from tuikit.core.buffer import Buffer
from tuikit.core.signal import Signal
from tuikit.core.container import Container


class Window(Container):

    """Window is rectangular part of screen containing widgets.

    Widgets are drawn into window, events are routed to widgets through window.

    """

    def __init__(self, buffer=None):
        """New buffer for the window will be created unless given existing
        `buffer` as parameter."""
        Container.__init__(self)
        self._buffer = None
        self._size = None
        self.sig_resized = Signal()
        self.buffer = buffer or Buffer()

    @property
    def buffer(self):
        return self._buffer

    @buffer.setter
    def buffer(self, buffer):
        # disconnect signals from old buffer
        if self._buffer:
            self.sig_resized.disconnect(self._buffer.resize)
        # replace the buffer
        self._buffer = buffer
        self._size = buffer.size
        # resize buffer when window gets resized
        self.sig_resized.connect(buffer.resize)

    @property
    def size(self):
        return self._size.readonly()

    def resize(self, w, h):
        self._buffer.resize(w, h)
        self.sig_resized(w, h)

    def draw(self, buffer, x=0, y=0):
        """Draw this window into buffer at x, y coords."""
        Container.draw(self, self.buffer)
        buffer.draw(self.buffer, x, y)