switch to tcell from termbox

This is a simple mostly straight forward switch to tcell in favor of
termbox.
It uses the tcell native api (not the compat layer) but does not make
use of most features.

Further changes should include moving to tcell's views.TextArea and the
general built in widget behaviour instead of the current ad hoc
implementation.

Regression: Cursor isn't shown in ex-line

8 files changed, 105 insertions, 101 deletions

diff --git a/lib/ui/borders.go b/lib/ui/borders.go
index 08071ad..38b35fd 100644
--- a/lib/ui/borders.go
+++ b/lib/ui/borders.go
@@ -1,7 +1,7 @@
 package ui
 
 import (
-	tb "github.com/nsf/termbox-go"
+	"github.com/gdamore/tcell"
 )
 
 const (
@@ -45,27 +45,23 @@ func (bordered *Bordered) Draw(ctx *Context) {
 	y := 0
 	width := ctx.Width()
 	height := ctx.Height()
-	cell := tb.Cell{
-		Ch: ' ',
-		Fg: tb.ColorBlack,
-		Bg: tb.ColorWhite,
-	}
+	style := tcell.StyleDefault.Background(tcell.ColorWhite).Foreground(tcell.ColorBlack)
 	if bordered.borders&BORDER_LEFT != 0 {
-		ctx.Fill(0, 0, 1, ctx.Height(), cell)
+		ctx.Fill(0, 0, 1, ctx.Height(), ' ', style)
 		x += 1
 		width -= 1
 	}
 	if bordered.borders&BORDER_TOP != 0 {
-		ctx.Fill(0, 0, ctx.Width(), 1, cell)
+		ctx.Fill(0, 0, ctx.Width(), 1, ' ', style)
 		y += 1
 		height -= 1
 	}
 	if bordered.borders&BORDER_RIGHT != 0 {
-		ctx.Fill(ctx.Width()-1, 0, 1, ctx.Height(), cell)
+		ctx.Fill(ctx.Width()-1, 0, 1, ctx.Height(), ' ', style)
 		width -= 1
 	}
 	if bordered.borders&BORDER_BOTTOM != 0 {
-		ctx.Fill(0, ctx.Height()-1, ctx.Width(), 1, cell)
+		ctx.Fill(0, ctx.Height()-1, ctx.Width(), 1, ' ', style)
 		height -= 1
 	}
 	subctx := ctx.Subcontext(x, y, width, height)
diff --git a/lib/ui/context.go b/lib/ui/context.go
index ca3f452..8031689 100644
--- a/lib/ui/context.go
+++ b/lib/ui/context.go
@@ -4,73 +4,77 @@ import (
 	"fmt"
 
 	"github.com/mattn/go-runewidth"
-	tb "github.com/nsf/termbox-go"
+	"github.com/gdamore/tcell"
+	"github.com/gdamore/tcell/views"
 )
 
 // A context allows you to draw in a sub-region of the terminal
 type Context struct {
-	x      int
-	y      int
-	width  int
-	height int
+	viewport *views.ViewPort
 }
 
 func (ctx *Context) X() int {
-	return ctx.x
+	x, _, _, _ := ctx.viewport.GetPhysical()
+	return x
 }
 
 func (ctx *Context) Y() int {
-	return ctx.y
+	_, y, _, _ := ctx.viewport.GetPhysical()
+	return y
 }
 
 func (ctx *Context) Width() int {
-	return ctx.width
+	width, _ := ctx.viewport.Size()
+	return width
 }
 
 func (ctx *Context) Height() int {
-	return ctx.height
+	_, height := ctx.viewport.Size()
+	return height
 }
 
-func NewContext(width, height int) *Context {
-	return &Context{0, 0, width, height}
+func NewContext(width, height int, screen tcell.Screen) *Context {
+	vp := views.NewViewPort(screen, 0, 0, width, height)
+	return &Context{vp}
 }
 
 func (ctx *Context) Subcontext(x, y, width, height int) *Context {
-	if x+width > ctx.width || y+height > ctx.height {
-		panic(fmt.Errorf("Attempted to create context larger than parent"))
+	vp_width, vp_height := ctx.viewport.Size()
+	if (x < 0 || y < 0) {
+		panic(fmt.Errorf("Attempted to create context with negative offset"))
 	}
-	return &Context{
-		x:      ctx.x + x,
-		y:      ctx.y + y,
-		width:  width,
-		height: height,
+	if (x + width > vp_width || y + height > vp_height) {
+		panic(fmt.Errorf("Attempted to create context larger than parent"))
 	}
+	vp := views.NewViewPort(ctx.viewport, x, y, width, height)
+	return &Context{vp}
 }
 
-func (ctx *Context) SetCell(x, y int, ch rune, fg, bg tb.Attribute) {
-	if x >= ctx.width || y >= ctx.height {
+func (ctx *Context) SetCell(x, y int, ch rune, style tcell.Style) {
+	width, height := ctx.viewport.Size()
+	if x >= width || y >= height {
 		panic(fmt.Errorf("Attempted to draw outside of context"))
 	}
-	tb.SetCell(ctx.x+x, ctx.y+y, ch, fg, bg)
+	crunes := []rune{}
+	ctx.viewport.SetContent(x, y, ch, crunes, style)
 }
 
-func (ctx *Context) Printf(x, y int, ref tb.Cell,
+func (ctx *Context) Printf(x, y int, style tcell.Style,
 	format string, a ...interface{}) int {
+	width, height := ctx.viewport.Size()
 
-	if x >= ctx.width || y >= ctx.height {
+	if x >= width || y >= height {
 		panic(fmt.Errorf("Attempted to draw outside of context"))
 	}
 
 	str := fmt.Sprintf(format, a...)
 
-	x += ctx.x
-	y += ctx.y
 	old_x := x
 
 	newline := func() bool {
 		x = old_x
 		y++
-		return y < ctx.height
+		return y < height
 	}
 	for _, ch := range str {
 		if str == " こんにちは " {
@@ -84,9 +88,10 @@ func (ctx *Context) Printf(x, y int, ref tb.Cell,
 		case '\r':
 			x = old_x
 		default:
-			tb.SetCell(x, y, ch, ref.Fg, ref.Bg)
+			crunes := []rune{}
+			ctx.viewport.SetContent(x, y, ch, crunes, style)
 			x += runewidth.RuneWidth(ch)
-			if x == old_x+ctx.width {
+			if x == old_x + width {
 				if !newline() {
 					return runewidth.StringWidth(str)
 				}
@@ -97,13 +102,20 @@ func (ctx *Context) Printf(x, y int, ref tb.Cell,
 	return runewidth.StringWidth(str)
 }
 
-func (ctx *Context) Fill(x, y, width, height int, ref tb.Cell) {
-	_x := x
-	_y := y
-	for ; y < _y+height && y < ctx.height; y++ {
-		for ; x < _x+width && x < ctx.width; x++ {
-			ctx.SetCell(x, y, ref.Ch, ref.Fg, ref.Bg)
-		}
-		x = _x
-	}
+//func (ctx *Context) Screen() tcell.Screen {
+//	return ctx.screen
+//}
+
+func (ctx *Context) Fill(x, y, width, height int, rune rune, style tcell.Style) {
+	vp := views.NewViewPort(ctx.viewport, x, y, width, height)
+	vp.Fill(rune, style)
+}
+
+func (ctx *Context) SetCursor(x, y int) {
+	// FIXME: Cursor needs to be set on tcell.Screen, or layout has to
+	// provide a CellModel
+	// cv := views.NewCellView()
+	// cv.Init()
+	// cv.SetView(ctx.viewport)
+	// cv.SetCursor(x, y)
 }
diff --git a/lib/ui/fill.go b/lib/ui/fill.go
index 3c6f0a5..4d36478 100644
--- a/lib/ui/fill.go
+++ b/lib/ui/fill.go
@@ -1,7 +1,7 @@
 package ui
 
 import (
-	tb "github.com/nsf/termbox-go"
+	"github.com/gdamore/tcell"
 )
 
 type Fill rune
@@ -13,7 +13,7 @@ func NewFill(f rune) Fill {
 func (f Fill) Draw(ctx *Context) {
 	for x := 0; x < ctx.Width(); x += 1 {
 		for y := 0; y < ctx.Height(); y += 1 {
-			ctx.SetCell(x, y, rune(f), tb.ColorDefault, tb.ColorDefault)
+			ctx.SetCell(x, y, rune(f), tcell.StyleDefault)
 		}
 	}
 }
diff --git a/lib/ui/interactive.go b/lib/ui/interactive.go
index efab828..2d4f099 100644
--- a/lib/ui/interactive.go
+++ b/lib/ui/interactive.go
@@ -1,17 +1,17 @@
 package ui
 
 import (
-	tb "github.com/nsf/termbox-go"
+	"github.com/gdamore/tcell"
 )
 
 type Interactive interface {
 	// Returns true if the event was handled by this component
-	Event(event tb.Event) bool
+	Event(event tcell.Event) bool
 }
 
 type Simulator interface {
 	// Queues up the given input events for simulation
-	Simulate(events []tb.Event)
+	Simulate(events []tcell.Event)
 }
 
 type DrawableInteractive interface {
diff --git a/lib/ui/stack.go b/lib/ui/stack.go
index 9f81db8..3c66f5a 100644
--- a/lib/ui/stack.go
+++ b/lib/ui/stack.go
@@ -3,7 +3,7 @@ package ui
 import (
 	"fmt"
 
-	tb "github.com/nsf/termbox-go"
+	"github.com/gdamore/tcell"
 )
 
 type Stack struct {
@@ -29,12 +29,7 @@ func (stack *Stack) Draw(ctx *Context) {
 	if len(stack.children) > 0 {
 		stack.Peek().Draw(ctx)
 	} else {
-		cell := tb.Cell{
-			Fg: tb.ColorDefault,
-			Bg: tb.ColorDefault,
-			Ch: ' ',
-		}
-		ctx.Fill(0, 0, ctx.Width(), ctx.Height(), cell)
+		ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', tcell.StyleDefault)
 	}
 }
 
diff --git a/lib/ui/tab.go b/lib/ui/tab.go
index e6a8aa5..d0635c7 100644
--- a/lib/ui/tab.go
+++ b/lib/ui/tab.go
@@ -1,7 +1,7 @@
 package ui
 
 import (
-	tb "github.com/nsf/termbox-go"
+	"github.com/gdamore/tcell"
 )
 
 type Tabs struct {
@@ -72,21 +72,14 @@ func (tabs *Tabs) Select(index int) {
 func (strip *TabStrip) Draw(ctx *Context) {
 	x := 0
 	for i, tab := range strip.Tabs {
-		cell := tb.Cell{
-			Fg: tb.ColorBlack,
-			Bg: tb.ColorWhite,
-		}
+		style := tcell.StyleDefault.Background(tcell.ColorWhite).Foreground(tcell.ColorBlack)
 		if strip.Selected == i {
-			cell.Fg = tb.ColorDefault
-			cell.Bg = tb.ColorDefault
+			style = style.Reverse(true)
 		}
-		x += ctx.Printf(x, 0, cell, " %s ", tab.Name)
-	}
-	cell := tb.Cell{
-		Fg: tb.ColorBlack,
-		Bg: tb.ColorWhite,
+		x += ctx.Printf(x, 0, style, " %s ", tab.Name)
 	}
-	ctx.Fill(x, 0, ctx.Width()-x, 1, cell)
+	style := tcell.StyleDefault.Background(tcell.ColorWhite).Foreground(tcell.ColorBlack)
+	ctx.Fill(x, 0, ctx.Width()-x, 1, ' ', style)
 }
 
 func (strip *TabStrip) Invalidate() {
diff --git a/lib/ui/text.go b/lib/ui/text.go
index 6164837..e2e218c 100644
--- a/lib/ui/text.go
+++ b/lib/ui/text.go
@@ -2,7 +2,7 @@ package ui
 
 import (
 	"github.com/mattn/go-runewidth"
-	tb "github.com/nsf/termbox-go"
+	"github.com/gdamore/tcell"
 )
 
 const (
@@ -14,8 +14,8 @@ const (
 type Text struct {
 	text         string
 	strategy     uint
-	fg           tb.Attribute
-	bg           tb.Attribute
+	fg           tcell.Color
+	bg           tcell.Color
 	onInvalidate func(d Drawable)
 }
 
@@ -35,7 +35,7 @@ func (t *Text) Strategy(strategy uint) *Text {
 	return t
 }
 
-func (t *Text) Color(fg tb.Attribute, bg tb.Attribute) *Text {
+func (t *Text) Color(fg tcell.Color, bg tcell.Color) *Text {
 	t.fg = fg
 	t.bg = bg
 	t.Invalidate()
@@ -44,11 +44,6 @@ func (t *Text) Color(fg tb.Attribute, bg tb.Attribute) *Text {
 
 func (t *Text) Draw(ctx *Context) {
 	size := runewidth.StringWidth(t.text)
-	cell := tb.Cell{
-		Ch: ' ',
-		Fg: t.fg,
-		Bg: t.bg,
-	}
 	x := 0
 	if t.strategy == TEXT_CENTER {
 		x = (ctx.Width() - size) / 2
@@ -56,8 +51,9 @@ func (t *Text) Draw(ctx *Context) {
 	if t.strategy == TEXT_RIGHT {
 		x = ctx.Width() - size
 	}
-	ctx.Fill(0, 0, ctx.Width(), ctx.Height(), cell)
-	ctx.Printf(x, 0, cell, "%s", t.text)
+	style := tcell.StyleDefault.Background(t.bg).Foreground(t.fg)
+	ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', style)
+	ctx.Printf(x, 0, style, t.text)
 }
 
 func (t *Text) OnInvalidate(onInvalidate func(d Drawable)) {
diff --git a/lib/ui/ui.go b/lib/ui/ui.go
index e9b4e9b..d3eacf2 100644
--- a/lib/ui/ui.go
+++ b/lib/ui/ui.go
@@ -1,7 +1,7 @@
 package ui
 
 import (
-	tb "github.com/nsf/termbox-go"
+	"github.com/gdamore/tcell"
 
 	"git.sr.ht/~sircmpwn/aerc2/config"
 )
@@ -10,30 +10,41 @@ type UI struct {
 	Exit    bool
 	Content DrawableInteractive
 	ctx     *Context
+	screen  tcell.Screen
 
-	tbEvents      chan tb.Event
+	tcEvents      chan tcell.Event
 	invalidations chan interface{}
 }
 
 func Initialize(conf *config.AercConfig,
 	content DrawableInteractive) (*UI, error) {
 
-	if err := tb.Init(); err != nil {
+	screen, err := tcell.NewScreen()
+	if err != nil {
 		return nil, err
 	}
-	width, height := tb.Size()
+
+	if err = screen.Init(); err != nil {
+		return nil, err
+	}
+
+	screen.Clear()
+	screen.HideCursor()
+
+	width, height := screen.Size()
+
 	state := UI{
 		Content: content,
-		ctx:     NewContext(width, height),
+		ctx:     NewContext(width, height, screen),
+		screen:  screen,
 
-		tbEvents:      make(chan tb.Event, 10),
+		tcEvents:      make(chan tcell.Event, 10),
 		invalidations: make(chan interface{}),
 	}
-	tb.SetInputMode(tb.InputEsc | tb.InputMouse)
-	tb.SetOutputMode(tb.Output256)
+	//tb.SetOutputMode(tb.Output256)
 	go (func() {
 		for !state.Exit {
-			state.tbEvents <- tb.PollEvent()
+			state.tcEvents <- screen.PollEvent()
 		}
 	})()
 	go (func() { state.invalidations <- nil })()
@@ -44,27 +55,28 @@ func Initialize(conf *config.AercConfig,
 }
 
 func (state *UI) Close() {
-	tb.Close()
+	state.screen.Fini()
 }
 
 func (state *UI) Tick() bool {
 	select {
-	case event := <-state.tbEvents:
-		switch event.Type {
-		case tb.EventKey:
+	case event := <-state.tcEvents:
+		switch event := event.(type) {
+		case *tcell.EventKey:
 			// TODO: temporary
-			if event.Key == tb.KeyEsc {
+			if event.Key() == tcell.KeyEsc {
 				state.Exit = true
 			}
-		case tb.EventResize:
-			tb.Clear(tb.ColorDefault, tb.ColorDefault)
-			state.ctx = NewContext(event.Width, event.Height)
+		case *tcell.EventResize:
+			state.screen.Clear()
+			width, height := event.Size()
+			state.ctx = NewContext(width, height, state.screen)
 			state.Content.Invalidate()
 		}
 		state.Content.Event(event)
 	case <-state.invalidations:
 		state.Content.Draw(state.ctx)
-		tb.Flush()
+		state.screen.Show()
 	default:
 		return false
 	}