI_remlink(&ts->gp_brushes, brush);
		BLI_insertlinkbefore(&ts->gp_brushes, brush->prev, brush);
	}
	else if (direction == GP_BRUSH_MOVE_DOWN) {
		/* down */
		BLI_remlink(&ts->gp_brushes, brush);
		BLI_insertlinkafter(&ts->gp_brushes, brush->next, brush);
	}
	else {
		BLI_assert(0);
	}

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_brush_move(wmOperatorType *ot)
{
	static EnumPropertyItem slot_move[] = {
		{GP_BRUSH_MOVE_UP, "UP", 0, "Up", ""},
		{GP_BRUSH_MOVE_DOWN, "DOWN", 0, "Down", ""},
		{0, NULL, 0, NULL, NULL }
	};

	/* identifiers */
	ot->name = "Move Brush";
	ot->idname = "GPENCIL_OT_brush_move";
	ot->description = "Move the active Grease Pencil drawing brush up/down in the list";

	/* api callbacks */
	ot->exec = gp_brush_move_exec;
	ot->poll = gp_active_brush_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	ot->prop = RNA_def_enum(ot->srna, "type", slot_move, GP_BRUSH_MOVE_UP, "Type", "");
}

/* ******************* Brush create presets ************************** */

static int gp_brush_presets_create_exec(bContext *C, wmOperator *UNUSED(op))
{
	ToolSettings *ts = CTX_data_tool_settings(C);
	BKE_gpencil_brush_init_presets(ts);

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_brush_presets_create(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Create Preset Brushes";
	ot->idname = "GPENCIL_OT_brush_presets_create";
	ot->description = "Create a set of predefined Grease Pencil drawing brushes";

	/* api callbacks */
	ot->exec = gp_brush_presets_create_exec;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

}

/* ***************** Copy Brush ************************ */

static int gp_brush_copy_exec(bContext *C, wmOperator *op)
{
	ToolSettings *ts = CTX_data_tool_settings(C);

	/* if there's no existing container */
	if (ts == NULL) {
		BKE_report(op->reports, RPT_ERROR, "Nowhere for brush data to go");
		return OPERATOR_CANCELLED;
	}

	bGPDbrush *brush = BKE_gpencil_brush_getactive(ts);
	bGPDbrush *newbrush;

	/* sanity checks */
	if (ELEM(NULL, brush))
		return OPERATOR_CANCELLED;

	/* create a brush and duplicate data */
	newbrush = BKE_gpencil_brush_addnew(ts, brush->info, true);
	newbrush->thickness = brush->thickness;
	newbrush->draw_smoothfac = brush->draw_smoothfac;
	newbrush->draw_smoothlvl = brush->draw_smoothlvl;
	newbrush->sublevel = brush->sublevel;
	newbrush->flag = brush->flag;
	newbrush->draw_sensitivity = brush->draw_sensitivity;
	newbrush->draw_strength = brush->draw_strength;
	newbrush->draw_jitter = brush->draw_jitter;
	newbrush->draw_angle = brush->draw_angle;
	newbrush->draw_angle_factor = brush->draw_angle_factor;
	newbrush->draw_random_press = brush->draw_random_press;
	newbrush->draw_random_sub = brush->draw_random_sub;

	/* free automatic curves created by default (replaced by copy) */
	curvemapping_free(newbrush->cur_sensitivity);
	curvemapping_free(newbrush->cur_strength);
	curvemapping_free(newbrush->cur_jitter);

	/* make a copy of curves */
	newbrush->cur_sensitivity = curvemapping_copy(brush->cur_sensitivity);
	newbrush->cur_strength = curvemapping_copy(brush->cur_strength);
	newbrush->cur_jitter = curvemapping_copy(brush->cur_jitter);

	BKE_gpencil_brush_setactive(ts, newbrush);
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_brush_copy(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Copy Brush";
	ot->idname = "GPENCIL_OT_brush_copy";
	ot->description = "Copy current Grease Pencil drawing brush";

	/* callbacks */
	ot->exec = gp_brush_copy_exec;
	ot->poll = gp_active_brush_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* ***************** Select Brush ************************ */

static int gp_brush_select_exec(bContext *C, wmOperator *op)
{
	ToolSettings *ts = CTX_data_tool_settings(C);

	/* if there's no existing container */
	if (ts == NULL) {
		BKE_report(op->reports, RPT_ERROR, "Nowhere to go");
		return OPERATOR_CANCELLED;
	}

	const int index = RNA_int_get(op->ptr, "index");
	bGPDbrush *brush = BLI_findlink(&ts->gp_brushes, index);
	/* sanity checks */
	if (ELEM(NULL, brush)) {
		return OPERATOR_CANCELLED;
	}

	BKE_gpencil_brush_setactive(ts, brush);

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_brush_select(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Select Brush";
	ot->idname = "GPENCIL_OT_brush_select";
	ot->description = "Select a Grease Pencil drawing brush";

	/* callbacks */
	ot->exec = gp_brush_select_exec;
	ot->poll = gp_active_brush_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* properties */
	RNA_def_int(ot->srna, "index", 0, 0, INT_MAX, "Index", "Index of Drawing Brush", 0, INT_MAX);
}

/* ************************************************ */
/* Palette Operators */

/* ******************* Add New Palette ************************ */

/* add new palette - wrapper around API */
static int gp_palette_add_exec(bContext *C, wmOperator *op)
{
	bGPdata **gpd_ptr = ED_gpencil_data_get_pointers(C, NULL);

	/* if there's no existing Grease-Pencil data there, add some */
	if (gpd_ptr == NULL) {
		BKE_report(op->reports, RPT_ERROR, "Nowhere for grease pencil data to go");
		return OPERATOR_CANCELLED;
	}
	if (*gpd_ptr == NULL)
		*gpd_ptr = BKE_gpencil_data_addnew(DATA_("GPencil"));

	/* add new palette now */
	BKE_gpencil_palette_addnew(*gpd_ptr, DATA_("GP_Palette"), true);

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palette_add(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Add Palette";
	ot->idname = "GPENCIL_OT_palette_add";
	ot->description = "Add new Grease Pencil palette for the active Grease Pencil data-block";

	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* callbacks */
	ot->exec = gp_palette_add_exec;
	ot->poll = gp_add_poll;
}

/* ******************* Remove Active Palette ************************* */

static int gp_palette_remove_exec(bContext *C, wmOperator *op)
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDpalette *palette = BKE_gpencil_palette_getactive(gpd);

	/* sanity checks */
	if (ELEM(NULL, gpd, palette))
		return OPERATOR_CANCELLED;

	if (BLI_listbase_count_ex(&gpd->palettes, 2) < 2) {
		BKE_report(op->reports, RPT_ERROR, "Grease Pencil needs a palette, unable to delete the last one");
		return OPERATOR_CANCELLED;
	}


	/* make the palette before this the new active palette
	 * - use the one after if this is the first
	 * - if this is the only palette, this naturally becomes NULL
	 */
	if (palette->prev)
		BKE_gpencil_palette_setactive(gpd, palette->prev);
	else
		BKE_gpencil_palette_setactive(gpd, palette->next);

	/* delete the palette now... */
	BKE_gpencil_palette_delete(gpd, palette);

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palette_remove(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Remove palette";
	ot->idname = "GPENCIL_OT_palette_remove";
	ot->description = "Remove active Grease Pencil palette";

	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* callbacks */
	ot->exec = gp_palette_remove_exec;
	ot->poll = gp_active_palette_poll;
}

/* ********************** Change Palette ***************************** */

static int gp_palette_change_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(evt))
{
	uiPopupMenu *pup;
	uiLayout *layout;

	/* call the menu, which will call this operator again, hence the canceled */
	pup = UI_popup_menu_begin(C, op->type->name, ICON_NONE);
	layout = UI_popup_menu_layout(pup);
	uiItemsEnumO(layout, "GPENCIL_OT_palette_change", "palette");
	UI_popup_menu_end(C, pup);

	return OPERATOR_INTERFACE;
}

static int gp_palette_change_exec(bContext *C, wmOperator *op)
{
	bGPdata *gpd = CTX_data_gpencil_data(C);
	bGPDpalette *palette = NULL;
	int palette_num = RNA_enum_get(op->ptr, "palette");

	/* Get palette or create new one */
	if (palette_num == -1) {
		/* Create palette */
		palette = BKE_gpencil_palette_addnew(gpd, DATA_("GP_Palette"), true);
	}
	else {
		/* Try to get palette */
		palette = BLI_findlink(&gpd->palettes, palette_num);

		if (palette == NULL) {
			BKE_reportf(op->reports, RPT_ERROR, "Cannot change to non-existent palette (index = %d)", palette_num);
			return OPERATOR_CANCELLED;
		}
	}

	/* Set active palette */
	BKE_gpencil_palette_setactive(gpd, palette);

	/* updates */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palette_change(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Change Palette";
	ot->idname = "GPENCIL_OT_palette_change";
	ot->description = "Change active Grease Pencil palette";

	/* callbacks */
	ot->invoke = gp_palette_change_invoke;
	ot->exec = gp_palette_change_exec;
	ot->poll = gp_active_palette_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* gp palette to use (dynamic enum) */
	ot->prop = RNA_def_enum(ot->srna, "palette", DummyRNA_DEFAULT_items, 0, "Grease Pencil Palette", "");
	RNA_def_enum_funcs(ot->prop, ED_gpencil_palettes_enum_itemf);
}

/* ******************* Lock and hide any color non used in current layer ************************** */

static int gp_palette_lock_layer_exec(bContext *C, wmOperator *UNUSED(op))
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDpalette *palette;

	/* sanity checks */
	if (ELEM(NULL, gpd))
		return OPERATOR_CANCELLED;

	palette = BKE_gpencil_palette_getactive(gpd);
	if (ELEM(NULL, palette))
		return OPERATOR_CANCELLED;

	/* first lock and hide all colors */
	for (bGPDpalettecolor *palcolor = palette->colors.first; palcolor; palcolor = palcolor->next) {
		palcolor->flag |= PC_COLOR_LOCKED;
		palcolor->flag |= PC_COLOR_HIDE;
	}

	/* loop all selected strokes and unlock any color used in active layer */
	for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
		/* only editable and visible layers are considered */
		if (gpencil_layer_is_editable(gpl) && (gpl->actframe != NULL) && (gpl->flag & GP_LAYER_ACTIVE)) {
			for (bGPDstroke *gps = gpl->actframe->strokes.last; gps; gps = gps->prev) {
				/* skip strokes that are invalid for current view */
				if (ED_gpencil_stroke_can_use(C, gps) == false)
					continue;

				/* unlock/unhide color if not unlocked before */
				if (gps->palcolor != NULL) {
					gps->palcolor->flag &= ~PC_COLOR_LOCKED;
					gps->palcolor->flag &= ~PC_COLOR_HIDE;
				}
			}
		}
	}
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palette_lock_layer(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Disable Unused Layer Colors";
	ot->idname = "GPENCIL_OT_palette_lock_layer";
	ot->description = "Lock and hide any color not used in any layer";

	/* api callbacks */
	ot->exec = gp_palette_lock_layer_exec;
	ot->poll = gp_active_layer_poll;
}

/* ************************************************ */
/* Palette Colors Operators */

/* ******************* Add New Palette ************************ */

/* add new palette - wrapper around API */
static int gp_palettecolor_add_exec(bContext *C, wmOperator *op)
{
	bGPdata **gpd_ptr = ED_gpencil_data_get_pointers(C, NULL);

	/* if there's no existing Grease-Pencil data there, add some */
	if (gpd_ptr == NULL) {
		BKE_report(op->reports, RPT_ERROR, "Nowhere for grease pencil data to go");
		return OPERATOR_CANCELLED;
	}
	if (*gpd_ptr == NULL)
		*gpd_ptr = BKE_gpencil_data_addnew(DATA_("GPencil"));

	/* verify palette */
	bGPDpalette *palette = BKE_gpencil_palette_getactive(*gpd_ptr);
	if (palette == NULL)
		palette = BKE_gpencil_palette_addnew(*gpd_ptr, DATA_("GP_Palette"), true);

	/* add new palette color now */
	BKE_gpencil_palettecolor_addnew(palette, DATA_("Color"), true);

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palettecolor_add(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Add Palette Color";
	ot->idname = "GPENCIL_OT_palettecolor_add";
	ot->description = "Add new Grease Pencil palette color for the active Grease Pencil data-block";

	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* callbacks */
	ot->exec = gp_palettecolor_add_exec;
	ot->poll = gp_add_poll;
}

/* ******************* Remove Active Palette color ************************* */

static int gp_palettecolor_remove_exec(bContext *C, wmOperator *UNUSED(op))
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDpalette *palette = BKE_gpencil_palette_getactive(gpd);
	bGPDpalettecolor *color = BKE_gpencil_palettecolor_getactive(palette);

	/* sanity checks */
	if (ELEM(NULL, gpd, palette, color))
		return OPERATOR_CANCELLED;

	/* make the palette color before this the new active color
	 * - use the one after if this is the first
	 * - if this is the only color, this naturally becomes NULL
	 */
	if (color->prev)
		BKE_gpencil_palettecolor_setactive(palette, color->prev);
	else
		BKE_gpencil_palettecolor_setactive(palette, color->next);

	/* delete the strokes */
	BKE_gpencil_palettecolor_delete_strokes(gpd, color->info);

	/* delete the palette color now... */
	BKE_gpencil_palettecolor_delete(palette, color);

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palettecolor_remove(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Remove palette color";
	ot->idname = "GPENCIL_OT_palettecolor_remove";
	ot->description = "Remove active Grease Pencil palette color";

	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* callbacks */
	ot->exec = gp_palettecolor_remove_exec;
	ot->poll = gp_active_palettecolor_poll;
}

/* ********************** Isolate palette color **************************** */

static int gp_isolate_palettecolor_exec(bContext *C, wmOperator *op)
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDpalette *palette = BKE_gpencil_palette_getactive(gpd);
	bGPDpalettecolor *active_color = BKE_gpencil_palettecolor_getactive(palette);
	bGPDpalettecolor *palcolor;

	int flags = PC_COLOR_LOCKED;
	bool isolate = false;

	if (RNA_boolean_get(op->ptr, "affect_visibility"))
		flags |= PC_COLOR_HIDE;

	if (ELEM(NULL, gpd, active_color)) {
		BKE_report(op->reports, RPT_ERROR, "No active color to isolate");
		return OPERATOR_CANCELLED;
	}

	/* Test whether to isolate or clear all flags */
	for (palcolor = palette->colors.first; palcolor; palcolor = palcolor->next) {
		/* Skip if this is the active one */
		if (palcolor == active_color)
			continue;

		/* If the flags aren't set, that means that the color is
		 * not alone, so we have some colors to isolate still
		 */
		if ((palcolor->flag & flags) == 0) {
			isolate = true;
			break;
		}
	}

	/* Set/Clear flags as appropriate */
	if (isolate) {
		/* Set flags on all "other" colors */
		for (palcolor = palette->colors.first; palcolor; palcolor = palcolor->next) {
			if (palcolor == active_color)
				continue;
			else
				palcolor->flag |= flags;
		}
	}
	else {
		/* Clear flags - Restore everything else */
		for (palcolor = palette->colors.first; palcolor; palcolor = palcolor->next) {
			palcolor->flag &= ~flags;
		}
	}

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palettecolor_isolate(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Isolate Palette Color";
	ot->idname = "GPENCIL_OT_palettecolor_isolate";
	ot->description = "Toggle whether the active color is the only one that is editable and/or visible";

	/* callbacks */
	ot->exec = gp_isolate_palettecolor_exec;
	ot->poll = gp_active_palettecolor_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* properties */
	RNA_def_boolean(ot->srna, "affect_visibility", false, "Affect Visibility", "In addition to toggling "
	                "the editability, also affect the visibility");
}

/* *********************** Hide Palette colors ******************************** */

static int gp_palettecolor_hide_exec(bContext *C, wmOperator *op)
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDpalette *palette = BKE_gpencil_palette_getactive(gpd);
	bGPDpalettecolor *palcolor = BKE_gpencil_palettecolor_getactive(palette);

	bool unselected = RNA_boolean_get(op->ptr, "unselected");

	/* sanity checks */
	if (ELEM(NULL, gpd, palette, palcolor))
		return OPERATOR_CANCELLED;

	if (unselected) {
		bGPDpalettecolor *color;

		/* hide unselected */
		for (color = palette->colors.first; color; color = color->next) {
			if (color != palcolor) {
				color->flag |= PC_COLOR_HIDE;
			}
		}
	}
	else {
		/* hide selected/active */
		palcolor->flag |= PC_COLOR_HIDE;
	}

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palettecolor_hide(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Hide Color(s)";
	ot->idname = "GPENCIL_OT_palettecolor_hide";
	ot->description = "Hide selected/unselected Grease Pencil colors";

	/* callbacks */
	ot->exec = gp_palettecolor_hide_exec;
	ot->poll = gp_active_palettecolor_poll; /* NOTE: we need an active color to play with */

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* props */
	RNA_def_boolean(ot->srna, "unselected", 0, "Unselected", "Hide unselected rather than selected colors");
}

/* ********************** Show All Colors ***************************** */

/* poll callback for showing colors */
static int gp_palettecolor_reveal_poll(bContext *C)
{
	return ED_gpencil_data_get_active(C) != NULL;
}

static int gp_palettecolor_reveal_exec(bContext *C, wmOperator *UNUSED(op))
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDpalette *palette = BKE_gpencil_palette_getactive(gpd);
	bGPDpalettecolor *palcolor;

	/* sanity checks */
	if (ELEM(NULL, gpd, palette))
		return OPERATOR_CANCELLED;

	/* make all colors visible */
	for (palcolor = palette->colors.first; palcolor; palcolor = palcolor->next) {
		palcolor->flag &= ~PC_COLOR_HIDE;
	}

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palettecolor_reveal(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Show All Colors";
	ot->idname = "GPENCIL_OT_palettecolor_reveal";
	ot->description = "Unhide all hidden Grease Pencil palette colors";

	/* callbacks */
	ot->exec = gp_palettecolor_reveal_exec;
	ot->poll = gp_palettecolor_reveal_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* ***************** Lock/Unlock All Palette colors ************************ */

static int gp_palettecolor_lock_all_exec(bContext *C, wmOperator *UNUSED(op))
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDpalette *palette = BKE_gpencil_palette_getactive(gpd);
	bGPDpalettecolor *palcolor;

	/* sanity checks */
	if (ELEM(NULL, gpd, palette))
		return OPERATOR_CANCELLED;

	/* make all layers non-editable */
	for (palcolor = palette->colors.first; palcolor; palcolor = palcolor->next) {
		palcolor->flag |= PC_COLOR_LOCKED;
	}

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palettecolor_lock_all(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Lock All Colors";
	ot->idname = "GPENCIL_OT_palettecolor_lock_all";
	ot->description = "Lock all Grease Pencil colors to prevent them from being accidentally modified";

	/* callbacks */
	ot->exec = gp_palettecolor_lock_all_exec;
	ot->poll = gp_palettecolor_reveal_poll; /* XXX: could use dedicated poll later */

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* -------------------------- */

static int gp_palettecolor_unlock_all_exec(bContext *C, wmOperator *UNUSED(op))
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDpalette *palette = BKE_gpencil_palette_getactive(gpd);
	bGPDpalettecolor *palcolor;

	/* sanity checks */
	if (ELEM(NULL, gpd, palette))
		return OPERATOR_CANCELLED;

	/* make all layers editable again*/
	for (palcolor = palette->colors.first; palcolor; palcolor = palcolor->next) {
		palcolor->flag &= ~PC_COLOR_LOCKED;
	}

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palettecolor_unlock_all(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Unlock All Colors";
	ot->idname = "GPENCIL_OT_palettecolor_unlock_all";
	ot->description = "Unlock all Grease Pencil colors so that they can be edited";

	/* callbacks */
	ot->exec = gp_palettecolor_unlock_all_exec;
	ot->poll = gp_palettecolor_reveal_poll; /* XXX: could use dedicated poll later */

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* ******************* Move Color Up/Down ************************** */

enum {
	GP_COLOR_MOVE_UP = -1,
	GP_COLOR_MOVE_DOWN = 1
};

static int gp_palettecolor_move_exec(bContext *C, wmOperator *op)
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDpalette *palette = BKE_gpencil_palette_getactive(gpd);
	bGPDpalettecolor *palcolor = BKE_gpencil_palettecolor_getactive(palette);

	int direction = RNA_enum_get(op->ptr, "direction");

	/* sanity checks */
	if (ELEM(NULL, gpd, palette, palcolor))
		return OPERATOR_CANCELLED;

	/* up or down? */
	if (direction == GP_COLOR_MOVE_UP) {
		/* up */
		BLI_remlink(&palette->colors, palcolor);
		BLI_insertlinkbefore(&palette->colors, palcolor->prev, palcolor);
	}
	else if (direction == GP_COLOR_MOVE_DOWN) {
		/* down */
		BLI_remlink(&palette->colors, palcolor);
		BLI_insertlinkafter(&palette->colors, palcolor->next, palcolor);
	}
	else {
		BLI_assert(0);
	}

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palettecolor_move(wmOperatorType *ot)
{
	static EnumPropertyItem slot_move[] = {
		{GP_COLOR_MOVE_UP, "UP", 0, "Up", ""},
		{GP_COLOR_MOVE_DOWN, "DOWN", 0, "Down", ""},
		{0, NULL, 0, NULL, NULL}
	};

	/* identifiers */
	ot->name = "Move Palette color";
	ot->idname = "GPENCIL_OT_palettecolor_move";
	ot->description = "Move the active Grease Pencil palette color up/down in the list";

	/* api callbacks */
	ot->exec = gp_palettecolor_move_exec;
	ot->poll = gp_palettecolor_reveal_poll; /* XXX: could use dedicated poll later */

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	ot->prop = RNA_def_enum(ot->srna, "direction", slot_move, GP_COLOR_MOVE_UP, "Direction", "");
}

/* ***************** Select all strokes using Palette color ************************ */

static int gp_palettecolor_select_exec(bContext *C, wmOperator *UNUSED(op))
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDpalette *palette = BKE_gpencil_palette_getactive(gpd);
	bGPDpalettecolor *palcolor = BKE_gpencil_palettecolor_getactive(palette);

	/* sanity checks */
	if (ELEM(NULL, gpd, palette, palcolor))
		return OPERATOR_CANCELLED;

	/* read all strokes and select*/
	for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
		/* only editable and visible layers are considered */
		if (gpencil_layer_is_editable(gpl) && (gpl->actframe != NULL)) {
			/* verify something to do */
			for (bGPDstroke *gps = gpl->actframe->strokes.first; gps; gps = gps->next) {
				/* skip strokes that are invalid for current view */
				if (ED_gpencil_stroke_can_use(C, gps) == false)
					continue;
				/* check if the color is editable */
				if (ED_gpencil_stroke_color_use(gpl, gps) == false)
					continue;

				/* select */
				if (strcmp(palcolor->info, gps->colorname) == 0) {
					bGPDspoint *pt;
					int i;

					gps->flag |= GP_STROKE_SELECT;
					for (i = 0, pt = gps->points; i < gps->totpoints; i++, pt++) {
						pt->flag |= GP_SPOINT_SELECT;
					}
				}
			}
		}
	}
	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palettecolor_select(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Select Color";
	ot->idname = "GPENCIL_OT_palettecolor_select";
	ot->description = "Select all Grease Pencil strokes using current color";

	/* callbacks */
	ot->exec = gp_palettecolor_select_exec;
	ot->poll = gp_palettecolor_reveal_poll; /* XXX: could use dedicated poll later */

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* ***************** Copy Palette color ************************ */

static int gp_palettecolor_copy_exec(bContext *C, wmOperator *UNUSED(op))
{
	bGPdata *gpd = ED_gpencil_data_get_active(C);
	bGPDpalette *palette = BKE_gpencil_palette_getactive(gpd);
	bGPDpalettecolor *palcolor = BKE_gpencil_palettecolor_getactive(palette);
	bGPDpalettecolor *newcolor;

	/* sanity checks */
	if (ELEM(NULL, gpd, palette, palcolor))
		return OPERATOR_CANCELLED;

	/* create a new color and duplicate data */
	newcolor = BKE_gpencil_palettecolor_addnew(palette, palcolor->info, true);
	copy_v4_v4(newcolor->color, palcolor->color);
	copy_v4_v4(newcolor->fill, palcolor->fill);
	newcolor->flag = palcolor->flag;

	/* notifiers */
	WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);

	return OPERATOR_FINISHED;
}

void GPENCIL_OT_palettecolor_copy(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Copy Color";
	ot->idname = "GPENCIL_OT_palettecolor_copy";
	ot->description = "Copy current Grease Pencil palette color";

	/* callbacks */
	ot->exec = gp_palettecolor_copy_exec;
	ot->poll = gp_active_palettecolor_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}