buttons_context.c

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/*
 * $Id: buttons_context.c 38370 2011-07-13 17:52:23Z blendix $
 *
 * ***** 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
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <stdlib.h>
#include <string.h>

#include "MEM_guardedalloc.h"

#include "BLI_listbase.h"
#include "BLI_utildefines.h"

#include "DNA_armature_types.h"
#include "DNA_lamp_types.h"
#include "DNA_material_types.h"
#include "DNA_node_types.h"
#include "DNA_scene_types.h"
#include "DNA_world_types.h"
#include "DNA_brush_types.h"

#include "BKE_context.h"
#include "BKE_action.h"
#include "BKE_material.h"
#include "BKE_modifier.h"
#include "BKE_paint.h"
#include "BKE_particle.h"
#include "BKE_screen.h"
#include "BKE_texture.h"


#include "RNA_access.h"

#include "ED_armature.h"
#include "ED_screen.h"
#include "ED_physics.h"

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

#include "buttons_intern.h"     // own include

typedef struct ButsContextPath {
        PointerRNA ptr[8];
        int len;
        int flag;
        int tex_ctx;
} ButsContextPath;

static int set_pointer_type(ButsContextPath *path, bContextDataResult *result, StructRNA *type)
{
        PointerRNA *ptr;
        int a;

        for(a=0; a<path->len; a++) {
                ptr= &path->ptr[a];

                if(RNA_struct_is_a(ptr->type, type)) {
                        CTX_data_pointer_set(result, ptr->id.data, ptr->type, ptr->data);
                        return 1;
                }
        }

        return 0;
}

static PointerRNA *get_pointer_type(ButsContextPath *path, StructRNA *type)
{
        PointerRNA *ptr;
        int a;

        for(a=0; a<path->len; a++) {
                ptr= &path->ptr[a];

                if(RNA_struct_is_a(ptr->type, type))
                        return ptr;
        }

        return NULL;
}

/************************* Creating the Path ************************/

static int buttons_context_path_scene(ButsContextPath *path)
{
        PointerRNA *ptr= &path->ptr[path->len-1];

        /* this one just verifies */
        return RNA_struct_is_a(ptr->type, &RNA_Scene);
}

/* note: this function can return 1 without adding a world to the path
 * so the buttons stay visible, but be sure to check the ID type if a ID_WO */
static int buttons_context_path_world(ButsContextPath *path)
{
        Scene *scene;
        World *world;
        PointerRNA *ptr= &path->ptr[path->len-1];

        /* if we already have a (pinned) world, we're done */
        if(RNA_struct_is_a(ptr->type, &RNA_World)) {
                return 1;
        }
        /* if we have a scene, use the scene's world */
        else if(buttons_context_path_scene(path)) {
                scene= path->ptr[path->len-1].data;
                world= scene->world;
                
                if(world) {
                        RNA_id_pointer_create(&scene->world->id, &path->ptr[path->len]);
                        path->len++;
                        return 1;
                }
                else {
                        return 1;
                }
        }

        /* no path to a world possible */
        return 0;
}


static int buttons_context_path_object(ButsContextPath *path)
{
        Scene *scene;
        Object *ob;
        PointerRNA *ptr= &path->ptr[path->len-1];

        /* if we already have a (pinned) object, we're done */
        if(RNA_struct_is_a(ptr->type, &RNA_Object)) {
                return 1;
        }
        /* if we have a scene, use the scene's active object */
        else if(buttons_context_path_scene(path)) {
                scene= path->ptr[path->len-1].data;
                ob= (scene->basact)? scene->basact->object: NULL;

                if(ob) {
                        RNA_id_pointer_create(&ob->id, &path->ptr[path->len]);
                        path->len++;

                        return 1;
                }
        }

        /* no path to a object possible */
        return 0;
}

static int buttons_context_path_data(ButsContextPath *path, int type)
{
        Object *ob;
        PointerRNA *ptr= &path->ptr[path->len-1];

        /* if we already have a data, we're done */
        if(RNA_struct_is_a(ptr->type, &RNA_Mesh) && (type == -1 || type == OB_MESH)) return 1;
        else if(RNA_struct_is_a(ptr->type, &RNA_Curve) && (type == -1 || ELEM3(type, OB_CURVE, OB_SURF, OB_FONT))) return 1;
        else if(RNA_struct_is_a(ptr->type, &RNA_Armature) && (type == -1 || type == OB_ARMATURE)) return 1;
        else if(RNA_struct_is_a(ptr->type, &RNA_MetaBall) && (type == -1 || type == OB_MBALL)) return 1;
        else if(RNA_struct_is_a(ptr->type, &RNA_Lattice) && (type == -1 || type == OB_LATTICE)) return 1;
        else if(RNA_struct_is_a(ptr->type, &RNA_Camera) && (type == -1 || type == OB_CAMERA)) return 1;
        else if(RNA_struct_is_a(ptr->type, &RNA_Lamp) && (type == -1 || type == OB_LAMP)) return 1;
        /* try to get an object in the path, no pinning supported here */
        else if(buttons_context_path_object(path)) {
                ob= path->ptr[path->len-1].data;

                if(ob && (type == -1 || type == ob->type)) {
                        RNA_id_pointer_create(ob->data, &path->ptr[path->len]);
                        path->len++;

                        return 1;
                }
        }

        /* no path to data possible */
        return 0;
}

static int buttons_context_path_modifier(ButsContextPath *path)
{
        Object *ob;

        if(buttons_context_path_object(path)) {
                ob= path->ptr[path->len-1].data;

                if(ob && ELEM5(ob->type, OB_MESH, OB_CURVE, OB_FONT, OB_SURF, OB_LATTICE))
                        return 1;
        }

        return 0;
}

static int buttons_context_path_material(ButsContextPath *path, int for_texture)
{
        Object *ob;
        PointerRNA *ptr= &path->ptr[path->len-1];
        Material *ma;

        /* if we already have a (pinned) material, we're done */
        if(RNA_struct_is_a(ptr->type, &RNA_Material)) {
                return 1;
        }
        /* if we have an object, use the object material slot */
        else if(buttons_context_path_object(path)) {
                ob= path->ptr[path->len-1].data;

                if(ob && ob->type && (ob->type<OB_LAMP)) {
                        ma= give_current_material(ob, ob->actcol);
                        RNA_id_pointer_create(&ma->id, &path->ptr[path->len]);
                        path->len++;

                        if(for_texture && give_current_material_texture_node(ma))
                                return 1;
                        
                        ma= give_node_material(ma);
                        if(ma) {
                                RNA_id_pointer_create(&ma->id, &path->ptr[path->len]);
                                path->len++;
                        }                       
                        return 1;
                }
        }

        /* no path to a material possible */
        return 0;
}

static int buttons_context_path_bone(ButsContextPath *path)
{
        bArmature *arm;
        EditBone *edbo;

        /* if we have an armature, get the active bone */
        if(buttons_context_path_data(path, OB_ARMATURE)) {
                arm= path->ptr[path->len-1].data;

                if(arm->edbo) {
                        if(arm->act_edbone) {
                                edbo= arm->act_edbone;
                                RNA_pointer_create(&arm->id, &RNA_EditBone, edbo, &path->ptr[path->len]);
                                path->len++;
                                return 1;
                        }
                }
                else {
                        if(arm->act_bone) {
                                RNA_pointer_create(&arm->id, &RNA_Bone, arm->act_bone, &path->ptr[path->len]);
                                path->len++;
                                return 1;
                        }
                }
        }

        /* no path to a bone possible */
        return 0;
}

static int buttons_context_path_pose_bone(ButsContextPath *path)
{
        PointerRNA *ptr= &path->ptr[path->len-1];

        /* if we already have a (pinned) PoseBone, we're done */
        if(RNA_struct_is_a(ptr->type, &RNA_PoseBone)) {
                return 1;
        }

        /* if we have an armature, get the active bone */
        if(buttons_context_path_object(path)) {
                Object *ob= path->ptr[path->len-1].data;
                bArmature *arm= ob->data; /* path->ptr[path->len-1].data - works too */

                if(ob->type != OB_ARMATURE || arm->edbo) {
                        return 0;
                }
                else {
                        if(arm->act_bone) {
                                bPoseChannel *pchan= get_pose_channel(ob->pose, arm->act_bone->name);
                                if(pchan) {
                                        RNA_pointer_create(&ob->id, &RNA_PoseBone, pchan, &path->ptr[path->len]);
                                        path->len++;
                                        return 1;
                                }
                        }
                }
        }

        /* no path to a bone possible */
        return 0;
}


static int buttons_context_path_particle(ButsContextPath *path)
{
        Object *ob;
        ParticleSystem *psys;
        PointerRNA *ptr= &path->ptr[path->len-1];

        /* if we already have (pinned) particle settings, we're done */
        if(RNA_struct_is_a(ptr->type, &RNA_ParticleSettings)) {
                return 1;
        }
        /* if we have an object, get the active particle system */
        if(buttons_context_path_object(path)) {
                ob= path->ptr[path->len-1].data;

                if(ob && ob->type == OB_MESH) {
                        psys= psys_get_current(ob);

                        RNA_pointer_create(&ob->id, &RNA_ParticleSystem, psys, &path->ptr[path->len]);
                        path->len++;
                        return 1;
                }
        }

        /* no path to a particle system possible */
        return 0;
}

static int buttons_context_path_brush(ButsContextPath *path)
{
        Scene *scene;
        Brush *br= NULL;
        PointerRNA *ptr= &path->ptr[path->len-1];

        /* if we already have a (pinned) brush, we're done */
        if(RNA_struct_is_a(ptr->type, &RNA_Brush)) {
                return 1;
        }
        /* if we have a scene, use the toolsettings brushes */
        else if(buttons_context_path_scene(path)) {
                scene= path->ptr[path->len-1].data;

                if(scene)
                        br= paint_brush(paint_get_active(scene));

                if(br) {
                        RNA_id_pointer_create((ID *)br, &path->ptr[path->len]);
                        path->len++;

                        return 1;
                }
        }

        /* no path to a brush possible */
        return 0;
}

static int buttons_context_path_texture(ButsContextPath *path)
{
        Material *ma;
        Lamp *la;
        Brush *br;
        World *wo;
        ParticleSystem *psys;
        Tex *tex;
        PointerRNA *ptr= &path->ptr[path->len-1];
        int orig_len = path->len;

        /* if we already have a (pinned) texture, we're done */
        if(RNA_struct_is_a(ptr->type, &RNA_Texture)) {
                return 1;
        }
        /* try brush */
        if((path->tex_ctx == SB_TEXC_BRUSH) && buttons_context_path_brush(path)) {
                br= path->ptr[path->len-1].data;
                
                if(br) {
                        tex= give_current_brush_texture(br);

                        RNA_id_pointer_create(&tex->id, &path->ptr[path->len]);
                        path->len++;
                        return 1;
                }
        }
        /* try world */
        if((path->tex_ctx == SB_TEXC_WORLD) && buttons_context_path_world(path)) {
                wo= path->ptr[path->len-1].data;

                if(wo && GS(wo->id.name)==ID_WO) {
                        tex= give_current_world_texture(wo);

                        RNA_id_pointer_create(&tex->id, &path->ptr[path->len]);
                        path->len++;
                        return 1;
                }
        }
        /* try particles */
        if((path->tex_ctx == SB_TEXC_PARTICLES) && buttons_context_path_particle(path)) {
                if(path->ptr[path->len-1].type == &RNA_ParticleSettings) {
                        ParticleSettings *part = path->ptr[path->len-1].data;

                        tex= give_current_particle_texture(part);
                        RNA_id_pointer_create(&tex->id, &path->ptr[path->len]);
                        path->len++;
                        return 1;
                }
                else {
                        psys= path->ptr[path->len-1].data;

                        if(psys && psys->part && GS(psys->part->id.name)==ID_PA) {
                                tex= give_current_particle_texture(psys->part);

                                RNA_id_pointer_create(&tex->id, &path->ptr[path->len]);
                                path->len++;
                                return 1;
                        }
                }
        }
        /* try material */
        if(buttons_context_path_material(path, 1)) {
                ma= path->ptr[path->len-1].data;

                if(ma) {
                        tex= give_current_material_texture(ma);

                        RNA_id_pointer_create(&tex->id, &path->ptr[path->len]);
                        path->len++;
                        return 1;
                }
        }
        /* try lamp */
        if(buttons_context_path_data(path, OB_LAMP)) {
                la= path->ptr[path->len-1].data;

                if(la) {
                        tex= give_current_lamp_texture(la);

                        RNA_id_pointer_create(&tex->id, &path->ptr[path->len]);
                        path->len++;
                        return 1;
                }
        }
        /* try brushes again in case of no material, lamp, etc */
        path->len = orig_len;
        if(buttons_context_path_brush(path)) {
                br= path->ptr[path->len-1].data;
                
                if(br) {
                        tex= give_current_brush_texture(br);
                        
                        RNA_id_pointer_create(&tex->id, &path->ptr[path->len]);
                        path->len++;
                        return 1;
                }
        }

        /* no path to a texture possible */
        return 0;
}


static int buttons_context_path(const bContext *C, ButsContextPath *path, int mainb, int flag)
{
        SpaceButs *sbuts= CTX_wm_space_buts(C);
        ID *id;
        int found;

        memset(path, 0, sizeof(*path));
        path->flag= flag;
        path->tex_ctx = sbuts->texture_context;

        /* if some ID datablock is pinned, set the root pointer */
        if(sbuts->pinid) {
                id= sbuts->pinid;

                RNA_id_pointer_create(id, &path->ptr[0]);
                path->len++;
        }

        /* no pinned root, use scene as root */
        if(path->len == 0) {
                id= (ID*)CTX_data_scene(C);
                RNA_id_pointer_create(id, &path->ptr[0]);
                path->len++;
        }

        /* now for each buttons context type, we try to construct a path,
         * tracing back recursively */
        switch(mainb) {
                case BCONTEXT_SCENE:
                case BCONTEXT_RENDER:
                        found= buttons_context_path_scene(path);
                        break;
                case BCONTEXT_WORLD:
                        found= buttons_context_path_world(path);
                        break;
                case BCONTEXT_OBJECT:
                case BCONTEXT_PHYSICS:
                case BCONTEXT_CONSTRAINT:
                        found= buttons_context_path_object(path);
                        break;
                case BCONTEXT_MODIFIER:
                        found= buttons_context_path_modifier(path);
                        break;
                case BCONTEXT_DATA:
                        found= buttons_context_path_data(path, -1);
                        break;
                case BCONTEXT_PARTICLE:
                        found= buttons_context_path_particle(path);
                        break;
                case BCONTEXT_MATERIAL:
                        found= buttons_context_path_material(path, 0);
                        break;
                case BCONTEXT_TEXTURE:
                        found= buttons_context_path_texture(path);
                        break;
                case BCONTEXT_BONE:
                        found= buttons_context_path_bone(path);
                        if(!found)
                                found= buttons_context_path_data(path, OB_ARMATURE);
                        break;
                case BCONTEXT_BONE_CONSTRAINT:
                        found= buttons_context_path_pose_bone(path);
                        break;
                default:
                        found= 0;
                        break;
        }

        return found;
}

static int buttons_shading_context(const bContext *C, int mainb)
{
        Object *ob= CTX_data_active_object(C);

        if(ELEM3(mainb, BCONTEXT_MATERIAL, BCONTEXT_WORLD, BCONTEXT_TEXTURE))
                return 1;
        if(mainb == BCONTEXT_DATA && ob && ELEM(ob->type, OB_LAMP, OB_CAMERA))
                return 1;
        
        return 0;
}

static int buttons_shading_new_context(const bContext *C, int flag)
{
        Object *ob= CTX_data_active_object(C);

        if(flag & (1 << BCONTEXT_MATERIAL))
                return BCONTEXT_MATERIAL;
        else if(ob && ELEM(ob->type, OB_LAMP, OB_CAMERA) && (flag & (1 << BCONTEXT_DATA)))
                return BCONTEXT_DATA;
        else if(flag & (1 << BCONTEXT_WORLD))
                return BCONTEXT_WORLD;
        
        return BCONTEXT_RENDER;
}

void buttons_context_compute(const bContext *C, SpaceButs *sbuts)
{
        ButsContextPath *path;
        PointerRNA *ptr;
        int a, pflag= 0, flag= 0;

        if(!sbuts->path)
                sbuts->path= MEM_callocN(sizeof(ButsContextPath), "ButsContextPath");
        
        path= sbuts->path;
        
        /* for each context, see if we can compute a valid path to it, if
         * this is the case, we know we have to display the button */
        for(a=0; a<BCONTEXT_TOT; a++) {
                if(buttons_context_path(C, path, a, pflag)) {
                        flag |= (1<<a);

                        /* setting icon for data context */
                        if(a == BCONTEXT_DATA) {
                                ptr= &path->ptr[path->len-1];

                                if(ptr->type)
                                        sbuts->dataicon= RNA_struct_ui_icon(ptr->type);
                                else
                                        sbuts->dataicon= ICON_EMPTY_DATA;
                        }
                }
        }

        /* always try to use the tab that was explicitly
         * set to the user, so that once that context comes
         * back, the tab is activated again */
        sbuts->mainb= sbuts->mainbuser;

        /* in case something becomes invalid, change */
        if((flag & (1 << sbuts->mainb)) == 0) {
                if(sbuts->flag & SB_SHADING_CONTEXT) {
                        /* try to keep showing shading related buttons */
                        sbuts->mainb= buttons_shading_new_context(C, flag);
                }
                else if(flag & BCONTEXT_OBJECT) {
                        sbuts->mainb= BCONTEXT_OBJECT;
                }
                else {
                        for(a=0; a<BCONTEXT_TOT; a++) {
                                if(flag & (1 << a)) {
                                        sbuts->mainb= a;
                                        break;
                                }
                        }
                }
        }

        buttons_context_path(C, path, sbuts->mainb, pflag);

        if(!(flag & (1 << sbuts->mainb))) {
                if(flag & (1 << BCONTEXT_OBJECT))
                        sbuts->mainb= BCONTEXT_OBJECT;
                else
                        sbuts->mainb= BCONTEXT_SCENE;
        }

        if(buttons_shading_context(C, sbuts->mainb))
                sbuts->flag |= SB_SHADING_CONTEXT;
        else
                sbuts->flag &= ~SB_SHADING_CONTEXT;

        sbuts->pathflag= flag;
}

/************************* Context Callback ************************/

const char *buttons_context_dir[] = {
        "world", "object", "mesh", "armature", "lattice", "curve",
        "meta_ball", "lamp", "camera", "material", "material_slot",
        "texture", "texture_slot", "bone", "edit_bone", "pose_bone", "particle_system", "particle_system_editable",
        "cloth", "soft_body", "fluid", "smoke", "collision", "brush", NULL};

int buttons_context(const bContext *C, const char *member, bContextDataResult *result)
{
        SpaceButs *sbuts= CTX_wm_space_buts(C);
        ButsContextPath *path= sbuts?sbuts->path:NULL;

        if(!path)
                return 0;

        /* here we handle context, getting data from precomputed path */
        if(CTX_data_dir(member)) {
                CTX_data_dir_set(result, buttons_context_dir);
                return 1;
        }
        else if(CTX_data_equals(member, "world")) {
                set_pointer_type(path, result, &RNA_World);
                return 1;
        }
        else if(CTX_data_equals(member, "object")) {
                set_pointer_type(path, result, &RNA_Object);
                return 1;
        }
        else if(CTX_data_equals(member, "mesh")) {
                set_pointer_type(path, result, &RNA_Mesh);
                return 1;
        }
        else if(CTX_data_equals(member, "armature")) {
                set_pointer_type(path, result, &RNA_Armature);
                return 1;
        }
        else if(CTX_data_equals(member, "lattice")) {
                set_pointer_type(path, result, &RNA_Lattice);
                return 1;
        }
        else if(CTX_data_equals(member, "curve")) {
                set_pointer_type(path, result, &RNA_Curve);
                return 1;
        }
        else if(CTX_data_equals(member, "meta_ball")) {
                set_pointer_type(path, result, &RNA_MetaBall);
                return 1;
        }
        else if(CTX_data_equals(member, "lamp")) {
                set_pointer_type(path, result, &RNA_Lamp);
                return 1;
        }
        else if(CTX_data_equals(member, "camera")) {
                set_pointer_type(path, result, &RNA_Camera);
                return 1;
        }
        else if(CTX_data_equals(member, "material")) {
                set_pointer_type(path, result, &RNA_Material);
                return 1;
        }
        else if(CTX_data_equals(member, "texture")) {
                set_pointer_type(path, result, &RNA_Texture);
                return 1;
        }
        else if(CTX_data_equals(member, "material_slot")) {
                PointerRNA *ptr= get_pointer_type(path, &RNA_Object);

                if(ptr) {
                        Object *ob= ptr->data;

                        if(ob && ob->type && (ob->type<OB_LAMP) && ob->totcol)
                                CTX_data_pointer_set(result, &ob->id, &RNA_MaterialSlot, ob->mat+ob->actcol-1);
                }

                return 1;
        }
        else if(CTX_data_equals(member, "texture_node")) {
                PointerRNA *ptr;

                if((ptr=get_pointer_type(path, &RNA_Material))) {
                        Material *ma= ptr->data;

                        if(ma) {
                                bNode *node= give_current_material_texture_node(ma);
                                CTX_data_pointer_set(result, &ma->id, &RNA_Node, node);
                        }
                }

                return 1;
        }
        else if(CTX_data_equals(member, "texture_slot")) {
                PointerRNA *ptr;

                if((ptr=get_pointer_type(path, &RNA_Material))) {
                        Material *ma= ptr->data;

                        /* if we have a node material, get slot from material in material node */
                        if(ma && ma->use_nodes && ma->nodetree) {
                                /* if there's an active texture node in the node tree,
                                 * then that texture is in context directly, without a texture slot */
                                if (give_current_material_texture_node(ma))
                                        return 0;
                                
                                ma= give_node_material(ma);
                                if (ma)
                                        CTX_data_pointer_set(result, &ma->id, &RNA_MaterialTextureSlot, ma->mtex[(int)ma->texact]);
                                else
                                        return 0;
                        } else if(ma) {
                                CTX_data_pointer_set(result, &ma->id, &RNA_MaterialTextureSlot, ma->mtex[(int)ma->texact]);
                        }
                }
                else if((ptr=get_pointer_type(path, &RNA_Lamp))) {
                        Lamp *la= ptr->data;

                        if(la)
                                CTX_data_pointer_set(result, &la->id, &RNA_LampTextureSlot, la->mtex[(int)la->texact]);
                }
                else if((ptr=get_pointer_type(path, &RNA_World))) {
                        World *wo= ptr->data;

                        if(wo)
                                CTX_data_pointer_set(result, &wo->id, &RNA_WorldTextureSlot, wo->mtex[(int)wo->texact]);
                }
                else if((ptr=get_pointer_type(path, &RNA_Brush))) { /* how to get this into context? */
                        Brush *br= ptr->data;

                        if(br)
                                CTX_data_pointer_set(result, &br->id, &RNA_BrushTextureSlot, &br->mtex);
                }
                else if((ptr=get_pointer_type(path, &RNA_ParticleSystem))) {
                        ParticleSettings *part= ((ParticleSystem *)ptr->data)->part;

                        if(part)
                                CTX_data_pointer_set(result, &part->id, &RNA_ParticleSettingsTextureSlot, part->mtex[(int)part->texact]);
                }

                return 1;
        }
        else if(CTX_data_equals(member, "bone")) {
                set_pointer_type(path, result, &RNA_Bone);
                return 1;
        }
        else if(CTX_data_equals(member, "edit_bone")) {
                set_pointer_type(path, result, &RNA_EditBone);
                return 1;
        }
        else if(CTX_data_equals(member, "pose_bone")) {
                set_pointer_type(path, result, &RNA_PoseBone);
                return 1;
        }
        else if(CTX_data_equals(member, "particle_system")) {
                set_pointer_type(path, result, &RNA_ParticleSystem);
                return 1;
        }
        else if(CTX_data_equals(member, "particle_system_editable")) {
                if(PE_poll((bContext*)C))
                        set_pointer_type(path, result, &RNA_ParticleSystem);
                else
                        CTX_data_pointer_set(result, NULL, &RNA_ParticleSystem, NULL);
                return 1;
        }       
        else if(CTX_data_equals(member, "cloth")) {
                PointerRNA *ptr= get_pointer_type(path, &RNA_Object);

                if(ptr && ptr->data) {
                        Object *ob= ptr->data;
                        ModifierData *md= modifiers_findByType(ob, eModifierType_Cloth);
                        CTX_data_pointer_set(result, &ob->id, &RNA_ClothModifier, md);
                        return 1;
                }
        }
        else if(CTX_data_equals(member, "soft_body")) {
                PointerRNA *ptr= get_pointer_type(path, &RNA_Object);

                if(ptr && ptr->data) {
                        Object *ob= ptr->data;
                        ModifierData *md= modifiers_findByType(ob, eModifierType_Softbody);
                        CTX_data_pointer_set(result, &ob->id, &RNA_SoftBodyModifier, md);
                        return 1;
                }
        }
        else if(CTX_data_equals(member, "fluid")) {
                PointerRNA *ptr= get_pointer_type(path, &RNA_Object);

                if(ptr && ptr->data) {
                        Object *ob= ptr->data;
                        ModifierData *md= modifiers_findByType(ob, eModifierType_Fluidsim);
                        CTX_data_pointer_set(result, &ob->id, &RNA_FluidSimulationModifier, md);
                        return 1;
                }
        }
        
        else if(CTX_data_equals(member, "smoke")) {
                PointerRNA *ptr= get_pointer_type(path, &RNA_Object);

                if(ptr && ptr->data) {
                        Object *ob= ptr->data;
                        ModifierData *md= modifiers_findByType(ob, eModifierType_Smoke);
                        CTX_data_pointer_set(result, &ob->id, &RNA_SmokeModifier, md);
                        return 1;
                }
        }
        else if(CTX_data_equals(member, "collision")) {
                PointerRNA *ptr= get_pointer_type(path, &RNA_Object);

                if(ptr && ptr->data) {
                        Object *ob= ptr->data;
                        ModifierData *md= modifiers_findByType(ob, eModifierType_Collision);
                        CTX_data_pointer_set(result, &ob->id, &RNA_CollisionModifier, md);
                        return 1;
                }
        }
        else if(CTX_data_equals(member, "brush")) {
                set_pointer_type(path, result, &RNA_Brush);
                return 1;
        }
        else {
                return 0; /* not found */
        }

        return -1; /* found but not available */
}

/************************* Drawing the Path ************************/

static void pin_cb(bContext *C, void *UNUSED(arg1), void *UNUSED(arg2))
{
        SpaceButs *sbuts= CTX_wm_space_buts(C);

        if(sbuts->flag & SB_PIN_CONTEXT) {
                sbuts->pinid= buttons_context_id_path(C);
        }
        else
                sbuts->pinid= NULL;
        
        ED_area_tag_redraw(CTX_wm_area(C));
}

void buttons_context_draw(const bContext *C, uiLayout *layout)
{
        SpaceButs *sbuts= CTX_wm_space_buts(C);
        ButsContextPath *path= sbuts->path;
        uiLayout *row;
        uiBlock *block;
        uiBut *but;
        PointerRNA *ptr;
        char namebuf[128], *name;
        int a, icon;

        if(!path)
                return;

        row= uiLayoutRow(layout, 1);
        uiLayoutSetAlignment(row, UI_LAYOUT_ALIGN_LEFT);

        block= uiLayoutGetBlock(row);
        uiBlockSetEmboss(block, UI_EMBOSSN);
        but= uiDefIconButBitC(block, ICONTOG, SB_PIN_CONTEXT, 0, ICON_UNPINNED, 0, 0, UI_UNIT_X, UI_UNIT_Y, &sbuts->flag, 0, 0, 0, 0, "Follow context or keep fixed datablock displayed");
        uiButSetFunc(but, pin_cb, NULL, NULL);

        for(a=0; a<path->len; a++) {
                ptr= &path->ptr[a];

                if(a != 0)
                        uiItemL(row, "", VICO_SMALL_TRI_RIGHT_VEC);

                if(ptr->data) {
                        icon= RNA_struct_ui_icon(ptr->type);
                        name= RNA_struct_name_get_alloc(ptr, namebuf, sizeof(namebuf));

                        if(name) {
                                if(!ELEM(sbuts->mainb, BCONTEXT_RENDER, BCONTEXT_SCENE) && ptr->type == &RNA_Scene)
                                        uiItemLDrag(row, ptr, "", icon); /* save some space */
                                else
                                        uiItemLDrag(row, ptr, name, icon);
                                                                 
                                if(name != namebuf)
                                        MEM_freeN(name);
                        }
                        else
                                uiItemL(row, "", icon);
                }
        }
}

static void buttons_panel_context(const bContext *C, Panel *pa)
{
        buttons_context_draw(C, pa->layout);
}

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

        pt= MEM_callocN(sizeof(PanelType), "spacetype buttons panel context");
        strcpy(pt->idname, "BUTTONS_PT_context");
        strcpy(pt->label, "Context");
        pt->draw= buttons_panel_context;
        pt->flag= PNL_NO_HEADER;
        BLI_addtail(&art->paneltypes, pt);
}

ID *buttons_context_id_path(const bContext *C)
{
        SpaceButs *sbuts= CTX_wm_space_buts(C);
        ButsContextPath *path= sbuts->path;
        PointerRNA *ptr;
        int a;

        if(path->len) {
                for(a=path->len-1; a>=0; a--) {
                        ptr= &path->ptr[a];

                        /* pin particle settings instead of system, since only settings are an idblock*/
                        if(sbuts->mainb == BCONTEXT_PARTICLE && sbuts->flag & SB_PIN_CONTEXT) {
                                if(ptr->type == &RNA_ParticleSystem && ptr->data) {
                                        ParticleSystem *psys = (ParticleSystem *)ptr->data;
                                        return &psys->part->id;
                                }
                        }

                        if(ptr->id.data) {
                                return ptr->id.data;
                                break;
                        }
                }
        }

        return NULL;
}