wxlua-users Mailing List for wxLua

Hi John,

As I've been working through the code to figure out how to inherit a
new class from wxApp (similar to how wxLuaPrintout inherits from
wxPrintout), I wondered if it's possible to do most of it at the Lua
level (with a bit of help from C++).

If the binding generator identifies all wxwidgets classes that can be
passed as parameters and creates inherited *Lua* classes, the I can do
something like this:

local app = wx.wxGetApp()
-- recast wxApp to wxLuaApp
local newapp = app:GetInstance():DynamicCast("wxLuaApp")
newapp.MacOpenFiles = function(files) ... end
-- register the new app with wxwidgets
app:SetInstance(newapp)

This will also allow "true" inheritance from wxwidgets classes at the
Lua level, which I find lacking in wxlua right now (unless I'm missing
something).

The implementation would automate most of the work that would need to
be done manually for these inherited classes: (1) pick a class based
on whether it's passed as a parameter or not; if it's difficult to do
automatically, the list can be pre-assigned; (2) generate a proper
class definition; and (3) create stubs for virtual methods that will
check for properties assigned in the derived class (in the example
above it would be MacOpenFiles method).

One of the challenges I see is the initialization that needs to assign
the current lua state (m_wxlState) as I'm not sure when it needs to
happen (as DynamicCast doesn't create a new object). Maybe DynamicCast
can check if the cast is to one of wxLua* classes and do the
assignment? This problem remains even when the class definitions are
done "manually", so I'd be interested in any suggestions on how to
address this.

Is there a method to get the current Lua state (wxlState) to use in
virtual functions:

void wxApp::MacOpenFiles(const wxArrayString& filenames)
{
    wxLuaState m_wxlState = s_wxlState // <== not sure what to put here

Related question: I'm trying to use wxEVT_LUA_ERROR and
wxEVT_LUA_PRINT form the Lua code, but can't find any examples on how
to set it up. Any pointers? Thank you.




Paul.

Hi John,

It seems like I'll need to create a derived class for wxLuaApp
(similar to wxLuaPrintout) and add those Mac* methods to that class.
Then the app can be set using wxGetApp::SetInstance() method, which
should trigger those Mac* methods as expected. This also eliminates
the issue with getting the Lua state, but I still need to figure out
how to initialize the application fields properly... Or is there a
better way?

Paul.

On Thu, May 5, 2016 at 10:59 PM, Paul K <pau...@ya...> wrote:
> Hi John,
>
>> 1. Memory leak in wxlua: http://sourceforge.net/p/wxlua/mailman/message/34430092/
>> 2. MacOpenFiles and related methods: http://sourceforge.net/p/wxlua/mailman/message/34559782/
>> 3. wxButton class is missing all the methods from wxAnyButton class
>> 4. Several other methods missing: http://sourceforge.net/p/wxlua/mailman/message/32988247/
>
> I've been making good progress updating wxlua API for wxwidgets 3.1.x
> and have processed about dozen or so classes, so adding all the
> missing methods is much less of a priority for me.
>
> I tried to add MacOpenFiles processing and ran into an issue with
> getting access to the current Lua state. Here is what I currently
> have:
>
> %override wxLua_wxApp_MacOpenFiles
> void wxApp::MacOpenFiles(const wxArrayString& filenames)
> {
>     wxLuaState m_wxlState = s_wxlState // <== not sure what to put here
>
>     if (m_wxlState.Ok() && !m_wxlState.GetCallBaseClassFunction() &&
>         m_wxlState.HasDerivedMethod(this, "MacOpenFiles", true))
>     {
>         int nOldTop = m_wxlState.lua_GetTop();
>         m_wxlState.wxluaT_PushUserDataType(this, wxluatype_wxApp, true);
>         m_wxlState.PushwxArrayStringTable(filenames);
>
>         m_wxlState.LuaPCall(2, 0);
>         m_wxlState.lua_SetTop(nOldTop-1); // -1 to remove pushed
> derived method func too
>     }
>     m_wxlState.SetCallBaseClassFunction(false); // clear flag always
> }
> %end
>
> I would have used s_wxlState, but it's "static" in the Lua module, so
> not available outside of that file. It doesn't solve all the problems,
> but it could set me on the right track. When I make s_wxlState
> non-static, I do get a linker error about duplicate
> wxApp::MacOpenFiles method, so any ideas on how to avoid this, would
> be useful too.
>
> Paul.

Hi John,

> 1. Memory leak in wxlua: http://sourceforge.net/p/wxlua/mailman/message/34430092/
> 2. MacOpenFiles and related methods: http://sourceforge.net/p/wxlua/mailman/message/34559782/
> 3. wxButton class is missing all the methods from wxAnyButton class
> 4. Several other methods missing: http://sourceforge.net/p/wxlua/mailman/message/32988247/

I've been making good progress updating wxlua API for wxwidgets 3.1.x
and have processed about dozen or so classes, so adding all the
missing methods is much less of a priority for me.

I tried to add MacOpenFiles processing and ran into an issue with
getting access to the current Lua state. Here is what I currently
have:

%override wxLua_wxApp_MacOpenFiles
void wxApp::MacOpenFiles(const wxArrayString& filenames)
{
    wxLuaState m_wxlState = s_wxlState // <== not sure what to put here

    if (m_wxlState.Ok() && !m_wxlState.GetCallBaseClassFunction() &&
        m_wxlState.HasDerivedMethod(this, "MacOpenFiles", true))
    {
        int nOldTop = m_wxlState.lua_GetTop();
        m_wxlState.wxluaT_PushUserDataType(this, wxluatype_wxApp, true);
        m_wxlState.PushwxArrayStringTable(filenames);

        m_wxlState.LuaPCall(2, 0);
        m_wxlState.lua_SetTop(nOldTop-1); // -1 to remove pushed
derived method func too
    }
    m_wxlState.SetCallBaseClassFunction(false); // clear flag always
}
%end

I would have used s_wxlState, but it's "static" in the Lua module, so
not available outside of that file. It doesn't solve all the problems,
but it could set me on the right track. When I make s_wxlState
non-static, I do get a linker error about duplicate
wxApp::MacOpenFiles method, so any ideas on how to avoid this, would
be useful too.

Paul.