lib/qt_console.py

   1 # source: http://stackoverflow.com/questions/2758159/how-to-embed-a-python-interpreter-in-a-pyqt-widget
   2
   3 import sys, os, re
   4 import traceback
   5 from PyQt4 import QtCore
   6 from PyQt4 import QtGui
   7
   8
   9
  10 class Console(QtGui.QPlainTextEdit):
  11     def __init__(self, prompt='>> ', startup_message='', parent=None):
  12         QtGui.QPlainTextEdit.__init__(self, parent)
  13
  14         self.prompt = prompt
  15         self.history = []
  16         self.namespace = {}
  17         self.construct = []
  18
  19         self.setGeometry(50, 75, 600, 400)
  20         self.setWordWrapMode(QtGui.QTextOption.WrapAnywhere)
  21         self.setUndoRedoEnabled(False)
  22         self.document().setDefaultFont(QtGui.QFont("monospace", 10, QtGui.QFont.Normal))
  23         self.showMessage(startup_message)
  24
  25         self.updateNamespace({'run':self.run_script})
  26
  27     def run_script(self, filename):
  28         with open(filename) as f:
  29             script = f.read()
  30         result = eval(script, self.namespace, self.namespace)
  31
  32
  33
  34     def updateNamespace(self, namespace):
  35         self.namespace.update(namespace)
  36
  37     def showMessage(self, message):
  38         self.appendPlainText(message)
  39         self.newPrompt()
  40
  41     def clear(self):
  42         self.setPlainText('')
  43         self.newPrompt()
  44
  45     def newPrompt(self):
  46         if self.construct:
  47             prompt = '.' * len(self.prompt)
  48         else:
  49             prompt = self.prompt
  50
  51         self.completions_pos = self.textCursor().position()
  52         self.completions_visible = False
  53
  54         self.appendPlainText(prompt)
  55         self.moveCursor(QtGui.QTextCursor.End)
  56
  57     def getCommand(self):
  58         doc = self.document()
  59         curr_line = unicode(doc.findBlockByLineNumber(doc.lineCount() - 1).text())
  60         curr_line = curr_line.rstrip()
  61         curr_line = curr_line[len(self.prompt):]
  62         return curr_line
  63
  64     def setCommand(self, command):
  65         if self.getCommand() == command:
  66             return
  67         self.moveCursor(QtGui.QTextCursor.End)
  68         self.moveCursor(QtGui.QTextCursor.StartOfLine, QtGui.QTextCursor.KeepAnchor)
  69         for i in range(len(self.prompt)):
  70             self.moveCursor(QtGui.QTextCursor.Right, QtGui.QTextCursor.KeepAnchor)
  71         self.textCursor().removeSelectedText()
  72         self.textCursor().insertText(command)
  73         self.moveCursor(QtGui.QTextCursor.End)
  74
  75
  76     def show_completions(self, completions):
  77         if self.completions_visible:
  78             self.hide_completions()
  79
  80         c = self.textCursor()
  81         c.setPosition(self.completions_pos)
  82
  83         completions = map(lambda x: x.split('.')[-1], completions)
  84         t = '\n' + ' '.join(completions)
  85         if len(t) > 500:
  86             t = t[:500] + '...'
  87         c.insertText(t)
  88         self.completions_end = c.position()
  89
  90         self.moveCursor(QtGui.QTextCursor.End)
  91         self.completions_visible = True
  92
  93
  94     def hide_completions(self):
  95         if not self.completions_visible:
  96             return
  97         c = self.textCursor()
  98         c.setPosition(self.completions_pos)
  99         l = self.completions_end - self.completions_pos
 100         for x in range(l): c.deleteChar()
 101
 102         self.moveCursor(QtGui.QTextCursor.End)
 103         self.completions_visible = False
 104
 105
 106     def getConstruct(self, command):
 107         if self.construct:
 108             prev_command = self.construct[-1]
 109             self.construct.append(command)
 110             if not prev_command and not command:
 111                 ret_val = '\n'.join(self.construct)
 112                 self.construct = []
 113                 return ret_val
 114             else:
 115                 return ''
 116         else:
 117             if command and command[-1] == (':'):
 118                 self.construct.append(command)
 119                 return ''
 120             else:
 121                 return command
 122
 123     def getHistory(self):
 124         return self.history
 125
 126     def setHisory(self, history):
 127         self.history = history
 128
 129     def addToHistory(self, command):
 130         if command and (not self.history or self.history[-1] != command):
 131             self.history.append(command)
 132         self.history_index = len(self.history)
 133
 134     def getPrevHistoryEntry(self):
 135         if self.history:
 136             self.history_index = max(0, self.history_index - 1)
 137             return self.history[self.history_index]
 138         return ''
 139
 140     def getNextHistoryEntry(self):
 141         if self.history:
 142             hist_len = len(self.history)
 143             self.history_index = min(hist_len, self.history_index + 1)
 144             if self.history_index < hist_len:
 145                 return self.history[self.history_index]
 146         return ''
 147
 148     def getCursorPosition(self):
 149         return self.textCursor().columnNumber() - len(self.prompt)
 150
 151     def setCursorPosition(self, position):
 152         self.moveCursor(QtGui.QTextCursor.StartOfLine)
 153         for i in range(len(self.prompt) + position):
 154             self.moveCursor(QtGui.QTextCursor.Right)
 155
 156     def runCommand(self):
 157         command = self.getCommand()
 158         self.addToHistory(command)
 159
 160         command = self.getConstruct(command)
 161
 162         if command:
 163             tmp_stdout = sys.stdout
 164
 165             class stdoutProxy():
 166                 def __init__(self, write_func):
 167                     self.write_func = write_func
 168                     self.skip = False
 169
 170                 def flush(self):
 171                     pass
 172
 173                 def write(self, text):
 174                     if not self.skip:
 175                         stripped_text = text.rstrip('\n')
 176                         self.write_func(stripped_text)
 177                         QtCore.QCoreApplication.processEvents()
 178                     self.skip = not self.skip
 179
 180             if command == 'help()':
 181                 self.appendPlainText("no help here!")
 182                 self.newPrompt()
 183                 return
 184
 185             sys.stdout = stdoutProxy(self.appendPlainText)
 186             try:
 187                 try:
 188                     result = eval(command, self.namespace, self.namespace)
 189                     if result != None:
 190                         self.appendPlainText(repr(result))
 191                 except SyntaxError:
 192                     exec command in self.namespace
 193             except SystemExit:
 194                 self.close()
 195             except:
 196                 traceback_lines = traceback.format_exc().split('\n')
 197                 # Remove traceback mentioning this file, and a linebreak
 198                 for i in (3,2,1,-1):
 199                     traceback_lines.pop(i)
 200                 self.appendPlainText('\n'.join(traceback_lines))
 201             sys.stdout = tmp_stdout
 202         self.newPrompt()
 203
 204     def keyPressEvent(self, event):
 205         if event.key() == QtCore.Qt.Key_Tab:
 206             self.completions()
 207             return
 208
 209         self.hide_completions()
 210
 211         if event.key() in (QtCore.Qt.Key_Enter, QtCore.Qt.Key_Return):
 212             self.runCommand()
 213             return
 214         if event.key() == QtCore.Qt.Key_Home:
 215             self.setCursorPosition(0)
 216             return
 217         if event.key() == QtCore.Qt.Key_PageUp:
 218             return
 219         elif event.key() in (QtCore.Qt.Key_Left, QtCore.Qt.Key_Backspace):
 220             if self.getCursorPosition() == 0:
 221                 return
 222         elif event.key() == QtCore.Qt.Key_Up:
 223             self.setCommand(self.getPrevHistoryEntry())
 224             return
 225         elif event.key() == QtCore.Qt.Key_Down:
 226             self.setCommand(self.getNextHistoryEntry())
 227             return
 228         elif event.key() == QtCore.Qt.Key_L and event.modifiers() == QtCore.Qt.ControlModifier:
 229             self.clear()
 230
 231         super(Console, self).keyPressEvent(event)
 232
 233
 234
 235     def completions(self):
 236         cmd = self.getCommand()
 237         lastword = re.split(' |\(|\)',cmd)[-1]
 238         beginning = cmd[0:-len(lastword)]
 239
 240         path = lastword.split('.')
 241         ns = self.namespace.keys()
 242
 243         if len(path) == 1:
 244             ns = ns
 245             prefix = ''
 246         else:
 247             obj = self.namespace.get(path[0])
 248             prefix = path[0] + '.'
 249             ns = dir(obj)
 250
 251
 252         completions = []
 253         for x in ns:
 254             if x[0] == '_':continue
 255             xx = prefix + x
 256             if xx.startswith(lastword):
 257                 completions.append(xx)
 258
 259         if not completions:
 260             self.hide_completions()
 261         elif len(completions) == 1:
 262             self.hide_completions()
 263             self.setCommand(beginning + completions[0])
 264         else:
 265             # find common prefix
 266             p = os.path.commonprefix(completions)
 267             if len(p)>len(lastword):
 268                 self.hide_completions()
 269                 self.setCommand(beginning + p)
 270             else:
 271                 self.show_completions(completions)
 272
 273
 274 welcome_message = '''
 275    ---------------------------------------------------------------
 276      Welcome to a primitive Python interpreter.
 277    ---------------------------------------------------------------
 278 '''
 279
 280 if __name__ == '__main__':
 281     app = QtGui.QApplication(sys.argv)
 282     console = Console(startup_message=welcome_message)
 283     console.updateNamespace({'myVar1' : app, 'myVar2' : 1234})
 284     console.show();
 285     sys.exit(app.exec_())