gocui: fake file potential example. can I send this to open()?

Signed-off-by: Jeff Carr <jcarr@wit.com>

toolkit/gocui/fakefile.go

@@ -3,22 +3,25 @@ package main
 import (
 	"bytes"
 	"io"
+	"errors"
 )
 
 type FakeFile struct {
-	buffer bytes.Buffer
+	reader *bytes.Reader
+	buffer *bytes.Buffer
 	offset int64
 }
 
 func (f *FakeFile) Read(p []byte) (n int, err error) {
-	n, err = f.buffer.ReadAt(p, f.offset)
+	n, err = f.reader.ReadAt(p, f.offset)
 	f.offset += int64(n)
 	return n, err
 }
 
 func (f *FakeFile) Write(p []byte) (n int, err error) {
-	n, err = f.buffer.WriteAt(p, f.offset)
+	n, err = f.buffer.Write(p)
 	f.offset += int64(n)
+	f.reader.Reset(f.buffer.Bytes())
 	return n, err
 }
 
@@ -33,13 +36,23 @@ func (f *FakeFile) Seek(offset int64, whence int) (int64, error) {
 	case io.SeekEnd:
 		newOffset = int64(f.buffer.Len()) + offset
 	default:
-		return 0, io.ErrInvalidWhence
+		return 0, errors.New("Seek: whence not at start,current or end")
 	}
+	// never can get here right?
 
 	if newOffset < 0 {
-		return 0, io.ErrInvalidWhence
+		return 0, errors.New("Seek: offset < 0")
 	}
 
 	f.offset = newOffset
 	return f.offset, nil
 }
+
+func NewFakeFile() *FakeFile {
+	buf := &bytes.Buffer{}
+	return &FakeFile{
+		reader: bytes.NewReader(buf.Bytes()),
+		buffer: buf,
+		offset: 0,
+	}
+}

toolkit/gocui/showMsg.go

@@ -45,6 +45,7 @@ func showMsg(g *gocui.Gui, v *gocui.View) error {
 		fmt.Fprintln(v, l)
 	}
 	// g.SetViewOnTop("msg")
-	g.SetViewOnBottom("msg")
+	g.SetViewBeneath("msg", "help", 24)
+	// g.SetViewOnBottom("msg")
 	return nil
 }