osd: make window switcher more Openbox-like in terms of key precessing

Before this commit, keystrokes were interpreted based on following
hard-coded rules while the window switcher is active:

  1. Up/Left arrow keys cycle the window forward.
  2. Down/Right arrow keys cycle the window backward.
  3. Other keystrokes cycle the window in the initial direction specified
     by NextWindow/PreviousWindow actions. But while Shift key is pressed,
     the direction is inverted.

...and keybind actions were never executed.

However, this lead to a counter-intuitive behavior for new, especially
pre-Openbox users. For example, in the following keybinds, after the user
activates the window switcher with Super+n, Super+p cycles the window
_forward_:

  <keybind key="W-n">
    <action name="NextWindow" />
  </keybind>
  <keybind key="W-p">
    <action name="PreviousWindow" />
  </keybind>

This is because the key 'n' is recognized just as a normal key in the
third hard-coded rule.

So this commit changes the rules to be more Openbox-like:

  1. Up/Left arrow keys cycles the window forward.
  2. Down/Right arrow keys cycles the window backward.
  3. Other keystrokes are matched against keybinds and execute their
     actions. If they include NextWindow/PreviousWindow action, it cycles
     the selected window forward/backward even while the window switcher
     is active.

src/osd.c

@@ -160,14 +160,6 @@ restore_preview_node(struct server *server)
 	}
 }
 
-static bool
-shift_is_pressed(struct server *server)
-{
-	uint32_t modifiers = wlr_keyboard_get_modifiers(
-			&server->seat.keyboard_group->keyboard);
-	return modifiers & WLR_MODIFIER_SHIFT;
-}
-
 void
 osd_begin(struct server *server, enum lab_cycle_dir direction)
 {
@@ -175,10 +167,6 @@ osd_begin(struct server *server, enum lab_cycle_dir direction)
 		return;
 	}
 
-	/* Remember direction so it can be followed by subsequent key presses */
-	server->osd_state.initial_direction = direction;
-	server->osd_state.initial_keybind_contained_shift =
-		shift_is_pressed(server);
 	server->osd_state.cycle_view = get_next_cycle_view(server,
 		server->osd_state.cycle_view, direction);