added -w flag

README.md

@@ -2,7 +2,7 @@
 
 An RPN calculator with a simple terminal interface
 
-<img src="tiny.png"></img>
+![Basil](tiny.png)
 
 **Commands:**
 

main.go

@@ -8,14 +8,18 @@ import (
 )
 
 func main() {
-	var height int
+	var (
+		height int
+		width int
+	)
 
 	pflag.IntVarP(&height, "height", "H", 10, "set how many elements are displayed at once")
+	pflag.IntVarP(&width, "width", "w", 30, "set the width of the stack window")
 	pflag.Parse()
 
 	// start the ui, trapping errors
 
-	if u, e := ui.NewUi(height); e == nil {
+	if u, e := ui.NewUi(height, width); e == nil {
 		if err := u.Start(); err != nil {
 			printErr(e)
 		}

ui/draw.go

@@ -2,18 +2,10 @@ package ui
 
 import (
 	"fmt"
-	"strings"
 	"strconv"
 	"github.com/gdamore/tcell"
 )
 
-const width = 30
-
-var (
-	strw = strconv.Itoa(width)
-	bar = strings.Repeat("─", width) // barrier decoration string
-)
-
 // draw text to the screen
 
 func addstr(s tcell.Screen, style tcell.Style, x int, y int, text string) {
@@ -24,15 +16,9 @@ func addstr(s tcell.Screen, style tcell.Style, x int, y int, text string) {
 	}
 }
 
-// draw the barrier decoration...
-
-func drawLine(s tcell.Screen, x, y int) {
-	addstr(s, tcell.StyleDefault, x, y, bar)
-}
-
 // allign and trim our text
 
-func drawAligned(s tcell.Screen, x, y int, text string) {
+func drawAligned(s tcell.Screen, x, y, width int, text string) {
 	disp := text
 
 	// if there isn't enough room, add "..."
@@ -41,5 +27,5 @@ func drawAligned(s tcell.Screen, x, y int, text string) {
 		disp = disp[:l - (l - width) - 3] + "..."
 	}
 
-	addstr(s, tcell.StyleDefault, x, y, fmt.Sprintf("%" + strw + "s", disp))
+	addstr(s, tcell.StyleDefault, x, y, fmt.Sprintf("%" + strconv.Itoa(width) + "s", disp))
 }

ui/ui.go

@@ -7,22 +7,25 @@ import (
 	"github.com/geremachek/basil/stack"
 )
 
-var clearLine = strings.Repeat(" ", width)
-
 type ui struct {
 	stack *stack.Stack
 	buff *lineBuff
 
 	scr tcell.Screen
+
 	height int
+	width int
+
+	clearLine string
+
 	running bool
 }
 
 // create a new ui struct
 
-func NewUi(h int) (*ui, error) {
+func NewUi(h, w int) (*ui, error) {
 	if s, err := tcell.NewScreen(); err == nil {
-		return &ui { stack.NewStack(), newLineBuff(0, h+2), s, h, true }, nil
+		return &ui { stack.NewStack(), newLineBuff(0, h+2), s, h, w, strings.Repeat(" ", w), true }, nil
 	} else {
 		return &ui{}, err
 	}
@@ -35,7 +38,7 @@ func (u *ui) drawStackWindow() {
 		y := u.height-1
 
 		for i := u.stack.Size()-1; i >= 0 && y >= 0; i-- {
-			drawAligned(u.scr, 0, y, strconv.FormatFloat(u.stack.Get(i), 'f', -1, 64))
+			drawAligned(u.scr, 0, y, u.width, strconv.FormatFloat(u.stack.Get(i), 'f', -1, 64))
 			y--
 		}
 	}
@@ -45,7 +48,7 @@ func (u *ui) drawStackWindow() {
 
 func (u *ui) clearStackWindow(lines int) {
 	for y := u.height-1; y >= u.height-lines; y-- {
-		addstr(u.scr, tcell.StyleDefault, 0, y, clearLine)
+		addstr(u.scr, tcell.StyleDefault, 0, y, u.clearLine)
 	}
 }
 
@@ -60,7 +63,13 @@ func (u ui) drawAngleMode() {
 		m = 'R'
 	}
 
-	u.scr.SetContent(width+1, u.height, m, []rune(""), tcell.StyleDefault)
+	u.scr.SetContent(u.width+1, u.height, m, []rune(""), tcell.StyleDefault)
+}
+
+// draw the barrier decoration...
+
+func (u ui) drawLine() {
+	addstr(u.scr, tcell.StyleDefault, 0, u.height, strings.Repeat("─", u.width))
 }
 
 // match keys with actions
@@ -100,7 +109,7 @@ func (u *ui) Start() error {
 	if e := u.scr.Init(); e == nil {
 		// draw to the screen
 
-		drawLine(u.scr, 0, u.height)
+		u.drawLine()
 		u.drawAngleMode()
 
 		u.scr.ShowCursor(0, u.height + 2)