Lua Radio buttons

Forum: Programming and Scripting
Topic: Lua Radio buttons
started by: u2musicmike

Posted by u2musicmike on Jan. 24 2007,20:34

I am trying to get radio buttons to work in a short lua program:

Code Sample

selbc = fltk:Fl_Round_Button(130,20,18,25,"Breads_Cereals")
-- selbc:value(1)
selbc:type(fltk.FL_RADIO_BUTTON)
selbc:selection_color(fltk.FL_RED)

selmd = fltk:Fl_Round_Button(260,20,18,25,"Main Dishes")
selmd:type(fltk.FL_RADIO_BUTTON)
selmd:selection_color(fltk.FL_RED)

selveg = fltk:Fl_Round_Button(130,40,18,25,"Vegetables")
selveg:type(fltk.FL_RADIO_BUTTON)
selveg:selection_color(fltk.FL_RED)

selmisc = fltk:Fl_Round_Button(260,40,18,25,"Miscellaneous")
selmisc:type(fltk.FL_RADIO_BUTTON)
selmisc:selection_color(fltk.FL_RED)

-- setonly():void

if selmisc:value() == 1 then
foodcat = "Miscellaneous"
elseif selmd:value() == 1 then
foodcat = "Main Dishes"
elseif selveg:value() == 1 then
foodcat = "Vegetables"
elseif selbc:value() == 1 then
foodcat = "Breads_Cereals"
end

No matter what I click the value is never set unless I do it manually. I tried to do it like the fdtool program but I am missing something. Can somebody point me to a site that has some lua radio button code?

Posted by roberts on Jan. 24 2007,21:11

What is your enclosing container, group or window?
What gui is going to have the callback attached so you can display the results of the radio button selection.

We have 5 lua programs that use radio buttons, from simple to more complex for you to study.

icontool
mouse-config
rdesktop
wallpaper
fdtool

Posted by mikshaw on Jan. 24 2007,22:22

Something like this might help?

Code Sample

function catfood(self)
foodcat=self:label();
print(foodcat);
end

w=fltk.Fl_Window(300,100,"catfood");
selbc = fltk:Fl_Round_Button(30,20,18,25,"Breads_Cereals")
selbc:type(fltk.FL_RADIO_BUTTON); selbc:callback(catfood);
--
selmd = fltk:Fl_Round_Button(160,20,18,25,"Main Dishes")
selmd:type(fltk.FL_RADIO_BUTTON); selmd:callback(catfood);
--
selveg = fltk:Fl_Round_Button(30,40,18,25,"Vegetables")
selveg:type(fltk.FL_RADIO_BUTTON); selveg:callback(catfood);
--
selmisc = fltk:Fl_Round_Button(160,40,18,25,"Miscellaneous")
selmisc:type(fltk.FL_RADIO_BUTTON); selmisc:callback(catfood);

w:show();
Fl:run();

If you have multiple sets of radio buttons you'll probably need to create a unique group for each set of buttons. Also, this example uses the label of each button to determine the value of foodcat

Posted by u2musicmike on Jan. 26 2007,15:41

Thanks for the help. I was really stuck. The radio buttons work now. That is a pretty neat trick to pull the labels from the buttons. I don't know the lua programming language very well but I am trying to build a data entry form for a sqlite database. As a starting point I took the window routines from the fdtool.lua program and changed a few things like button names and input fields. If I can get it to produce the sql statement that I want I will post the code or make a dsl package.

One thing that I found strange was the function has to be before the radio button statements.

Posted by mikshaw on Jan. 26 2007,18:12

Apparently some languages don't require the function to be defined first, but Lua seems to be one that does. I assume this is because Lua is interpreted line-by-line at runtime, so it needs to know what a callback does before it can use the callback. Maybe the function could first be declared without being fully defined, like in C, but I haven't really had any need or desire to experiment with that yet.

I know nothing about using sql databases yet, so I can't help there. So far my experience with saving and retreiving data has been in parsing plain text rc files, like many of the DSL tools do.