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Diffstat (limited to 'gr-wxgui/src/python/common.py')
| -rw-r--r-- | gr-wxgui/src/python/common.py | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/gr-wxgui/src/python/common.py b/gr-wxgui/src/python/common.py index 9c97ce1eca..fa11b3152f 100644 --- a/gr-wxgui/src/python/common.py +++ b/gr-wxgui/src/python/common.py @@ -19,6 +19,85 @@ # Boston, MA 02110-1301, USA. # +################################################## +# conditional disconnections of wx flow graph +################################################## +import wx +from gnuradio import gr + +class wxgui_hb(object): + """ + The wxgui hier block helper/wrapper class: + A hier block should inherit from this class to make use of the wxgui connect method. + To use, call wxgui_connect in place of regular connect; self.win must be defined. + The implementation will conditionally enable the copy block after the source (self). + This condition depends on weather or not the window is visible with the parent notebooks. + This condition will be re-checked on every ui update event. + """ + + def wxgui_connect(self, *points): + """ + Use wxgui connect when the first point is the self source of the hb. + The win property of this object should be set to the wx window. + When this method tries to connect self to the next point, + it will conditionally make this connection based on the visibility state. + All other points will be connected normally. + """ + try: + assert points[0] == self or points[0][0] == self + copy = gr.copy(self._hb.input_signature().sizeof_stream_item(0)) + handler = self._handler_factory(copy.set_enabled) + handler(False) #initially disable the copy block + self._bind_to_visible_event(win=self.win, handler=handler) + points = list(points) + points.insert(1, copy) #insert the copy block into the chain + except (AssertionError, IndexError): pass + self.connect(*points) #actually connect the blocks + + @staticmethod + def _handler_factory(handler): + """ + Create a function that will cache the visibility flag, + and only call the handler when that flag changes. + @param handler the function to call on a change + @return a function of 1 argument + """ + cache = [None] + def callback(visible): + if cache[0] == visible: return + cache[0] = visible + #print visible, handler + handler(visible) + return callback + + @staticmethod + def _bind_to_visible_event(win, handler): + """ + Bind a handler to a window when its visibility changes. + Specifically, call the handler when the window visibility changes. + This condition is checked on every update ui event. + @param win the wx window + @param handler a function of 1 param + """ + #is the window visible in the hierarchy + def is_wx_window_visible(my_win): + while True: + parent = my_win.GetParent() + if not parent: return True #reached the top of the hierarchy + #if we are hidden, then finish, otherwise keep traversing up + if isinstance(parent, wx.Notebook) and parent.GetCurrentPage() != my_win: return False + my_win = parent + #call the handler, the arg is shown or not + def handler_factory(my_win, my_handler): + return lambda *args: my_handler(is_wx_window_visible(my_win)) + handler = handler_factory(win, handler) + #bind the handler to all the parent notebooks + win.Bind(wx.EVT_UPDATE_UI, handler) + +################################################## +# Helpful Functions +################################################## + #A macro to apply an index to a key index_key = lambda key, i: "%s_%d"%(key, i+1) |