Editor refactoring. Add doc. Simplify _examples.

_examples/delete.go

@@ -21,8 +21,6 @@ var (
 )
 
 func main() {
-	var err error
-
 	g := gocui.NewGui()
 	if err := g.Init(); err != nil {
 		log.Panicln(err)
@@ -37,8 +35,7 @@ func main() {
 		log.Panicln(err)
 	}
 
-	err = g.MainLoop()
-	if err != nil && err != gocui.ErrQuit {
+	if err := g.MainLoop(); err != nil && err != gocui.ErrQuit {
 		log.Panicln(err)
 	}
 }

_examples/demo.go

@@ -187,8 +187,6 @@ func layout(g *gocui.Gui) error {
 }
 
 func main() {
-	var err error
-
 	g := gocui.NewGui()
 	if err := g.Init(); err != nil {
 		log.Panicln(err)
@@ -203,8 +201,7 @@ func main() {
 	g.SelFgColor = gocui.ColorBlack
 	g.Cursor = true
 
-	err = g.MainLoop()
-	if err != nil && err != gocui.ErrQuit {
+	if err := g.MainLoop(); err != nil && err != gocui.ErrQuit {
 		log.Panicln(err)
 	}
 }

_examples/goroutine.go

@@ -79,20 +79,18 @@ func counter(g *gocui.Gui) {
 		case <-done:
 			return
 		case <-time.After(500 * time.Millisecond):
+			mu.Lock()
+			n := ctr
+			ctr++
+			mu.Unlock()
+
 			g.Execute(func(g *gocui.Gui) error {
 				v, err := g.View("ctr")
 				if err != nil {
 					return err
 				}
-
-				mu.Lock()
-				n := ctr
-				ctr++
-				mu.Unlock()
-
 				v.Clear()
 				fmt.Fprintln(v, n)
-
 				return nil
 			})
 		}

_examples/layout.go

@@ -32,8 +32,6 @@ func quit(g *gocui.Gui, v *gocui.View) error {
 }
 
 func main() {
-	var err error
-
 	g := gocui.NewGui()
 	if err := g.Init(); err != nil {
 		log.Panicln(err)
@@ -46,8 +44,7 @@ func main() {
 		log.Panicln(err)
 	}
 
-	err = g.MainLoop()
-	if err != nil && err != gocui.ErrQuit {
+	if err := g.MainLoop(); err != nil && err != gocui.ErrQuit {
 		log.Panicln(err)
 	}
 }

_examples/mouse.go

@@ -12,8 +12,6 @@ import (
 )
 
 func main() {
-	var err error
-
 	g := gocui.NewGui()
 	if err := g.Init(); err != nil {
 		log.Panicln(err)
@@ -29,8 +27,7 @@ func main() {
 	g.Cursor = true
 	g.Mouse = true
 
-	err = g.MainLoop()
-	if err != nil && err != gocui.ErrQuit {
+	if err := g.MainLoop(); err != nil && err != gocui.ErrQuit {
 		log.Panicln(err)
 	}
 }

_examples/overlap.go

@@ -56,8 +56,6 @@ func quit(g *gocui.Gui, v *gocui.View) error {
 }
 
 func main() {
-	var err error
-
 	g := gocui.NewGui()
 	if err := g.Init(); err != nil {
 		log.Panicln(err)
@@ -69,8 +67,7 @@ func main() {
 		log.Panicln(err)
 	}
 
-	err = g.MainLoop()
-	if err != nil && err != gocui.ErrQuit {
+	if err := g.MainLoop(); err != nil && err != gocui.ErrQuit {
 		log.Panicln(err)
 	}
 }

_examples/stdin.go

@@ -27,8 +27,7 @@ func main() {
 	}
 	g.Cursor = true
 
-	err := g.MainLoop()
-	if err != nil && err != gocui.ErrQuit {
+	if err := g.MainLoop(); err != nil && err != gocui.ErrQuit {
 		log.Fatalln(err)
 	}
 }

_examples/wrap.go

@@ -32,8 +32,6 @@ func quit(g *gocui.Gui, v *gocui.View) error {
 }
 
 func main() {
-	var err error
-
 	g := gocui.NewGui()
 	if err := g.Init(); err != nil {
 		log.Panicln(err)
@@ -45,8 +43,7 @@ func main() {
 		log.Panicln(err)
 	}
 
-	err = g.MainLoop()
-	if err != nil && err != gocui.ErrQuit {
+	if err := g.MainLoop(); err != nil && err != gocui.ErrQuit {
 		log.Panicln(err)
 	}
 }

doc.go

@@ -5,36 +5,106 @@
 /*
 Package gocui allows to create console user interfaces.
 
-Example:
+Create a new GUI:
 
-	func layout(g *gocui.Gui) error {
-		maxX, maxY := g.Size()
-		if v, err := g.SetView("center", maxX/2-10, maxY/2, maxX/2+10, maxY/2+2); err != nil {
-			if err != gocui.ErrUnknownView {
-				return err
-			}
-			fmt.Fprintln(v, "This is an example")
+	g := gocui.NewGui()
+	if err := g.Init(); err != nil {
+		// handle error
+	}
+	defer g.Close()
+
+	// Set layout and key bindings
+	// ...
+
+	if err := g.MainLoop(); err != nil && err != gocui.ErrQuit {
+		// handle error
+	}
+
+Set the layout function:
+
+	g.SetLayout(fcn)
+
+On each iteration of the GUI's main loop, the "layout function" will be
+executed.  These layout functions can be used to set-up and update the main
+application views, being possible to freely switch between them. Also, it is
+important to mention that a main loop iteration is executed on each reported
+event (key-press, mouse event, window resize, etc).
+
+GUIs are composed by Views, you can think of it as free text buffers. Views
+implement the io.ReadWriter interface, so you can just write to them if you
+want to modify their content and the same is valid for reading.
+
+Create and intialize a view with absolute coordinates:
+
+	if v, err := g.SetView("viewname", 2, 2, 22, 7); err != nil {
+		if err != gocui.ErrUnknownView {
+			// handle error
 		}
+		fmt.Fprintln(v, "This is a new view")
+		// ...
+	}
+
+Views can also being created using relative coordinates:
+
+	maxX, maxY := g.Size()
+	if v, err := g.SetView("viewname", maxX/2-30, maxY/2, maxX/2+30, maxY/2+2); err != nil {
+		// ...
+	}
+
+IMPORTANT: Views can only be created, destroyed or updated in two ways: from a
+layout funcion or via *Gui.Execute(). The reason for this is that it allows
+gocui to be conccurent-safe. So, if you want to update your GUI from a
+goroutine, you must use *Gui.Execute(). For example:
+
+	g.Execute(func(g *gocui.Gui) error {
+		v, err := g.View("viewname")
+		if err != nil {
+			// handle error
+		}
+		v.Clear()
+		fmt.Fprintln(v, "Writing from different goroutines")
 		return nil
+	})
+
+Configure keybindings:
+
+	if err := g.SetKeybinding("viewname", gocui.KeyEnter, gocui.ModNone, fcn); err != nil {
+		// handle error
 	}
-	func quit(g *gocui.Gui, v *gocui.View) error {
-		return gocui.ErrQuit
+
+gocui implements full mouse support than can be enabled with:
+
+	g.Mouse = true
+
+Mouse events are handled like any other keybinding:
+
+	if err := g.SetKeybinding("viewname", gocui.MouseLeft, gocui.ModNone, fcn); err != nil {
+		// handle error
 	}
-	func main() {
-		var err error
-		g := gocui.NewGui()
-		if err := g.Init(); err != nil {
-			log.Panicln(err)
-		}
-		defer g.Close()
-		g.SetLayout(layout)
-		if err := g.SetKeybinding("", gocui.KeyCtrlC, gocui.ModNone, quit); err != nil {
-			log.Panicln(err)
-		}
-		err = g.MainLoop()
-		if err != nil && err != gocui.ErrQuit {
-			log.Panicln(err)
+
+By default, gocui provides a basic edition mode. This mode can be extended
+and customized creating a new Editor and asigning it to *Gui.Editor:
+
+	type Editor interface {
+		Edit(v *View, key Key, ch rune, mod Modifier)
+	}
+
+DefaultEditor can be taken as example to create your own custom Editor:
+
+	var DefaultEditor = EditorFunc(simpleEditor)
+
+	func simpleEditor(v *View, key Key, ch rune, mod Modifier) {
+		switch {
+		case ch != 0 && mod == 0:
+			v.EditWrite(ch)
+		case key == KeySpace:
+			v.EditWrite(' ')
+		case key == KeyBackspace || key == KeyBackspace2:
+			v.EditDelete(true)
+		// ...
 		}
 	}
+
+For more information, see the examples in folder "_examples/".
 */
 package gocui

edit.go

@@ -6,11 +6,6 @@ package gocui
 
 const maxInt = int(^uint(0) >> 1)
 
-// Edit allows to define the editor that manages the edition mode,
-// including keybindings or cursor behaviour. DefaultEditor is used by
-// default.
-var Edit = EditorFunc(DefaultEditor)
-
 // Editor interface must be satisfied by gocui editors.
 type Editor interface {
 	Edit(v *View, key Key, ch rune, mod Modifier)
@@ -26,8 +21,11 @@ func (f EditorFunc) Edit(v *View, key Key, ch rune, mod Modifier) {
 	f(v, key, ch, mod)
 }
 
-// DefaultEditor is used as the default gocui editor.
-func DefaultEditor(v *View, key Key, ch rune, mod Modifier) {
+// DefaultEditor is the default editor.
+var DefaultEditor Editor = EditorFunc(simpleEditor)
+
+// simpleEditor is used as the default gocui editor.
+func simpleEditor(v *View, key Key, ch rune, mod Modifier) {
 	switch {
 	case ch != 0 && mod == 0:
 		v.EditWrite(ch)

gui.go

@@ -19,7 +19,7 @@ type userEvent struct {
 }
 
 var (
-	// ErrQuit is used to decide if the MainLoop finished succesfully.
+	// ErrQuit is used to decide if the MainLoop finished successfully.
 	ErrQuit = errors.New("quit")
 
 	// ErrUnknownView allows to assert if a View must be initialized.
@@ -50,6 +50,11 @@ type Gui struct {
 
 	// If Mouse is true then mouse events will be enabled.
 	Mouse bool
+
+	// Editor allows to define the editor that manages the edition mode,
+	// including keybindings or cursor behaviour. DefaultEditor is used by
+	// default.
+	Editor Editor
 }
 
 // NewGui returns a new Gui object.
@@ -68,6 +73,7 @@ func (g *Gui) Init() error {
 	g.maxX, g.maxY = termbox.Size()
 	g.BgColor = ColorBlack
 	g.FgColor = ColorWhite
+	g.Editor = DefaultEditor
 	return nil
 }
 
@@ -220,7 +226,7 @@ func (g *Gui) Execute(h Handler) {
 }
 
 // SetLayout sets the current layout. A layout is a function that
-// will be called everytime the gui is re-drawed, it must contain
+// will be called every time the gui is redrawn, it must contain
 // the base views and its initializations.
 func (g *Gui) SetLayout(layout Handler) {
 	g.layout = layout
@@ -493,8 +499,8 @@ func (g *Gui) onKey(ev *termbox.Event) error {
 
 	switch ev.Type {
 	case termbox.EventKey:
-		if g.currentView != nil && g.currentView.Editable && Edit != nil {
-			Edit(g.currentView, Key(ev.Key), ev.Ch, Modifier(ev.Mod))
+		if g.currentView != nil && g.currentView.Editable && g.Editor != nil {
+			g.Editor.Edit(g.currentView, Key(ev.Key), ev.Ch, Modifier(ev.Mod))
 		}
 		curView = g.currentView
 	case termbox.EventMouse:

view.go

@@ -419,7 +419,7 @@ func (v *View) breakLine(x, y int) error {
 }
 
 // Buffer returns a string with the contents of the view's internal
-// buffer
+// buffer.
 func (v *View) Buffer() string {
 	str := ""
 	for _, l := range v.lines {
@@ -429,7 +429,7 @@ func (v *View) Buffer() string {
 }
 
 // ViewBuffer returns a string with the contents of the view's buffer that is
-// showed to the user
+// shown to the user.
 func (v *View) ViewBuffer() string {
 	str := ""
 	for _, l := range v.viewLines {