Move Backend enum to usertypes

Otherwise we have a cyclic import

qutebrowser/browser/commands.py

@@ -453,7 +453,7 @@ class CommandDispatcher:
         self._open(url, tab, background, window)
 
     @cmdutils.register(instance='command-dispatcher', scope='window',
-                       backend=tabmod.Backend.QtWebKit)
+                       backend=usertypes.Backend.QtWebKit)
     @cmdutils.argument('where', choices=['prev', 'next', 'up', 'increment',
                                          'decrement'])
     def navigate(self, where: str, tab=False, bg=False, window=False):
@@ -486,7 +486,7 @@ class CommandDispatcher:
 
         if where in ['prev', 'next']:
             # FIXME:qtwebengine have a proper API for this
-            if widget.backend == tabmod.Backend.QtWebEngine:
+            if widget.backend == usertypes.Backend.QtWebEngine:
                 raise cmdexc.CommandError(":navigate prev/next is not "
                                           "supported yet with QtWebEngine")
             page = widget._widget.page()  # pylint: disable=protected-access
@@ -1126,7 +1126,7 @@ class CommandDispatcher:
             raise cmdexc.CommandError(str(e))
 
     @cmdutils.register(instance='command-dispatcher', name='inspector',
-                       scope='window', backend=tabmod.Backend.QtWebKit)
+                       scope='window', backend=usertypes.Backend.QtWebKit)
     def toggle_inspector(self):
         """Toggle the web inspector.
 
@@ -1155,7 +1155,7 @@ class CommandDispatcher:
                 tab.data.inspector.show()
 
     @cmdutils.register(instance='command-dispatcher', scope='window',
-                       backend=tabmod.Backend.QtWebKit)
+                       backend=usertypes.Backend.QtWebKit)
     @cmdutils.argument('dest_old', hide=True)
     def download(self, url=None, dest_old=None, *, mhtml_=False, dest=None):
         """Download a given URL, or current page if no URL given.
@@ -1329,7 +1329,7 @@ class CommandDispatcher:
 
     @cmdutils.register(instance='command-dispatcher',
                        modes=[KeyMode.insert], hide=True, scope='window',
-                       backend=tabmod.Backend.QtWebKit)
+                       backend=usertypes.Backend.QtWebKit)
     def open_editor(self):
         """Open an external editor with the currently selected form field.
 
@@ -1378,7 +1378,7 @@ class CommandDispatcher:
 
     @cmdutils.register(instance='command-dispatcher',
                        modes=[KeyMode.insert], hide=True, scope='window',
-                       needs_js=True, backend=tabmod.Backend.QtWebKit)
+                       needs_js=True, backend=usertypes.Backend.QtWebKit)
     def paste_primary(self):
         """Paste the primary selection at cursor position."""
         # FIXME:qtwebengine have a proper API for this
@@ -1671,11 +1671,11 @@ class CommandDispatcher:
         """
         tab = self._current_widget()
 
-        if tab.backend == tabmod.Backend.QtWebKit:
+        if tab.backend == usertypes.Backend.QtWebKit:
             assert QWebPage is not None
             member = getattr(QWebPage, action, None)
             base = QWebPage.WebAction
-        elif tab.backend == tabmod.Backend.QtWebEngine:
+        elif tab.backend == usertypes.Backend.QtWebEngine:
             assert QWebEnginePage is not None
             member = getattr(QWebEnginePage, action, None)
             base = QWebEnginePage.WebAction

qutebrowser/browser/hints.py

@@ -31,7 +31,6 @@ from PyQt5.QtGui import QMouseEvent
 from PyQt5.QtWebKit import QWebElement
 from PyQt5.QtWebKitWidgets import QWebPage
 
-from qutebrowser.browser import tab as tabmod
 from qutebrowser.config import config
 from qutebrowser.keyinput import modeman, modeparsers
 from qutebrowser.browser.webkit import webelem
@@ -764,7 +763,7 @@ class HintManager(QObject):
 
     @cmdutils.register(instance='hintmanager', scope='tab', name='hint',
                        star_args_optional=True, maxsplit=2,
-                       backend=tabmod.Backend.QtWebKit)
+                       backend=usertypes.Backend.QtWebKit)
     @cmdutils.argument('win_id', win_id=True)
     def start(self, rapid=False, group=webelem.Group.all, target=Target.normal,
               *args, win_id):

qutebrowser/browser/tab.py

@@ -33,9 +33,6 @@ from qutebrowser.utils import utils, objreg, usertypes, message
 tab_id_gen = itertools.count(0)
 
 
-Backend = usertypes.enum('Backend', ['QtWebKit', 'QtWebEngine'])
-
-
 def create(win_id, parent=None):
     """Get a QtWebKit/QtWebEngine tab object.
 

qutebrowser/browser/webengine/webenginetab.py

@@ -258,7 +258,7 @@ class WebEngineViewTab(tabmod.AbstractTab):
         self.search = WebEngineSearch(parent=self)
         self._set_widget(widget)
         self._connect_signals()
-        self.backend = tabmod.Backend.QtWebEngine
+        self.backend = usertypes.Backend.QtWebEngine
 
     def openurl(self, url):
         self._widget.load(url)

qutebrowser/browser/webkit/webkittab.py

@@ -462,7 +462,7 @@ class WebViewTab(tabmod.AbstractTab):
         self._set_widget(widget)
         self._connect_signals()
         self.zoom.set_default()
-        self.backend = tabmod.Backend.QtWebKit
+        self.backend = usertypes.Backend.QtWebKit
 
     def openurl(self, url):
         self._widget.openurl(url)

qutebrowser/commands/command.py

@@ -29,7 +29,6 @@ from qutebrowser.commands import cmdexc, argparser
 from qutebrowser.utils import (log, utils, message, docutils, objreg,
                                usertypes, typing)
 from qutebrowser.utils import debug as debug_utils
-from qutebrowser.browser import tab as tabmod
 
 
 class ArgInfo:
@@ -183,8 +182,8 @@ class Command:
                 "{}: This command needs javascript enabled.".format(self.name))
 
         backend_mapping = {
-            'webkit': tabmod.Backend.QtWebKit,
+            'webkit': usertypes.Backend.QtWebKit,
-            'webengine': tabmod.Backend.QtWebEngine,
+            'webengine': usertypes.Backend.QtWebEngine,
         }
         used_backend = backend_mapping[objreg.get('args').backend]
         if self.backend is not None and used_backend != self.backend:

qutebrowser/utils/usertypes.py

@@ -251,6 +251,10 @@ LoadStatus = enum('LoadStatus', ['none', 'success', 'success_https', 'error',
                                  'warn', 'loading'])
 
 
+# Backend of a tab
+Backend = enum('Backend', ['QtWebKit', 'QtWebEngine'])
+
+
 class Question(QObject):
 
     """A question asked to the user, e.g. via the status bar.

tests/unit/commands/test_cmdutils.py

@@ -23,7 +23,6 @@ import pytest
 
 from qutebrowser.commands import cmdutils, cmdexc, argparser, command
 from qutebrowser.utils import usertypes, typing, objreg
-from qutebrowser.browser import tab as tabmod
 
 
 @pytest.fixture(autouse=True)
@@ -373,10 +372,10 @@ class TestRun:
         fake_args.backend = 'webkit'
 
     @pytest.mark.parametrize('backend, used, ok', [
-        (tabmod.Backend.QtWebEngine, 'webengine', True),
+        (usertypes.Backend.QtWebEngine, 'webengine', True),
-        (tabmod.Backend.QtWebEngine, 'webkit', False),
+        (usertypes.Backend.QtWebEngine, 'webkit', False),
-        (tabmod.Backend.QtWebKit, 'webengine', False),
+        (usertypes.Backend.QtWebKit, 'webengine', False),
-        (tabmod.Backend.QtWebKit, 'webkit', True),
+        (usertypes.Backend.QtWebKit, 'webkit', True),
         (None, 'webengine', True),
         (None, 'webkit', True),
     ])
@@ -402,7 +401,7 @@ class TestRun:
         display an error instead of crashing.
         """
         @cmdutils.register(instance='doesnotexist',
-                           backend=tabmod.Backend.QtWebEngine)
+                           backend=usertypes.Backend.QtWebEngine)
         def fun(self):
             """Blah."""
             pass