F

+field
Form field base class. See +CheckBox, +Radio, +TextField, +RgbPicker.
(field X . @)
Function to access another field from the current field. The first argument can be either a symbol (to access a named 'gui' component) or a positive or negative number (to access a field relative to the current one). In both cases the 'get' algorithm is applied to all following arguments.

    (gui '(+View +TextField) '(field -1 'obj 'ort) 30)
    
+FixField
+FixField accepts and returns scaled fixpoint numbers. This field needs an argument that determines the scale factor.

    (gui '(+FixField) 3 10)
    
See also +NumField, +TextField and Input fields.
+FileField
This field evaluates an 'exe' to find and open/create a file, then loads/modifies/stores the text in that file. See also +TextField.
+Focus
+Focus is a prefix class used to set the keyboard focus on a specific GUI element. For example, it can be used to put the initial focus on a specific input field in a search dialog. Examples of this usage can be found in the demo app supplied with the PicoLisp distribution, in gui.l:

    (de choCuSu (Dst)
       (diaform '(Dst)
          (<grid> "--.-.-."
             ,"Number" (gui 'nr '(+Var +NumField) '*CuSuNr 10)
             ,"Name" (gui 'nm '(+Focus +Var +TextField) '*CuSuNm 30)
             ,"Phone" (gui 'tel '(+Var +TelField) '*CuSuTel 20)
             (searchButton '(init> (: home query)))
             ,"Zip" (gui 'plz '(+Var +TextField) '*CuSuPlz 10)
             ,"City" (gui 'ort '(+Var +TextField) '*CuSuOrt 30)
             ,"Mobile" (gui 'mob '(+Var +TelField) '*CuSuMob 20)
             (resetButton '(nr nm tel plz ort mob query)) )
             .
             .
             .
      
In the code above, +Focus is used to give initial focus to the "Name" input field.
+Force
Button prefix class which may force the action even if an error occurred. Without it, an 'error' will always inhibit further button handling. See also +Button.
+Fmt
+Fmt is a prefix class that combines +Set and +Val, taking two functions as arguments. This example will display upper case characters, while returning lower case characters internally:

    (gui '(+Fmt +TextField) uppc lowc 30)
    
See also +Set, +Val and formatting.
form
The basic form function. Handles operations common to the concrete form types in the library. See idForm, diaform.