Merge pull request #2832 from johncosker/cycle-hotkey-rev

Add 'key_back' optional hotkey for CycleHotkeyLabel to allow cycling backwards.

docs/changelog.txt

@@ -55,6 +55,7 @@ changelog.txt uses a syntax similar to RST, with a few special sequences:
 
 ## Lua
 - `overlay`: overlay widgets can now specify focus paths for the viewscreens they attach to so they only appear in specific contexts. see `overlay-dev-guide` for details.
+- ``widgets.CycleHotkeyLabel``: Added ``key_back`` optional parameter to cycle backwards.
 
 ## Removed
 

docs/dev/Lua API.rst

@@ -4817,6 +4817,7 @@ cycle through by pressing a specified hotkey or clicking on the text.
 It has the following attributes:
 
 :key: The hotkey keycode to display, e.g. ``'CUSTOM_A'``.
+:key_back: Similar to ``key``, but will cycle backwards (optional)
 :label: The string (or a function that returns a string) to display after the
     hotkey.
 :label_width: The number of spaces to allocate to the ``label`` (for use in
@@ -4834,9 +4835,10 @@ the ``option_idx`` instance variable.
 
 The CycleHotkeyLabel widget implements the following methods:
 
-* ``cyclehotkeylabel:cycle()``
+* ``cyclehotkeylabel:cycle([backwards])``
 
     Cycles the selected option and triggers the ``on_change`` callback.
+    If ``backwards`` is defined and is truthy, the cycle direction will be reversed
 
 * ``cyclehotkeylabel:setOption(value_or_index, call_on_change)``
 

library/lua/gui/widgets.lua

@@ -1440,6 +1440,7 @@ CycleHotkeyLabel = defclass(CycleHotkeyLabel, Label)
 
 CycleHotkeyLabel.ATTRS{
     key=DEFAULT_NIL,
+    key_back=DEFAULT_NIL,
     label=DEFAULT_NIL,
     label_width=DEFAULT_NIL,
     options=DEFAULT_NIL,
@@ -1451,6 +1452,7 @@ function CycleHotkeyLabel:init()
     self:setOption(self.initial_option)
 
     self:setText{
+        self.key_back ~= nil and {key=self.key_back, key_sep='', width=0, on_activate=self:callback('cycle', true)} or {},
         {key=self.key, key_sep=': ', text=self.label, width=self.label_width,
          on_activate=self:callback('cycle')},
         ' ',
@@ -1459,12 +1461,14 @@ function CycleHotkeyLabel:init()
     }
 end
 
-function CycleHotkeyLabel:cycle()
+function CycleHotkeyLabel:cycle(backwards)
     local old_option_idx = self.option_idx
-    if self.option_idx == #self.options then
+    if self.option_idx == #self.options and not backwards then
         self.option_idx = 1
+    elseif self.option_idx == 1 and backwards then
+        self.option_idx = #self.options
     else
-        self.option_idx = self.option_idx + 1
+        self.option_idx = self.option_idx + (not backwards and 1 or -1)
     end
     if self.on_change then
         self.on_change(self:getOptionValue(),