Export Rime::Switcher

[amorphobia]

This change export Rime::Switcher to Lua, so that users can directly manipulate it in a lua_processor.

My situation is to toggle a switch through selecting candidates, instead of key bindings. Following is partial of the processor's code:

local function processor(key, env)
  local context = env.engine.context
  local switcher = Switcher(env.engine)
  local user_config = switcher.user_config

  -- get option_name and some_bool_value

  if --[[ some condition --]] then
    context:set_option(option_name, some_bool_value)
    if switcher:is_auto_save(option_name) then
      user_config:set_bool("var/option/" .. option_name, some_bool_value)
    end
    context:clear()
    return kAccepted
  end
end

[hchunhui]

Looks good, but do we really need Switcher?
I think a commit notifier should be enough: #23 (comment)

[amorphobia]

Looks good, but do we really need Switcher?
I think a commit notifier should be enough: #23 (comment)

I'll try it, but I think Switcher provide more convenience in some situations. I have following concerns:

1. Is a notifier capable to call the callback function without actually commit the text? I'm not familiar with notifiers. Would you mind to show me an example? Thanks.
2. Switcher provides some handy functions like IsAutoSave. Though we can implement it in Lua by traversing the config under "switcher/save_options", IsAutoSave might be easier.
3. Is there a way to access Switcher::user_config without exporting Switcher? It's first loaded here. To get the user config without Switcher, we still need to add some functions.

[amorphobia]

traversing the config

Actually we cannot traverse the config untill Config::GetList has been wrapped.

[hchunhui]

OK, Switcher provides more convenience. Exporting more low level functions is a long-term plan.

Please also commit a simple script that uses Switcher as an example. After that I will merge the PR.

[shewer]

Looks good, but do we really need Switcher?
I think a commit notifier should be enough: #23 (comment)

I'll try it, but I think Switcher provide more convenience in some situations. I have following concerns:

1. Is a notifier capable to call the callback function without actually commit the text? I'm not familiar with notifiers. Would you mind to show me an example? Thanks.

librime-lua/src/types.cc

Line 470 in 0fdf0ad

{ "commit_notifier", WRAPMEM(T::commit_notifier) },

https://github.com/rime/librime/blob/99e269c8eb251deddbad9b0d2c4d965b228f8006/src/rime/context.h#L21

function init(env)
       local  commit_notifier=env.engine.context.commit_notifier
       env. commit_notifier_connected = commit_notifer:connect( function(ctx)  ... end )
       env.option_update_notifier_connected=env.engine.context.option_update_notifier:connect( function(ctx,option_name) 
       if option_name== "ascii_mode" then  
       end
end 

)  
end 
function fini(env)
      env.commit_notifier_connected:disconnect()
      env.option_update_notifier_connected:disconnect()
end 

2. Switcher provides some handy functions like IsAutoSave. Though we can implement it in Lua by traversing the config under "switcher/save_options", IsAutoSave might be easier.
3. Is there a way to access Switcher::user_config without exporting Switcher? It's first loaded here. To get the user config without Switcher,

[shewer]

請教一下 SwitcherReg make() 爲何 用 New Switcher(engine)
swicher.cc 沒有 Switcher::Switcher(engine)
只有 Switcher(const Ticket* ticket)

另外 switcher:active() ，menu 無法操作

[amorphobia]

我看到 engine.cc 里直接使用了 New<Switcher>(this), 所以我直接拿来用了。

以下是我的猜测

第一是因为 Switcher 是 Engine 的 public 继承

第二是 New 这个 function 本身只生成了一个新的 shared_ptr<T>, 其参数是 rvalue, 会不会根本就没有调用 T 的 constructor?

至于 active, 我还不了解其作用，所以没有在 lua 里使用过，可能需要一个新 issue 来讨论吧。