def update(self):

        # TODO - None of this code is optimized yet.

        # "Dirty" means that the cell's state has been altered on the backend and it needs to be redrawn on pygame.Surface object (which will make the cell "clean").
        for x in range(self._width):
            for y in range(self._height):
                # Skip if previous char was a CJK wide char
                if x > 0 and iswide(self._screenchar[x-1][y]):
                    # Set this unprinted char to a dummy value. Otherwise, it will screw up following chars (thanks to this same check) if it happened to have the value of a wide char.
                    self._screenchar[x][y] = None
                    continue

                if self._screendirty[x][y]: # draw to surfaceobj all the dirty cells.
                    self._screendirty[x][y] = False

                    # modify the fg and bg color if there is a tint
                    cellfgcolor, cellbgcolor = self.getdisplayedcolors(x, y)

                    # fill in the entire background of the cell
                    cellrect = pygame.Rect(self._cellwidth * x, self._cellheight * y, self._cellwidth, self._cellheight)

                    if self._screenchar[x][y] is None:
                        self._surfaceobj.fill(ERASECOLOR, cellrect)
                        continue

                    self._surfaceobj.fill(cellbgcolor, cellrect)

                    if self._screenchar[x][y] == ' ':
                        continue # don't need to render anything if it is just a space character.

                    # render the character and draw it to the surface
                    charsurf = self._font.render(self._screenchar[x][y], 1, cellfgcolor, cellbgcolor)
                    charrect = charsurf.get_rect()
                    charrect.centerx = self._cellwidth * x + int(self._cellwidth*getcharwidth(self._screenchar[x][y]) / 2)
                    charrect.bottom = self._cellheight * (y + 1) # TODO - not correct, this would put stuff like g, p, q higher than normal.
                    self._surfaceobj.blit(charsurf, charrect)

        self._drawinputcursor()

        # automatically blit to "window surface" pygame.Surface object if it was set.
        if self._windowsurface is not None and self._autoblit:
            self._windowsurface.blit(self._surfaceobj, self._surfaceobj.get_rect())
            if self._autodisplayupdate:
                pygame.display.update()
Update the encapsulated pygame.Surface object to match the state of this PygcurseSurface object. This needs to be done before the pygame.Surface object is blitted to the screen if you want the most up-to-date state displayed.
dataset/ETHPy150Open asweigart/pygcurse/pygcurse/__init__.py/PygcurseSurface.update