view.Line() returns trailing \x00 byte

[ERnsTL]

Greetings,

In relation to issue #54, which is now fixed, there is an issue remaining: view.Line(0) returns the whole line and no second line exists in the Enter key handler, but there is a trailing \x00 = null byte returned by view.Line(0).

Test program for cut and paste; the issue shows up in function readToken:

package main

import (
    "fmt"
    "log"
    "os"

    "github.com/jroimartin/gocui"
)

func main() {
    g, _ := gocui.NewGui(gocui.OutputNormal)
    defer g.Close()

    g.SetManagerFunc(layout)
    if err := g.SetKeybinding("", gocui.KeyCtrlC, gocui.ModNone, quit); err != nil {
        log.Panicln(err)
    }
    if err := g.SetKeybinding("token", gocui.KeyEnter, gocui.ModNone, readToken); err != nil {
        log.Panicln(err)
    }

    if err := g.MainLoop(); err != nil && err != gocui.ErrQuit {
        log.Panicln(err)
    }
}

func quit(g *gocui.Gui, v *gocui.View) error {
    return gocui.ErrQuit
}

func readToken(g *gocui.Gui, v *gocui.View) error {
    //FIXME issue is here
    token, _ := v.Line(0)
    /*
    NOTE: second line does correctly not exist -> handlers are now correctly run before inserting newline automatically
    if line2, err := v.Line(1); err != nil {
      log.Fatalln("got expected error on access to non-existant line 2:", err)
    } else {
      fmt.Printf("received line 2! should not happen: >%s<, hex=%x, len=%d\n", line2, line2, len(line2))
    }
    */
    g.Close()
    // output shows \x00 byte at end
    fmt.Printf("user has entered: >%s<, hex=%x, len=%d\n", token, token, len(token))
    os.Exit(0)
    return nil
}

func layout(g *gocui.Gui) error {
    maxX, maxY := g.Size()

    // Overlap (front)
    passLen := 25
    // calculate position for centering
    //TODO is this possible more easily to center a view of given size?
    x0 := (maxX - passLen - 2) / 2
    y0 := (maxY - 3) / 2
    if v, err := g.SetView("token", x0, y0, x0+passLen+2, y0+2); err != nil {
        if err != gocui.ErrUnknownView {
            return err
        }
        v.Title = "Enter security token"
        v.Editable = true
        v.Wrap = false
        if _, err := g.SetCurrentView("token"); err != nil {
            return err
        }
    }

    return nil
}

[jroimartin]

Thanks for reporting the issue! Could it be the same issue as #69 ?

[ERnsTL]

With regards to how the issue manifests, yes, this seems to be the same issue, though above test program does not do any complex editing, just asks the user for a string and catches the Enter key.

[ERnsTL]

So the solution of this issue if I understand #69 correctly - depends on editing mode rewrite? Then it will be gone?

[jroimartin]

Exactly, the editing mode rewrite will fix these issues. BTW is it ok if I close this issue? We can continue the discussion in #69.

[ERnsTL]

Sure, I see this issue is also linked back, so closing is perfectly fine.