Add example for mask

_examples/mask.go

@@ -0,0 +1,72 @@
+// Copyright 2015 The gocui Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/jroimartin/gocui"
+)
+
+func main() {
+	g := gocui.NewGui()
+	if err := g.Init(); err != nil {
+		log.Fatalln(err)
+	}
+	defer g.Close()
+
+	g.SetLayout(layout)
+	if err := initKeybindings(g); err != nil {
+		log.Fatalln(err)
+	}
+
+	if err := g.MainLoop(); err != nil && err != gocui.ErrQuit {
+		log.Fatalln(err)
+	}
+}
+
+func layout(g *gocui.Gui) error {
+	maxX, maxY := g.Size()
+
+	if v, err := g.SetView("legend", maxX-23, 0, maxX-1, 3); err != nil {
+		if err != gocui.ErrUnknownView {
+			return err
+		}
+		v.Title = "Keybindings"
+		fmt.Fprintln(v, "^a: Set mask")
+		fmt.Fprintln(v, "^c: Exit")
+	}
+
+	if v, err := g.SetView("input", 0, 0, maxX-24, maxY-1); err != nil {
+		if err != gocui.ErrUnknownView {
+			return err
+		}
+		if err := g.SetCurrentView("input"); err != nil {
+			return err
+		}
+		v.Editable = true
+		v.Wrap = true
+	}
+
+	return nil
+}
+
+func initKeybindings(g *gocui.Gui) error {
+	if err := g.SetKeybinding("", gocui.KeyCtrlC, gocui.ModNone,
+		func(g *gocui.Gui, v *gocui.View) error {
+			return gocui.ErrQuit
+		}); err != nil {
+		return err
+	}
+	if err := g.SetKeybinding("input", gocui.KeyCtrlA, gocui.ModNone,
+		func(g *gocui.Gui, v *gocui.View) error {
+			v.Mask ^= '*'
+			return nil
+		}); err != nil {
+		return err
+	}
+	return nil
+}

view.go

@@ -61,7 +61,8 @@ type View struct {
 	// If Frame is true, Title allows to configure a title for the view.
 	Title string
 
-	// If set and view is Editable, displays the mask instead of the real content
+	// If Mask is true, the View will display the mask instead of the real
+	// content
 	Mask rune
 }