/*
 * ***** 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) 2009 Blender Foundation.
 * All rights reserved.
 *
 * 
 * Contributor(s): Blender Foundation, Joshua Leung
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/editors/space_graph/graph_buttons.c
 *  \ingroup spgraph
 */


#include <string.h>
#include <stdio.h>
#include <math.h>
#include <float.h>

#include "DNA_anim_types.h"
#include "DNA_object_types.h"
#include "DNA_scene_types.h"

#include "MEM_guardedalloc.h"

#include "BLI_math.h"
#include "BLI_blenlib.h"
#include "BLI_editVert.h"
#include "BLI_rand.h"
#include "BLI_utildefines.h"

#include "BKE_context.h"
#include "BKE_depsgraph.h"
#include "BKE_fcurve.h"
#include "BKE_main.h"
#include "BKE_screen.h"
#include "BKE_unit.h"


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

#include "RNA_access.h"

#include "ED_anim_api.h"
#include "ED_keyframing.h"
#include "ED_screen.h"

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

#include "graph_intern.h"	// own include

/* XXX */

/* temporary definition for limits of float number buttons (FLT_MAX tends to infinity with old system) */
#define UI_FLT_MAX 	10000.0f


/* ******************* graph editor space & buttons ************** */

#define B_REDR 1

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

static void do_graph_region_buttons(bContext *UNUSED(C), void *UNUSED(arg), int event)
{
	//Scene *scene= CTX_data_scene(C);
	
	switch(event) {

	}
	
	/* default for now */
	//WM_event_add_notifier(C, NC_OBJECT|ND_TRANSFORM, ob);
}

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

static int graph_panel_context(const bContext *C, bAnimListElem **ale, FCurve **fcu)
{
	bAnimContext ac;
	bAnimListElem *elem= NULL;
	
	/* for now, only draw if we could init the anim-context info (necessary for all animation-related tools) 
	 * to work correctly is able to be correctly retrieved. There's no point showing empty panels?
	 */
	if (ANIM_animdata_get_context(C, &ac) == 0) 
		return 0;
	
	/* try to find 'active' F-Curve */
	elem= get_active_fcurve_channel(&ac);
	if(elem == NULL) 
		return 0;
	
	if(fcu)
		*fcu= (FCurve*)elem->data;
	if(ale)
		*ale= elem;
	else
		MEM_freeN(elem);
	
	return 1;
}

static int graph_panel_poll(const bContext *C, PanelType *UNUSED(pt))
{
	return graph_panel_context(C, NULL, NULL);
}

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

/* Graph Editor View Settings */
static void graph_panel_view(const bContext *C, Panel *pa)
{
	bScreen *sc= CTX_wm_screen(C);
	SpaceIpo *sipo= CTX_wm_space_graph(C);
	Scene *scene= CTX_data_scene(C);
	PointerRNA spaceptr, sceneptr;
	uiLayout *col, *subcol, *row;
	
	/* get RNA pointers for use when creating the UI elements */
	RNA_id_pointer_create(&scene->id, &sceneptr);
	RNA_pointer_create(&sc->id, &RNA_SpaceGraphEditor, sipo, &spaceptr);

	/* 2D-Cursor */
	col= uiLayoutColumn(pa->layout, 0);
		uiItemR(col, &spaceptr, "show_cursor", 0, NULL, ICON_NONE);
		
		subcol= uiLayoutColumn(col, 1);
		uiLayoutSetActive(subcol, RNA_boolean_get(&spaceptr, "show_cursor")); 
			uiItemO(subcol, "Cursor from Selection", ICON_NONE, "GRAPH_OT_frame_jump");
		
		subcol= uiLayoutColumn(col, 1);
		uiLayoutSetActive(subcol, RNA_boolean_get(&spaceptr, "show_cursor")); 
			row= uiLayoutSplit(subcol, 0.7, 1);
				uiItemR(row, &sceneptr, "frame_current", 0, "Cursor X", ICON_NONE);
				uiItemEnumO(row, "GRAPH_OT_snap", "To Keys", 0, "type", GRAPHKEYS_SNAP_CFRA);
			row= uiLayoutSplit(subcol, 0.7, 1);
				uiItemR(row, &spaceptr, "cursor_position_y", 0, "Cursor Y", ICON_NONE);
				uiItemEnumO(row, "GRAPH_OT_snap", "To Keys", 0, "type", GRAPHKEYS_SNAP_VALUE);
}

/* ******************* active F-Curve ************** */

static void graph_panel_properties(const bContext *C, Panel *pa)
{
	bAnimListElem *ale;
	FCurve *fcu;
	PointerRNA fcu_ptr;
	uiLayout *layout = pa->layout;
	uiLayout *col, *row, *subrow;
	uiBlock *block;
	char name[256];
	int icon = 0;

	if (!graph_panel_context(C, &ale, &fcu))
		return;
	
	block= uiLayoutGetBlock(layout);
	uiBlockSetHandleFunc(block, do_graph_region_buttons, NULL);
	
	/* F-Curve pointer */
	RNA_pointer_create(ale->id, &RNA_FCurve, fcu, &fcu_ptr);
	
	/* user-friendly 'name' for F-Curve */
	// TODO: only show the path if this is invalid?
	col= uiLayoutColumn(layout, 0);
		icon= getname_anim_fcurve(name, ale->id, fcu);
		uiItemL(col, name, icon);
		
	/* RNA-Path Editing - only really should be enabled when things aren't working */
	col= uiLayoutColumn(layout, 1);
		uiLayoutSetEnabled(col, (fcu->flag & FCURVE_DISABLED)!=0); 
		uiItemR(col, &fcu_ptr, "data_path", 0, "", ICON_RNA);
		uiItemR(col, &fcu_ptr, "array_index", 0, NULL, ICON_NONE);
		
	/* color settings */
	col= uiLayoutColumn(layout, 1);
		uiItemL(col, "Display Color:", ICON_NONE);
		
		row= uiLayoutRow(col, 1);
			uiItemR(row, &fcu_ptr, "color_mode", 0, "", ICON_NONE);
			
			subrow= uiLayoutRow(row, 1);
				uiLayoutSetEnabled(subrow, (fcu->color_mode==FCURVE_COLOR_CUSTOM));
				uiItemR(subrow, &fcu_ptr, "color", 0, "", ICON_NONE);
	
	MEM_freeN(ale);
}

/* ******************* active Keyframe ************** */

/* get 'active' keyframe for panel editing */
static short get_active_fcurve_keyframe_edit(FCurve *fcu, BezTriple **bezt, BezTriple **prevbezt)
{
	BezTriple *b;
	int i;
	
	/* zero the pointers */
	*bezt = *prevbezt = NULL;
	
	/* sanity checks */
	if ((fcu->bezt == NULL) || (fcu->totvert == 0))
		return 0;
		
	/* find first selected keyframe for now, and call it the active one 
	 *	- this is a reasonable assumption, given that whenever anyone 
	 *	  wants to edit numerically, there is likely to only be 1 vert selected
	 */
	for (i=0, b=fcu->bezt; i < fcu->totvert; i++, b++) {
		if (BEZSELECTED(b)) {
			/* found 
			 *	- 'previous' is either the one before, of the keyframe itself (which is still fine)
			 *		XXX: we can just make this null instead if needed
			 */
			*prevbezt = (i > 0) ? b-1 : b;
			*bezt = b;
			
			return 1;
		}
	}
	
	/* not found */
	return 0;
}

/* update callback for active keyframe properties - base updates stuff */
static void graphedit_activekey_update_cb(bContext *UNUSED(C), void *fcu_ptr, void *UNUSED(bezt_ptr))
{
	FCurve *fcu = (FCurve *)fcu_ptr;
	
	/* make sure F-Curve and its handles are still valid after this editing */
	sort_time_fcurve(fcu);
	testhandles_fcurve(fcu);
}

/* update callback for active keyframe properties - handle-editing wrapper */
static void graphedit_activekey_handles_cb(bContext *C, void *fcu_ptr, void *bezt_ptr)
{
	BezTriple *bezt = (BezTriple *)bezt_ptr;
	
	/* since editing the handles, make sure they're set to types which are receptive to editing 
	 * see transform_conversions.c :: createTransGraphEditData(), last step in second loop
	 */
	if (ELEM(bezt->h1, HD_AUTO, HD_AUTO_ANIM) && ELEM(bezt->h2, HD_AUTO, HD_AUTO_ANIM)) {
		/* by changing to aligned handles, these can now be moved... */
		bezt->h1= HD_ALIGN;
		bezt->h2= HD_ALIGN;
	}
	
	/* now call standard updates */
	graphedit_activekey_update_cb(C, fcu_ptr, bezt_ptr);
}

static void graph_panel_key_properties(const bContext *C, Panel *pa)
{
	bAnimListElem *ale;
	FCurve *fcu;
	BezTriple *bezt, *prevbezt;
	
	uiLayout *layout = pa->layout;
	uiLayout *col;
	uiBlock *block;

	if (!graph_panel_context(C, &ale, &fcu))
		return;
	
	block = uiLayoutGetBlock(layout);
	uiBlockSetHandleFunc(block, do_graph_region_buttons, NULL);
	
	/* only show this info if there are keyframes to edit */
	if (get_active_fcurve_keyframe_edit(fcu, &bezt, &prevbezt)) {
		PointerRNA bezt_ptr, id_ptr, fcu_prop_ptr;
		PropertyRNA *fcu_prop = NULL;
		uiBut *but;
		int unit = B_UNIT_NONE;
		
		/* RNA pointer to keyframe, to allow editing */
		RNA_pointer_create(ale->id, &RNA_Keyframe, bezt, &bezt_ptr);
		
		/* get property that F-Curve affects, for some unit-conversion magic */
		RNA_id_pointer_create(ale->id, &id_ptr);
		if (RNA_path_resolve(&id_ptr, fcu->rna_path, &fcu_prop_ptr, &fcu_prop) && fcu_prop) {
			/* determine the unit for this property */
			unit = RNA_SUBTYPE_UNIT(RNA_property_subtype(fcu_prop));
		}		
		
		/* interpolation */
		col= uiLayoutColumn(layout, 0);
			uiItemR(col, &bezt_ptr, "interpolation", 0, NULL, ICON_NONE);
			
		/* numerical coordinate editing 
		 * 	- we use the button-versions of the calls so that we can attach special update handlers
		 * 	  and unit conversion magic that cannot be achieved using a purely RNA-approach
		 */
		// XXX: 
		col= uiLayoutColumn(layout, 1);
			/* keyframe itself */
			{
				uiItemL(col, "Key:", ICON_NONE);
				
				but = uiDefButR(block, NUM, B_REDR, "Frame", 0, 0, UI_UNIT_X, UI_UNIT_Y, &bezt_ptr, "co", 0, 0, 0, -1, -1, NULL);
				uiButSetFunc(but, graphedit_activekey_update_cb, fcu, bezt);
				
				but = uiDefButR(block, NUM, B_REDR, "Value", 0, 0, UI_UNIT_X, UI_UNIT_Y, &bezt_ptr, "co", 1, 0, 0, -1, -1, NULL);
				uiButSetFunc(but, graphedit_activekey_update_cb, fcu, bezt);
				uiButSetUnitType(but, unit);
			}
			
			/* previous handle - only if previous was Bezier interpolation */
			if ((prevbezt) && (prevbezt->ipo == BEZT_IPO_BEZ)) {
				uiItemL(col, "Left Handle:", ICON_NONE);
				
				but = uiDefButR(block, NUM, B_REDR, "X", 0, 0, UI_UNIT_X, UI_UNIT_Y, &bezt_ptr, "handle_left", 0, 0, 0, -1, -1, NULL);
				uiButSetFunc(but, graphedit_activekey_handles_cb, fcu, bezt);		
				
				but = uiDefButR(block, NUM, B_REDR, "Y", 0, 0, UI_UNIT_X, UI_UNIT_Y, &bezt_ptr, "handle_left", 1, 0, 0, -1, -1, NULL);
				uiButSetFunc(but, graphedit_activekey_handles_cb, fcu, bezt);
				uiButSetUnitType(but, unit);
			}
			
			/* next handle - only if current is Bezier interpolation */
			if (bezt->ipo == BEZT_IPO_BEZ) {
				uiItemL(col, "Right Handle:", ICON_NONE);
				
				but = uiDefButR(block, NUM, B_REDR, "X", 0, 0, UI_UNIT_X, UI_UNIT_Y, &bezt_ptr, "handle_right", 0, 0, 0, -1, -1, NULL);
				uiButSetFunc(but, graphedit_activekey_handles_cb, fcu, bezt);
				
				but = uiDefButR(block, NUM, B_REDR, "Y", 0, 0, UI_UNIT_X, UI_UNIT_Y, &bezt_ptr, "handle_right", 1, 0, 0, -1, -1, NULL);
				uiButSetFunc(but, graphedit_activekey_handles_cb, fcu, bezt);
				uiButSetUnitType(but, unit);
			}
	}
	else {
		if ((fcu->bezt == NULL) && (fcu->modifiers.first)) {
			/* modifiers only - so no keyframes to be active */
			uiItemL(layout, "F-Curve only has F-Modifiers", ICON_NONE);
			uiItemL(layout, "See Modifiers panel below", ICON_INFO);
		}
		else if (fcu->fpt) {
			/* samples only */
			uiItemL(layout, "F-Curve doesn't have any keyframes as it only contains sampled points", ICON_NONE);
		}
		else
			uiItemL(layout, "No active keyframe on F-Curve", ICON_NONE);
	}
	
	MEM_freeN(ale);
}

/* ******************* drivers ******************************** */

#define B_IPO_DEPCHANGE 	10

static void do_graph_region_driver_buttons(bContext *C, void *UNUSED(arg), int event)
{
	Main *bmain= CTX_data_main(C);
	Scene *scene= CTX_data_scene(C);
	
	switch (event) {
		case B_IPO_DEPCHANGE:
		{
			/* rebuild depsgraph for the new deps */
			DAG_scene_sort(bmain, scene);
			
			/* force an update of depsgraph */
			DAG_ids_flush_update(bmain, 0);
		}
			break;
	}
	
	/* default for now */
	WM_event_add_notifier(C, NC_SCENE|ND_FRAME, scene); // XXX could use better notifier
}

/* callback to remove the active driver */
static void driver_remove_cb (bContext *C, void *ale_v, void *UNUSED(arg))
{
	bAnimListElem *ale= (bAnimListElem *)ale_v;
	ID *id= ale->id;
	FCurve *fcu= ale->data;
	ReportList *reports = CTX_wm_reports(C);
	
	/* try to get F-Curve that driver lives on, and ID block which has this AnimData */
	if (ELEM(NULL, id, fcu))
		return;
	
	/* call API method to remove this driver  */	
	ANIM_remove_driver(reports, id, fcu->rna_path, fcu->array_index, 0);
}

/* callback to add a target variable to the active driver */
static void driver_add_var_cb (bContext *UNUSED(C), void *driver_v, void *UNUSED(arg))
{
	ChannelDriver *driver= (ChannelDriver *)driver_v;
	
	/* add a new variable */
	driver_add_new_variable(driver);
}

/* callback to remove target variable from active driver */
static void driver_delete_var_cb (bContext *UNUSED(C), void *driver_v, void *dvar_v)
{
	ChannelDriver *driver= (ChannelDriver *)driver_v;
	DriverVar *dvar= (DriverVar *)dvar_v;
	
	/* remove the active variable */
	driver_free_variable(driver, dvar);
}

/* callback to reset the driver's flags */
static void driver_update_flags_cb (bContext *UNUSED(C), void *fcu_v, void *UNUSED(arg))
{
	FCurve *fcu= (FCurve *)fcu_v;
	ChannelDriver *driver= fcu->driver;
	
	/* clear invalid flags */
	fcu->flag &= ~FCURVE_DISABLED; // XXX?
	driver->flag &= ~DRIVER_FLAG_INVALID;
}

/* drivers panel poll */
static int graph_panel_drivers_poll(const bContext *C, PanelType *UNUSED(pt))
{
	SpaceIpo *sipo= CTX_wm_space_graph(C);

	if(sipo->mode != SIPO_MODE_DRIVERS)
		return 0;

	return graph_panel_context(C, NULL, NULL);
}

/* settings for 'single property' driver variable type */
static void graph_panel_driverVar__singleProp(uiLayout *layout, ID *id, DriverVar *dvar)
{
	DriverTarget *dtar= &dvar->targets[0];
	PointerRNA dtar_ptr;
	uiLayout *row, *col;
	
	/* initialise RNA pointer to the target */
	RNA_pointer_create(id, &RNA_DriverTarget, dtar, &dtar_ptr); 
	
	/* Target ID */
	row= uiLayoutRow(layout, 0);
		uiTemplateAnyID(row, &dtar_ptr, "id", "id_type", "Prop:");
	
	/* Target Property */
	// TODO: make this less technical...
	if (dtar->id) {
		PointerRNA root_ptr;
		
		/* get pointer for resolving the property selected */
		RNA_id_pointer_create(dtar->id, &root_ptr);
		
		col= uiLayoutColumn(layout, 1);
		/* rna path */
		uiTemplatePathBuilder(col, &dtar_ptr, "data_path", &root_ptr, "Path");
	}
}

/* settings for 'rotation difference' driver variable type */
static void graph_panel_driverVar__rotDiff(uiLayout *layout, ID *id, DriverVar *dvar)
{
	DriverTarget *dtar= &dvar->targets[0];
	DriverTarget *dtar2= &dvar->targets[1];
	Object *ob1 = (Object *)dtar->id;
	Object *ob2 = (Object *)dtar2->id;
	PointerRNA dtar_ptr, dtar2_ptr;
	uiLayout *col;
	
	/* initialise RNA pointer to the target */
	RNA_pointer_create(id, &RNA_DriverTarget, dtar, &dtar_ptr); 
	RNA_pointer_create(id, &RNA_DriverTarget, dtar2, &dtar2_ptr); 
	
	/* Bone 1 */
	col= uiLayoutColumn(layout, 1);
		uiTemplateAnyID(col, &dtar_ptr, "id", "id_type", "Bone 1:");
		
		if (dtar->id && ob1->pose) {
			PointerRNA tar_ptr;
			
			RNA_pointer_create(dtar->id, &RNA_Pose, ob1->pose, &tar_ptr);
			uiItemPointerR(col, &dtar_ptr, "bone_target", &tar_ptr, "bones", "", ICON_BONE_DATA);
		}
	
	col= uiLayoutColumn(layout, 1);
		uiTemplateAnyID(col, &dtar2_ptr, "id", "id_type", "Bone 2:");
		
		if (dtar2->id && ob2->pose) {
			PointerRNA tar_ptr;
			
			RNA_pointer_create(dtar2->id, &RNA_Pose, ob2->pose, &tar_ptr);
			uiItemPointerR(col, &dtar2_ptr, "bone_target", &tar_ptr, "bones", "", ICON_BONE_DATA);
		}
}

/* settings for 'location difference' driver variable type */
static void graph_panel_driverVar__locDiff(uiLayout *layout, ID *id, DriverVar *dvar)
{
	DriverTarget *dtar= &dvar->targets[0];
	DriverTarget *dtar2= &dvar->targets[1];
	Object *ob1 = (Object *)dtar->id;
	Object *ob2 = (Object *)dtar2->id;
	PointerRNA dtar_ptr, dtar2_ptr;
	uiLayout *col;
	
	/* initialise RNA pointer to the target */
	RNA_pointer_create(id, &RNA_DriverTarget, dtar, &dtar_ptr); 
	RNA_pointer_create(id, &RNA_DriverTarget, dtar2, &dtar2_ptr); 
	
	/* Bone 1 */
	col= uiLayoutColumn(layout, 1);
		uiTemplateAnyID(col, &dtar_ptr, "id", "id_type", "Ob/Bone 1:");
		
		if (dtar->id && ob1->pose) {
			PointerRNA tar_ptr;
			
			RNA_pointer_create(dtar->id, &RNA_Pose, ob1->pose, &tar_ptr);
			uiItemPointerR(col, &dtar_ptr, "bone_target", &tar_ptr, "bones", "", ICON_BONE_DATA);
		}
		
		uiItemR(col, &dtar_ptr, "transform_space", 0, NULL, ICON_NONE);
	
	col= uiLayoutColumn(layout, 1);
		uiTemplateAnyID(col, &dtar2_ptr, "id", "id_type", "Ob/Bone 2:");
		
		if (dtar2->id && ob2->pose) {
			PointerRNA tar_ptr;
			
			RNA_pointer_create(dtar2->id, &RNA_Pose, ob2->pose, &tar_ptr);
			uiItemPointerR(col, &dtar2_ptr, "bone_target", &tar_ptr, "bones", "", ICON_BONE_DATA);
		}
		
		uiItemR(col, &dtar2_ptr, "transform_space", 0, NULL, ICON_NONE);
}

/* settings for 'transform channel' driver variable type */
static void graph_panel_driverVar__transChan(uiLayout *layout, ID *id, DriverVar *dvar)
{
	DriverTarget *dtar= &dvar->targets[0];
	Object *ob = (Object *)dtar->id;
	PointerRNA dtar_ptr;
	uiLayout *col, *subcol;
	
	/* initialise RNA pointer to the target */
	RNA_pointer_create(id, &RNA_DriverTarget, dtar, &dtar_ptr); 
	
	/* properties */
	col= uiLayoutColumn(layout, 1);
		uiTemplateAnyID(col, &dtar_ptr, "id", "id_type", "Ob/Bone:");
		
		if (dtar->id && ob->pose) {
			PointerRNA tar_ptr;
			
			RNA_pointer_create(dtar->id, &RNA_Pose, ob->pose, &tar_ptr);
			uiItemPointerR(col, &dtar_ptr, "bone_target", &tar_ptr, "bones", "", ICON_BONE_DATA);
		}
		
		subcol= uiLayoutColumn(layout, 1);
			uiItemR(subcol, &dtar_ptr, "transform_type", 0, NULL, ICON_NONE);
			uiItemR(subcol, &dtar_ptr, "transform_space", 0, "Space", ICON_NONE);
}

/* driver settings for active F-Curve (only for 'Drivers' mode) */
static void graph_panel_drivers(const bContext *C, Panel *pa)
{
	bAnimListElem *ale;
	FCurve *fcu;
	ChannelDriver *driver;
	DriverVar *dvar;
	
	PointerRNA driver_ptr;
	uiLayout *col;
	uiBlock *block;
	uiBut *but;
	
	/* Get settings from context */
	if (!graph_panel_context(C, &ale, &fcu))
		return;
	driver= fcu->driver;
	
	/* set event handler for panel */
	block= uiLayoutGetBlock(pa->layout); // xxx?
	uiBlockSetHandleFunc(block, do_graph_region_driver_buttons, NULL);
	
	/* general actions - management */
	col= uiLayoutColumn(pa->layout, 0);
	block= uiLayoutGetBlock(col);
		but= uiDefBut(block, BUT, B_IPO_DEPCHANGE, "Update Dependencies", 0, 0, 10*UI_UNIT_X, 22, NULL, 0.0, 0.0, 0, 0, "Force updates of dependencies");
		uiButSetFunc(but, driver_update_flags_cb, fcu, NULL);
		
		but= uiDefBut(block, BUT, B_IPO_DEPCHANGE, "Remove Driver", 0, 0, 10*UI_UNIT_X, 18, NULL, 0.0, 0.0, 0, 0, "Remove this driver");
		uiButSetNFunc(but, driver_remove_cb, MEM_dupallocN(ale), NULL);
		
	/* driver-level settings - type, expressions, and errors */
	RNA_pointer_create(ale->id, &RNA_Driver, driver, &driver_ptr);
	
	col= uiLayoutColumn(pa->layout, 1);
	block= uiLayoutGetBlock(col);
		uiItemR(col, &driver_ptr, "type", 0, NULL, ICON_NONE);
		
		/* show expression box if doing scripted drivers, and/or error messages when invalid drivers exist */
		if (driver->type == DRIVER_TYPE_PYTHON) {
			/* expression */
			uiItemR(col, &driver_ptr, "expression", 0, "Expr", ICON_NONE);
			
			/* errors? */
			if (driver->flag & DRIVER_FLAG_INVALID)
				uiItemL(col, "ERROR: invalid Python expression", ICON_ERROR);
		}
		else {
			/* errors? */
			if (driver->flag & DRIVER_FLAG_INVALID)
				uiItemL(col, "ERROR: invalid target channel(s)", ICON_ERROR);
		}
		
	col= uiLayoutColumn(pa->layout, 1);
		/* debug setting */
		uiItemR(col, &driver_ptr, "show_debug_info", 0, NULL, ICON_NONE);
		
		/* value of driver */
		if (driver->flag & DRIVER_FLAG_SHOWDEBUG) {
			uiLayout *row= uiLayoutRow(col, 1);
			char valBuf[32];
			
			uiItemL(row, "Driver Value:", ICON_NONE);
			
			sprintf(valBuf, "%.3f", driver->curval);
			uiItemL(row, valBuf, ICON_NONE);
		}
	
	/* add driver variables */
	col= uiLayoutColumn(pa->layout, 0);
	block= uiLayoutGetBlock(col);
		but= uiDefBut(block, BUT, B_IPO_DEPCHANGE, "Add Variable", 0, 0, 10*UI_UNIT_X, UI_UNIT_Y, NULL, 0.0, 0.0, 0, 0, "Add a new target variable for this Driver");
		uiButSetFunc(but, driver_add_var_cb, driver, NULL);
	
	/* loop over targets, drawing them */
	for (dvar= driver->variables.first; dvar; dvar= dvar->next) {
		PointerRNA dvar_ptr;
		uiLayout *box, *row;
		
		/* sub-layout column for this variable's settings */
		col= uiLayoutColumn(pa->layout, 1);
		
		/* header panel */
		box= uiLayoutBox(col);
			/* first row context info for driver */
			RNA_pointer_create(ale->id, &RNA_DriverVariable, dvar, &dvar_ptr);
			
			row= uiLayoutRow(box, 0);
			block= uiLayoutGetBlock(row);
				/* variable name */
				uiItemR(row, &dvar_ptr, "name", 0, "", ICON_NONE);
				
				/* remove button */
				uiBlockSetEmboss(block, UI_EMBOSSN);
					but= uiDefIconBut(block, BUT, B_IPO_DEPCHANGE, ICON_X, 290, 0, UI_UNIT_X, UI_UNIT_Y, NULL, 0.0, 0.0, 0.0, 0.0, "Delete target variable");
					uiButSetFunc(but, driver_delete_var_cb, driver, dvar);
				uiBlockSetEmboss(block, UI_EMBOSS);
			
			/* variable type */
			row= uiLayoutRow(box, 0);
				uiItemR(row, &dvar_ptr, "type", 0, "", ICON_NONE);
				
		/* variable type settings */
		box= uiLayoutBox(col);
			/* controls to draw depends on the type of variable */
			switch (dvar->type) {
				case DVAR_TYPE_SINGLE_PROP:	/* single property */
					graph_panel_driverVar__singleProp(box, ale->id, dvar);
					break;
				case DVAR_TYPE_ROT_DIFF: /* rotational difference */
					graph_panel_driverVar__rotDiff(box, ale->id, dvar);
					break;
				case DVAR_TYPE_LOC_DIFF: /* location difference */
					graph_panel_driverVar__locDiff(box, ale->id, dvar);
					break;
				case DVAR_TYPE_TRANSFORM_CHAN: /* transform channel */
					graph_panel_driverVar__transChan(box, ale->id, dvar);
					break;
			}
			
		/* value of variable */
		if (driver->flag & DRIVER_FLAG_SHOWDEBUG) {
			char valBuf[32];
			
			box= uiLayoutBox(col);
			row= uiLayoutRow(box, 1);
				uiItemL(row, "Value:", ICON_NONE);
				
				sprintf(valBuf, "%.3f", dvar->curval);
				uiItemL(row, valBuf, ICON_NONE);
		}
	}
	
	/* cleanup */
	MEM_freeN(ale);
}

/* ******************* f-modifiers ******************************** */
/* all the drawing code is in editors/animation/fmodifier_ui.c */

#define B_FMODIFIER_REDRAW		20

static void do_graph_region_modifier_buttons(bContext *C, void *UNUSED(arg), int event)
{
	switch (event) {
		case B_FMODIFIER_REDRAW: // XXX this should send depsgraph updates too
			WM_event_add_notifier(C, NC_ANIMATION, NULL); // XXX need a notifier specially for F-Modifiers
			break;
	}
}

static void graph_panel_modifiers(const bContext *C, Panel *pa)	
{
	bAnimListElem *ale;
	FCurve *fcu;
	FModifier *fcm;
	uiLayout *col, *row;
	uiBlock *block;
	
	if (!graph_panel_context(C, &ale, &fcu))
		return;
	
	block= uiLayoutGetBlock(pa->layout);
	uiBlockSetHandleFunc(block, do_graph_region_modifier_buttons, NULL);
	
	/* 'add modifier' button at top of panel */
	{
		row= uiLayoutRow(pa->layout, 0);
		block= uiLayoutGetBlock(row);
		
		// XXX for now, this will be a operator button which calls a 'add modifier' operator
		uiDefButO(block, BUT, "GRAPH_OT_fmodifier_add", WM_OP_INVOKE_REGION_WIN, "Add Modifier", 10, 0, 150, 20, "Adds a new F-Curve Modifier for the active F-Curve");
		
		/* copy/paste (as sub-row)*/
		row= uiLayoutRow(row, 1);
			uiItemO(row, "", ICON_COPYDOWN, "GRAPH_OT_fmodifier_copy");
			uiItemO(row, "", ICON_PASTEDOWN, "GRAPH_OT_fmodifier_paste");
	}
	
	/* draw each modifier */
	for (fcm= fcu->modifiers.first; fcm; fcm= fcm->next) {
		col= uiLayoutColumn(pa->layout, 1);
		
		ANIM_uiTemplate_fmodifier_draw(col, ale->id, &fcu->modifiers, fcm);
	}

	MEM_freeN(ale);
}

/* ******************* general ******************************** */

void graph_buttons_register(ARegionType *art)
{
	PanelType *pt;

	pt= MEM_callocN(sizeof(PanelType), "spacetype graph panel view");
	strcpy(pt->idname, "GRAPH_PT_view");
	strcpy(pt->label, "View Properties");
	pt->draw= graph_panel_view;
	pt->flag |= PNL_DEFAULT_CLOSED;
	BLI_addtail(&art->paneltypes, pt);
	
	pt= MEM_callocN(sizeof(PanelType), "spacetype graph panel properties");
	strcpy(pt->idname, "GRAPH_PT_properties");
	strcpy(pt->label, "Active F-Curve");
	pt->draw= graph_panel_properties;
	pt->poll= graph_panel_poll;
	BLI_addtail(&art->paneltypes, pt);
	
	pt= MEM_callocN(sizeof(PanelType), "spacetype graph panel properties");
	strcpy(pt->idname, "GRAPH_PT_key_properties");
	strcpy(pt->label, "Active Keyframe");
	pt->draw= graph_panel_key_properties;
	pt->poll= graph_panel_poll;
	BLI_addtail(&art->paneltypes, pt);


	pt= MEM_callocN(sizeof(PanelType), "spacetype graph panel drivers");
	strcpy(pt->idname, "GRAPH_PT_drivers");
	strcpy(pt->label, "Drivers");
	pt->draw= graph_panel_drivers;
	pt->poll= graph_panel_drivers_poll;
	BLI_addtail(&art->paneltypes, pt);

	pt= MEM_callocN(sizeof(PanelType), "spacetype graph panel modifiers");
	strcpy(pt->idname, "GRAPH_PT_modifiers");
	strcpy(pt->label, "Modifiers");
	pt->draw= graph_panel_modifiers;
	pt->poll= graph_panel_poll;
	BLI_addtail(&art->paneltypes, pt);
}

static int graph_properties(bContext *C, wmOperator *UNUSED(op))
{
	ScrArea *sa= CTX_wm_area(C);
	ARegion *ar= graph_has_buttons_region(sa);
	
	if(ar)
		ED_region_toggle_hidden(C, ar);

	return OPERATOR_FINISHED;
}

void GRAPH_OT_properties(wmOperatorType *ot)
{
	ot->name= "Properties";
	ot->idname= "GRAPH_OT_properties";
	ot->description= "Toggle display properties panel";
	
	ot->exec= graph_properties;
	ot->poll= ED_operator_graphedit_active;

	/* flags */
	ot->flag= 0;
}