modeparsers: Refactor how hints are handled

Instead of binding hints to fake :follow-hint commands, we now use a separate
CommandKeyParser and ask that for its match result.

If the key matches with the command parser, it is bound in hint mode, so we
clear the hint keystring and defer to the command handling instead.

If it doesn't, we continue hint handling as usual - however, the HintKeyParser
is now not a CommandKeyParser anymore, so we don't have to deal with command
parsing (and have a custom execute implementation instead).

Closes #4504
Fixes #4392
Fixes #4368
Helps with #5084, though it doesn't completely fix that yet.
Supersedes #3742 (fix for #3735)
Supersedes #4691 (fix for #4264)

2 files changed, 19 insertions, 23 deletions

diff --git a/qutebrowser/keyinput/keyutils.py b/qutebrowser/keyinput/keyutils.py
index 142bedd2f..b95f4a55d 100644
--- a/qutebrowser/keyinput/keyutils.py
+++ b/qutebrowser/keyinput/keyutils.py
@@ -180,21 +180,6 @@ def _is_printable(key: Qt.Key) -> bool:
     return key <= 0xff and key not in [Qt.Key_Space, _NIL_KEY]
 
 
-def is_special_hint_mode(key: Qt.Key, modifiers: _ModifierType) -> bool:
-    """Check whether this key should clear the keychain in hint mode.
-
-    When we press "s<Escape>", we don't want <Escape> to be handled as part of
-    a key chain in hint mode.
-    """
-    _assert_plain_key(key)
-    _assert_plain_modifier(modifiers)
-    if is_modifier_key(key):
-        return False
-    return not (_is_printable(key) and
-                modifiers in [Qt.ShiftModifier, Qt.NoModifier,
-                              Qt.KeypadModifier])
-
-
 def is_special(key: Qt.Key, modifiers: _ModifierType) -> bool:
     """Check whether this key requires special key syntax."""
     _assert_plain_key(key)
diff --git a/qutebrowser/keyinput/modeparsers.py b/qutebrowser/keyinput/modeparsers.py
index e848250c0..a55639898 100644
--- a/qutebrowser/keyinput/modeparsers.py
+++ b/qutebrowser/keyinput/modeparsers.py
@@ -136,7 +136,7 @@ class NormalKeyParser(CommandKeyParser):
         self._inhibited = False
 
 
-class HintKeyParser(CommandKeyParser):
+class HintKeyParser(basekeyparser.BaseKeyParser):
 
     """KeyChainParser for hints.
 
@@ -151,8 +151,12 @@ class HintKeyParser(CommandKeyParser):
                  hintmanager: hints.HintManager,
                  parent: QObject = None) -> None:
         super().__init__(mode=usertypes.KeyMode.hint, win_id=win_id,
-                         commandrunner=commandrunner, parent=parent,
-                         supports_count=False)
+                         parent=parent, supports_count=False)
+        self._command_parser = CommandKeyParser(mode=usertypes.KeyMode.hint,
+                                                win_id=win_id,
+                                                commandrunner=commandrunner,
+                                                parent=self,
+                                                supports_count=False)
         self._hintmanager = hintmanager
         self._filtertext = ''
         self._last_press = LastPress.none
@@ -198,11 +202,14 @@ class HintKeyParser(CommandKeyParser):
         if dry_run:
             return super().handle(e, dry_run=True)
 
-        if keyutils.is_special_hint_mode(Qt.Key(e.key()), e.modifiers()):
-            log.keyboard.debug("Got special key, clearing keychain")
+        assert not dry_run
+
+        if (self._command_parser.handle(e, dry_run=True) !=
+                QKeySequence.NoMatch):
+            log.keyboard.debug("Handling key via command parser")
             self.clear_keystring()
+            return self._command_parser.handle(e)
 
-        assert not dry_run
         match = super().handle(e)
 
         if match == QKeySequence.PartialMatch:
@@ -227,11 +234,15 @@ class HintKeyParser(CommandKeyParser):
                              `self._filtertext`.
         """
         self._read_config()
-        self.bindings.update({keyutils.KeySequence.parse(s):
-                              'follow-hint -s ' + s for s in strings})
+        self.bindings.update({keyutils.KeySequence.parse(s): s
+                              for s in strings})
         if not preserve_filter:
             self._filtertext = ''
 
+    def execute(self, cmdstr: str, count: int = None) -> None:
+        assert count is None
+        self._hintmanager.handle_partial_key(cmdstr)
+
 
 class RegisterKeyParser(CommandKeyParser):