class MainLoop(object): """ This is the standard main loop implementation for a single interactive session. :param widget: the topmost widget used for painting the screen, stored as :attr:`widget` and may be modified. Must be a box widget. :type widget: widget instance :param palette: initial palette for screen :type palette: iterable of palette entries :param screen: screen to use, default is a new :class:`raw_display.Screen` instance; stored as :attr:`screen` :type screen: display module screen instance :param handle_mouse: ``True`` to ask :attr:`.screen` to process mouse events :type handle_mouse: bool :param input_filter: a function to filter input before sending it to :attr:`.widget`, called from :meth:`.input_filter` :type input_filter: callable :param unhandled_input: a function called when input is not handled by :attr:`.widget`, called from :meth:`.unhandled_input` :type unhandled_input: callable :param event_loop: if :attr:`.screen` supports external an event loop it may be given here, default is a new :class:`SelectEventLoop` instance; stored as :attr:`.event_loop` :type event_loop: event loop instance :param pop_ups: `True` to wrap :attr:`.widget` with a :class:`PopUpTarget` instance to allow any widget to open a pop-up anywhere on the screen :type pop_ups: boolean .. attribute:: screen The screen object this main loop uses for screen updates and reading input .. attribute:: event_loop The event loop object this main loop uses for waiting on alarms and IO """ def __init__(self, widget, palette=(), screen=None, handle_mouse=True, input_filter=None, unhandled_input=None, event_loop=None, pop_ups=False): self._widget = widget self.handle_mouse = handle_mouse self.pop_ups = pop_ups # triggers property setting side-effect if not screen: from urwid import raw_display screen = raw_display.Screen() if palette: screen.register_palette(palette) self.screen = screen self.screen_size = None self._unhandled_input = unhandled_input self._input_filter = input_filter if not hasattr(screen, 'get_input_descriptors' ) and event_loop is not None: raise NotImplementedError("screen object passed " "%r does not support external event loops" % (screen,)) if event_loop is None: event_loop = SelectEventLoop() self.event_loop = event_loop self._input_timeout = None self._watch_pipes = {} def _set_widget(self, widget): self._widget = widget if self.pop_ups: self._topmost_widget.original_widget = self._widget else: self._topmost_widget = self._widget widget = property(lambda self:self._widget, _set_widget, doc= """ Property for the topmost widget used to draw the screen. This must be a box widget. """) def _set_pop_ups(self, pop_ups): self._pop_ups = pop_ups if pop_ups: self._topmost_widget = PopUpTarget(self._widget) else: self._topmost_widget = self._widget pop_ups = property(lambda self:self._pop_ups, _set_pop_ups) def set_alarm_in(self, sec, callback, user_data=None): """ Schedule an alarm in *sec* seconds that will call *callback* from the within the :meth:`run` method. :param sec: seconds until alarm :type sec: float :param callback: function to call with two parameters: this main loop object and *user_data* :type callback: callable """ def cb(): callback(self, user_data) return self.event_loop.alarm(sec, cb) def set_alarm_at(self, tm, callback, user_data=None): """ Schedule an alarm at *tm* time that will call *callback* from the within the :meth:`run` function. Returns a handle that may be passed to :meth:`remove_alarm`. :param tm: time to call callback e.g. ``time.time() + 5`` :type tm: float :param callback: function to call with two parameters: this main loop object and *user_data* :type callback: callable """ def cb(): callback(self, user_data) return self.event_loop.alarm(tm - time.time(), cb) def remove_alarm(self, handle): """ Remove an alarm. Return ``True`` if *handle* was found, ``False`` otherwise. """ return self.event_loop.remove_alarm(handle) def watch_pipe(self, callback): """ Create a pipe for use by a subprocess or thread to trigger a callback in the process/thread running the main loop. :param callback: function taking one parameter to call from within the process/thread running the main loop :type callback: callable This method returns a file descriptor attached to the write end of a pipe. The read end of the pipe is added to the list of files :attr:`event_loop` is watching. When data is written to the pipe the callback function will be called and passed a single value containing data read from the pipe. This method may be used any time you want to update widgets from another thread or subprocess. Data may be written to the returned file descriptor with ``os.write(fd, data)``. Ensure that data is less than 512 bytes (or 4K on Linux) so that the callback will be triggered just once with the complete value of data passed in. If the callback returns ``False`` then the watch will be removed from :attr:`event_loop` and the read end of the pipe will be closed. You are responsible for closing the write end of the pipe with ``os.close(fd)``. """ pipe_rd, pipe_wr = os.pipe() fcntl.fcntl(pipe_rd, fcntl.F_SETFL, os.O_NONBLOCK) watch_handle = None def cb(): data = os.read(pipe_rd, PIPE_BUFFER_READ_SIZE) rval = callback(data) if rval is False: self.event_loop.remove_watch_file(watch_handle) os.close(pipe_rd) watch_handle = self.event_loop.watch_file(pipe_rd, cb) self._watch_pipes[pipe_wr] = (watch_handle, pipe_rd) return pipe_wr def remove_watch_pipe(self, write_fd): """ Close the read end of the pipe and remove the watch created by :meth:`watch_pipe`. You are responsible for closing the write end of the pipe. Returns ``True`` if the watch pipe exists, ``False`` otherwise """ try: watch_handle, pipe_rd = self._watch_pipes.pop(write_fd) except KeyError: return False if not self.event_loop.remove_watch_file(watch_handle): return False os.close(pipe_rd) return True def watch_file(self, fd, callback): """ Call *callback* when *fd* has some data to read. No parameters are passed to callback. Returns a handle that may be passed to :meth:`remove_watch_file`. """ return self.event_loop.watch_file(fd, callback) def remove_watch_file(self, handle): """ Remove a watch file. Returns ``True`` if the watch file exists, ``False`` otherwise. """ return self.event_loop.remove_watch_file(handle) def run(self): """ Start the main loop handling input events and updating the screen. The loop will continue until an :exc:`ExitMainLoop` exception is raised. This method will use :attr:`screen`'s run_wrapper() method if :attr:`screen`'s start() method has not already been called. """ try: if self.screen.started: self._run() else: self.screen.run_wrapper(self._run) except ExitMainLoop: pass def _test_run(self): """ >>> w = _refl("widget") # _refl prints out function calls >>> w.render_rval = "fake canvas" # *_rval is used for return values >>> scr = _refl("screen") >>> scr.get_input_descriptors_rval = [42] >>> scr.get_cols_rows_rval = (20, 10) >>> scr.started = True >>> scr._urwid_signals = {} >>> evl = _refl("event_loop") >>> evl.enter_idle_rval = 1 >>> evl.watch_file_rval = 2 >>> ml = MainLoop(w, [], scr, event_loop=evl) >>> ml.run() # doctest:+ELLIPSIS screen.set_mouse_tracking() screen.get_cols_rows() widget.render((20, 10), focus=True) screen.draw_screen((20, 10), 'fake canvas') screen.get_input_descriptors() event_loop.watch_file(42, <bound method ...>) event_loop.enter_idle(<bound method ...>) event_loop.run() event_loop.remove_enter_idle(1) event_loop.remove_watch_file(2) >>> scr.started = False >>> ml.run() # doctest:+ELLIPSIS screen.run_wrapper(<bound method ...>) """ def _run(self): if self.handle_mouse: self.screen.set_mouse_tracking() if not hasattr(self.screen, 'get_input_descriptors'): return self._run_screen_event_loop() self.draw_screen() fd_handles = [] def reset_input_descriptors(only_remove=False): for handle in fd_handles: self.event_loop.remove_watch_file(handle) if only_remove: del fd_handles[:] else: fd_handles[:] = [ self.event_loop.watch_file(fd, self._update) for fd in self.screen.get_input_descriptors()] if not fd_handles and self._input_timeout is not None: self.event_loop.remove_alarm(self._input_timeout) try: signals.connect_signal(self.screen, INPUT_DESCRIPTORS_CHANGED, reset_input_descriptors) except NameError: pass # watch our input descriptors reset_input_descriptors() idle_handle = self.event_loop.enter_idle(self.entering_idle) # Go.. self.event_loop.run() # tidy up self.event_loop.remove_enter_idle(idle_handle) reset_input_descriptors(True) signals.disconnect_signal(self.screen, INPUT_DESCRIPTORS_CHANGED, reset_input_descriptors) def _update(self, timeout=False): """ >>> w = _refl("widget") >>> w.selectable_rval = True >>> w.mouse_event_rval = True >>> scr = _refl("screen") >>> scr.get_cols_rows_rval = (15, 5) >>> scr.get_input_nonblocking_rval = 1, ['y'], [121] >>> evl = _refl("event_loop") >>> ml = MainLoop(w, [], scr, event_loop=evl) >>> ml._input_timeout = "old timeout" >>> ml._update() # doctest:+ELLIPSIS event_loop.remove_alarm('old timeout') screen.get_input_nonblocking() event_loop.alarm(1, <function ...>) screen.get_cols_rows() widget.selectable() widget.keypress((15, 5), 'y') >>> scr.get_input_nonblocking_rval = None, [("mouse press", 1, 5, 4) ... ], [] >>> ml._update() screen.get_input_nonblocking() widget.mouse_event((15, 5), 'mouse press', 1, 5, 4, focus=True) >>> scr.get_input_nonblocking_rval = None, [], [] >>> ml._update() screen.get_input_nonblocking() """ if self._input_timeout is not None and not timeout: # cancel the timeout, something else triggered the update self.event_loop.remove_alarm(self._input_timeout) self._input_timeout = None max_wait, keys, raw = self.screen.get_input_nonblocking() if max_wait is not None: # if get_input_nonblocking wants to be called back # make sure it happens with an alarm self._input_timeout = self.event_loop.alarm(max_wait, lambda: self._update(timeout=True)) keys = self.input_filter(keys, raw) if keys: self.process_input(keys) if 'window resize' in keys: self.screen_size = None def _run_screen_event_loop(self): """ This method is used when the screen does not support using external event loops. The alarms stored in the SelectEventLoop in :attr:`event_loop` are modified by this method. """ next_alarm = None while True: self.draw_screen() if not next_alarm and self.event_loop._alarms: next_alarm = heapq.heappop(self.event_loop._alarms) keys = None while not keys: if next_alarm: sec = max(0, next_alarm[0] - time.time()) self.screen.set_input_timeouts(sec) else: self.screen.set_input_timeouts(None) keys, raw = self.screen.get_input(True) if not keys and next_alarm: sec = next_alarm[0] - time.time() if sec <= 0: break keys = self.input_filter(keys, raw) if keys: self.process_input(keys) while next_alarm: sec = next_alarm[0] - time.time() if sec > 0: break tm, callback = next_alarm callback() if self.event_loop._alarms: next_alarm = heapq.heappop(self.event_loop._alarms) else: next_alarm = None if 'window resize' in keys: self.screen_size = None def _test_run_screen_event_loop(self): """ >>> w = _refl("widget") >>> scr = _refl("screen") >>> scr.get_cols_rows_rval = (10, 5) >>> scr.get_input_rval = [], [] >>> ml = MainLoop(w, screen=scr) >>> def stop_now(loop, data): ... raise ExitMainLoop() >>> handle = ml.set_alarm_in(0, stop_now) >>> try: ... ml._run_screen_event_loop() ... except ExitMainLoop: ... pass screen.get_cols_rows() widget.render((10, 5), focus=True) screen.draw_screen((10, 5), None) screen.set_input_timeouts(0) screen.get_input(True) """ def process_input(self, keys): """ This method will pass keyboard input and mouse events to :attr:`widget`. This method is called automatically from the :meth:`run` method when there is input, but may also be called to simulate input from the user. *keys* is a list of input returned from :attr:`screen`'s get_input() or get_input_nonblocking() methods. Returns ``True`` if any key was handled by a widget or the :meth:`unhandled_input` method. """ if not self.screen_size: self.screen_size = self.screen.get_cols_rows() something_handled = False for k in keys: if k == 'window resize': continue if is_mouse_event(k): event, button, col, row = k if self._topmost_widget.mouse_event(self.screen_size, event, button, col, row, focus=True ): k = None elif self._topmost_widget.selectable(): k = self._topmost_widget.keypress(self.screen_size, k) if k: if command_map[k] == REDRAW_SCREEN: self.screen.clear() something_handled = True else: something_handled |= bool(self.unhandled_input(k)) else: something_handled = True return something_handled def _test_process_input(self): """ >>> w = _refl("widget") >>> w.selectable_rval = True >>> scr = _refl("screen") >>> scr.get_cols_rows_rval = (10, 5) >>> ml = MainLoop(w, [], scr) >>> ml.process_input(['enter', ('mouse drag', 1, 14, 20)]) screen.get_cols_rows() widget.selectable() widget.keypress((10, 5), 'enter') widget.mouse_event((10, 5), 'mouse drag', 1, 14, 20, focus=True) True """ def input_filter(self, keys, raw): """ This function is passed each all the input events and raw keystroke values. These values are passed to the *input_filter* function passed to the constructor. That function must return a list of keys to be passed to the widgets to handle. If no *input_filter* was defined this implementation will return all the input events. """ if self._input_filter: return self._input_filter(keys, raw) return keys def unhandled_input(self, input): """ This function is called with any input that was not handled by the widgets, and calls the *unhandled_input* function passed to the constructor. If no *unhandled_input* was defined then the input will be ignored. *input* is the keyboard or mouse input. The *unhandled_input* function should return ``True`` if it handled the input. """ if self._unhandled_input: return self._unhandled_input(input) def entering_idle(self): """ This method is called whenever the event loop is about to enter the idle state. :meth:`draw_screen` is called here to update the screen when anything has changed. """ if self.screen.started: self.draw_screen() def draw_screen(self): """ Render the widgets and paint the screen. This method is called automatically from :meth:`entering_idle`. If you modify the widgets displayed outside of handling input or responding to an alarm you will need to call this method yourself to repaint the screen. """ if not self.screen_size: self.screen_size = self.screen.get_cols_rows() canvas = self._topmost_widget.render(self.screen_size, focus=True) self.screen.draw_screen(self.screen_size, canvas)
def _set_pop_ups(self, pop_ups): self._pop_ups = pop_ups if pop_ups: self._topmost_widget = PopUpTarget(self._widget) else: self._topmost_widget = self._widget
class MainLoop(object): """ This is the standard main loop implementation for a single interactive session. :param widget: the topmost widget used for painting the screen, stored as :attr:`widget` and may be modified. Must be a box widget. :type widget: widget instance :param palette: initial palette for screen :type palette: iterable of palette entries :param screen: screen to use, default is a new :class:`raw_display.Screen` instance; stored as :attr:`screen` :type screen: display module screen instance :param handle_mouse: ``True`` to ask :attr:`.screen` to process mouse events :type handle_mouse: bool :param input_filter: a function to filter input before sending it to :attr:`.widget`, called from :meth:`.input_filter` :type input_filter: callable :param unhandled_input: a function called when input is not handled by :attr:`.widget`, called from :meth:`.unhandled_input` :type unhandled_input: callable :param event_loop: if :attr:`.screen` supports external an event loop it may be given here, default is a new :class:`SelectEventLoop` instance; stored as :attr:`.event_loop` :type event_loop: event loop instance :param pop_ups: `True` to wrap :attr:`.widget` with a :class:`PopUpTarget` instance to allow any widget to open a pop-up anywhere on the screen :type pop_ups: boolean .. attribute:: screen The screen object this main loop uses for screen updates and reading input .. attribute:: event_loop The event loop object this main loop uses for waiting on alarms and IO """ def __init__(self, widget, palette=(), screen=None, handle_mouse=True, input_filter=None, unhandled_input=None, event_loop=None, pop_ups=False): self._widget = widget self.handle_mouse = handle_mouse self.pop_ups = pop_ups # triggers property setting side-effect if not screen: from urwid import raw_display screen = raw_display.Screen() if palette: screen.register_palette(palette) self.screen = screen self.screen_size = None self._unhandled_input = unhandled_input self._input_filter = input_filter if not hasattr(screen, 'get_input_descriptors') and event_loop is not None: raise NotImplementedError( "screen object passed " "%r does not support external event loops" % (screen, )) if event_loop is None: event_loop = SelectEventLoop() self.event_loop = event_loop self._input_timeout = None self._watch_pipes = {} def _set_widget(self, widget): self._widget = widget if self.pop_ups: self._topmost_widget.original_widget = self._widget else: self._topmost_widget = self._widget widget = property(lambda self: self._widget, _set_widget, doc=""" Property for the topmost widget used to draw the screen. This must be a box widget. """) def _set_pop_ups(self, pop_ups): self._pop_ups = pop_ups if pop_ups: self._topmost_widget = PopUpTarget(self._widget) else: self._topmost_widget = self._widget pop_ups = property(lambda self: self._pop_ups, _set_pop_ups) def set_alarm_in(self, sec, callback, user_data=None): """ Schedule an alarm in *sec* seconds that will call *callback* from the within the :meth:`run` method. :param sec: seconds until alarm :type sec: float :param callback: function to call with two parameters: this main loop object and *user_data* :type callback: callable """ def cb(): callback(self, user_data) return self.event_loop.alarm(sec, cb) def set_alarm_at(self, tm, callback, user_data=None): """ Schedule an alarm at *tm* time that will call *callback* from the within the :meth:`run` function. Returns a handle that may be passed to :meth:`remove_alarm`. :param tm: time to call callback e.g. ``time.time() + 5`` :type tm: float :param callback: function to call with two parameters: this main loop object and *user_data* :type callback: callable """ def cb(): callback(self, user_data) return self.event_loop.alarm(tm - time.time(), cb) def remove_alarm(self, handle): """ Remove an alarm. Return ``True`` if *handle* was found, ``False`` otherwise. """ return self.event_loop.remove_alarm(handle) def watch_pipe(self, callback): """ Create a pipe for use by a subprocess or thread to trigger a callback in the process/thread running the main loop. :param callback: function taking one parameter to call from within the process/thread running the main loop :type callback: callable This method returns a file descriptor attached to the write end of a pipe. The read end of the pipe is added to the list of files :attr:`event_loop` is watching. When data is written to the pipe the callback function will be called and passed a single value containing data read from the pipe. This method may be used any time you want to update widgets from another thread or subprocess. Data may be written to the returned file descriptor with ``os.write(fd, data)``. Ensure that data is less than 512 bytes (or 4K on Linux) so that the callback will be triggered just once with the complete value of data passed in. If the callback returns ``False`` then the watch will be removed from :attr:`event_loop` and the read end of the pipe will be closed. You are responsible for closing the write end of the pipe with ``os.close(fd)``. """ pipe_rd, pipe_wr = os.pipe() fcntl.fcntl(pipe_rd, fcntl.F_SETFL, os.O_NONBLOCK) watch_handle = None def cb(): data = os.read(pipe_rd, PIPE_BUFFER_READ_SIZE) rval = callback(data) if rval is False: self.event_loop.remove_watch_file(watch_handle) os.close(pipe_rd) watch_handle = self.event_loop.watch_file(pipe_rd, cb) self._watch_pipes[pipe_wr] = (watch_handle, pipe_rd) return pipe_wr def remove_watch_pipe(self, write_fd): """ Close the read end of the pipe and remove the watch created by :meth:`watch_pipe`. You are responsible for closing the write end of the pipe. Returns ``True`` if the watch pipe exists, ``False`` otherwise """ try: watch_handle, pipe_rd = self._watch_pipes.pop(write_fd) except KeyError: return False if not self.event_loop.remove_watch_file(watch_handle): return False os.close(pipe_rd) return True def watch_file(self, fd, callback): """ Call *callback* when *fd* has some data to read. No parameters are passed to callback. Returns a handle that may be passed to :meth:`remove_watch_file`. """ return self.event_loop.watch_file(fd, callback) def remove_watch_file(self, handle): """ Remove a watch file. Returns ``True`` if the watch file exists, ``False`` otherwise. """ return self.event_loop.remove_watch_file(handle) def run(self): """ Start the main loop handling input events and updating the screen. The loop will continue until an :exc:`ExitMainLoop` exception is raised. This method will use :attr:`screen`'s run_wrapper() method if :attr:`screen`'s start() method has not already been called. """ try: if self.screen.started: self._run() else: self.screen.run_wrapper(self._run) except ExitMainLoop: pass def _test_run(self): """ >>> w = _refl("widget") # _refl prints out function calls >>> w.render_rval = "fake canvas" # *_rval is used for return values >>> scr = _refl("screen") >>> scr.get_input_descriptors_rval = [42] >>> scr.get_cols_rows_rval = (20, 10) >>> scr.started = True >>> scr._urwid_signals = {} >>> evl = _refl("event_loop") >>> evl.enter_idle_rval = 1 >>> evl.watch_file_rval = 2 >>> ml = MainLoop(w, [], scr, event_loop=evl) >>> ml.run() # doctest:+ELLIPSIS screen.set_mouse_tracking() screen.get_cols_rows() widget.render((20, 10), focus=True) screen.draw_screen((20, 10), 'fake canvas') screen.get_input_descriptors() event_loop.watch_file(42, <bound method ...>) event_loop.enter_idle(<bound method ...>) event_loop.run() event_loop.remove_enter_idle(1) event_loop.remove_watch_file(2) >>> scr.started = False >>> ml.run() # doctest:+ELLIPSIS screen.run_wrapper(<bound method ...>) """ def _run(self): if self.handle_mouse: self.screen.set_mouse_tracking() if not hasattr(self.screen, 'get_input_descriptors'): return self._run_screen_event_loop() self.draw_screen() fd_handles = [] def reset_input_descriptors(only_remove=False): for handle in fd_handles: self.event_loop.remove_watch_file(handle) if only_remove: del fd_handles[:] else: fd_handles[:] = [ self.event_loop.watch_file(fd, self._update) for fd in self.screen.get_input_descriptors() ] if not fd_handles and self._input_timeout is not None: self.event_loop.remove_alarm(self._input_timeout) try: signals.connect_signal(self.screen, INPUT_DESCRIPTORS_CHANGED, reset_input_descriptors) except NameError: pass # watch our input descriptors reset_input_descriptors() idle_handle = self.event_loop.enter_idle(self.entering_idle) # Go.. self.event_loop.run() # tidy up self.event_loop.remove_enter_idle(idle_handle) reset_input_descriptors(True) signals.disconnect_signal(self.screen, INPUT_DESCRIPTORS_CHANGED, reset_input_descriptors) def _update(self, timeout=False): """ >>> w = _refl("widget") >>> w.selectable_rval = True >>> w.mouse_event_rval = True >>> scr = _refl("screen") >>> scr.get_cols_rows_rval = (15, 5) >>> scr.get_input_nonblocking_rval = 1, ['y'], [121] >>> evl = _refl("event_loop") >>> ml = MainLoop(w, [], scr, event_loop=evl) >>> ml._input_timeout = "old timeout" >>> ml._update() # doctest:+ELLIPSIS event_loop.remove_alarm('old timeout') screen.get_input_nonblocking() event_loop.alarm(1, <function ...>) screen.get_cols_rows() widget.selectable() widget.keypress((15, 5), 'y') >>> scr.get_input_nonblocking_rval = None, [("mouse press", 1, 5, 4) ... ], [] >>> ml._update() screen.get_input_nonblocking() widget.mouse_event((15, 5), 'mouse press', 1, 5, 4, focus=True) >>> scr.get_input_nonblocking_rval = None, [], [] >>> ml._update() screen.get_input_nonblocking() """ if self._input_timeout is not None and not timeout: # cancel the timeout, something else triggered the update self.event_loop.remove_alarm(self._input_timeout) self._input_timeout = None max_wait, keys, raw = self.screen.get_input_nonblocking() if max_wait is not None: # if get_input_nonblocking wants to be called back # make sure it happens with an alarm self._input_timeout = self.event_loop.alarm( max_wait, lambda: self._update(timeout=True)) keys = self.input_filter(keys, raw) if keys: self.process_input(keys) if 'window resize' in keys: self.screen_size = None def _run_screen_event_loop(self): """ This method is used when the screen does not support using external event loops. The alarms stored in the SelectEventLoop in :attr:`event_loop` are modified by this method. """ next_alarm = None while True: self.draw_screen() if not next_alarm and self.event_loop._alarms: next_alarm = heapq.heappop(self.event_loop._alarms) keys = None while not keys: if next_alarm: sec = max(0, next_alarm[0] - time.time()) self.screen.set_input_timeouts(sec) else: self.screen.set_input_timeouts(None) keys, raw = self.screen.get_input(True) if not keys and next_alarm: sec = next_alarm[0] - time.time() if sec <= 0: break keys = self.input_filter(keys, raw) if keys: self.process_input(keys) while next_alarm: sec = next_alarm[0] - time.time() if sec > 0: break tm, callback = next_alarm callback() if self.event_loop._alarms: next_alarm = heapq.heappop(self.event_loop._alarms) else: next_alarm = None if 'window resize' in keys: self.screen_size = None def _test_run_screen_event_loop(self): """ >>> w = _refl("widget") >>> scr = _refl("screen") >>> scr.get_cols_rows_rval = (10, 5) >>> scr.get_input_rval = [], [] >>> ml = MainLoop(w, screen=scr) >>> def stop_now(loop, data): ... raise ExitMainLoop() >>> handle = ml.set_alarm_in(0, stop_now) >>> try: ... ml._run_screen_event_loop() ... except ExitMainLoop: ... pass screen.get_cols_rows() widget.render((10, 5), focus=True) screen.draw_screen((10, 5), None) screen.set_input_timeouts(0) screen.get_input(True) """ def process_input(self, keys): """ This method will pass keyboard input and mouse events to :attr:`widget`. This method is called automatically from the :meth:`run` method when there is input, but may also be called to simulate input from the user. *keys* is a list of input returned from :attr:`screen`'s get_input() or get_input_nonblocking() methods. Returns ``True`` if any key was handled by a widget or the :meth:`unhandled_input` method. """ if not self.screen_size: self.screen_size = self.screen.get_cols_rows() something_handled = False for k in keys: if k == 'window resize': continue if is_mouse_event(k): event, button, col, row = k if self._topmost_widget.mouse_event(self.screen_size, event, button, col, row, focus=True): k = None elif self._topmost_widget.selectable(): k = self._topmost_widget.keypress(self.screen_size, k) if k: if command_map[k] == REDRAW_SCREEN: self.screen.clear() something_handled = True else: something_handled |= bool(self.unhandled_input(k)) else: something_handled = True return something_handled def _test_process_input(self): """ >>> w = _refl("widget") >>> w.selectable_rval = True >>> scr = _refl("screen") >>> scr.get_cols_rows_rval = (10, 5) >>> ml = MainLoop(w, [], scr) >>> ml.process_input(['enter', ('mouse drag', 1, 14, 20)]) screen.get_cols_rows() widget.selectable() widget.keypress((10, 5), 'enter') widget.mouse_event((10, 5), 'mouse drag', 1, 14, 20, focus=True) True """ def input_filter(self, keys, raw): """ This function is passed each all the input events and raw keystroke values. These values are passed to the *input_filter* function passed to the constructor. That function must return a list of keys to be passed to the widgets to handle. If no *input_filter* was defined this implementation will return all the input events. """ if self._input_filter: return self._input_filter(keys, raw) return keys def unhandled_input(self, input): """ This function is called with any input that was not handled by the widgets, and calls the *unhandled_input* function passed to the constructor. If no *unhandled_input* was defined then the input will be ignored. *input* is the keyboard or mouse input. The *unhandled_input* function should return ``True`` if it handled the input. """ if self._unhandled_input: return self._unhandled_input(input) def entering_idle(self): """ This method is called whenever the event loop is about to enter the idle state. :meth:`draw_screen` is called here to update the screen when anything has changed. """ if self.screen.started: self.draw_screen() def draw_screen(self): """ Render the widgets and paint the screen. This method is called automatically from :meth:`entering_idle`. If you modify the widgets displayed outside of handling input or responding to an alarm you will need to call this method yourself to repaint the screen. """ if not self.screen_size: self.screen_size = self.screen.get_cols_rows() canvas = self._topmost_widget.render(self.screen_size, focus=True) self.screen.draw_screen(self.screen_size, canvas)
class MainLoop(object): def __init__(self, widget, palette=[], screen=None, handle_mouse=True, input_filter=None, unhandled_input=None, event_loop=None, pop_ups=False): """ Simple main loop implementation. widget -- topmost widget used for painting the screen, stored as self.widget and may be modified palette -- initial palette for screen screen -- screen object or None to use raw_display.Screen, stored as self.screen handle_mouse -- True to process mouse events, passed to self.screen input_filter -- a function to filter input before sending it to self.widget, called from self.input_filter unhandled_input -- a function called when input is not handled by self.widget, called from self.unhandled_input event_loop -- if screen supports external an event loop it may be given here, or leave as None to use SelectEventLoop, stored as self.event_loop pop_ups -- True to wrap self.widget with a PopUpTarget instance to allow any widget to open a pop-up anywhere on the screen This is the standard main loop implementation with a single screen. The widget passed must be a box widget. """ self._widget = widget self.handle_mouse = handle_mouse self.pop_ups = pop_ups # triggers property setting side-effect if not screen: from urwid import raw_display screen = raw_display.Screen() if palette: screen.register_palette(palette) self.screen = screen self.screen_size = None self._unhandled_input = unhandled_input self._input_filter = input_filter if not hasattr(screen, 'get_input_descriptors' ) and event_loop is not None: raise NotImplementedError("screen object passed " "%r does not support external event loops" % (screen,)) if event_loop is None: event_loop = SelectEventLoop() self.event_loop = event_loop self._input_timeout = None self._watch_pipes = {} def _set_widget(self, widget): self._widget = widget if self.pop_ups: self._topmost_widget.original_widget = self._widget else: self._topmost_widget = self._widget widget = property(lambda self:self._widget, _set_widget) def _set_pop_ups(self, pop_ups): self._pop_ups = pop_ups if pop_ups: self._topmost_widget = PopUpTarget(self._widget) else: self._topmost_widget = self._widget pop_ups = property(lambda self:self._pop_ups, _set_pop_ups) def set_alarm_in(self, sec, callback, user_data=None): """ Schedule an alarm in sec seconds that will call callback(main_loop, user_data) from the within the run() function. sec -- floating point seconds until alarm callback -- callback(main_loop, user_data) callback function user_data -- object to pass to callback """ def cb(): callback(self, user_data) return self.event_loop.alarm(sec, cb) def set_alarm_at(self, tm, callback, user_data=None): """ Schedule at tm time that will call callback(main_loop, user_data) from the within the run() function. Returns a handle that may be passed to remove_alarm() tm -- floating point local time of alarm callback -- callback(main_loop, user_data) callback function user_data -- object to pass to callback """ def cb(): callback(self, user_data) return self.event_loop.alarm(tm - time.time(), cb) def remove_alarm(self, handle): """ Remove an alarm. Return True if the handle was found, False otherwise. """ return self.event_loop.remove_alarm(handle) def watch_pipe(self, callback): """ Create a pipe for use by a subprocess or thread to trigger a callback in the process/thread running the MainLoop. callback -- function to call MainLoop.run thread/process This function returns a file descriptor attached to the write end of a pipe. The read end of the pipe is added to the list of files the event loop is watching. When data is written to the pipe the callback function will be called and passed a single value containing data read. This method should be used any time you want to update widgets from another thread or subprocess. Data may be written to the returned file descriptor with os.write(fd, data). Ensure that data is less than 512 bytes (or 4K on Linux) so that the callback will be triggered just once with the complete value of data passed in. If the callback returns False then the watch will be removed and the read end of the pipe will be closed. You are responsible for closing the write end of the pipe. """ pipe_rd, pipe_wr = os.pipe() fcntl.fcntl(pipe_rd, fcntl.F_SETFL, os.O_NONBLOCK) watch_handle = None def cb(): data = os.read(pipe_rd, PIPE_BUFFER_READ_SIZE) rval = callback(data) if rval is False: self.event_loop.remove_watch_file(watch_handle) os.close(pipe_rd) watch_handle = self.event_loop.watch_file(pipe_rd, cb) self._watch_pipes[pipe_wr] = (watch_handle, pipe_rd) return pipe_wr def remove_watch_pipe(self, write_fd): """ Close the read end of the pipe and remove the watch created by watch_pipe(). You are responsible for closing the write end of the pipe. Returns True if the watch pipe exists, False otherwise """ try: watch_handle, pipe_rd = self._watch_pipes.pop(write_fd) except KeyError: return False if not self.event_loop.remove_watch_file(watch_handle): return False os.close(pipe_rd) return True def watch_file(self, fd, callback): """ Call callback() when fd has some data to read. No parameters are passed to callback. Returns a handle that may be passed to remove_watch_file() fd -- file descriptor to watch for input callback -- function to call when input is available """ return self.event_loop.watch_file(fd, callback) def remove_watch_file(self, handle): """ Remove a watch file. Returns True if the watch file exists, False otherwise. """ return self.event_loop.remove_watch_file(handle) def run(self): """ Start the main loop handling input events and updating the screen. The loop will continue until an ExitMainLoop exception is raised. This function will call screen.run_wrapper() if screen.start() has not already been called. >>> w = _refl("widget") # _refl prints out function calls >>> w.render_rval = "fake canvas" # *_rval is used for return values >>> scr = _refl("screen") >>> scr.get_input_descriptors_rval = [42] >>> scr.get_cols_rows_rval = (20, 10) >>> scr.started = True >>> scr._urwid_signals = {} >>> evl = _refl("event_loop") >>> evl.enter_idle_rval = 1 >>> evl.watch_file_rval = 2 >>> ml = MainLoop(w, [], scr, event_loop=evl) >>> ml.run() # doctest:+ELLIPSIS screen.set_mouse_tracking() screen.get_cols_rows() widget.render((20, 10), focus=True) screen.draw_screen((20, 10), 'fake canvas') screen.get_input_descriptors() event_loop.watch_file(42, <bound method ...>) event_loop.enter_idle(<bound method ...>) event_loop.run() event_loop.remove_enter_idle(1) event_loop.remove_watch_file(2) >>> scr.started = False >>> ml.run() # doctest:+ELLIPSIS screen.run_wrapper(<bound method ...>) """ try: if self.screen.started: self._run() else: self.screen.run_wrapper(self._run) except ExitMainLoop: pass def _run(self): if self.handle_mouse: self.screen.set_mouse_tracking() if not hasattr(self.screen, 'get_input_descriptors'): return self._run_screen_event_loop() self.draw_screen() fd_handles = [] def reset_input_descriptors(only_remove=False): for handle in fd_handles: self.event_loop.remove_watch_file(handle) if only_remove: return fd_handles[:] = [ self.event_loop.watch_file(fd, self._update) for fd in self.screen.get_input_descriptors()] try: signals.connect_signal(self.screen, INPUT_DESCRIPTORS_CHANGED, reset_input_descriptors) except NameError: pass # watch our input descriptors reset_input_descriptors() idle_handle = self.event_loop.enter_idle(self.entering_idle) # Go.. self.event_loop.run() # tidy up self.event_loop.remove_enter_idle(idle_handle) reset_input_descriptors(True) signals.disconnect_signal(self.screen, INPUT_DESCRIPTORS_CHANGED, reset_input_descriptors) def _update(self, timeout=False): """ >>> w = _refl("widget") >>> w.selectable_rval = True >>> w.mouse_event_rval = True >>> scr = _refl("screen") >>> scr.get_cols_rows_rval = (15, 5) >>> scr.get_input_nonblocking_rval = 1, ['y'], [121] >>> evl = _refl("event_loop") >>> ml = MainLoop(w, [], scr, event_loop=evl) >>> ml._input_timeout = "old timeout" >>> ml._update() # doctest:+ELLIPSIS event_loop.remove_alarm('old timeout') screen.get_input_nonblocking() event_loop.alarm(1, <function ...>) screen.get_cols_rows() widget.selectable() widget.keypress((15, 5), 'y') >>> scr.get_input_nonblocking_rval = None, [("mouse press", 1, 5, 4) ... ], [] >>> ml._update() screen.get_input_nonblocking() widget.mouse_event((15, 5), 'mouse press', 1, 5, 4, focus=True) >>> scr.get_input_nonblocking_rval = None, [], [] >>> ml._update() screen.get_input_nonblocking() """ if self._input_timeout is not None and not timeout: # cancel the timeout, something else triggered the update self.event_loop.remove_alarm(self._input_timeout) self._input_timeout = None max_wait, keys, raw = self.screen.get_input_nonblocking() if max_wait is not None: # if get_input_nonblocking wants to be called back # make sure it happens with an alarm self._input_timeout = self.event_loop.alarm(max_wait, lambda: self._update(timeout=True)) keys = self.input_filter(keys, raw) if keys: self.process_input(keys) if 'window resize' in keys: self.screen_size = None def _run_screen_event_loop(self): """ This method is used when the screen does not support using external event loops. The alarms stored in the SelectEventLoop in self.event_loop are modified by this method. """ next_alarm = None while True: self.draw_screen() if not next_alarm and self.event_loop._alarms: next_alarm = heapq.heappop(self.event_loop._alarms) keys = None while not keys: if next_alarm: sec = max(0, next_alarm[0] - time.time()) self.screen.set_input_timeouts(sec) else: self.screen.set_input_timeouts(None) keys, raw = self.screen.get_input(True) if not keys and next_alarm: sec = next_alarm[0] - time.time() if sec <= 0: break keys = self.input_filter(keys, raw) if keys: self.process_input(keys) while next_alarm: sec = next_alarm[0] - time.time() if sec > 0: break tm, callback, user_data = next_alarm callback(self, user_data) if self._alarms: next_alarm = heapq.heappop(self.event_loop._alarms) else: next_alarm = None if 'window resize' in keys: self.screen_size = None def process_input(self, keys): """ This function will pass keyboard input and mouse events to self.widget. This function is called automatically from the run() method when there is input, but may also be called to simulate input from the user. keys -- list of input returned from self.screen.get_input() Returns True if any key was handled by a widget or the unhandled_input() method. >>> w = _refl("widget") >>> w.selectable_rval = True >>> scr = _refl("screen") >>> scr.get_cols_rows_rval = (10, 5) >>> ml = MainLoop(w, [], scr) >>> ml.process_input(['enter', ('mouse drag', 1, 14, 20)]) screen.get_cols_rows() widget.selectable() widget.keypress((10, 5), 'enter') widget.mouse_event((10, 5), 'mouse drag', 1, 14, 20, focus=True) True """ if not self.screen_size: self.screen_size = self.screen.get_cols_rows() something_handled = False for k in keys: if k == 'window resize': continue if is_mouse_event(k): event, button, col, row = k if self._topmost_widget.mouse_event(self.screen_size, event, button, col, row, focus=True ): k = None elif self._topmost_widget.selectable(): k = self._topmost_widget.keypress(self.screen_size, k) if k: if command_map[k] == 'redraw screen': self.screen.clear() something_handled = True else: something_handled |= bool(self.unhandled_input(k)) else: something_handled = True return something_handled def input_filter(self, keys, raw): """ This function is passed each all the input events and raw keystroke values. These values are passed to the input_filter function passed to the constructor. That function must return a list of keys to be passed to the widgets to handle. If no input_filter was defined this implementation will return all the input events. input -- keyboard or mouse input """ if self._input_filter: return self._input_filter(keys, raw) return keys def unhandled_input(self, input): """ This function is called with any input that was not handled by the widgets, and calls the unhandled_input function passed to the constructor. If no unhandled_input was defined then the input will be ignored. input -- keyboard or mouse input The unhandled_input method should return True if it handled the input. """ if self._unhandled_input: return self._unhandled_input(input) def entering_idle(self): """ This function is called whenever the event loop is about to enter the idle state. self.draw_screen() is called here to update the screen if anything has changed. """ if self.screen.started: self.draw_screen() def draw_screen(self): """ Render the widgets and paint the screen. This function is called automatically from run() but may be called additional times if repainting is required without also processing input. """ if not self.screen_size: self.screen_size = self.screen.get_cols_rows() canvas = self._topmost_widget.render(self.screen_size, focus=True) self.screen.draw_screen(self.screen_size, canvas)
class MainLoop(object): def __init__(self, widget, palette=[], screen=None, handle_mouse=True, input_filter=None, unhandled_input=None, event_loop=None, pop_ups=False): """ Simple main loop implementation. widget -- topmost widget used for painting the screen, stored as self.widget and may be modified palette -- initial palette for screen screen -- screen object or None to use raw_display.Screen, stored as self.screen handle_mouse -- True to process mouse events, passed to self.screen input_filter -- a function to filter input before sending it to self.widget, called from self.input_filter unhandled_input -- a function called when input is not handled by self.widget, called from self.unhandled_input event_loop -- if screen supports external an event loop it may be given here, or leave as None to use SelectEventLoop, stored as self.event_loop pop_ups -- True to wrap self.widget with a PopUpTarget instance to allow any widget to open a pop-up anywhere on the screen This is the standard main loop implementation with a single screen. The widget passed must be a box widget. """ self._widget = widget self.handle_mouse = handle_mouse self.pop_ups = pop_ups # triggers property setting side-effect if not screen: from urwid import raw_display screen = raw_display.Screen() if palette: screen.register_palette(palette) self.screen = screen self.screen_size = None self._unhandled_input = unhandled_input self._input_filter = input_filter if not hasattr(screen, 'get_input_descriptors') and event_loop is not None: raise NotImplementedError( "screen object passed " "%r does not support external event loops" % (screen, )) if event_loop is None: event_loop = SelectEventLoop() self.event_loop = event_loop self._input_timeout = None self._watch_pipes = {} def _set_widget(self, widget): self._widget = widget if self.pop_ups: self._topmost_widget.original_widget = self._widget else: self._topmost_widget = self._widget widget = property(lambda self: self._widget, _set_widget) def _set_pop_ups(self, pop_ups): self._pop_ups = pop_ups if pop_ups: self._topmost_widget = PopUpTarget(self._widget) else: self._topmost_widget = self._widget pop_ups = property(lambda self: self._pop_ups, _set_pop_ups) def set_alarm_in(self, sec, callback, user_data=None): """ Schedule an alarm in sec seconds that will call callback(main_loop, user_data) from the within the run() function. sec -- floating point seconds until alarm callback -- callback(main_loop, user_data) callback function user_data -- object to pass to callback """ def cb(): callback(self, user_data) return self.event_loop.alarm(sec, cb) def set_alarm_at(self, tm, callback, user_data=None): """ Schedule at tm time that will call callback(main_loop, user_data) from the within the run() function. Returns a handle that may be passed to remove_alarm() tm -- floating point local time of alarm callback -- callback(main_loop, user_data) callback function user_data -- object to pass to callback """ def cb(): callback(self, user_data) return self.event_loop.alarm(tm - time.time(), cb) def remove_alarm(self, handle): """ Remove an alarm. Return True if the handle was found, False otherwise. """ return self.event_loop.remove_alarm(handle) def watch_pipe(self, callback): """ Create a pipe for use by a subprocess or thread to trigger a callback in the process/thread running the MainLoop. callback -- function to call MainLoop.run thread/process This function returns a file descriptor attached to the write end of a pipe. The read end of the pipe is added to the list of files the event loop is watching. When data is written to the pipe the callback function will be called and passed a single value containing data read. This method should be used any time you want to update widgets from another thread or subprocess. Data may be written to the returned file descriptor with os.write(fd, data). Ensure that data is less than 512 bytes (or 4K on Linux) so that the callback will be triggered just once with the complete value of data passed in. If the callback returns False then the watch will be removed and the read end of the pipe will be closed. You are responsible for closing the write end of the pipe. """ pipe_rd, pipe_wr = os.pipe() fcntl.fcntl(pipe_rd, fcntl.F_SETFL, os.O_NONBLOCK) watch_handle = None def cb(): data = os.read(pipe_rd, PIPE_BUFFER_READ_SIZE) rval = callback(data) if rval is False: self.event_loop.remove_watch_file(watch_handle) os.close(pipe_rd) watch_handle = self.event_loop.watch_file(pipe_rd, cb) self._watch_pipes[pipe_wr] = (watch_handle, pipe_rd) return pipe_wr def remove_watch_pipe(self, write_fd): """ Close the read end of the pipe and remove the watch created by watch_pipe(). You are responsible for closing the write end of the pipe. Returns True if the watch pipe exists, False otherwise """ try: watch_handle, pipe_rd = self._watch_pipes.remove(write_fd) except KeyError: return False if not self.event_loop.remove_watch_file(watch_handle): return False os.close(pipe_rd) return True def watch_file(self, fd, callback): """ Call callback() when fd has some data to read. No parameters are passed to callback. Returns a handle that may be passed to remove_watch_file() fd -- file descriptor to watch for input callback -- function to call when input is available """ return self.event_loop.watch_file(fd, callback) def remove_watch_file(self, handle): """ Remove a watch file. Returns True if the watch file exists, False otherwise. """ return self.event_loop.remove_watch_file(handle) def run(self): """ Start the main loop handling input events and updating the screen. The loop will continue until an ExitMainLoop exception is raised. This function will call screen.run_wrapper() if screen.start() has not already been called. >>> w = _refl("widget") # _refl prints out function calls >>> w.render_rval = "fake canvas" # *_rval is used for return values >>> scr = _refl("screen") >>> scr.get_input_descriptors_rval = [42] >>> scr.get_cols_rows_rval = (20, 10) >>> scr.started = True >>> scr._urwid_signals = {} >>> evl = _refl("event_loop") >>> evl.enter_idle_rval = 1 >>> evl.watch_file_rval = 2 >>> ml = MainLoop(w, [], scr, event_loop=evl) >>> ml.run() # doctest:+ELLIPSIS screen.set_mouse_tracking() screen.get_cols_rows() widget.render((20, 10), focus=True) screen.draw_screen((20, 10), 'fake canvas') screen.get_input_descriptors() event_loop.watch_file(42, <bound method ...>) event_loop.enter_idle(<bound method ...>) event_loop.run() event_loop.remove_enter_idle(1) event_loop.remove_watch_file(2) >>> scr.started = False >>> ml.run() # doctest:+ELLIPSIS screen.run_wrapper(<bound method ...>) """ try: if self.screen.started: self._run() else: self.screen.run_wrapper(self._run) except ExitMainLoop: pass def _run(self): if self.handle_mouse: self.screen.set_mouse_tracking() if not hasattr(self.screen, 'get_input_descriptors'): return self._run_screen_event_loop() self.draw_screen() fd_handles = [] def reset_input_descriptors(only_remove=False): for handle in fd_handles: self.event_loop.remove_watch_file(handle) if only_remove: return fd_handles[:] = [ self.event_loop.watch_file(fd, self._update) for fd in self.screen.get_input_descriptors() ] try: signals.connect_signal(self.screen, INPUT_DESCRIPTORS_CHANGED, reset_input_descriptors) except NameError: pass # watch our input descriptors reset_input_descriptors() idle_handle = self.event_loop.enter_idle(self.entering_idle) # Go.. self.event_loop.run() # tidy up self.event_loop.remove_enter_idle(idle_handle) reset_input_descriptors(True) signals.disconnect_signal(self.screen, INPUT_DESCRIPTORS_CHANGED, reset_input_descriptors) def _update(self, timeout=False): """ >>> w = _refl("widget") >>> w.selectable_rval = True >>> w.mouse_event_rval = True >>> scr = _refl("screen") >>> scr.get_cols_rows_rval = (15, 5) >>> scr.get_input_nonblocking_rval = 1, ['y'], [121] >>> evl = _refl("event_loop") >>> ml = MainLoop(w, [], scr, event_loop=evl) >>> ml._input_timeout = "old timeout" >>> ml._update() # doctest:+ELLIPSIS event_loop.remove_alarm('old timeout') screen.get_input_nonblocking() event_loop.alarm(1, <function ...>) screen.get_cols_rows() widget.selectable() widget.keypress((15, 5), 'y') >>> scr.get_input_nonblocking_rval = None, [("mouse press", 1, 5, 4) ... ], [] >>> ml._update() screen.get_input_nonblocking() widget.mouse_event((15, 5), 'mouse press', 1, 5, 4, focus=True) >>> scr.get_input_nonblocking_rval = None, [], [] >>> ml._update() screen.get_input_nonblocking() """ if self._input_timeout is not None and not timeout: # cancel the timeout, something else triggered the update self.event_loop.remove_alarm(self._input_timeout) self._input_timeout = None max_wait, keys, raw = self.screen.get_input_nonblocking() if max_wait is not None: # if get_input_nonblocking wants to be called back # make sure it happens with an alarm self._input_timeout = self.event_loop.alarm( max_wait, lambda: self._update(timeout=True)) keys = self.input_filter(keys, raw) if keys: self.process_input(keys) if 'window resize' in keys: self.screen_size = None def _run_screen_event_loop(self): """ This method is used when the screen does not support using external event loops. The alarms stored in the SelectEventLoop in self.event_loop are modified by this method. """ next_alarm = None while True: self.draw_screen() if not next_alarm and self.event_loop._alarms: next_alarm = heapq.heappop(self.event_loop._alarms) keys = None while not keys: if next_alarm: sec = max(0, next_alarm[0] - time.time()) self.screen.set_input_timeouts(sec) else: self.screen.set_input_timeouts(None) keys, raw = self.screen.get_input(True) if not keys and next_alarm: sec = next_alarm[0] - time.time() if sec <= 0: break keys = self.input_filter(keys, raw) if keys: self.process_input(keys) while next_alarm: sec = next_alarm[0] - time.time() if sec > 0: break tm, callback, user_data = next_alarm callback(self, user_data) if self._alarms: next_alarm = heapq.heappop(self.event_loop._alarms) else: next_alarm = None if 'window resize' in keys: self.screen_size = None def process_input(self, keys): """ This function will pass keyboard input and mouse events to self.widget. This function is called automatically from the run() method when there is input, but may also be called to simulate input from the user. keys -- list of input returned from self.screen.get_input() Returns True if any key was handled by a widget or the unhandled_input() method. >>> w = _refl("widget") >>> w.selectable_rval = True >>> scr = _refl("screen") >>> scr.get_cols_rows_rval = (10, 5) >>> ml = MainLoop(w, [], scr) >>> ml.process_input(['enter', ('mouse drag', 1, 14, 20)]) screen.get_cols_rows() widget.selectable() widget.keypress((10, 5), 'enter') widget.mouse_event((10, 5), 'mouse drag', 1, 14, 20, focus=True) True """ if not self.screen_size: self.screen_size = self.screen.get_cols_rows() something_handled = False for k in keys: if is_mouse_event(k): event, button, col, row = k if self._topmost_widget.mouse_event(self.screen_size, event, button, col, row, focus=True): k = None elif self._topmost_widget.selectable(): k = self._topmost_widget.keypress(self.screen_size, k) if k: if command_map[k] == 'redraw screen': self.screen.clear() something_handled = True else: something_handled |= bool(self.unhandled_input(k)) else: something_handled = True return something_handled def input_filter(self, keys, raw): """ This function is passed each all the input events and raw keystroke values. These values are passed to the input_filter function passed to the constructor. That function must return a list of keys to be passed to the widgets to handle. If no input_filter was defined this implementation will return all the input events. input -- keyboard or mouse input """ if self._input_filter: return self._input_filter(keys, raw) return keys def unhandled_input(self, input): """ This function is called with any input that was not handled by the widgets, and calls the unhandled_input function passed to the constructor. If no unhandled_input was defined then the input will be ignored. input -- keyboard or mouse input The unhandled_input method should return True if it handled the input. """ if self._unhandled_input: return self._unhandled_input(input) def entering_idle(self): """ This function is called whenever the event loop is about to enter the idle state. self.draw_screen() is called here to update the screen if anything has changed. """ if self.screen.started: self.draw_screen() def draw_screen(self): """ Renter the widgets and paint the screen. This function is called automatically from run() but may be called additional times if repainting is required without also processing input. """ if not self.screen_size: self.screen_size = self.screen.get_cols_rows() canvas = self._topmost_widget.render(self.screen_size, focus=True) self.screen.draw_screen(self.screen_size, canvas)