name : blocking_input.py """ This provides several classes used for blocking interaction with figure windows: :class:`BlockingInput` creates a callable object to retrieve events in a blocking way for interactive sessions :class:`BlockingKeyMouseInput` creates a callable object to retrieve key or mouse clicks in a blocking way for interactive sessions. Note: Subclass of BlockingInput. Used by waitforbuttonpress :class:`BlockingMouseInput` creates a callable object to retrieve mouse clicks in a blocking way for interactive sessions. Note: Subclass of BlockingInput. Used by ginput :class:`BlockingContourLabeler` creates a callable object to retrieve mouse clicks in a blocking way that will then be used to place labels on a ContourSet Note: Subclass of BlockingMouseInput. Used by clabel """ from __future__ import print_function from matplotlib import verbose from matplotlib.cbook import is_sequence_of_strings import matplotlib.lines as mlines class BlockingInput(object): """ Class that creates a callable object to retrieve events in a blocking way. """ def __init__(self, fig, eventslist=()): self.fig = fig assert is_sequence_of_strings( eventslist), "Requires a sequence of event name strings" self.eventslist = eventslist def on_event(self, event): """ Event handler that will be passed to the current figure to retrieve events. """ # Add a new event to list - using a separate function is # overkill for the base class, but this is consistent with # subclasses self.add_event(event) verbose.report("Event %i" % len(self.events)) # This will extract info from events self.post_event() # Check if we have enough events already if len(self.events) >= self.n and self.n > 0: self.fig.canvas.stop_event_loop() def post_event(self): """For baseclass, do nothing but collect events""" pass def cleanup(self): """Disconnect all callbacks""" for cb in self.callbacks: self.fig.canvas.mpl_disconnect(cb) self.callbacks = [] def add_event(self, event): """For base class, this just appends an event to events.""" self.events.append(event) def pop_event(self, index=-1): """ This removes an event from the event list. Defaults to removing last event, but an index can be supplied. Note that this does not check that there are events, much like the normal pop method. If not events exist, this will throw an exception. """ self.events.pop(index) def pop(self, index=-1): self.pop_event(index) pop.__doc__ = pop_event.__doc__ def __call__(self, n=1, timeout=30): """ Blocking call to retrieve n events """ assert isinstance(n, int), "Requires an integer argument" self.n = n self.events = [] self.callbacks = [] # Ensure that the figure is shown self.fig.show() # connect the events to the on_event function call for n in self.eventslist: self.callbacks.append( self.fig.canvas.mpl_connect(n, self.on_event)) try: # Start event loop self.fig.canvas.start_event_loop(timeout=timeout) finally: # Run even on exception like ctrl-c # Disconnect the callbacks self.cleanup() # Return the events in this case return self.events class BlockingMouseInput(BlockingInput): """ Class that creates a callable object to retrieve mouse clicks in a blocking way. This class will also retrieve keyboard clicks and treat them like appropriate mouse clicks (delete and backspace are like mouse button 3, enter is like mouse button 2 and all others are like mouse button 1). """ button_add = 1 button_pop = 3 button_stop = 2 def __init__(self, fig, mouse_add=1, mouse_pop=3, mouse_stop=2): BlockingInput.__init__(self, fig=fig, eventslist=('button_press_event', 'key_press_event')) self.button_add = mouse_add self.button_pop = mouse_pop self.button_stop = mouse_stop def post_event(self): """ This will be called to process events """ assert len(self.events) > 0, "No events yet" if self.events[-1].name == 'key_press_event': self.key_event() else: self.mouse_event() def mouse_event(self): '''Process a mouse click event''' event = self.events[-1] button = event.button if button == self.button_pop: self.mouse_event_pop(event) elif button == self.button_stop: self.mouse_event_stop(event) else: self.mouse_event_add(event) def key_event(self): ''' Process a key click event. This maps certain keys to appropriate mouse click events. ''' event = self.events[-1] if event.key is None: # at least in mac os X gtk backend some key returns None. return key = event.key.lower() if key in ['backspace', 'delete']: self.mouse_event_pop(event) elif key in ['escape', 'enter']: # on windows XP and wxAgg, the enter key doesn't seem to register self.mouse_event_stop(event) else: self.mouse_event_add(event) def mouse_event_add(self, event): """ Will be called for any event involving a button other than button 2 or 3. This will add a click if it is inside axes. """ if event.inaxes: self.add_click(event) else: # If not a valid click, remove from event list BlockingInput.pop(self, -1) def mouse_event_stop(self, event): """ Will be called for any event involving button 2. Button 2 ends blocking input. """ # Remove last event just for cleanliness BlockingInput.pop(self, -1) # This will exit even if not in infinite mode. This is # consistent with MATLAB and sometimes quite useful, but will # require the user to test how many points were actually # returned before using data. self.fig.canvas.stop_event_loop() def mouse_event_pop(self, event): """ Will be called for any event involving button 3. Button 3 removes the last click. """ # Remove this last event BlockingInput.pop(self, -1) # Now remove any existing clicks if possible if len(self.events) > 0: self.pop(event, -1) def add_click(self, event): """ This add the coordinates of an event to the list of clicks """ self.clicks.append((event.xdata, event.ydata)) verbose.report("input %i: %f,%f" % (len(self.clicks), event.xdata, event.ydata)) # If desired plot up click if self.show_clicks: line = mlines.Line2D([event.xdata], [event.ydata], marker='+', color='r') event.inaxes.add_line(line) self.marks.append(line) self.fig.canvas.draw() def pop_click(self, event, index=-1): """ This removes a click from the list of clicks. Defaults to removing the last click. """ self.clicks.pop(index) if self.show_clicks: mark = self.marks.pop(index) mark.remove() self.fig.canvas.draw() # NOTE: I do NOT understand why the above 3 lines does not work # for the keyboard backspace event on windows XP wxAgg. # maybe event.inaxes here is a COPY of the actual axes? def pop(self, event, index=-1): """ This removes a click and the associated event from the object. Defaults to removing the last click, but any index can be supplied. """ self.pop_click(event, index) BlockingInput.pop(self, index) def cleanup(self, event=None): # clean the figure if self.show_clicks: for mark in self.marks: mark.remove() self.marks = [] self.fig.canvas.draw() # Call base class to remove callbacks BlockingInput.cleanup(self) def __call__(self, n=1, timeout=30, show_clicks=True): """ Blocking call to retrieve n coordinate pairs through mouse clicks. """ self.show_clicks = show_clicks self.clicks = [] self.marks = [] BlockingInput.__call__(self, n=n, timeout=timeout) return self.clicks class BlockingContourLabeler(BlockingMouseInput): """ Class that creates a callable object that uses mouse clicks or key clicks on a figure window to place contour labels. """ def __init__(self, cs): self.cs = cs BlockingMouseInput.__init__(self, fig=cs.ax.figure) def add_click(self, event): self.button1(event) def pop_click(self, event, index=-1): self.button3(event) def button1(self, event): """ This will be called if an event involving a button other than 2 or 3 occcurs. This will add a label to a contour. """ # Shorthand if event.inaxes == self.cs.ax: self.cs.add_label_near(event.x, event.y, self.inline, inline_spacing=self.inline_spacing, transform=False) self.fig.canvas.draw() else: # Remove event if not valid BlockingInput.pop(self) def button3(self, event): """ This will be called if button 3 is clicked. This will remove a label if not in inline mode. Unfortunately, if one is doing inline labels, then there is currently no way to fix the broken contour - once humpty-dumpty is broken, he can't be put back together. In inline mode, this does nothing. """ if self.inline: pass else: self.cs.pop_label() self.cs.ax.figure.canvas.draw() def __call__(self, inline, inline_spacing=5, n=-1, timeout=-1): self.inline = inline self.inline_spacing = inline_spacing BlockingMouseInput.__call__(self, n=n, timeout=timeout, show_clicks=False) class BlockingKeyMouseInput(BlockingInput): """ Class that creates a callable object to retrieve a single mouse or keyboard click """ def __init__(self, fig): BlockingInput.__init__(self, fig=fig, eventslist=( 'button_press_event', 'key_press_event')) def post_event(self): """ Determines if it is a key event """ assert len(self.events) > 0, "No events yet" self.keyormouse = self.events[-1].name == 'key_press_event' def __call__(self, timeout=30): """ Blocking call to retrieve a single mouse or key click Returns True if key click, False if mouse, or None if timeout """ self.keyormouse = None BlockingInput.__call__(self, n=1, timeout=timeout) return self.keyormouse