OpenEuphoria

Re: NEWT :: selecting an item from a listbox

• Posted by K_D_R Dec 26, 2012
• 2015 views

Thanks, Greg, for the sample code. I am still having problems - here is the code I have been working with, the comments will show variations I have tried.

 include ../newt.e 
include std/machine.e 
procedure main() 
 
-- create a simple list of things  
sequence fruits = { "Apples", "Bananas", "Oranges" }  
     
    newtComponent form,  
	listbox, 
	buttonSubmit 
     
    newt:Init() 
    newt:Cls() 
     
    newt:CenteredWindow( 64, 24, "*Select Item" ) 
  
 -- create a new list box  
    listbox = newt:Listbox( 2, 2, 5, NULL )  
--  listbox = newt:Listbox( 2, 2, 5, NEWT_FLAG_RETURNEXIT )  
--  listbox = newt:Listbox( 18, 3, 10, NEWT_FLAG_SCROLL )  
--  listbox = newt:Listbox( 18, 3, 10, NEWT_FLAG_SCROLL ) 
--  newt:ListboxAppendEntry(listbox, "", 0) 
--  newt:ListboxAppendEntries(listbox, fruits, 0) 
     
  -- loop through the items  
  for index = 1 to length( fruits ) do  
    
	    -- allocate some memory  
	   atom ptr = allocate( 4, 1 ) -- 1 = automatically free  
	     
	    -- store the index of this item  
	    poke4( ptr, index )  
		      
	    --  add the item to the list box  
     newt:ListboxAppendEntry( listbox, fruits[index], ptr )  
  end for  
			        
    buttonSubmit = newt:Button( 22, 20, "Submit" ) 
     
    form = newt:Form( NULL, NULL, 0 ) 
    newt:FormAddComponents( form, { 
	listbox, 
	buttonSubmit 
	}) 
     
    --// run the form here //--  
    newt:FormRun(form) 
     
    -- get the selected "item" (our pointer above)  
    atom ptr = newt:ListboxGetCurrent( listbox )  
				  
    -- fetch the index from the pointer  
    integer index = peek4s( ptr )  
				   
    -- display the result  
    printf( 1, "you selected: %s\n", fruits[index] )  
     
    newt:FormDestroy(form) 
    newt:Finished() 
end procedure 
main() 
 

This is the ex.err file: 
 
/home/ken/euphoria/euprogs/eunewt/demo/fruit_listbox.ex:57 in procedure main()  
subscript value 32880 is out of bounds, reading from a sequence of length 3  
    retval (from inlined routine 'Finished' at 213) = <no value> 
    retval (from inlined routine 'Init' at 6) = <no value> 
    fruits = { 
               {65'A',112'p',112'p',108'l',101'e',115's'}, 
               {66'B',97'a',110'n',97'a',110'n',97'a',115's'}, 
               {79'O',114'r',97'a',110'n',103'g',101'e',115's'} 
             } 
    form = 18612064 
    listbox = 18755504 
    buttonSubmit = 18620320 
    index = 3 
    ptr = <no value> 
    ptr = 16715776 
    index = 32880 
 
... called from /home/ken/euphoria/euprogs/eunewt/demo/fruit_listbox.ex:62  
 
 
Public & Export & Global & Local Variables 
 
 /home/ken/euphoria/include/std/memconst.e: 
    DEP_really_works = 0 
    use_DEP = 1 
    FREE_RID = 2 
    kernel_dll = <no value> 
    memDLL_id = <no value> 
    VirtualAlloc_rid = <no value> 
    VirtualLock_rid = <no value> 
    VirtualUnlock_rid = <no value> 
    VirtualProtect_rid = <no value> 
    GetLastError_rid = <no value> 
    GetSystemInfo_rid = <no value> 
 
 /home/ken/euphoria/include/std/memory.e: 
    edges_only = <no value> 
    check_calls = 1 
    VirtualFree_rid = <no value> 
 
 /home/ken/euphoria/include/std/types.e: 
    Defined_Sets = { 
                     {98'b',99'c',100'd',102'f',103'g',104'h',106'j',107'k', 
108'l',109'm',110'n',112'p',113'q',114'r',115's',116't',118'v',119'w',120'x', 
121'y',122'z',66'B',67'C',68'D',70'F',71'G',72'H',74'J',75'K',76'L',77'M', 
78'N',80'P',81'Q',82'R',83'S',84'T',86'V',87'W',88'X',89'Y',90'Z'}, 
                     {97'a',101'e',105'i',111'o',117'u',65'A',69'E',73'I', 
79'O',85'U'}, 
                     { 
                       {48'0',57'9'}, 
                       {65'A',70'F'}, 
                       {97'a',102'f'} 
                     }, 
                     {32' ',9,10,13,11,160}, 
                     { 
                       {32' ',47'/'}, 
                       {58':',63'?'}, 
                       {91'[',96'`'}, 
                       {123'{',126'~'} 
                     }, 
                     { 
                       {32' ',126'~'} 
                     }, 
                     { 
                       {32' ',126'~'}, 
                       {32' ',32' '}, 
                       {9,9}, 
                       {10,10}, 
                       {13,13}, 
                       {8,8}, 
                       {7,7} 
                     }, 
                     { 
                       {97'a',122'z'} 
                     }, 
                     { 
                       {65'A',90'Z'} 
                     }, 
                     { 
                       {48'0',57'9'}, 
                       {97'a',122'z'}, 
                       {65'A',90'Z'} 
                     }, 
                     { 
                       {48'0',57'9'}, 
                       {97'a',122'z'}, 
                       {65'A',90'Z'}, 
                       {95'_',95'_'} 
                     }, 
                     { 
                       {97'a',122'z'}, 
                       {65'A',90'Z'} 
                     }, 
                     { 
                       {0,127} 
                     }, 
                     { 
                       {0,31}, 
                       {127,127} 
                     }, 
                     { 
                       {48'0',57'9'} 
                     }, 
                     { 
                       {33'!',126'~'} 
                     }, 
                     { 
                       {0,255} 
                     }, 
                     {95'_'}, 
                     {1,0} 
                   } 
 
 /home/ken/euphoria/include/std/machine.e: 
    FREE_ARRAY_RID = 1 
    page_size = 4096 
 
 /home/ken/euphoria/euprogs/eunewt/demo/../newt.e: 
    libnewt = 16605808 
 

Any suggestions will be appreciated!

Kennneth Rhodes