# $Id: drawable.py,v 1.15 2007/06/10 14:11:59 mggrant Exp $
#
# Xlib.xobject.drawable -- drawable objects (window and pixmap)
#
#    Copyright (C) 2000 Peter Liljenberg <petli@ctrl-c.liu.se>
#
#    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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

import string

from Xlib import X, Xatom, Xutil
from Xlib.protocol import request, rq

# Other X resource objects
import resource
import colormap
import cursor
import fontable

# Inter-client communication conventions
import icccm

class Drawable(resource.Resource):
    __drawable__ = resource.Resource.__resource__

    def get_geometry(self):
        return request.GetGeometry(display = self.display,
                                   drawable = self)

    def create_pixmap(self, width, height, depth):
        pid = self.display.allocate_resource_id()
        request.CreatePixmap(display = self.display,
                             depth = depth,
                             pid = pid,
                             drawable = self.id,
                             width = width,
                             height = height)

        cls = self.display.get_resource_class('pixmap', Pixmap)
        return cls(self.display, pid, owner = 1)

    def create_gc(self, **keys):
        cid = self.display.allocate_resource_id()
        request.CreateGC(display = self.display,
                         cid = cid,
                         drawable = self.id,
                         attrs = keys)

        cls = self.display.get_resource_class('gc', fontable.GC)
        return cls(self.display, cid, owner = 1)

    def copy_area(self, gc, src_drawable, src_x, src_y, width, height, dst_x, dst_y, onerror = None):
        request.CopyArea(display = self.display,
                         onerror = onerror,
                         src_drawable = src_drawable,
                         dst_drawable = self.id,
                         gc = gc,
                         src_x = src_x,
                         src_y = src_y,
                         dst_x = dst_x,
                         dst_y = dst_y,
                         width = width,
                         height = height)

    def copy_plane(self, gc, src_drawable, src_x, src_y, width, height,
                   dst_x, dst_y, bit_plane, onerror = None):
        request.CopyPlane(display = self.display,
                          onerror = onerror,
                          src_drawable = src_drawable,
                          dst_drawable = self.id,
                          gc = gc,
                          src_x = src_x,
                          src_y = src_y,
                          dst_x = dst_x,
                          dst_y = dst_y,
                          width = width,
                          height = height,
                          bit_plane = bit_plane)

    def poly_point(self, gc, coord_mode, points, onerror = None):
        request.PolyPoint(display = self.display,
                          onerror = onerror,
                          coord_mode = coord_mode,
                          drawable = self.id,
                          gc = gc,
                          points = points)

    def point(self, gc, x, y, onerror = None):
        request.PolyPoint(display = self.display,
                          onerror = onerror,
                          coord_mode = X.CoordModeOrigin,
                          drawable = self.id,
                          gc = gc,
                          points = [(x, y)])

    def poly_line(self, gc, coord_mode, points, onerror = None):
        request.PolyLine(display = self.display,
                         onerror = onerror,
                         coord_mode = coord_mode,
                         drawable = self.id,
                         gc = gc,
                         points = points)

    def line(self, gc, x1, y1, x2, y2, onerror = None):
        request.PolySegment(display = self.display,
                            onerror = onerror,
                            drawable = self.id,
                            gc = gc,
                            segments = [(x1, y1, x2, y2)])

    def poly_segment(self, gc, segments, onerror = None):
        request.PolySegment(display = self.display,
                            onerror = onerror,
                            drawable = self.id,
                            gc = gc,
                            segments = segments)

    def poly_rectangle(self, gc, rectangles, onerror = None):
        request.PolyRectangle(display = self.display,
                              onerror = onerror,
                              drawable = self.id,
                              gc = gc,
                              rectangles = rectangles)

    def rectangle(self, gc, x, y, width, height, onerror = None):
        request.PolyRectangle(display = self.display,
                              onerror = onerror,
                              drawable = self.id,
                              gc = gc,
                              rectangles = [(x, y, width, height)])


    def poly_arc(self, gc, arcs, onerror = None):
        request.PolyArc(display = self.display,
                        onerror = onerror,
                        drawable = self.id,
                        gc = gc,
                        arcs = arcs)

    def arc(self, gc,  x, y, width, height, angle1, angle2, onerror = None):
        request.PolyArc(display = self.display,
                        onerror = onerror,
                        drawable = self.id,
                        gc = gc,
                        arcs = [(x, y, width, height, angle1, angle2)])

    def fill_poly(self, gc, shape, coord_mode, points, onerror = None):
        request.FillPoly(display = self.display,
                         onerror = onerror,
                         shape = shape,
                         coord_mode = coord_mode,
                         drawable = self.id,
                         gc = gc,
                         points = points)

    def poly_fill_rectangle(self, gc, rectangles, onerror = None):
        request.PolyFillRectangle(display = self.display,
                                  onerror = onerror,
                                  drawable = self.id,
                                  gc = gc,
                                  rectangles = rectangles)

    def fill_rectangle(self, gc, x, y, width, height, onerror = None):
        request.PolyFillRectangle(display = self.display,
                                  onerror = onerror,
                                  drawable = self.id,
                                  gc = gc,
                                  rectangles = [(x, y, width, height)])

    def poly_fill_arc(self, gc, arcs, onerror = None):
        request.PolyFillArc(display = self.display,
                            onerror = onerror,
                            drawable = self.id,
                            gc = gc,
                            arcs = arcs)

    def fill_arc(self, gc,  x, y, width, height, angle1, angle2, onerror = None):
        request.PolyFillArc(display = self.display,
                            onerror = onerror,
                            drawable = self.id,
                            gc = gc,
                            arcs = [(x, y, width, height, angle1, angle2)])


    def put_image(self, gc, x, y, width, height, format,
                  depth, left_pad, data, onerror = None):
        request.PutImage(display = self.display,
                         onerror = onerror,
                         format = format,
                         drawable = self.id,
                         gc = gc,
                         width = width,
                         height = height,
                         dst_x = x,
                         dst_y = y,
                         left_pad = left_pad,
                         depth = depth,
                         data = data)

    # Trivial little method for putting PIL images.  Will break on anything
    # but depth 1 or 24...
    def put_pil_image(self, gc, x, y, image, onerror = None):
        width, height = image.size
        if image.mode == '1':
            format = X.XYBitmap
            depth = 1
            if self.display.info.bitmap_format_bit_order == 0:
                rawmode = '1;R'
            else:
                rawmode = '1'
            pad = self.display.info.bitmap_format_scanline_pad
            stride = roundup(width, pad) >> 3
        elif image.mode == 'RGB':
            format = X.ZPixmap
            depth = 24
            if self.display.info.image_byte_order == 0:
                rawmode = 'BGRX'
            else:
                rawmode = 'RGBX'
            pad = self.display.info.bitmap_format_scanline_pad
            unit = self.display.info.bitmap_format_scanline_unit
            stride = roundup(width * unit, pad) >> 3
        else:
            raise ValueError, 'Unknown data format'

        maxlen = (self.display.info.max_request_length << 2) \
                 - request.PutImage._request.static_size
        split = maxlen / stride

        x1 = 0
        x2 = width
        y1 = 0

        while y1 < height:
            h = min(height, split)
            if h < height:
                subimage = image.crop((x1, y1, x2, y1 + h))
            else:
                subimage = image
            w, h = subimage.size
            data = subimage.tostring("raw", rawmode, stride, 0)
            self.put_image(gc, x, y, w, h, format, depth, 0, data)
            y1 = y1 + h
            y = y + h


    def get_image(self, x, y, width, height, format, plane_mask):
        return request.GetImage(display = self.display,
                                format = format,
                                drawable = self.id,
                                x = x,
                                y = y,
                                width = width,
                                height = height,
                                plane_mask = plane_mask)

    def draw_text(self, gc, x, y, text, onerror = None):
        request.PolyText8(display = self.display,
                          onerror = onerror,
                          drawable = self.id,
                          gc = gc,
                          x = x,
                          y = y,
                          items = [text])

    def poly_text(self, gc, x, y, items, onerror = None):
        request.PolyText8(display = self.display,
                          onerror = onerror,
                          drawable = self.id,
                          gc = gc,
                          x = x,
                          y = y,
                          items = items)

    def poly_text_16(self, gc, x, y, items, onerror = None):
        request.PolyText16(display = self.display,
                           onerror = onerror,
                           drawable = self.id,
                           gc = gc,
                           x = x,
                           y = y,
                           items = items)

    def image_text(self, gc, x, y, string, onerror = None):
        request.ImageText8(display = self.display,
                           onerror = onerror,
                           drawable = self.id,
                           gc = gc,
                           x = x,
                           y = y,
                           string = string)

    def image_text_16(self, gc, x, y, string, onerror = None):
        request.ImageText16(display = self.display,
                            onerror = onerror,
                            drawable = self.id,
                            gc = gc,
                            x = x,
                            y = y,
                            string = string)

    def query_best_size(self, item_class, width, height):
        return request.QueryBestSize(display = self.display,
                                     item_class = item_class,
                                     drawable = self.id,
                                     width = width,
                                     height = height)

class Window(Drawable):
    __window__ = resource.Resource.__resource__

    def create_window(self, x, y, width, height, border_width, depth,
                      window_class =  X.CopyFromParent,
                      visual = X.CopyFromParent,
                      **keys):

        wid = self.display.allocate_resource_id()
        request.CreateWindow(display = self.display,
                             depth = depth,
                             wid = wid,
                             parent = self.id,
                             x = x,
                             y = y,
                             width = width,
                             height = height,
                             border_width = border_width,
                             window_class = window_class,
                             visual = visual,
                             attrs = keys)

        cls = self.display.get_resource_class('window', Window)
        return cls(self.display, wid, owner = 1)

    def change_attributes(self, onerror = None, **keys):
        request.ChangeWindowAttributes(display = self.display,
                                       onerror = onerror,
                                       window = self.id,
                                       attrs = keys)

    def get_attributes(self):
        return request.GetWindowAttributes(display = self.display,
                                           window = self.id)

    def destroy(self, onerror = None):
        request.DestroyWindow(display = self.display,
                              onerror = onerror,
                              window = self.id)

        self.display.free_resource_id(self.id)

    def destroy_sub_windows(self, onerror = None):
        request.DestroySubWindows(display = self.display,
                                  onerror = onerror,
                                  window = self.id)


    def change_save_set(self, mode, onerror = None):
        request.ChangeSaveSet(display = self.display,
                              onerror = onerror,
                              mode = mode,
                              window = self.id)

    def reparent(self, parent, x, y, onerror = None):
        request.ReparentWindow(display = self.display,
                               onerror = onerror,
                               window = self.id,
                               parent = parent,
                               x = x,
                               y = y)

    def map(self, onerror = None):
        request.MapWindow(display = self.display,
                          onerror = onerror,
                          window = self.id)

    def map_sub_windows(self, onerror = None):
        request.MapSubwindows(display = self.display,
                              onerror = onerror,
                              window = self.id)

    def unmap(self, onerror = None):
        request.UnmapWindow(display = self.display,
                            onerror = onerror,
                            window = self.id)

    def unmap_sub_windows(self, onerror = None):
        request.UnmapSubwindows(display = self.display,
                                onerror = onerror,
                                window = self.id)

    def configure(self, onerror = None, **keys):
        request.ConfigureWindow(display = self.display,
                                onerror = onerror,
                                window = self.id,
                                attrs = keys)

    def circulate(self, direction, onerror = None):
        request.CirculateWindow(display = self.display,
                                onerror = onerror,
                                direction = direction,
                                window = self.id)

    def raise_window(self, onerror = None):
        """alias for raising the window to the top - as in XRaiseWindow"""
        self.configure(onerror, stack_mode = X.Above)

    def query_tree(self):
        return request.QueryTree(display = self.display,
                                 window = self.id)


    def change_property(self, property, type, format, data,
                        mode = X.PropModeReplace, onerror = None):

        request.ChangeProperty(display = self.display,
                               onerror = onerror,
                               mode = mode,
                               window = self.id,
                               property = property,
                               type = type,
                               data = (format, data))

    def delete_property(self, property, onerror = None):
        request.DeleteProperty(display = self.display,
                               onerror = onerror,
                               window = self.id,
                               property = property)

    def get_property(self, property, type, offset, length, delete = 0):
        r = request.GetProperty(display = self.display,
                                delete = delete,
                                window = self.id,
                                property = property,
                                type = type,
                                long_offset = offset,
                                long_length = length)

        if r.property_type:
            fmt, value = r.value
            r.format = fmt
            r.value = value
            return r
        else:
            return None

    def get_full_property(self, property, type, sizehint = 10):
        prop = self.get_property(property, type, 0, sizehint)
        if prop:
            val = prop.value
            if prop.bytes_after:
                prop = self.get_property(property, type, sizehint,
                                         prop.bytes_after / 4 + 1)
                val = val + prop.value

            prop.value = val
            return prop
        else:
            return None

    def list_properties(self):
        r = request.ListProperties(display = self.display,
                                   window = self.id)
        return r.atoms

    def set_selection_owner(self, selection, time, onerror = None):
        request.SetSelectionOwner(display = self.display,
                                  onerror = onerror,
                                  window = self.id,
                                  selection = selection,
                                  time = time)

    def convert_selection(self, selection, target, property, time, onerror = None):
        request.ConvertSelection(display = self.display,
                                 onerror = onerror,
                                 requestor = self.id,
                                 selection = selection,
                                 target = target,
                                 property = property,
                                 time = time)

    def send_event(self, event, event_mask = 0, propagate = 0, onerror = None):
        request.SendEvent(display = self.display,
                          onerror = onerror,
                          propagate = propagate,
                          destination = self.id,
                          event_mask = event_mask,
                          event = event)

    def grab_pointer(self, owner_events, event_mask,
                     pointer_mode, keyboard_mode,
                     confine_to, cursor, time):

        r = request.GrabPointer(display = self.display,
                                owner_events = owner_events,
                                grab_window = self.id,
                                event_mask = event_mask,
                                pointer_mode = pointer_mode,
                                keyboard_mode = keyboard_mode,
                                confine_to = confine_to,
                                cursor = cursor,
                                time = time)
        return r.status

    def grab_button(self, button, modifiers, owner_events, event_mask,
                    pointer_mode, keyboard_mode,
                    confine_to, cursor, onerror = None):

        request.GrabButton(display = self.display,
                           onerror = onerror,
                           owner_events = owner_events,
                           grab_window = self.id,
                           event_mask = event_mask,
                           pointer_mode = pointer_mode,
                           keyboard_mode = keyboard_mode,
                           confine_to = confine_to,
                           cursor = cursor,
                           button = button,
                           modifiers = modifiers)

    def ungrab_button(self, button, modifiers, onerror = None):
        request.UngrabButton(display = self.display,
                             onerror = onerror,
                             button = button,
                             grab_window = self.id,
                             modifiers = modifiers)


    def grab_keyboard(self, owner_events, pointer_mode, keyboard_mode, time):
        r = request.GrabKeyboard(display = self.display,
                                 owner_events = owner_events,
                                 grab_window = self.id,
                                 time = time,
                                 pointer_mode = pointer_mode,
                                 keyboard_mode = keyboard_mode)

        return r.status

    def grab_key(self, key, modifiers, owner_events, pointer_mode, keyboard_mode, onerror = None):
        request.GrabKey(display = self.display,
                        onerror = onerror,
                        owner_events = owner_events,
                        grab_window = self.id,
                        modifiers = modifiers,
                        key = key,
                        pointer_mode = pointer_mode,
                        keyboard_mode = keyboard_mode)

    def ungrab_key(self, key, modifiers, onerror = None):
        request.UngrabKey(display = self.display,
                          onerror = onerror,
                          key = key,
                          grab_window = self.id,
                          modifiers = modifiers)

    def query_pointer(self):
        return request.QueryPointer(display = self.display,
                                    window = self.id)

    def get_motion_events(self, start, stop):
        r = request.GetMotionEvents(display = self.display,
                                    window = self.id,
                                    start = start,
                                    stop = stop)
        return r.events

    def translate_coords(self, src_window, src_x, src_y):
        return request.TranslateCoords(display = self.display,
                                       src_wid = src_window,
                                       dst_wid = self.id,
                                       src_x = src_x,
                                       src_y = src_y)

    def warp_pointer(self, x, y, src_window = 0, src_x = 0, src_y = 0,
                     src_width = 0, src_height = 0, onerror = None):

        request.WarpPointer(display = self.display,
                            onerror = onerror,
                            src_window = src_window,
                            dst_window = self.id,
                            src_x = src_x,
                            src_y = src_y,
                            src_width = src_width,
                            src_height = src_height,
                            dst_x = x,
                            dst_y = y)

    def set_input_focus(self, revert_to, time, onerror = None):
        request.SetInputFocus(display = self.display,
                              onerror = onerror,
                              revert_to = revert_to,
                              focus = self.id,
                              time = time)

    def clear_area(self, x = 0, y = 0, width = 0, height = 0, exposures = 0, onerror = None):
        request.ClearArea(display = self.display,
                          onerror = onerror,
                          exposures = exposures,
                          window = self.id,
                          x = x,
                          y = y,
                          width = width,
                          height = height)

    def create_colormap(self, visual, alloc):
        mid = self.display.allocate_resource_id()
        request.CreateColormap(display = self.display,
                               alloc = alloc,
                               mid = mid,
                               window = self.id,
                               visual = visual)
        cls = self.display.get_resource_class('colormap', colormap.Colormap)
        return cls(self.display, mid, owner = 1)

    def list_installed_colormaps(self):
        r = request.ListInstalledColormaps(display = self.display,
                                           window = self.id)
        return r.cmaps

    def rotate_properties(self, properties, delta, onerror = None):
        request.RotateProperties(display = self.display,
                                 onerror = onerror,
                                 window = self.id,
                                 delta = delta,
                                 properties = properties)

    def set_wm_name(self, name, onerror = None):
        self.change_property(Xatom.WM_NAME, Xatom.STRING, 8, name,
                             onerror = onerror)

    def get_wm_name(self):
        d = self.get_full_property(Xatom.WM_NAME, Xatom.STRING)
        if d is None or d.format != 8:
            return None
        else:
            return d.value

    def set_wm_icon_name(self, name, onerror = None):
        self.change_property(Xatom.WM_ICON_NAME, Xatom.STRING, 8, name,
                             onerror = onerror)

    def get_wm_icon_name(self):
        d = self.get_full_property(Xatom.WM_ICON_NAME, Xatom.STRING)
        if d is None or d.format != 8:
            return None
        else:
            return d.value


    def set_wm_class(self, inst, cls, onerror = None):
        self.change_property(Xatom.WM_CLASS, Xatom.STRING, 8,
                             '%s\0%s\0' % (inst, cls),
                             onerror = onerror)

    def get_wm_class(self):
        d = self.get_full_property(Xatom.WM_CLASS, Xatom.STRING)
        if d is None or d.format != 8:
            return None
        else:
            parts = string.split(d.value, '\0')
            if len(parts) < 2:
                return None
            else:
                return parts[0], parts[1]

    def set_wm_transient_for(self, window, onerror = None):
        self.change_property(Xatom.WM_TRANSIENT_FOR, Xatom.WINDOW,
                             32, window.id,
                             onerror = onerror)

    def get_wm_transient_for(self):
        d = self.get_property(Xatom.WM_TRANSIENT_FOR, Xatom.WINDOW, 0, 1)
        if d is None or d.format != 32 or len(d.value) < 1:
            return None
        else:
            cls = self.display.get_resource_class('window', Window)
            return cls(self.display, d.value[0])


    def set_wm_protocols(self, protocols, onerror = None):
        self.change_property(self.display.get_atom('WM_PROTOCOLS'),
                             Xatom.ATOM, 32, protocols,
                             onerror = onerror)

    def get_wm_protocols(self):
        d = self.get_full_property(self.display.get_atom('WM_PROTOCOLS'), Xatom.ATOM)
        if d is None or d.format != 32:
            return []
        else:
            return d.value

    def set_wm_colormap_windows(self, windows, onerror = None):
        self.change_property(self.display.get_atom('WM_COLORMAP_WINDOWS'),
                             Xatom.WINDOW, 32,
                             map(lambda w: w.id, windows),
                             onerror = onerror)

    def get_wm_colormap_windows(self):
        d = self.get_full_property(self.display.get_atom('WM_COLORMAP_WINDOWS'),
                                   Xatom.WINDOW)
        if d is None or d.format != 32:
            return []
        else:
            cls = self.display.get_resource_class('window', Window)
            return map(lambda i, d = self.display, c = cls: c(d, i),
                       d.value)


    def set_wm_client_machine(self, name, onerror = None):
        self.change_property(Xatom.WM_CLIENT_MACHINE, Xatom.STRING, 8, name,
                             onerror = onerror)

    def get_wm_client_machine(self):
        d = self.get_full_property(Xatom.WM_CLIENT_MACHINE, Xatom.STRING)
        if d is None or d.format != 8:
            return None
        else:
            return d.value

    def set_wm_normal_hints(self, hints = {}, onerror = None, **keys):
        self._set_struct_prop(Xatom.WM_NORMAL_HINTS, Xatom.WM_SIZE_HINTS,
                              icccm.WMNormalHints, hints, keys, onerror)

    def get_wm_normal_hints(self):
        return self._get_struct_prop(Xatom.WM_NORMAL_HINTS, Xatom.WM_SIZE_HINTS,
                                     icccm.WMNormalHints)

    def set_wm_hints(self, hints = {}, onerror = None, **keys):
        self._set_struct_prop(Xatom.WM_HINTS, Xatom.WM_HINTS,
                              icccm.WMHints, hints, keys, onerror)

    def get_wm_hints(self):
        return self._get_struct_prop(Xatom.WM_HINTS, Xatom.WM_HINTS,
                                     icccm.WMHints)

    def set_wm_state(self, hints = {}, onerror = None, **keys):
        atom = self.display.get_atom('WM_STATE')
        self._set_struct_prop(atom, atom, icccm.WMState, hints, keys, onerror)

    def get_wm_state(self):
        atom = self.display.get_atom('WM_STATE')
        return self._get_struct_prop(atom, atom, icccm.WMState)

    def set_wm_icon_size(self, hints = {}, onerror = None, **keys):
        self._set_struct_prop(Xatom.WM_ICON_SIZE, Xatom.WM_ICON_SIZE,
                              icccm.WMIconSize, hints, keys, onerror)

    def get_wm_icon_size(self):
        return self._get_struct_prop(Xatom.WM_ICON_SIZE, Xatom.WM_ICON_SIZE,
                                     icccm.WMIconSize)

    # Helper function for getting structured properties.
    # pname and ptype are atoms, and pstruct is a Struct object.
    # Returns a DictWrapper, or None

    def _get_struct_prop(self, pname, ptype, pstruct):
        r = self.get_property(pname, ptype, 0, pstruct.static_size / 4)
        if r and r.format == 32:
            value = r.value.tostring()
            if len(value) == pstruct.static_size:
                return pstruct.parse_binary(value, self.display)[0]

        return None

    # Helper function for setting structured properties.
    # pname and ptype are atoms, and pstruct is a Struct object.
    # hints is a mapping or a DictWrapper, keys is a mapping.  keys
    # will be modified.  onerror is the error handler.

    def _set_struct_prop(self, pname, ptype, pstruct, hints, keys, onerror):
        if isinstance(hints, rq.DictWrapper):
            keys.update(hints._data)
        else:
            keys.update(hints)

        value = apply(pstruct.to_binary, (), keys)

        self.change_property(pname, ptype, 32, value, onerror = onerror)


class Pixmap(Drawable):
    __pixmap__ = resource.Resource.__resource__

    def free(self, onerror = None):
        request.FreePixmap(display = self.display,
                           onerror = onerror,
                           pixmap = self.id)

        self.display.free_resource_id(self.id)

    def create_cursor(self, mask,
                      (fore_red, fore_green, fore_blue),
                      (back_red, back_green, back_blue),
                      x, y):
        cid = self.display.allocate_resource_id()
        request.CreateCursor(display = self.display,
                             cid = cid,
                             source = self.id,
                             mask = mask,
                             fore_red = fore_red,
                             fore_green = fore_green,
                             fore_blue = fore_blue,
                             back_red = back_red,
                             back_green = back_green,
                             back_blue = back_blue,
                             x = x,
                             y = y)
        cls = self.display.get_resource_class('cursor', cursor.Cursor)
        return cls(self.display, cid, owner = 1)


def roundup(value, unit):
    return (value + (unit - 1)) & ~(unit - 1)
