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

1 files changed, 49 insertions, 37 deletions

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)
 }