text: #!/usr/bin/env python
  #
  # Electrum-Ganja - lightweight Ganjacoin client
  # Copyright (C) 2018 The Electrum developers
  # Copyright (C) 2018 GanjaProject
  #
  # Permission is hereby granted, free of charge, to any person
  # obtaining a copy of this software and associated documentation files
  # (the "Software"), to deal in the Software without restriction,
  # including without limitation the rights to use, copy, modify, merge,
  # publish, distribute, sublicense, and/or sell copies of the Software,
  # and to permit persons to whom the Software is furnished to do so,
  # subject to the following conditions:
  #
  # The above copyright notice and this permission notice shall be
  # included in all copies or substantial portions of the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  # BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  # ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  # SOFTWARE.
  
  from PyQt5.QtGui import *
  from PyQt5.QtCore import *
  from PyQt5.QtWidgets import *
  from .util import ButtonsTextEdit
  
  class CompletionTextEdit(ButtonsTextEdit):
  
      def __init__(self, parent=None):
          super(CompletionTextEdit, self).__init__(parent)
          self.completer = None
          self.moveCursor(QTextCursor.End)
          self.disable_suggestions()
  
      def set_completer(self, completer):
          self.completer = completer
          self.initialize_completer()
  
      def initialize_completer(self):
          self.completer.setWidget(self)
          self.completer.setCompletionMode(QCompleter.PopupCompletion)
          self.completer.activated.connect(self.insert_completion)
          self.enable_suggestions()
  
      def insert_completion(self, completion):
          if self.completer.widget() != self:
              return
          text_cursor = self.textCursor()
          extra = len(completion) - len(self.completer.completionPrefix())
          text_cursor.movePosition(QTextCursor.Left)
          text_cursor.movePosition(QTextCursor.EndOfWord)
          if extra == 0:
              text_cursor.insertText(" ")
          else:
              text_cursor.insertText(completion[-extra:] + " ")
          self.setTextCursor(text_cursor)
  
      def text_under_cursor(self):
          tc = self.textCursor()
          tc.select(QTextCursor.WordUnderCursor)
          return tc.selectedText()
  
      def enable_suggestions(self):
          self.suggestions_enabled = True
  
      def disable_suggestions(self):
          self.suggestions_enabled = False
  
      def keyPressEvent(self, e):
          if self.isReadOnly():
              return
  
          if self.is_special_key(e):
              e.ignore()
              return
  
          QPlainTextEdit.keyPressEvent(self, e)
  
          ctrlOrShift = e.modifiers() and (Qt.ControlModifier or Qt.ShiftModifier)
          if self.completer is None or (ctrlOrShift and not e.text()):
              return
  
          if not self.suggestions_enabled:
              return
  
          eow = "~!@#$%^&*()_+{}|:\"<>?,./;'[]\\-="
          hasModifier = (e.modifiers() != Qt.NoModifier) and not ctrlOrShift
          completionPrefix = self.text_under_cursor()
  
          if hasModifier or not e.text() or len(completionPrefix) < 1 or eow.find(e.text()[-1]) >= 0:
              self.completer.popup().hide()
              return
  
          if completionPrefix != self.completer.completionPrefix():
              self.completer.setCompletionPrefix(completionPrefix)
              self.completer.popup().setCurrentIndex(self.completer.completionModel().index(0, 0))
  
          cr = self.cursorRect()
          cr.setWidth(self.completer.popup().sizeHintForColumn(0) + self.completer.popup().verticalScrollBar().sizeHint().width())
          self.completer.complete(cr)
  
      def is_special_key(self, e):
          if self.completer != None and self.completer.popup().isVisible():
              if e.key() in [Qt.Key_Enter, Qt.Key_Return]:
                  return True
          if e.key() in [Qt.Key_Tab, Qt.Key_Down, Qt.Key_Up]:
              return True
          return False
  
  if __name__ == "__main__":
      app = QApplication([])
      completer = QCompleter(["alabama", "arkansas", "avocado", "breakfast", "sausage"])
      te = CompletionTextEdit()
      te.set_completer(completer)
      te.show()
      app.exec_()
  