def _init_code_edit(self, backend):
        """
        Initializes the code editor (setup modes, panels and colors).
        """
        from pyqode.core import panels, modes
        self.modes.append(_LinkHighlighter(self.document()))
        self.background = self._formatter.color_scheme.background
        self.foreground = self._formatter.color_scheme.foreground
        self._reset_stylesheet()
        self.setCenterOnScroll(False)
        self.setMouseTracking(True)
        self.setUndoRedoEnabled(False)
        search_panel = panels.SearchAndReplacePanel()
        self.panels.append(search_panel, search_panel.Position.TOP)
        self.action_copy.setShortcut('Ctrl+Shift+C')
        self.action_paste.setShortcut('Ctrl+Shift+V')
        self.remove_action(self.action_undo, sub_menu=None)
        self.remove_action(self.action_redo, sub_menu=None)
        self.remove_action(self.action_cut, sub_menu=None)
        self.remove_action(self.action_duplicate_line, sub_menu=None)
        self.remove_action(self.action_indent)
        self.remove_action(self.action_un_indent)
        self.remove_action(self.action_goto_line)
        self.remove_action(search_panel.menu.menuAction())
        self.remove_menu(self._sub_menus['Advanced'])
        self.add_action(search_panel.actionSearch, sub_menu=None)
        self.modes.append(modes.ZoomMode())
        self.backend.start(backend)
Initializes the code editor (setup modes, panels and colors).