Layer actions and navigations features

1.9.0

- feat: New shortcuts:
  - `F2` in Paint and Edit to rename active layer
  - `Insert` add a new layer (same as Krita)
  - `Shift + Insert` add a new layer and immediately pop-up a rename box
  - `page up / page down` change active layer up/down with a temporary fade (settings in addon prefs)
- fix: error when tweaking `gp.duplicate_send_to_layer` shortcut

CHANGELOG.md

@@ -1,5 +1,15 @@
 # Changelog
 
+
+1.9.0
+
+- feat: New shortcuts:
+  - `F2` in Paint and Edit to rename active layer
+  - `Insert` add a new layer (same as Krita)
+  - `Shift + Insert` add a new layer and immediately pop-up a rename box
+  - `page up / page down` change active layer up/down with a temporary fade (settings in addon prefs)
+- fix: error when tweaking `gp.duplicate_send_to_layer` shortcut
+
 1.8.1
 
 - fix: Gp clipboard paste `Paste layers` don't skip empty frames anymore
@@ -13,7 +23,6 @@
 1.7.8
 
 - fix: reset rotation in draw cam mode keep view in the same place (counter camera rotation)
-- code: initial enhancement for palette linking
 
 1.7.7
 

OP_breakdowner.py

@@ -302,7 +302,7 @@ class OBJ_OT_breakdown_obj_anim(bpy.types.Operator):
 
 ### --- KEYMAP ---
 
-breakdowner_addon_keymaps = []
+addon_keymaps = []
 def register_keymaps():
     if bpy.app.background:
         return
@@ -322,16 +322,15 @@ def register_keymaps():
     if ops_id not in km.keymap_items:
         km = addon.keymaps.new(name='3D View', space_type='VIEW_3D')#EMPTY
         kmi = km.keymap_items.new(ops_id, type="E", value="PRESS", shift=True)
-        breakdowner_addon_keymaps.append((km, kmi))
+        addon_keymaps.append((km, kmi))
 
 def unregister_keymaps():
     if bpy.app.background:
         return
-    for km, kmi in breakdowner_addon_keymaps:
+    for km, kmi in addon_keymaps:
         km.keymap_items.remove(kmi)
 
-    breakdowner_addon_keymaps.clear()
+    addon_keymaps.clear()
-    # del breakdowner_addon_keymaps[:]
 
 ### --- REGISTER ---
 

OP_key_duplicate_send.py

@@ -4,8 +4,10 @@ from bpy.types import Operator
 
 def get_layer_list(self, context):
     '''return (identifier, name, description) of enum content'''
+    if not context:
+        return [('None', 'None','None')]
     if not context.object:
-        return
+        return [('None', 'None','None')]
     return [(l.info, l.info, '') for l in context.object.data.layers if l != context.object.data.layers.active]
     # try:
     # except:
@@ -23,7 +25,8 @@ class GPTB_OT_duplicate_send_to_layer(Operator) :
     layers_enum : bpy.props.EnumProperty(
         name="Duplicate to layers",
         description="Duplicate selected keys in active layer and send them to choosen layer",
-        items=get_layer_list
+        items=get_layer_list,
+        options={'HIDDEN'},
         )
 
     delete_source : bpy.props.BoolProperty(default=False, options={'SKIP_SAVE'})
@@ -110,12 +113,10 @@ def register_keymaps():
     # if not pref.kfj_use_shortcut:
     #     return
     addon = bpy.context.window_manager.keyconfigs.addon
-    # km = addon.keymaps.new(name = "Screen", space_type = "EMPTY")
     km = addon.keymaps.new(name = "Dopesheet", space_type = "DOPESHEET_EDITOR")
     kmi = km.keymap_items.new('gp.duplicate_send_to_layer', type='D', value="PRESS", ctrl=True, shift=True)
     addon_keymaps.append((km,kmi))
     
-    
     # km = addon.keymaps.new(name = "Dopesheet", space_type = "DOPESHEET_EDITOR") # try duplicating km (seem to be error at unregsiter)
     kmi = km.keymap_items.new('gp.duplicate_send_to_layer', type='X', value="PRESS", ctrl=True, shift=True)
     kmi.properties.delete_source = True

OP_layer_manager.py

@@ -633,6 +633,107 @@ def subscribe_handler(dummy):
     )
 
 
+##--- Add layers
+
+class GPTB_PT_layer_name_ui(bpy.types.Panel):
+    bl_space_type = 'TOPBAR'  # dummy
+    bl_region_type = 'HEADER'
+    bl_options = {'INSTANCED'}
+    bl_label = 'Layer Rename'
+    bl_ui_units_x = 14
+
+    def invoke(self, context, event):
+        # all_addons_l = get_modifier_list()
+        wm = context.window_manager
+        wm.invoke_props_dialog(self) # , width=600
+        return {'FINISHED'}
+    
+    def draw(self, context):
+        layout = self.layout
+
+        # def row_with_icon(layout, icon):
+        #     # Edit first editable button in popup
+        #     row = layout.row()
+        #     row.activate_init = True
+        #     row.label(icon=icon)
+        #     return row
+        # row = row_with_icon(layout, 'OUTLINER_DATA_GP_LAYER')
+        
+        row = layout.row()
+        row.activate_init = True
+        row.label(icon='OUTLINER_DATA_GP_LAYER')
+        row.prop(context.object.data.layers.active, 'info', text='')
+
+def add_layer(context):
+    bpy.ops.gpencil.layer_add()
+    context.object.data.layers.active.use_lights = False
+
+class GPTB_OT_add_gp_layer_with_rename(Operator):
+    bl_idname = "gp.add_layer_rename"
+    bl_label = "Add Rename GPencil Layer"
+    bl_description = "Create a new gp layer with use light toggled off and popup a rename box"
+    bl_options = {"REGISTER", "UNDO"}
+    @classmethod
+    def poll(cls, context):
+        return context.object and context.object.type == 'GPENCIL'
+
+    def execute(self, context):
+        add_layer(context)
+        bpy.ops.wm.call_panel(name="GPTB_PT_layer_name_ui", keep_open = False)
+        return {"FINISHED"}
+
+class GPTB_OT_add_gp_layer(Operator):
+    bl_idname = "gp.add_layer"
+    bl_label = "Add GPencil Layer"
+    bl_description = "Create a new gp layer with use light toggled off"
+    bl_options = {"REGISTER", "UNDO"}
+    @classmethod
+    def poll(cls, context):
+        return context.object and context.object.type == 'GPENCIL'
+
+    def execute(self, context):
+        add_layer(context)
+        return {"FINISHED"}
+
+
+addon_keymaps = []
+def register_keymaps():
+    addon = bpy.context.window_manager.keyconfigs.addon
+
+    ##---# Insert Layers
+    ## Insert new gp layer (with no use_light)
+    km = addon.keymaps.new(name = "Grease Pencil", space_type = "EMPTY") # global (only paint ?)
+    kmi = km.keymap_items.new('gp.add_layer', type='INSERT', value='PRESS')
+    addon_keymaps.append((km, kmi))
+
+    ## Insert new gp layer (with no use_light and immediately pop up a box to rename)
+    # km = addon.keymaps.new(name = "Grease Pencil", space_type = "EMPTY") # global (only paint ?)
+    kmi = km.keymap_items.new('gp.add_layer_rename', type='INSERT', value='PRESS', shift=True)
+    addon_keymaps.append((km, kmi))
+
+    ##---# F2 rename calls 
+    ## Direct rename active layer in Paint mode
+    km = addon.keymaps.new(name = "Grease Pencil Stroke Paint Mode", space_type = "EMPTY")
+    kmi = km.keymap_items.new('wm.call_panel', type='F2', value='PRESS')
+    kmi.properties.name = 'GPTB_PT_layer_name_ui'
+    kmi.properties.keep_open = False
+    addon_keymaps.append((km, kmi))
+
+    ## Same in edit mode
+    km = addon.keymaps.new(name = "Grease Pencil Stroke Edit Mode", space_type = "EMPTY")
+    kmi = km.keymap_items.new('wm.call_panel', type='F2', value='PRESS')
+    kmi.properties.name = 'GPTB_PT_layer_name_ui'
+    kmi.properties.keep_open = False
+    addon_keymaps.append((km, kmi))
+
+
+def unregister_keymaps():
+    for km, kmi in addon_keymaps:
+        km.keymap_items.remove(kmi)
+    addon_keymaps.clear()
+
+
+
 classes=(
     GPTB_OT_rename_gp_layer,
     GPTB_OT_layer_name_build,
@@ -640,9 +741,14 @@ classes=(
     GPTB_OT_layer_new_group,
     GPTB_OT_select_set_same_prefix,
     GPTB_OT_select_set_same_color,
+
+    ## Layer add and pop-up rename
+    GPTB_PT_layer_name_ui, # pop-up
+    GPTB_OT_add_gp_layer_with_rename, # shift+Ins
+    GPTB_OT_add_gp_layer, # Ins
 )
 
-def register(): 
+def register():
     for cls in classes:
         bpy.utils.register_class(cls)
     
@@ -650,8 +756,10 @@ def register():
     bpy.types.DOPESHEET_HT_header.append(gpencil_dopesheet_header)
     bpy.types.GPENCIL_MT_layer_context_menu.append(gpencil_layer_dropdown_menu)
     bpy.app.handlers.load_post.append(subscribe_handler) # need to restart after first activation
+    register_keymaps()
 
 def unregister():
+    unregister_keymaps()
     bpy.app.handlers.load_post.remove(subscribe_handler)
     bpy.types.GPENCIL_MT_layer_context_menu.remove(gpencil_layer_dropdown_menu)
     bpy.types.DOPESHEET_HT_header.remove(gpencil_dopesheet_header)

OP_layer_nav.py

@@ -0,0 +1,142 @@
+import bpy
+from . import utils
+
+class GPT_OT_layer_nav(bpy.types.Operator):
+    bl_idname = "gp.layer_nav"
+    bl_label = "GP Layer Navigator"
+    bl_description = "Change active GP layer and highlight active for a moment"
+    bl_options = {'REGISTER', 'INTERNAL', 'UNDO'}
+
+    direction : bpy.props.EnumProperty(
+        name='direction',
+        items=(('NONE', 'None', ''),('UP', 'Up', ''),('DOWN', 'Down', '')),
+        default='NONE',
+        description='Direction to change layer in active GPencil stack',
+        options={'SKIP_SAVE'})
+
+    ## hardcoded values
+    # interval = 0.04 # 0.1
+    # limit = 1.8
+    # fade_val = 0.35
+    # use_fade_in = True
+    # fade_in_time = 0.5
+
+    def invoke(self, context, event):
+        ## initialise vvalue from prefs
+        prefs = utils.get_addon_prefs()
+
+        if not prefs.nav_use_fade:
+            if self.direction == 'DOWN' or (event.type == 'PAGE_DOWN' and event.value == 'PRESS'):
+                utils.iterate_selector(context.object.data.layers, 'active_index', -1, info_attr = 'info')
+
+            if self.direction == 'UP' or (event.type == 'PAGE_UP' and event.value == 'PRESS'):
+                utils.iterate_selector(context.object.data.layers, 'active_index', 1, info_attr = 'info')
+            return {'FINISHED'}
+
+        self.interval = prefs.nav_interval
+        self.limit = prefs.nav_limit
+        self.fade_val = prefs.nav_fade_val
+        self.use_fade_in = prefs.nav_use_fade_in
+        self.fade_in_time = prefs.nav_fade_in_time
+
+        self.lapse = 0
+        wm = context.window_manager
+        args = (self, context)
+
+        if context.space_data.overlay.use_gpencil_fade_layers:
+            self.fade_target = context.space_data.overlay.gpencil_fade_layer
+        else:
+            self.fade_target = 1.0
+
+        self.fade_start = self.limit - self.fade_in_time
+
+        self.first = True
+        self._timer = wm.event_timer_add(self.interval, window=context.window) # 0.1
+        wm.modal_handler_add(self)
+        return {'RUNNING_MODAL'}
+
+    def store_settings(self, context):
+        self.org_use_gpencil_fade_layers = context.space_data.overlay.use_gpencil_fade_layers
+        self.org_gpencil_fade_layer = context.space_data.overlay.gpencil_fade_layer
+        context.space_data.overlay.use_gpencil_fade_layers = True
+        context.space_data.overlay.gpencil_fade_layer = self.fade_val
+
+    def modal(self, context, event):
+        trigger = False
+        if event.type in {'RIGHTMOUSE', 'ESC', 'LEFTMOUSE'}:
+            self.stop_mod(context)
+            return {'CANCELLED'}
+
+        if event.type == 'TIMER':
+            self.lapse += self.interval
+    
+            if self.lapse >= self.limit:
+                self.stop_mod(context)
+                return {'FINISHED'}
+            
+            ## Fade
+            if self.use_fade_in and (self.lapse > self.fade_start):
+                fade = utils.transfer_value(self.lapse, self.fade_start, self.limit, self.fade_val, self.fade_target)
+                # print(f'lapse {self.lapse} - fade {fade}')
+                context.space_data.overlay.gpencil_fade_layer = fade
+                        
+        if self.direction == 'DOWN' or (event.type == 'PAGE_DOWN' and event.value == 'PRESS'):
+            _val = utils.iterate_selector(context.object.data.layers, 'active_index', -1, info_attr = 'info')
+            trigger = True
+
+        if self.direction == 'UP' or (event.type == 'PAGE_UP' and event.value == 'PRESS'):
+            _val = utils.iterate_selector(context.object.data.layers, 'active_index', 1, info_attr = 'info')
+            # utils.iterate_selector(bpy.context.scene.grease_pencil.layers, 'active_index', 1, info_attr = 'info')#layers
+            trigger = True
+
+        if trigger:
+            self.direction = 'NONE'
+            if self.first:
+                self.store_settings(context)
+                self.first=False
+
+            if self.use_fade_in:
+                # reset fade to wanted value
+                context.space_data.overlay.gpencil_fade_layer = self.fade_val
+
+            self.lapse = 0 # reset counter
+            return {'RUNNING_MODAL'}#running modal prevent original usage to be triggered (capture keys)
+
+        return {'PASS_THROUGH'}
+
+    def stop_mod(self, context):
+        # restore fade
+        context.space_data.overlay.use_gpencil_fade_layers = self.org_use_gpencil_fade_layers
+        context.space_data.overlay.gpencil_fade_layer = self.org_gpencil_fade_layer
+        wm = context.window_manager
+        wm.event_timer_remove(self._timer)
+
+
+addon_keymaps = []
+
+def register_keymap():
+    addon = bpy.context.window_manager.keyconfigs.addon
+
+    km = addon.keymaps.new(name = "Grease Pencil Stroke Paint Mode", space_type = "EMPTY")
+    
+    kmi = km.keymap_items.new('gp.layer_nav', type='PAGE_UP', value='PRESS')
+    kmi.properties.direction = 'UP'
+    addon_keymaps.append((km, kmi))
+
+    kmi = km.keymap_items.new('gp.layer_nav', type='PAGE_DOWN', value='PRESS')
+    kmi.properties.direction = 'DOWN'
+    addon_keymaps.append((km, kmi))
+
+def unregister_keymap():
+    for km, kmi in addon_keymaps:
+        km.keymap_items.remove(kmi)
+
+    addon_keymaps.clear()
+
+def register():
+    bpy.utils.register_class(GPT_OT_layer_nav)
+    register_keymap()
+
+def unregister():
+    unregister_keymap()
+    bpy.utils.unregister_class(GPT_OT_layer_nav)

__init__.py

@@ -15,7 +15,7 @@ bl_info = {
 "name": "GP toolbox",
 "description": "Tool set for Grease Pencil in animation production",
 "author": "Samuel Bernou, Christophe Seux",
-"version": (1, 8, 1),
+"version": (1, 9, 0),
 "blender": (2, 91, 0),
 "location": "Sidebar (N menu) > Gpencil > Toolbox / Gpencil properties",
 "warning": "",
@@ -51,6 +51,7 @@ from . import OP_depth_move
 from . import OP_key_duplicate_send
 from . import OP_layer_manager
 from . import OP_layer_picker
+from . import OP_layer_nav
 from . import OP_material_picker
 from . import OP_eraser_brush
 from . import TOOL_eraser_brush
@@ -310,6 +311,38 @@ class GPTB_prefs(bpy.types.AddonPreferences):
 
     fixprops: bpy.props.PointerProperty(type = GP_PG_FixSettings)
 
+    ## GP Layer navigator
+
+    nav_use_fade : BoolProperty(
+        name='Fade Inactive Layers',
+        description='Fade Inactive layers to determine active layer in a glimpse',
+        default=True)    
+
+    nav_fade_val : FloatProperty(
+        name='Fade Value',
+        description='Fade value for other layers when navigating (0=invisible)',
+        default=0.35, min=0.0, max=0.95, step=1, precision=2)
+    
+    nav_limit : FloatProperty(
+        name='Fade Duration',
+        description='Time of other layer faded when using layer navigation',
+        default=1.4, min=0.1, max=5, step=2, precision=1, subtype='TIME', unit='TIME')
+    
+    nav_use_fade_in : BoolProperty(
+        name='Progressive Fade Back',
+        description='Use a fade on other layer when navigating',
+        default=True)
+
+    nav_fade_in_time : FloatProperty(
+        name='Fade-In Time',
+        description='Duration of the fade',
+        default=0.5, min=0.1, max=5, step=2, precision=2, subtype='TIME', unit='TIME')
+
+    nav_interval : FloatProperty(
+        name='Refresh Rate',
+        description='Refresh rate for fade updating (upper value means stepped fade)',
+        default=0.04, min=0.01, max=0.5, step=3, precision=2, subtype='TIME', unit='TIME')
+
     ## Temp cutter
     # temp_cutter_use_shortcut: BoolProperty(
     #     name = "Use temp cutter Shortcut",
@@ -415,6 +448,21 @@ class GPTB_prefs(bpy.types.AddonPreferences):
 
             box = layout.box()
             box.label(text='Tools options:')
+            
+            subbox= box.box()
+            subbox.label(text='Layer Navigation')
+            col = subbox.column()
+            col.prop(self, 'nav_use_fade')
+            if self.nav_use_fade:
+                row = col.row()
+                row.prop(self, 'nav_fade_val')
+                row.prop(self, 'nav_limit')
+                row = subbox.row(align=False)
+                row.prop(self, 'nav_use_fade_in')
+                if self.nav_use_fade_in:
+                    row.prop(self, 'nav_fade_in_time', text='Fade Back Time')
+                    # row.prop(self, 'nav_interval') # Do not expose refresh rate for now, not usefull to user...
+
             box.prop(self, 'use_precise_eraser')
             
         if self.pref_tabs == 'KEYS':
@@ -427,14 +475,15 @@ class GPTB_prefs(bpy.types.AddonPreferences):
             ## TOOL_eraser_brush.addon_keymaps # has a checkbox in
 
             prev_key_category = ''
-            kmi_see_list = []
             for kms in [
                         OP_keyframe_jump.addon_keymaps,
                         OP_copy_paste.addon_keymaps,
-                        OP_breakdowner.breakdowner_addon_keymaps,
+                        OP_breakdowner.addon_keymaps,
                         OP_key_duplicate_send.addon_keymaps,
                         OP_layer_picker.addon_keymaps,
                         OP_material_picker.addon_keymaps,
+                        OP_layer_nav.addon_keymaps,
+                        # OP_layer_manager.addon_keymaps, # Do not display, wm.call_panel call panel ops mixed with natives shortcut (F2)
                         ]:
 
                 ct = 0
@@ -644,6 +693,7 @@ def register():
     OP_eraser_brush.register()
     OP_material_picker.register()
     OP_layer_picker.register()
+    OP_layer_nav.register()
     TOOL_eraser_brush.register()
     handler_draw_cam.register()
     UI_tools.register()
@@ -670,6 +720,7 @@ def unregister():
     UI_tools.unregister()
     handler_draw_cam.unregister()
     TOOL_eraser_brush.unregister()
+    OP_layer_nav.unregister()
     OP_layer_picker.unregister()
     OP_material_picker.unregister()
     OP_eraser_brush.unregister()

keymaps.py

@@ -8,6 +8,8 @@ def register_keymaps():
     # km = addon.keymaps.new(name = "3D View", space_type = "VIEW_3D")# in 3D context
     # km = addon.keymaps.new(name = "Window", space_type = "EMPTY")# from everywhere
     
+
+    ## Sculpt mode toggles
     km = addon.keymaps.new(name = "Grease Pencil Stroke Sculpt Mode", space_type = "EMPTY", region_type='WINDOW')
 
     kmi = km.keymap_items.new('wm.context_toggle', type='ONE', value='PRESS')
@@ -22,6 +24,12 @@ def register_keymaps():
     kmi.properties.data_path='scene.tool_settings.use_gpencil_select_mask_segment'
     addon_keymaps.append((km, kmi))
 
+    ## T temp cutter (need disabling of native T shortcut, maybe expose a button to set the shortcut as user ?)
+    # km = addon.keymaps.new(name = "Grease Pencil", space_type = "EMPTY")
+    # kmi = km.keymap_items.new('gpencil.stroke_cutter', type='LEFTMOUSE', value='PRESS', key_modifier='T')
+    # kmi.properties.flat_caps=False
+    # addon_keymaps.append((km, kmi))
+
 def unregister_keymaps():
     for km, kmi in addon_keymaps:
         km.keymap_items.remove(kmi)

utils.py

@@ -30,19 +30,14 @@ def set_matrix(gp_frame,mat):
 
 # get view vector location (the 2 methods work fine)
 def get_view_origin_position():
-    #method 1
+    ## method 1
     # from bpy_extras import view3d_utils
     # region = bpy.context.region
     # rv3d = bpy.context.region_data
     # view_loc = view3d_utils.region_2d_to_origin_3d(region, rv3d, (region.width/2.0, region.height/2.0))
-    # print("view_loc1", view_loc)#Dbg
+    ## method 2
-
-    #method 2
     r3d = bpy.context.space_data.region_3d
     view_loc2 = r3d.view_matrix.inverted().translation
-    # print("view_loc2", view_loc2)#Dbg
-    # if view_loc != view_loc2: print('Might be an error when finding view coordinate')
-
     return view_loc2
 
 def location_to_region(worldcoords):
@@ -76,6 +71,10 @@ def object_derived_get(ob, scene):
     return ob_matrix_pairs
 
 
+# -----------------
+### Bmesh
+# -----------------
+
 def link_vert(v,ordered_vert) :
     for e in v.link_edges :
         other_vert = e.other_vert(v)
@@ -147,7 +146,11 @@ def gp_stroke_to_bmesh(strokes):
     return strokes_info
 
 
-def simple_draw_gp_stroke(pts,frame,width = 2, mat_id = 0):
+# -----------------
+### GP Drawing
+# -----------------
+
+def simple_draw_gp_stroke(pts, frame, width = 2, mat_id = 0):
     '''
     draw basic stroke by passing list of point 3D coordinate
     the frame to draw on and optional width parameter (default = 2)
@@ -169,11 +172,11 @@ def simple_draw_gp_stroke(pts,frame,width = 2, mat_id = 0):
     return stroke
 
 ## OLD - need update
-def draw_gp_stroke(loop_info,frame,palette,width = 2) :
+def draw_gp_stroke(loop_info, frame, palette, width = 2) :
     stroke = frame.strokes.new(palette)
 
     stroke.line_width = width
-    stroke.display_mode = '3DSPACE'# old->draw_mode
+    stroke.display_mode = '3DSPACE'# old -> draw_mode
 
     for i,info in enumerate(loop_info) :
         stroke.points.add()
@@ -894,13 +897,6 @@ def draw_kmi(km, kmi, layout):
 ### linking utility
 # -----------------
 
-"""
-def link_objects_in_blend(filepath, obj_name, link=True):
-    '''Link an object by name from a file, if link is False, append instead of linking'''
-    with bpy.data.libraries.load(filepath, link=link) as (data_from, data_to):
-        data_to.objects = [o for o in data_from.objects if o == obj_name] # c.startswith(obj_name)
-    return data_to.objects
- """
 def link_objects_in_blend(filepath, obj_name_list, link=True):
     '''Link an object by name from a file, if link is False, append instead of linking'''
     if isinstance(obj_name_list, str):
@@ -922,4 +918,37 @@ def check_objects_in_blend(filepath, avoid_camera=True):
             l = [o for o in data_from.objects if not any(x in o.lower() for x in ('camera', 'draw_cam', 'obj_cam'))]
         else:
             l = [o for o in data_from.objects]
-    return l
+    return l
+
+
+# -----------------
+### props handling
+# -----------------
+
+def iterate_selector(zone, attr, state, info_attr = None, active_access='active'):
+    '''Iterate with given attribute'''
+    item_number = len(zone)
+    if item_number <= 1:
+        return
+
+    if getattr(zone, attr) == None:
+        print('no', attr, 'in', zone)
+        return
+
+    if state: # swap
+        info = None
+        bottom = None
+        new_index = getattr(zone, attr) + state
+        setattr(zone, attr, new_index % item_number)
+
+        if new_index == item_number:
+            bottom = 1 # bottom reached, cycle to first
+        elif new_index < 0:
+            bottom = -1 # up reached, cycle to last
+
+        if info_attr:
+            active_item = getattr(zone, active_access) # active by default
+            if active_item:
+                info = getattr(active_item, info_attr)
+
+        return info, bottom