ugitlibs/qobserver.py

   1 #!/usr/bin/env python
   2 from PyQt4.QtCore import QObject
   3 from PyQt4.QtCore import SIGNAL
   4 from PyQt4.QtGui import QSpinBox
   5 from PyQt4.QtGui import QPixmap
   6 from PyQt4.QtGui import QTextEdit
   7 from PyQt4.QtGui import QLineEdit
   8 from PyQt4.QtGui import QListWidget
   9
  10 from observer import Observer
  11
  12 class QObserver(Observer, QObject):
  13
  14         def __init__(self, model, view):
  15                 Observer.__init__(self, model)
  16                 QObject.__init__(self)
  17
  18                 self.view = view
  19
  20                 self.__actions = {}
  21                 self.__callbacks = {}
  22                 self.__model_to_view = {}
  23                 self.__view_to_model = {}
  24
  25         def connect(self, obj, signal_str, *args):
  26                 '''Convenience function so that subclasses do not have
  27                 to import QtCore.SIGNAL.'''
  28                 signal = signal_str
  29                 if type(signal) is str:
  30                         signal = SIGNAL(signal)
  31                 return QObject.connect(obj, signal, *args)
  32
  33         def SLOT(self, *args):
  34                 '''Default slot to handle all Qt callbacks.
  35                 This method delegates to callbacks from add_signals.'''
  36
  37                 widget = self.sender()
  38                 sender = str(widget.objectName())
  39
  40                 if sender in self.__callbacks:
  41                         self.__callbacks[sender](*args)
  42
  43                 elif sender in self.__view_to_model:
  44                         model = self.model
  45                         model_attr = self.__view_to_model[sender]
  46                         if isinstance(widget, QTextEdit):
  47                                 value = str(widget.toPlainText())
  48                                 model.set(model_attr, value, notify=False)
  49                         elif isinstance(widget, QLineEdit):
  50                                 value = str(widget.text())
  51                                 model.set(model_attr, value, notify=False)
  52                         else:
  53                                 print("SLOT(): Unknown widget:", sender, widget)
  54
  55         def add_signals(self, signal_str, *objects):
  56                 '''Connects object's signal to the QObserver.'''
  57                 for obj in objects:
  58                         self.connect(obj, signal_str, self.SLOT)
  59
  60         def add_callbacks(self, callbacks):
  61                 '''Registers callbacks that are called in response to GUI events.'''
  62                 for sender, callback in callbacks.iteritems():
  63                         self.__callbacks[sender] = callback
  64
  65         def model_to_view(self, model_attr, *widget_names):
  66                 '''Binds model attributes to qt widgets(model->view)'''
  67                 self.add_subject(model_attr)
  68                 self.__model_to_view[model_attr] = widget_names
  69                 for widget_name in widget_names:
  70                         self.__view_to_model[widget_name] = model_attr
  71
  72         def add_actions(self, model_attr, callback):
  73                 '''Register view actions that are called in response to
  74                 view changes.(view->model)'''
  75                 self.add_subject(model_attr)
  76                 self.__actions[model_attr] = callback
  77
  78         def subject_changed(self, attr, value):
  79                 '''Sends a model attribute to the view(model->view)'''
  80                 if attr in self.__model_to_view:
  81                         for widget_name in self.__model_to_view[attr]:
  82                                 widget = getattr(self.view, widget_name)
  83                                 if isinstance(widget, QSpinBox):
  84                                         widget.setValue(value)
  85                                 elif isinstance(widget, QPixmap):
  86                                         widget.load(value)
  87                                 elif isinstance(widget, QTextEdit):
  88                                         widget.setText(value)
  89                                 elif isinstance(widget, QLineEdit):
  90                                         widget.setText(value)
  91                                 elif isinstance(widget, QListWidget):
  92                                         widget.clear()
  93                                         for i in value: widget.addItem(i)
  94                                 else:
  95                                         print('subject_changed(): '
  96                                                 + 'Unknown widget:',
  97                                                 widget_name, widget)
  98
  99                 if attr not in self.__actions:
 100                         return
 101                 widgets = []
 102                 if attr in self.__model_to_view:
 103                         for widget_name in self.__model_to_view[attr]:
 104                                 widget = getattr(self.view, widget_name)
 105                                 widgets.append(widget)
 106                 # Call the model callback w/ the view's widgets as the args
 107                 self.__actions[attr](*widgets)