Modern Tui TuiApp Update

Home › Terminal TUI Library › Application Loop › TuiApp.Update

TuiApp.Update

Reacts to one event and returns what the loop should do next; it never draws.

Syntax

TuiApp.Update( byref e as TuiEvent ) as TuiCmd

Description

React to one event and return what the loop should do. NEVER DRAW HERE. Events are drained before rendering, so a held arrow key applies every repeat and the frame is drawn once with the final state.

Example

#import "std/numeric"
#import "std/tui"
using tui, numeric

type App2 extends TuiApp
    as int32 sel
    declare function Init( ) as TuiCmd override
    declare function Update( byref e as TuiEvent ) as TuiCmd override
    declare sub View( byref f as TuiFrame ) override
end type

function App2.Init( ) as TuiCmd : sel = 0 : return TuiNone( ) : end function

function App2.Update( byref e as TuiEvent ) as TuiCmd
    select case e.kind
    case TUIEVENT_KEY
        select case e.key.code
        case TUIKEY_ESCAPE : return TuiQuit( 0 )
        case TUIKEY_DOWN   : sel += 1 : return TuiRedraw( )
        case TUIKEY_UP     : sel -= 1 : return TuiRedraw( )
        end select
    case TUIEVENT_RESIZE
        return TuiRedraw( )       '' the loop already resized the screen
    end select
    return TuiNone( )
end function

sub App2.View( byref f as TuiFrame ) : end sub

See also

TuiApp	TuiApp.View	TuiCmd	TuiRedraw	TuiTick	TuiSuspend
TuiApp.Init	TuiApp.Shutdown	TuiNone	TuiQuit	TuiInvalidate	TuiRun

---

Library: Terminal TUI Library
Category: Terminal TUI Library
Documented under: Application Loop
Working examples: hello.tiko · form.tiko · dashboard.tiko

---

Home · Keyword Index