vendor gocui

1 files changed, 646 insertions, 0 deletions

diff --git a/vendor/github.com/jroimartin/gocui/gui.go b/vendor/github.com/jroimartin/gocui/gui.go
new file mode 100644
index 00000000..39579dc4
--- /dev/null
+++ b/vendor/github.com/jroimartin/gocui/gui.go
@@ -0,0 +1,646 @@
+// Copyright 2014 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 gocui
+
+import (
+	"errors"
+
+	"github.com/nsf/termbox-go"
+)
+
+// Handler represents a handler that can be used to update or modify the GUI.
+type Handler func(*Gui) error
+
+// userEvent represents an event triggered by the user.
+type userEvent struct {
+	h Handler
+}
+
+var (
+	// ErrQuit is used to decide if the MainLoop finished successfully.
+	ErrQuit = errors.New("quit")
+
+	// ErrUnknownView allows to assert if a View must be initialized.
+	ErrUnknownView = errors.New("unknown view")
+)
+
+// Gui represents the whole User Interface, including the views, layouts
+// and keybindings.
+type Gui struct {
+	tbEvents    chan termbox.Event
+	userEvents  chan userEvent
+	views       []*View
+	currentView *View
+	layout      Handler
+	keybindings []*keybinding
+	maxX, maxY  int
+
+	// BgColor and FgColor allow to configure the background and foreground
+	// colors of the GUI.
+	BgColor, FgColor Attribute
+
+	// SelBgColor and SelFgColor are used to configure the background and
+	// foreground colors of the selected line, when it is highlighted.
+	SelBgColor, SelFgColor Attribute
+
+	// If Cursor is true then the cursor is enabled.
+	Cursor bool
+
+	// If Mouse is true then mouse events will be enabled.
+	Mouse bool
+
+	// If InputEsc is true, when ESC sequence is in the buffer and it doesn't
+	// match any known sequence, ESC means KeyEsc.
+	InputEsc 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.
+func NewGui() *Gui {
+	return &Gui{}
+}
+
+// Init initializes the library. This function must be called before
+// any other functions.
+func (g *Gui) Init() error {
+	if err := termbox.Init(); err != nil {
+		return err
+	}
+	g.tbEvents = make(chan termbox.Event, 20)
+	g.userEvents = make(chan userEvent, 20)
+	g.maxX, g.maxY = termbox.Size()
+	g.BgColor = ColorBlack
+	g.FgColor = ColorWhite
+	g.Editor = DefaultEditor
+	return nil
+}
+
+// Close finalizes the library. It should be called after a successful
+// initialization and when gocui is not needed anymore.
+func (g *Gui) Close() {
+	termbox.Close()
+}
+
+// Size returns the terminal's size.
+func (g *Gui) Size() (x, y int) {
+	return g.maxX, g.maxY
+}
+
+// SetRune writes a rune at the given point, relative to the top-left
+// corner of the terminal. It checks if the position is valid and applies
+// the gui's colors.
+func (g *Gui) SetRune(x, y int, ch rune) error {
+	if x < 0 || y < 0 || x >= g.maxX || y >= g.maxY {
+		return errors.New("invalid point")
+	}
+	termbox.SetCell(x, y, ch, termbox.Attribute(g.FgColor), termbox.Attribute(g.BgColor))
+	return nil
+}
+
+// Rune returns the rune contained in the cell at the given position.
+// It checks if the position is valid.
+func (g *Gui) Rune(x, y int) (rune, error) {
+	if x < 0 || y < 0 || x >= g.maxX || y >= g.maxY {
+		return ' ', errors.New("invalid point")
+	}
+	c := termbox.CellBuffer()[y*g.maxX+x]
+	return c.Ch, nil
+}
+
+// SetView creates a new view with its top-left corner at (x0, y0)
+// and the bottom-right one at (x1, y1). If a view with the same name
+// already exists, its dimensions are updated; otherwise, the error
+// ErrUnknownView is returned, which allows to assert if the View must
+// be initialized. It checks if the position is valid.
+func (g *Gui) SetView(name string, x0, y0, x1, y1 int) (*View, error) {
+	if x0 >= x1 || y0 >= y1 {
+		return nil, errors.New("invalid dimensions")
+	}
+	if name == "" {
+		return nil, errors.New("invalid name")
+	}
+
+	if v, err := g.View(name); err == nil {
+		v.x0 = x0
+		v.y0 = y0
+		v.x1 = x1
+		v.y1 = y1
+		v.tainted = true
+		return v, nil
+	}
+
+	v := newView(name, x0, y0, x1, y1)
+	v.BgColor, v.FgColor = g.BgColor, g.FgColor
+	v.SelBgColor, v.SelFgColor = g.SelBgColor, g.SelFgColor
+	g.views = append(g.views, v)
+	return v, ErrUnknownView
+}
+
+// SetViewOnTop sets the given view on top of the existing ones.
+func (g *Gui) SetViewOnTop(name string) (*View, error) {
+	for i, v := range g.views {
+		if v.name == name {
+			s := append(g.views[:i], g.views[i+1:]...)
+			g.views = append(s, v)
+			return v, nil
+		}
+	}
+	return nil, ErrUnknownView
+}
+
+// View returns a pointer to the view with the given name, or error
+// ErrUnknownView if a view with that name does not exist.
+func (g *Gui) View(name string) (*View, error) {
+	for _, v := range g.views {
+		if v.name == name {
+			return v, nil
+		}
+	}
+	return nil, ErrUnknownView
+}
+
+// ViewByPosition returns a pointer to a view matching the given position, or
+// error ErrUnknownView if a view in that position does not exist.
+func (g *Gui) ViewByPosition(x, y int) (*View, error) {
+	for _, v := range g.views {
+		if x > v.x0 && x < v.x1 && y > v.y0 && y < v.y1 {
+			return v, nil
+		}
+	}
+	return nil, ErrUnknownView
+}
+
+// ViewPosition returns the coordinates of the view with the given name, or
+// error ErrUnknownView if a view with that name does not exist.
+func (g *Gui) ViewPosition(name string) (x0, y0, x1, y1 int, err error) {
+	for _, v := range g.views {
+		if v.name == name {
+			return v.x0, v.y0, v.x1, v.y1, nil
+		}
+	}
+	return 0, 0, 0, 0, ErrUnknownView
+}
+
+// DeleteView deletes a view by name.
+func (g *Gui) DeleteView(name string) error {
+	for i, v := range g.views {
+		if v.name == name {
+			g.views = append(g.views[:i], g.views[i+1:]...)
+			return nil
+		}
+	}
+	return ErrUnknownView
+}
+
+// SetCurrentView gives the focus to a given view.
+func (g *Gui) SetCurrentView(name string) error {
+	for _, v := range g.views {
+		if v.name == name {
+			g.currentView = v
+			return nil
+		}
+	}
+	return ErrUnknownView
+}
+
+// CurrentView returns the currently focused view, or nil if no view
+// owns the focus.
+func (g *Gui) CurrentView() *View {
+	return g.currentView
+}
+
+// SetKeybinding creates a new keybinding. If viewname equals to ""
+// (empty string) then the keybinding will apply to all views. key must
+// be a rune or a Key.
+func (g *Gui) SetKeybinding(viewname string, key interface{}, mod Modifier, h KeybindingHandler) error {
+	var kb *keybinding
+
+	k, ch, err := getKey(key)
+	if err != nil {
+		return err
+	}
+	kb = newKeybinding(viewname, k, ch, mod, h)
+	g.keybindings = append(g.keybindings, kb)
+	return nil
+}
+
+// DeleteKeybinding deletes a keybinding.
+func (g *Gui) DeleteKeybinding(viewname string, key interface{}, mod Modifier) error {
+	k, ch, err := getKey(key)
+	if err != nil {
+		return err
+	}
+
+	for i, kb := range g.keybindings {
+		if kb.viewName == viewname && kb.ch == ch && kb.key == k && kb.mod == mod {
+			g.keybindings = append(g.keybindings[:i], g.keybindings[i+1:]...)
+			return nil
+		}
+	}
+	return errors.New("keybinding not found")
+}
+
+// DeleteKeybindings deletes all keybindings of view.
+func (g *Gui) DeleteKeybindings(viewname string) {
+	var s []*keybinding
+	for _, kb := range g.keybindings {
+		if kb.viewName != viewname {
+			s = append(s, kb)
+		}
+	}
+	g.keybindings = s
+}
+
+// getKey takes an empty interface with a key and returns the corresponding
+// typed Key or rune.
+func getKey(key interface{}) (Key, rune, error) {
+	switch t := key.(type) {
+	case Key:
+		return t, 0, nil
+	case rune:
+		return 0, t, nil
+	default:
+		return 0, 0, errors.New("unknown type")
+	}
+}
+
+// Execute executes the given handler. This function can be called safely from
+// a goroutine in order to update the GUI. It is important to note that it
+// won't be executed immediately, instead it will be added to the user events
+// queue.
+func (g *Gui) Execute(h Handler) {
+	go func() { g.userEvents <- userEvent{h: h} }()
+}
+
+// SetLayout sets the current layout. A layout is a function that
+// 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
+	g.currentView = nil
+	g.views = nil
+	go func() { g.tbEvents <- termbox.Event{Type: termbox.EventResize} }()
+}
+
+// MainLoop runs the main loop until an error is returned. A successful
+// finish should return ErrQuit.
+func (g *Gui) MainLoop() error {
+	go func() {
+		for {
+			g.tbEvents <- termbox.PollEvent()
+		}
+	}()
+
+	inputMode := termbox.InputAlt
+	if g.InputEsc {
+		inputMode = termbox.InputEsc
+	}
+	if g.Mouse {
+		inputMode |= termbox.InputMouse
+	}
+	termbox.SetInputMode(inputMode)
+
+	if err := g.flush(); err != nil {
+		return err
+	}
+	for {
+		select {
+		case ev := <-g.tbEvents:
+			if err := g.handleEvent(&ev); err != nil {
+				return err
+			}
+		case ev := <-g.userEvents:
+			if err := ev.h(g); err != nil {
+				return err
+			}
+		}
+		if err := g.consumeevents(); err != nil {
+			return err
+		}
+		if err := g.flush(); err != nil {
+			return err
+		}
+	}
+}
+
+// consumeevents handles the remaining events in the events pool.
+func (g *Gui) consumeevents() error {
+	for {
+		select {
+		case ev := <-g.tbEvents:
+			if err := g.handleEvent(&ev); err != nil {
+				return err
+			}
+		case ev := <-g.userEvents:
+			if err := ev.h(g); err != nil {
+				return err
+			}
+		default:
+			return nil
+		}
+	}
+}
+
+// handleEvent handles an event, based on its type (key-press, error,
+// etc.)
+func (g *Gui) handleEvent(ev *termbox.Event) error {
+	switch ev.Type {
+	case termbox.EventKey, termbox.EventMouse:
+		return g.onKey(ev)
+	case termbox.EventError:
+		return ev.Err
+	default:
+		return nil
+	}
+}
+
+// flush updates the gui, re-drawing frames and buffers.
+func (g *Gui) flush() error {
+	if g.layout == nil {
+		return errors.New("Null layout")
+	}
+
+	termbox.Clear(termbox.Attribute(g.FgColor), termbox.Attribute(g.BgColor))
+
+	maxX, maxY := termbox.Size()
+	// if GUI's size has changed, we need to redraw all views
+	if maxX != g.maxX || maxY != g.maxY {
+		for _, v := range g.views {
+			v.tainted = true
+		}
+	}
+	g.maxX, g.maxY = maxX, maxY
+
+	if err := g.layout(g); err != nil {
+		return err
+	}
+	for _, v := range g.views {
+		if v.Frame {
+			if err := g.drawFrame(v); err != nil {
+				return err
+			}
+			if err := g.drawCorners(v); err != nil {
+				return err
+			}
+			if v.Title != "" {
+				if err := g.drawTitle(v); err != nil {
+					return err
+				}
+			}
+		}
+
+		if err := g.draw(v); err != nil {
+			return err
+		}
+	}
+	if err := g.drawIntersections(); err != nil {
+		return err
+	}
+	termbox.Flush()
+	return nil
+
+}
+
+// drawFrame draws the horizontal and vertical edges of a view.
+func (g *Gui) drawFrame(v *View) error {
+	for x := v.x0 + 1; x < v.x1 && x < g.maxX; x++ {
+		if x < 0 {
+			continue
+		}
+		if v.y0 > -1 && v.y0 < g.maxY {
+			if err := g.SetRune(x, v.y0, '─'); err != nil {
+				return err
+			}
+		}
+		if v.y1 > -1 && v.y1 < g.maxY {
+			if err := g.SetRune(x, v.y1, '─'); err != nil {
+				return err
+			}
+		}
+	}
+	for y := v.y0 + 1; y < v.y1 && y < g.maxY; y++ {
+		if y < 0 {
+			continue
+		}
+		if v.x0 > -1 && v.x0 < g.maxX {
+			if err := g.SetRune(v.x0, y, '│'); err != nil {
+				return err
+			}
+		}
+		if v.x1 > -1 && v.x1 < g.maxX {
+			if err := g.SetRune(v.x1, y, '│'); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// drawCorners draws the corners of the view.
+func (g *Gui) drawCorners(v *View) error {
+	if v.x0 >= 0 && v.y0 >= 0 && v.x0 < g.maxX && v.y0 < g.maxY {
+		if err := g.SetRune(v.x0, v.y0, '┌'); err != nil {
+			return err
+		}
+	}
+	if v.x1 >= 0 && v.y0 >= 0 && v.x1 < g.maxX && v.y0 < g.maxY {
+		if err := g.SetRune(v.x1, v.y0, '┐'); err != nil {
+			return err
+		}
+	}
+	if v.x0 >= 0 && v.y1 >= 0 && v.x0 < g.maxX && v.y1 < g.maxY {
+		if err := g.SetRune(v.x0, v.y1, '└'); err != nil {
+			return err
+		}
+	}
+	if v.x1 >= 0 && v.y1 >= 0 && v.x1 < g.maxX && v.y1 < g.maxY {
+		if err := g.SetRune(v.x1, v.y1, '┘'); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// drawTitle draws the title of the view.
+func (g *Gui) drawTitle(v *View) error {
+	if v.y0 < 0 || v.y0 >= g.maxY {
+		return nil
+	}
+
+	for i, ch := range v.Title {
+		x := v.x0 + i + 2
+		if x < 0 {
+			continue
+		} else if x > v.x1-2 || x >= g.maxX {
+			break
+		}
+		if err := g.SetRune(x, v.y0, ch); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// draw manages the cursor and calls the draw function of a view.
+func (g *Gui) draw(v *View) error {
+	if g.Cursor {
+		if v := g.currentView; v != nil {
+			vMaxX, vMaxY := v.Size()
+			if v.cx < 0 {
+				v.cx = 0
+			} else if v.cx >= vMaxX {
+				v.cx = vMaxX - 1
+			}
+			if v.cy < 0 {
+				v.cy = 0
+			} else if v.cy >= vMaxY {
+				v.cy = vMaxY - 1
+			}
+
+			gMaxX, gMaxY := g.Size()
+			cx, cy := v.x0+v.cx+1, v.y0+v.cy+1
+			if cx >= 0 && cx < gMaxX && cy >= 0 && cy < gMaxY {
+				termbox.SetCursor(cx, cy)
+			} else {
+				termbox.HideCursor()
+			}
+		}
+	} else {
+		termbox.HideCursor()
+	}
+
+	v.clearRunes()
+	if err := v.draw(); err != nil {
+		return err
+	}
+	return nil
+}
+
+// drawIntersections draws the corners of each view, based on the type
+// of the edges that converge at these points.
+func (g *Gui) drawIntersections() error {
+	for _, v := range g.views {
+		if ch, ok := g.intersectionRune(v.x0, v.y0); ok {
+			if err := g.SetRune(v.x0, v.y0, ch); err != nil {
+				return err
+			}
+		}
+		if ch, ok := g.intersectionRune(v.x0, v.y1); ok {
+			if err := g.SetRune(v.x0, v.y1, ch); err != nil {
+				return err
+			}
+		}
+		if ch, ok := g.intersectionRune(v.x1, v.y0); ok {
+			if err := g.SetRune(v.x1, v.y0, ch); err != nil {
+				return err
+			}
+		}
+		if ch, ok := g.intersectionRune(v.x1, v.y1); ok {
+			if err := g.SetRune(v.x1, v.y1, ch); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// intersectionRune returns the correct intersection rune at a given
+// point.
+func (g *Gui) intersectionRune(x, y int) (rune, bool) {
+	if x < 0 || y < 0 || x >= g.maxX || y >= g.maxY {
+		return ' ', false
+	}
+
+	chTop, _ := g.Rune(x, y-1)
+	top := verticalRune(chTop)
+	chBottom, _ := g.Rune(x, y+1)
+	bottom := verticalRune(chBottom)
+	chLeft, _ := g.Rune(x-1, y)
+	left := horizontalRune(chLeft)
+	chRight, _ := g.Rune(x+1, y)
+	right := horizontalRune(chRight)
+
+	var ch rune
+	switch {
+	case top && bottom && left && right:
+		ch = '┼'
+	case top && bottom && !left && right:
+		ch = '├'
+	case top && bottom && left && !right:
+		ch = '┤'
+	case !top && bottom && left && right:
+		ch = '┬'
+	case top && !bottom && left && right:
+		ch = '┴'
+	default:
+		return ' ', false
+	}
+	return ch, true
+}
+
+// verticalRune returns if the given character is a vertical rune.
+func verticalRune(ch rune) bool {
+	if ch == '│' || ch == '┼' || ch == '├' || ch == '┤' {
+		return true
+	}
+	return false
+}
+
+// verticalRune returns if the given character is a horizontal rune.
+func horizontalRune(ch rune) bool {
+	if ch == '─' || ch == '┼' || ch == '┬' || ch == '┴' {
+		return true
+	}
+	return false
+}
+
+// onKey manages key-press events. A keybinding handler is called when
+// a key-press or mouse event satisfies a configured keybinding. Furthermore,
+// currentView's internal buffer is modified if currentView.Editable is true.
+func (g *Gui) onKey(ev *termbox.Event) error {
+	switch ev.Type {
+	case termbox.EventKey:
+		if err := g.execKeybindings(g.currentView, ev); err != nil {
+			return err
+		}
+		if g.currentView != nil && g.currentView.Editable && g.Editor != nil {
+			g.Editor.Edit(g.currentView, Key(ev.Key), ev.Ch, Modifier(ev.Mod))
+		}
+	case termbox.EventMouse:
+		mx, my := ev.MouseX, ev.MouseY
+		v, err := g.ViewByPosition(mx, my)
+		if err != nil {
+			break
+		}
+		if err := v.SetCursor(mx-v.x0-1, my-v.y0-1); err != nil {
+			return err
+		}
+		if err := g.execKeybindings(v, ev); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// execKeybindings executes the keybinding handlers that match the passed view
+// and event.
+func (g *Gui) execKeybindings(v *View, ev *termbox.Event) error {
+	for _, kb := range g.keybindings {
+		if kb.h == nil {
+			continue
+		}
+		if kb.matchKeypress(Key(ev.Key), ev.Ch, Modifier(ev.Mod)) && kb.matchView(v) {
+			if err := kb.h(g, v); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}