# ##### 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.
#
# ##### END GPL LICENSE BLOCK #####

# <pep8 compliant>


from bpy.types import Menu, UIList
from bpy.app.translations import pgettext_iface as iface_


def gpencil_stroke_placement_settings(context, layout):
    if context.space_data.type == 'VIEW_3D':
        propname = "gpencil_stroke_placement_view3d"
    elif context.space_data.type == 'SEQUENCE_EDITOR':
        propname = "gpencil_stroke_placement_sequencer_preview"
    elif context.space_data.type == 'IMAGE_EDITOR':
        propname = "gpencil_stroke_placement_image_editor"
    else:
        propname = "gpencil_stroke_placement_view2d"

    ts = context.tool_settings

    col = layout.column(align=True)

    col.label(text="Stroke Placement:")

    row = col.row(align=True)
    row.prop_enum(ts, propname, 'VIEW')
    row.prop_enum(ts, propname, 'CURSOR')

    if context.space_data.type == 'VIEW_3D':
        row = col.row(align=True)
        row.prop_enum(ts, propname, 'SURFACE')
        row.prop_enum(ts, propname, 'STROKE')

        row = col.row(align=False)
        row.active = getattr(ts, propname) in {'SURFACE', 'STROKE'}
        row.prop(ts, "use_gpencil_stroke_endpoints")


def gpencil_active_brush_settings_simple(context, layout):
    brush = context.active_gpencil_brush

    col = layout.column()
    col.label("Active Brush:      ")

    row = col.row(align=True)
    row.operator_context = 'EXEC_REGION_WIN'
    row.operator_menu_enum("gpencil.brush_change", "brush", text="", icon='BRUSH_DATA')
    row.prop(brush, "name", text="")

    col.prop(brush, "line_width", slider=True)
    row = col.row(align=True)
    row.prop(brush, "use_random_pressure", text='', icon='RNDCURVE')
    row.prop(brush, "pen_sensitivity_factor", slider=True)
    row.prop(brush, "use_pressure", text='', icon='STYLUS_PRESSURE')
    row = col.row(align=True)
    row.prop(brush, "use_random_strength", text='', icon='RNDCURVE')
    row.prop(brush, "strength", slider=True)
    row.prop(brush, "use_strength_pressure", text='', icon='STYLUS_PRESSURE')
    row = col.row(align=True)
    row.prop(brush, "jitter", slider=True)
    row.prop(brush, "use_jitter_pressure", text='', icon='STYLUS_PRESSURE')
    row = col.row()
    row.prop(brush, "angle", slider=True)
    row.prop(brush, "angle_factor", text="Factor", slider=True)


class GreasePencilDrawingToolsPanel:
    # subclass must set
    # bl_space_type = 'IMAGE_EDITOR'
    bl_label = "Grease Pencil"
    bl_category = "Grease Pencil"
    bl_region_type = 'TOOLS'

    @staticmethod
    def draw(self, context):
        layout = self.layout

        is_3d_view = context.space_data.type == 'VIEW_3D'
        is_clip_editor = context.space_data.type == 'CLIP_EDITOR'

        col = layout.column(align=True)

        col.label(text="Draw:")
        row = col.row(align=True)
        row.operator("gpencil.draw", icon='GREASEPENCIL', text="Draw").mode = 'DRAW'
        row.operator("gpencil.draw", icon='FORCE_CURVE', text="Erase").mode = 'ERASER'  # XXX: Needs a dedicated icon

        row = col.row(align=True)
        row.operator("gpencil.draw", icon='LINE_DATA', text="Line").mode = 'DRAW_STRAIGHT'
        row.operator("gpencil.draw", icon='MESH_DATA', text="Poly").mode = 'DRAW_POLY'

        sub = col.column(align=True)
        sub.prop(context.tool_settings, "use_gpencil_additive_drawing", text="Additive Drawing")
        sub.prop(context.tool_settings, "use_gpencil_continuous_drawing", text="Continuous Drawing")
        sub.prop(context.tool_settings, "use_gpencil_draw_onback", text="Draw on Back")

        col.separator()
        col.separator()

        if context.space_data.type in {'VIEW_3D', 'CLIP_EDITOR'}:
            col.separator()
            col.label("Data Source:")
            row = col.row(align=True)
            if is_3d_view:
                row.prop(context.tool_settings, "grease_pencil_source", expand=True)
            elif is_clip_editor:
                row.prop(context.space_data, "grease_pencil_source", expand=True)

        col.separator()
        col.separator()

        gpencil_stroke_placement_settings(context, col)

        gpd = context.gpencil_data

        if gpd and not is_3d_view:
            layout.separator()
            layout.separator()

            col = layout.column(align=True)
            col.prop(gpd, "use_stroke_edit_mode", text="Enable Editing", icon='EDIT', toggle=True)

        if is_3d_view:
            col.separator()
            col.separator()

            col.label(text="Tools:")
            col.operator_menu_enum("gpencil.convert", text="Convert to Geometry...", property="type")
            col.operator("view3d.ruler")


class GreasePencilStrokeEditPanel:
    # subclass must set
    # bl_space_type = 'IMAGE_EDITOR'
    bl_label = "Edit Strokes"
    bl_category = "Grease Pencil"
    bl_region_type = 'TOOLS'
    bl_options = {'DEFAULT_CLOSED'}

    @classmethod
    def poll(cls, context):
        if context.gpencil_data is None:
            return False

        gpd = context.gpencil_data
        return bool(context.editable_gpencil_strokes) and bool(gpd.use_stroke_edit_mode)

    @staticmethod
    def draw(self, context):
        layout = self.layout

        is_3d_view = context.space_data.type == 'VIEW_3D'

        if not is_3d_view:
            layout.label(text="Select:")
            col = layout.column(align=True)
            col.operator("gpencil.select_all", text="Select All")
            col.operator("gpencil.select_border")
            col.operator("gpencil.select_circle")

            layout.separator()

            col = layout.column(align=True)
            col.operator("gpencil.select_linked")
            col.operator("gpencil.select_more")
            col.operator("gpencil.select_less")
            col.operator("gpencil.palettecolor_select")

        layout.label(text="Edit:")
        row = layout.row(align=True)
        row.operator("gpencil.copy", text="Copy")
        row.operator("gpencil.paste", text="Paste").type = 'COPY'
        row.operator("gpencil.paste", text="Paste & Merge").type = 'MERGE'

        col = layout.column(align=True)
        col.operator("gpencil.delete")
        col.operator("gpencil.duplicate_move", text="Duplicate")
        if is_3d_view:
            col.operator("gpencil.stroke_cyclical_set", text="Toggle Cyclic").type = 'TOGGLE'

        layout.separator()

        if not is_3d_view:
            col = layout.column(align=True)
            col.operator("transform.translate")                # icon='MAN_TRANS'
            col.operator("transform.rotate")                   # icon='MAN_ROT'
            col.operator("transform.resize", text="Scale")     # icon='MAN_SCALE'

            layout.separator()

        col = layout.column(align=True)
        col.operator("transform.bend", text="Bend")
        col.operator("transform.mirror", text="Mirror")
        col.operator("transform.shear", text="Shear")
        col.operator("transform.tosphere", text="To Sphere")

        layout.separator()
        col = layout.column(align=True)
        col.operator_menu_enum("gpencil.stroke_arrange", text="Arrange Strokes...", property="direction")
        col.operator("gpencil.stroke_change_color", text="Move to Color")

        layout.separator()
        col = layout.column(align=True)
        col.operator("gpencil.stroke_join", text="Join").type = 'JOIN'
        col.operator("gpencil.stroke_join", text="Join & Copy").type = 'JOINCOPY'
        col.operator("gpencil.stroke_flip", text="Flip Direction")

        gpd = context.gpencil_data
        if gpd:
            col.prop(gpd, "show_stroke_direction", text="Show Directions")

        if is_3d_view:
            layout.separator()
            layout.operator("gpencil.reproject")


class GreasePencilBrushPanel:
    # subclass must set
    # bl_space_type = 'IMAGE_EDITOR'
    bl_label = "Drawing Brushes"
    bl_category = "Grease Pencil"
    bl_region_type = 'TOOLS'

    @staticmethod
    def draw(self, context):
        layout = self.layout

        row = layout.row()
        col = row.column()
        ts = context.scene.tool_settings
        if len(ts.gpencil_brushes) >= 2:
            brows = 3
        else:
            brows = 2
        col.template_list("GPENCIL_UL_brush", "", ts, "gpencil_brushes", ts.gpencil_brushes, "active_index", rows=brows)

        col = row.column()

        sub = col.column(align=True)
        sub.operator("gpencil.brush_add", icon='ZOOMIN', text="")
        sub.operator("gpencil.brush_remove", icon='ZOOMOUT', text="")
        sub.menu("GPENCIL_MT_brush_specials", icon='DOWNARROW_HLT', text="")
        brush = context.active_gpencil_brush
        if brush:
            if len(ts.gpencil_brushes) > 1:
                col.separator()
                sub = col.column(align=True)
                sub.operator("gpencil.brush_move", icon='TRIA_UP', text="").type = 'UP'
                sub.operator("gpencil.brush_move", icon='TRIA_DOWN', text="").type = 'DOWN'

        # Brush details
        if brush is not None:
            row = layout.row()
            row.prop(brush, "line_width")
            row = layout.row(align=True)
            row.prop(brush, "use_random_pressure", text='', icon='RNDCURVE')
            row.prop(brush, "pen_sensitivity_factor", slider=True)
            row.prop(brush, "use_pressure", text='', icon='STYLUS_PRESSURE')
            row = layout.row(align=True)
            row.prop(brush, "use_random_strength", text='', icon='RNDCURVE')
            row.prop(brush, "strength", slider=True)
            row.prop(brush, "use_strength_pressure", text='', icon='STYLUS_PRESSURE')
            row = layout.row(align=True)
            row.prop(brush, "random_press", slider=True)

            row = layout.row(align=True)
            row.prop(brush, "jitter", slider=True)
            row.prop(brush, "use_jitter_pressure", text='', icon='STYLUS_PRESSURE')
            row = layout.row()
            row.prop(brush, "angle", slider=True)
            row.prop(brush, "angle_factor", text="Factor", slider=True)

            box = layout.box()
            col = box.column(align=True)
            col.label(text="Stroke Quality:")
            col.prop(brush, "pen_smooth_factor")
            col.prop(brush, "pen_smooth_steps")
            col.separator()
            row = col.row(align=False)
            row.prop(brush, "pen_subdivision_steps")
            row.prop(brush, "random_subdiv", text='Randomness', slider=True)


class GreasePencilStrokeSculptPanel:
    # subclass must set
    # bl_space_type = 'IMAGE_EDITOR'
    bl_label = "Sculpt Strokes"
    bl_category = "Grease Pencil"
    bl_region_type = 'TOOLS'

    @classmethod
    def poll(cls, context):
        if context.gpencil_data is None:
            return False

        gpd = context.gpencil_data
        return bool(context.editable_gpencil_strokes) and bool(gpd.use_stroke_edit_mode)

    @staticmethod
    def draw(self, context):
        layout = self.layout

        settings = context.tool_settings.gpencil_sculpt
        tool = settings.tool
        brush = settings.brush

        layout.column().prop(settings, "tool")

        col = layout.column()
        col.prop(brush, "size", slider=True)
        row = col.row(align=True)
        row.prop(brush, "strength", slider=True)
        row.prop(brush, "use_pressure_strength", text="")
        col.prop(brush, "use_falloff")
        if tool in {'SMOOTH', 'RANDOMIZE'}:
            row = layout.row(align=True)
            row.prop(settings, "affect_position", text="Position", icon='MESH_DATA', toggle=True)
            row.prop(settings, "affect_strength", text="Strength", icon='COLOR', toggle=True)
            row.prop(settings, "affect_thickness", text="Thickness", icon='LINE_DATA', toggle=True)

        layout.separator()

        if tool == 'THICKNESS':
            layout.row().prop(brush, "direction", expand=True)
        elif tool == 'PINCH':
            row = layout.row(align=True)
            row.prop_enum(brush, "direction", 'ADD', text="Pinch")
            row.prop_enum(brush, "direction", 'SUBTRACT', text="Inflate")
        elif settings.tool == 'TWIST':
            row = layout.row(align=True)
            row.prop_enum(brush, "direction", 'SUBTRACT', text="CW")
            row.prop_enum(brush, "direction", 'ADD', text="CCW")

        row = layout.row(align=True)
        row.prop(settings, "use_select_mask")
        row = layout.row(align=True)
        row.prop(settings, "selection_alpha", slider=True)

        if tool == 'SMOOTH':
            layout.prop(brush, "affect_pressure")


class GreasePencilBrushCurvesPanel:
    # subclass must set
    # bl_space_type = 'IMAGE_EDITOR'
    bl_label = "Brush Curves"
    bl_category = "Grease Pencil"
    bl_region_type = 'TOOLS'
    bl_options = {'DEFAULT_CLOSED'}

    @classmethod
    def poll(cls, context):
        if context.active_gpencil_brush is None:
            return False

        brush = context.active_gpencil_brush
        return bool(brush)

    @staticmethod
    def draw(self, context):
        layout = self.layout
        brush = context.active_gpencil_brush
        # Brush
        layout.label("Sensitivity")
        box = layout.box()
        box.template_curve_mapping(brush, "curve_sensitivity", brush=True)

        layout.label("Strength")
        box = layout.box()
        box.template_curve_mapping(brush, "curve_strength", brush=True)

        layout.label("Jitter")
        box = layout.box()
        box.template_curve_mapping(brush, "curve_jitter", brush=True)


###############################

class GPENCIL_PIE_tool_palette(Menu):
    """A pie menu for quick access to Grease Pencil tools"""
    bl_label = "Grease Pencil Tools"

    def draw(self, context):
        layout = self.layout

        pie = layout.menu_pie()
        gpd = context.gpencil_data

        # W - Drawing Types
        col = pie.column()
        col.operator("gpencil.draw", text="Draw", icon='GREASEPENCIL').mode = 'DRAW'
        col.operator("gpencil.draw", text="Straight Lines", icon='LINE_DATA').mode = 'DRAW_STRAIGHT'
        col.operator("gpencil.draw", text="Poly", icon='MESH_DATA').mode = 'DRAW_POLY'

        # E - Eraser
        # XXX: needs a dedicated icon...
        col = pie.column()
        col.operator("gpencil.draw", text="Eraser", icon='FORCE_CURVE').mode = 'ERASER'

        # E - "Settings" Palette is included here too, since it needs to be in a stable position...
        if gpd and gpd.layers.active:
            col.separator()
            col.operator("wm.call_menu_pie", text="Settings...", icon='SCRIPTWIN').name = "GPENCIL_PIE_settings_palette"

        # Editing tools
        if gpd:
            if gpd.use_stroke_edit_mode and context.editable_gpencil_strokes:
                # S - Exit Edit Mode
                pie.operator("gpencil.editmode_toggle", text="Exit Edit Mode", icon='EDIT')

                # N - Transforms
                col = pie.column()
                row = col.row(align=True)
                row.operator("transform.translate", icon='MAN_TRANS')
                row.operator("transform.rotate", icon='MAN_ROT')
                row.operator("transform.resize", text="Scale", icon='MAN_SCALE')
                row = col.row(align=True)
                row.label("Proportional Edit:")
                row.prop(context.tool_settings, "proportional_edit", text="", icon_only=True)
                row.prop(context.tool_settings, "proportional_edit_falloff", text="", icon_only=True)

                # NW - Select (Non-Modal)
                col = pie.column()
                col.operator("gpencil.select_all", text="Select All", icon='PARTICLE_POINT')
                col.operator("gpencil.select_all", text="Select Inverse", icon='BLANK1')
                col.operator("gpencil.select_linked", text="Select Linked", icon='LINKED')
                col.operator("gpencil.palettecolor_select", text="Select Color", icon='COLOR')

                # NE - Select (Modal)
                col = pie.column()
                col.operator("gpencil.select_border", text="Border Select", icon='BORDER_RECT')
                col.operator("gpencil.select_circle", text="Circle Select", icon='META_EMPTY')
                col.operator("gpencil.select_lasso", text="Lasso Select", icon='BORDER_LASSO')

                # SW - Edit Tools
                col = pie.column()
                col.operator("gpencil.duplicate_move", icon='PARTICLE_PATH', text="Duplicate")
                col.operator("gpencil.delete", icon='X', text="Delete...")

                # SE - More Tools
                pie.operator("wm.call_menu_pie", text="More...").name = "GPENCIL_PIE_tools_more"
            else:
                # Toggle Edit Mode
                pie.operator("gpencil.editmode_toggle", text="Enable Stroke Editing", icon='EDIT')


class GPENCIL_PIE_settings_palette(Menu):
    """A pie menu for quick access to Grease Pencil settings"""
    bl_label = "Grease Pencil Settings"

    @classmethod
    def poll(cls, context):
        return bool(context.gpencil_data and context.active_gpencil_layer)

    def draw(self, context):
        layout = self.layout

        pie = layout.menu_pie()
        gpd = context.gpencil_data
        gpl = context.active_gpencil_layer
        palcolor = context.active_gpencil_palettecolor
        brush = context.active_gpencil_brush

        is_editmode = bool(gpd and gpd.use_stroke_edit_mode and context.editable_gpencil_strokes)

        # W - Stroke draw settings
        col = pie.column(align=True)
        if palcolor is not None:
            col.label(text="Stroke")
            col.prop(palcolor, "color", text="")
            col.prop(palcolor, "alpha", text="", slider=True)

        # E - Fill draw settings
        col = pie.column(align=True)
        if palcolor is not None:
            col.label(text="Fill")
            col.prop(palcolor, "fill_color", text="")
            col.prop(palcolor, "fill_alpha", text="", slider=True)

        # S Brush settings
        gpencil_active_brush_settings_simple(context, pie)

        # N - Active Layer
        col = pie.column()
        col.label("Active Layer:      ")

        row = col.row()
        row.operator_context = 'EXEC_REGION_WIN'
        row.operator_menu_enum("gpencil.layer_change", "layer", text="", icon='GREASEPENCIL')
        row.prop(gpl, "info", text="")
        row.operator("gpencil.layer_remove", text="", icon='X')

        row = col.row()
        row.prop(gpl, "lock")
        row.prop(gpl, "hide")
        col.prop(gpl, "use_onion_skinning")

        # NW/NE/SW/SE - These operators are only available in editmode
        # as they require strokes to be selected to work
        if is_editmode:
            # NW - Move stroke Down
            col = pie.column(align=True)
            col.label("Arrange Strokes")
            col.operator("gpencil.stroke_arrange", text="Send to Back").direction = 'BOTTOM'
            col.operator("gpencil.stroke_arrange", text="Send Backward").direction = 'DOWN'

            # NE - Move stroke Up
            col = pie.column(align=True)
            col.label("Arrange Strokes")
            col.operator("gpencil.stroke_arrange", text="Bring to Front").direction = 'TOP'
            col.operator("gpencil.stroke_arrange", text="Bring Forward").direction = 'UP'

            # SW - Move stroke to color
            col = pie.column(align=True)
            col.operator("gpencil.stroke_change_color", text="Move to Color")

            # SE - Join strokes
            col = pie.column(align=True)
            col.label("Join Strokes")
            row = col.row()
            row.operator("gpencil.stroke_join", text="Join").type = 'JOIN'
            row.operator("gpencil.stroke_join", text="Join & Copy").type = 'JOINCOPY'
            col.operator("gpencil.stroke_flip", text="Flip direction")

            col.prop(gpd, "show_stroke_direction", text="Show drawing direction")


class GPENCIL_PIE_tools_more(Menu):
    """A pie menu for accessing more Grease Pencil tools"""
    bl_label = "More Grease Pencil Tools"

    @classmethod
    def poll(cls, context):
        gpd = context.gpencil_data
        return bool(gpd and gpd.use_stroke_edit_mode and context.editable_gpencil_strokes)

    def draw(self, context):
        layout = self.layout

        pie = layout.menu_pie()
        # gpd = context.gpencil_data

        col = pie.column(align=True)
        col.operator("gpencil.copy", icon='COPYDOWN', text="Copy")
        col.operator("gpencil.paste", icon='PASTEDOWN', text="Paste")

        col = pie.column(align=True)
        col.operator("gpencil.select_more", icon='ZOOMIN')
        col.operator("gpencil.select_less", icon='ZOOMOUT')

        pie.operator("transform.mirror", icon='MOD_MIRROR')
        pie.operator("transform.bend", icon='MOD_SIMPLEDEFORM')
        pie.operator("transform.shear", icon='MOD_TRIANGULATE')
        pie.operator("transform.tosphere", icon='MOD_MULTIRES')

        pie.operator("gpencil.convert", icon='OUTLINER_OB_CURVE', text="Convert...")
        pie.operator("wm.call_menu_pie", text="Back to Main Palette...").name = "GPENCIL_PIE_tool_palette"


class GPENCIL_PIE_sculpt(Menu):
    """A pie menu for accessing Grease Pencil stroke sculpting settings"""
    bl_label = "Grease Pencil Sculpt"

    @classmethod
    def poll(cls, context):
        gpd = context.gpencil_data
        return bool(gpd and gpd.use_stroke_edit_mode and context.editable_gpencil_strokes)

    def draw(self, context):
        layout = self.layout

        pie = layout.menu_pie()

        settings = context.tool_settings.gpencil_sculpt
        brush = settings.brush

        # W - Launch Sculpt Mode
        col = pie.column()
        # col.label("Tool:")
        col.prop(settings, "tool", text="")
        col.operator("gpencil.brush_paint", text="Sculpt", icon='SCULPTMODE_HLT')

        # E - Common Settings
        col = pie.column(align=True)
        col.prop(brush, "size", slider=True)
        row = col.row(align=True)
        row.prop(brush, "strength", slider=True)
        # row.prop(brush, "use_pressure_strength", text="", icon_only=True)
        col.prop(brush, "use_falloff")
        if settings.tool in {'SMOOTH', 'RANDOMIZE'}:
            row = col.row(align=True)
            row.prop(settings, "affect_position", text="Position", icon='MESH_DATA', toggle=True)
            row.prop(settings, "affect_strength", text="Strength", icon='COLOR', toggle=True)
            row.prop(settings, "affect_thickness", text="Thickness", icon='LINE_DATA', toggle=True)

        # S - Change Brush Type Shortcuts
        row = pie.row()
        row.prop_enum(settings, "tool", value='GRAB')
        row.prop_enum(settings, "tool", value='PUSH')
        row.prop_enum(settings, "tool", value='CLONE')

        # N - Change Brush Type Shortcuts
        row = pie.row()
        row.prop_enum(settings, "tool", value='SMOOTH')
        row.prop_enum(settings, "tool", value='THICKNESS')
        row.prop_enum(settings, "tool", value='STRENGTH')
        row.prop_enum(settings, "tool", value='RANDOMIZE')


###############################


class GPENCIL_MT_snap(Menu):
    bl_label = "Snap"

    def draw(self, context):
        layout = self.layout

        layout.operator("gpencil.snap_to_grid", text="Selection to Grid")
        layout.operator("gpencil.snap_to_cursor", text="Selection to Cursor").use_offset = False
        layout.operator("gpencil.snap_to_cursor", text="Selection to Cursor (Offset)").use_offset = True

        layout.separator()

        layout.operator("gpencil.snap_cursor_to_selected", text="Cursor to Selected")
        layout.operator("view3d.snap_cursor_to_center", text="Cursor to Center")
        layout.operator("view3d.snap_cursor_to_grid", text="Cursor to Grid")


###############################


class GPENCIL_UL_brush(UIList):
    def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
        # assert(isinstance(item, bpy.types.GPencilBrush)
        brush = item

        if self.layout_type in {'DEFAULT', 'COMPACT'}:
            row = layout.row(align=True)
            row.prop(brush, "name", text="", emboss=False, icon='BRUSH_DATA')
        elif self.layout_type == 'GRID':
            layout.alignment = 'CENTER'
            layout.label(text="", icon_value=icon)


class GPENCIL_UL_palettecolor(UIList):
    def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
        # assert(isinstance(item, bpy.types.PaletteColor)
        palcolor = item

        if self.layout_type in {'DEFAULT', 'COMPACT'}:
            if palcolor.lock:
                layout.active = False

            split = layout.split(percentage=0.25)
            row = split.row(align=True)
            row.prop(palcolor, "color", text="", emboss=palcolor.is_stroke_visible)
            row.prop(palcolor, "fill_color", text="", emboss=palcolor.is_fill_visible)
            split.prop(palcolor, "name", text="", emboss=False)

            row = layout.row(align=True)
            row.prop(palcolor, "lock", text="", emboss=False)
            row.prop(palcolor, "hide", text="", emboss=False)
            if palcolor.ghost is True:
                icon = 'GHOST_DISABLED'
            else:
                icon = 'GHOST_ENABLED'
            row.prop(palcolor, "ghost", text="", icon=icon, emboss=False)

        elif self.layout_type == 'GRID':
            layout.alignment = 'CENTER'
            layout.label(text="", icon_value=icon)


class GPENCIL_UL_layer(UIList):
    def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
        # assert(isinstance(item, bpy.types.GPencilLayer)
        gpl = item

        if self.layout_type in {'DEFAULT', 'COMPACT'}:
            if gpl.lock:
                layout.active = False

            row = layout.row(align=True)
            if gpl.is_parented:
                icon = 'BONE_DATA'
            else:
                icon = 'BLANK1'

            row.label(text="", icon=icon)
            row.prop(gpl, "info", text="", emboss=False)

            row = layout.row(align=True)
            row.prop(gpl, "lock", text="", emboss=False)
            row.prop(gpl, "hide", text="", emboss=False)
            row.prop(gpl, "unlock_color", text="", emboss=False)
        elif self.layout_type == 'GRID':
            layout.alignment = 'CENTER'
            layout.label(text="", icon_value=icon)


class GPENCIL_MT_layer_specials(Menu):
    bl_label = "Layer"

    def draw(self, context):
        layout = self.layout

        layout.operator("gpencil.layer_duplicate", icon='COPY_ID')  # XXX: needs a dedicated icon

        layout.separator()

        layout.operator("gpencil.reveal", icon='RESTRICT_VIEW_OFF', text="Show All")
        layout.operator("gpencil.hide", icon='RESTRICT_VIEW_ON', text="Hide Others").unselected = True

        layout.separator()

        layout.operator("gpencil.lock_all", icon='LOCKED', text="Lock All")
        layout.operator("gpencil.unlock_all", icon='UNLOCKED', text="UnLock All")

        layout.separator()

        layout.operator("gpencil.layer_merge", icon='NLA', text="Merge Down")


class GPENCIL_MT_brush_specials(Menu):
    bl_label = "Layer"

    def draw(self, context):
        layout = self.layout
        layout.operator("gpencil.brush_copy", icon='PASTEDOWN', text="Copy current drawing brush")
        layout.operator("gpencil.brush_presets_create", icon='HELP', text="Create a set of predefined brushes")


class GPENCIL_MT_palettecolor_specials(Menu):
    bl_label = "Layer"

    def draw(self, context):
        layout = self.layout

        layout.operator("gpencil.palettecolor_reveal", icon='RESTRICT_VIEW_OFF', text="Show All")
        layout.operator("gpencil.palettecolor_hide", icon='RESTRICT_VIEW_ON', text="Hide Others").unselected = True

        layout.separator()

        layout.operator("gpencil.palettecolor_lock_all", icon='LOCKED', text="Lock All")
        layout.operator("gpencil.palettecolor_unlock_all", icon='UNLOCKED', text="UnLock All")
        layout.operator("gpencil.palettecolor_copy", icon='PASTEDOWN', text="Copy Color")

        layout.separator()

        layout.operator("gpencil.palettecolor_select", icon='COLOR', text="Select Strokes")


class GreasePencilDataPanel:
    # subclass must set
    # bl_space_type = 'IMAGE_EDITOR'
    bl_label = "Grease Pencil Layers"
    bl_region_type = 'UI'

    @staticmethod
    def draw_header(self, context):
        self.layout.prop(context.space_data, "show_grease_pencil", text="")

    @staticmethod
    def draw(self, context):
        layout = self.layout

        # owner of Grease Pencil data
        gpd_owner = context.gpencil_data_owner
        gpd = context.gpencil_data

        # Owner Selector
        if context.space_data.type == 'VIEW_3D':
            layout.prop(context.tool_settings, "grease_pencil_source", expand=True)
        elif context.space_data.type == 'CLIP_EDITOR':
            layout.prop(context.space_data, "grease_pencil_source", expand=True)

        # Grease Pencil data selector
        layout.template_ID(gpd_owner, "grease_pencil", new="gpencil.data_add", unlink="gpencil.data_unlink")

        # Grease Pencil data...
        if (gpd is None) or (not gpd.layers):
            layout.operator("gpencil.layer_add", text="New Layer")
        else:
            self.draw_layers(context, layout, gpd)

    def draw_layers(self, context, layout, gpd):
        row = layout.row()

        col = row.column()
        if len(gpd.layers) >= 2:
            layer_rows = 5
        else:
            layer_rows = 2
        col.template_list("GPENCIL_UL_layer", "", gpd, "layers", gpd.layers, "active_index", rows=layer_rows)

        col = row.column()

        sub = col.column(align=True)
        sub.operator("gpencil.layer_add", icon='ZOOMIN', text="")
        sub.operator("gpencil.layer_remove", icon='ZOOMOUT', text="")

        gpl = context.active_gpencil_layer
        if gpl:
            sub.menu("GPENCIL_MT_layer_specials", icon='DOWNARROW_HLT', text="")

            if len(gpd.layers) > 1:
                col.separator()

                sub = col.column(align=True)
                sub.operator("gpencil.layer_move", icon='TRIA_UP', text="").type = 'UP'
                sub.operator("gpencil.layer_move", icon='TRIA_DOWN', text="").type = 'DOWN'

                col.separator()

                sub = col.column(align=True)
                sub.operator("gpencil.layer_isolate", icon='LOCKED', text="").affect_visibility = False
                sub.operator("gpencil.layer_isolate", icon='RESTRICT_VIEW_OFF', text="").affect_visibility = True

        if gpl:
            self.draw_layer(context, layout, gpl)

    def draw_layer(self, context, layout, gpl):
        row = layout.row(align=True)
        row.prop(gpl, "opacity", text="Opacity", slider=True)

        # Layer options
        split = layout.split(percentage=0.5)
        split.active = not gpl.lock
        split.prop(gpl, "show_x_ray")
        split.prop(gpl, "show_points")

        # Offsets + Parenting (where available)
        if context.space_data.type == 'VIEW_3D':
            split = layout.split(percentage=0.5)
        else:
            split = layout.column()  # parenting is not available in 2D editors...
        split.active = not gpl.lock

        # Offsets - Color Tint
        col = split.column()
        subcol = col.column(align=True)
        subcol.label("Tint")
        subcol.prop(gpl, "tint_color", text="")
        subcol.prop(gpl, "tint_factor", text="Factor", slider=True)

        # Offsets - Thickness
        row = col.row(align=True)
        row.prop(gpl, "line_change", text="Thickness Change", slider=True)
        row.operator("gpencil.stroke_apply_thickness", icon='STYLUS_PRESSURE', text="")

        # Parenting 
        if context.space_data.type == 'VIEW_3D':
            col = split.column(align=True)
            col.label(text="Parent:")
            col.prop(gpl, "parent", text="")

            sub = col.column()
            sub.prop(gpl, "parent_type", text="")
            parent = gpl.parent
            if parent and gpl.parent_type == 'BONE' and parent.type == 'ARMATURE':
                sub.prop_search(gpl, "parent_bone", parent.data, "bones", text="")

        layout.separator()

        # Full-Row - Frame Locking (and Delete Frame)
        row = layout.row(align=True)
        row.active = not gpl.lock

        if gpl.active_frame:
            lock_status = iface_("Locked") if gpl.lock_frame else iface_("Unlocked")
            lock_label = iface_("Frame: %d (%s)") % (gpl.active_frame.frame_number, lock_status)
        else:
            lock_label = iface_("Lock Frame")
        row.prop(gpl, "lock_frame", text=lock_label, icon='UNLOCKED')
        row.operator("gpencil.active_frame_delete", text="", icon='X')

        layout.separator()

        # Onion skinning
        col = layout.column(align=True)
        col.active = not gpl.lock

        row = col.row()
        row.prop(gpl, "use_onion_skinning")
        row.prop(gpl, "use_ghost_custom_colors", text="", icon='COLOR')

        split = col.split(percentage=0.5)
        split.active = gpl.use_onion_skinning

        # - Before Frames
        sub = split.column(align=True)
        row = sub.row(align=True)
        row.active = gpl.use_ghost_custom_colors
        row.prop(gpl, "before_color", text="")
        sub.prop(gpl, "ghost_before_range", text="Before")

        # - After Frames
        sub = split.column(align=True)
        row = sub.row(align=True)
        row.active = gpl.use_ghost_custom_colors
        row.prop(gpl, "after_color", text="")
        sub.prop(gpl, "ghost_after_range", text="After")


class GreasePencilPaletteColorPanel:
    # subclass must set
    bl_label = "Grease Pencil Colors"
    bl_region_type = 'UI'

    @classmethod
    def poll(cls, context):
        if context.gpencil_data is None:
            return False

        gpd = context.gpencil_data
        return bool(gpd.layers.active)

    @staticmethod
    def draw(self, context):
        layout = self.layout
        palette = context.active_gpencil_palette

        if palette:
            row = layout.row(align=True)
            row.operator_context = 'EXEC_REGION_WIN'
            row.operator_menu_enum("gpencil.palette_change", "palette", text="", icon='COLOR')
            row.prop(palette, "name", text="")
            row.operator("gpencil.palette_add", icon='ZOOMIN', text="")
            row.operator("gpencil.palette_remove", icon='X', text="")

            # Palette colors
            row = layout.row()
            col = row.column()
            if len(palette.colors) >= 2:
                color_rows = 5
            else:
                color_rows = 2
            col.template_list("GPENCIL_UL_palettecolor", "", palette, "colors", palette.colors, "active_index",
                              rows=color_rows)

            col = row.column()

            sub = col.column(align=True)
            sub.operator("gpencil.palettecolor_add", icon='ZOOMIN', text="")
            sub.operator("gpencil.palettecolor_remove", icon='ZOOMOUT', text="")

            palcol = context.active_gpencil_palettecolor
            if palcol:
                sub.menu("GPENCIL_MT_palettecolor_specials", icon='DOWNARROW_HLT', text="")

            if len(palette.colors) > 1:
                col.separator()

                sub = col.column(align=True)
                sub.operator("gpencil.palettecolor_move", icon='TRIA_UP', text="").direction = 'UP'
                sub.operator("gpencil.palettecolor_move", icon='TRIA_DOWN', text="").direction = 'DOWN'

                row = layout.row()
                sub = row.row(align=True)
                sub.label(text="Isolate:") # based on active color only
                sub.operator("gpencil.palettecolor_isolate", icon='LOCKED', text="").affect_visibility = False
                sub.operator("gpencil.palettecolor_isolate", icon='RESTRICT_VIEW_OFF', text="").affect_visibility = True
                sub = row.row(align=True)
                sub.label(text="Lock:") # based on other stuff...
                sub.operator("gpencil.stroke_lock_color", icon='BORDER_RECT', text="")
                sub.operator("gpencil.palette_lock_layer", icon='COLOR', text="")

            pcolor = palette.colors.active
            if pcolor:
                self.draw_palettecolors(layout, pcolor)

    # Draw palette colors
    def draw_palettecolors(self, layout, pcolor):
        # color settings
        split = layout.split(percentage=0.5)
        split.active = not pcolor.lock

        # Column 1 - Stroke
        col = split.column(align=True)
        col.active = not pcolor.lock
        col.label(text="Stroke:")
        col.prop(pcolor, "color", text="")
        col.prop(pcolor, "alpha", slider=True)

        # Column 2 - Fill
        col = split.column(align=True)
        col.active = not pcolor.lock
        col.label(text="Fill:")
        col.prop(pcolor, "fill_color", text="")
        col.prop(pcolor, "fill_alpha", text="Opacity", slider=True)

        # Options
        split = layout.split(percentage=0.5)
        split.active = not pcolor.lock

        col = split.column(align=True)
        col.active = not pcolor.lock
        col.prop(pcolor, "use_volumetric_strokes")
        col = split.column(align=True)
        col.active = not pcolor.lock
        col.prop(pcolor, "use_hq_fill")


class GreasePencilToolsPanel:
    # For use in "2D" Editors without their own toolbar
    # subclass must set
    # bl_space_type = 'IMAGE_EDITOR'
    # bl_options = {'DEFAULT_CLOSED'}
    bl_label = "Grease Pencil Settings"
    bl_region_type = 'UI'

    @classmethod
    def poll(cls, context):
        return (context.gpencil_data is not None)

    @staticmethod
    def draw(self, context):
        layout = self.layout

        # gpd_owner = context.gpencil_data_owner
        gpd = context.gpencil_data

        layout.prop(gpd, "use_stroke_edit_mode", text="Enable Editing", icon='EDIT', toggle=True)

        layout.separator()

        layout.label("Proportional Edit:")
        row = layout.row()
        row.prop(context.tool_settings, "proportional_edit", text="")
        row.prop(context.tool_settings, "proportional_edit_falloff", text="")

        layout.separator()
        layout.separator()

        gpencil_active_brush_settings_simple(context, layout)

        layout.separator()

        gpencil_stroke_placement_settings(context, layout)
