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Diffstat (limited to 'lib/python2.7/idlelib/WidgetRedirector.py')
-rw-r--r-- | lib/python2.7/idlelib/WidgetRedirector.py | 126 |
1 files changed, 0 insertions, 126 deletions
diff --git a/lib/python2.7/idlelib/WidgetRedirector.py b/lib/python2.7/idlelib/WidgetRedirector.py deleted file mode 100644 index 7c341f2..0000000 --- a/lib/python2.7/idlelib/WidgetRedirector.py +++ /dev/null @@ -1,126 +0,0 @@ -from Tkinter import * - -class WidgetRedirector: - - """Support for redirecting arbitrary widget subcommands. - - Some Tk operations don't normally pass through Tkinter. For example, if a - character is inserted into a Text widget by pressing a key, a default Tk - binding to the widget's 'insert' operation is activated, and the Tk library - processes the insert without calling back into Tkinter. - - Although a binding to <Key> could be made via Tkinter, what we really want - to do is to hook the Tk 'insert' operation itself. - - When a widget is instantiated, a Tcl command is created whose name is the - same as the pathname widget._w. This command is used to invoke the various - widget operations, e.g. insert (for a Text widget). We are going to hook - this command and provide a facility ('register') to intercept the widget - operation. - - In IDLE, the function being registered provides access to the top of a - Percolator chain. At the bottom of the chain is a call to the original - Tk widget operation. - - """ - def __init__(self, widget): - self._operations = {} - self.widget = widget # widget instance - self.tk = tk = widget.tk # widget's root - w = widget._w # widget's (full) Tk pathname - self.orig = w + "_orig" - # Rename the Tcl command within Tcl: - tk.call("rename", w, self.orig) - # Create a new Tcl command whose name is the widget's pathname, and - # whose action is to dispatch on the operation passed to the widget: - tk.createcommand(w, self.dispatch) - - def __repr__(self): - return "WidgetRedirector(%s<%s>)" % (self.widget.__class__.__name__, - self.widget._w) - - def close(self): - for operation in list(self._operations): - self.unregister(operation) - widget = self.widget; del self.widget - orig = self.orig; del self.orig - tk = widget.tk - w = widget._w - tk.deletecommand(w) - # restore the original widget Tcl command: - tk.call("rename", orig, w) - - def register(self, operation, function): - self._operations[operation] = function - setattr(self.widget, operation, function) - return OriginalCommand(self, operation) - - def unregister(self, operation): - if operation in self._operations: - function = self._operations[operation] - del self._operations[operation] - if hasattr(self.widget, operation): - delattr(self.widget, operation) - return function - else: - return None - - def dispatch(self, operation, *args): - '''Callback from Tcl which runs when the widget is referenced. - - If an operation has been registered in self._operations, apply the - associated function to the args passed into Tcl. Otherwise, pass the - operation through to Tk via the original Tcl function. - - Note that if a registered function is called, the operation is not - passed through to Tk. Apply the function returned by self.register() - to *args to accomplish that. For an example, see ColorDelegator.py. - - ''' - m = self._operations.get(operation) - try: - if m: - return m(*args) - else: - return self.tk.call((self.orig, operation) + args) - except TclError: - return "" - - -class OriginalCommand: - - def __init__(self, redir, operation): - self.redir = redir - self.operation = operation - self.tk = redir.tk - self.orig = redir.orig - self.tk_call = self.tk.call - self.orig_and_operation = (self.orig, self.operation) - - def __repr__(self): - return "OriginalCommand(%r, %r)" % (self.redir, self.operation) - - def __call__(self, *args): - return self.tk_call(self.orig_and_operation + args) - - -def main(): - root = Tk() - root.wm_protocol("WM_DELETE_WINDOW", root.quit) - text = Text() - text.pack() - text.focus_set() - redir = WidgetRedirector(text) - global previous_tcl_fcn - def my_insert(*args): - print "insert", args - previous_tcl_fcn(*args) - previous_tcl_fcn = redir.register("insert", my_insert) - root.mainloop() - redir.unregister("insert") # runs after first 'close window' - redir.close() - root.mainloop() - root.destroy() - -if __name__ == "__main__": - main() |