Edit Book: Add an option to turn off drag and drop editing of text (Preferences->Editor)

src/calibre/gui2/tweak_book/__init__.py

@@ -69,6 +69,7 @@ d['add_cover_preserve_aspect_ratio'] = False
 d['templates'] = {}
 d['auto_close_tags'] = True
 d['restore_book_state'] = True
+d['editor_accepts_drops'] = True
 del d
 
 ucase_map = {l:string.ascii_uppercase[i] for i, l in enumerate(string.ascii_lowercase)}

src/calibre/gui2/tweak_book/editor/text.py

@@ -119,6 +119,7 @@ class TextEdit(PlainTextEdit):
 
     def apply_settings(self, prefs=None, dictionaries_changed=False):  # {{{
         prefs = prefs or tprefs
+        self.setAcceptDrops(prefs.get('editor_accepts_drops', True))
         self.setLineWrapMode(QPlainTextEdit.WidgetWidth if prefs['editor_line_wrap'] else QPlainTextEdit.NoWrap)
         theme = get_theme(prefs['editor_theme'])
         self.apply_theme(theme)

src/calibre/gui2/tweak_book/preferences.py

@@ -220,6 +220,13 @@ class EditorSettings(BasicSettings):
             ' for easy correction as you type.'))
         l.addRow(lw)
 
+        lw = self('editor_accepts_drops')
+        lw.setText(_('Allow drag and drop editing of text'))
+        lw.setToolTip('<p>' + _(
+        'Allow using drag and drop to move text around in the editor.'
+        ' It can be useful to turn this off if you have a misbehaving touchpad.'))
+        l.addRow(lw)
+
         self.dictionaries = d = QPushButton(_('Manage &spelling dictionaries'), self)
         d.setSizePolicy(QSizePolicy.Fixed, QSizePolicy.Fixed)
         d.clicked.connect(self.manage_dictionaries)