Adding option to draw container borders in color.

And updating the faketerm diff function to also display differences in
options.

container/container.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/mum4k/termdash/area"
 	"github.com/mum4k/termdash/canvas"
+	"github.com/mum4k/termdash/cell"
 	"github.com/mum4k/termdash/draw"
 	"github.com/mum4k/termdash/terminalapi"
 )
@@ -126,7 +127,7 @@ func (c *Container) draw() error {
 		if err != nil {
 			return err
 		}
-		if err := draw.Box(cvs, ar, c.opts.border); err != nil {
+		if err := draw.Box(cvs, ar, c.opts.border, cell.FgColor(c.opts.borderColor)); err != nil {
 			return err
 		}
 	}

container/container_test.go

@@ -277,6 +277,29 @@ func TestDraw(t *testing.T) {
 				return ft
 			},
 		},
+		{
+			desc:     "sets border color",
+			termSize: image.Point{4, 4},
+			container: func(ft *faketerm.Terminal) *Container {
+				return New(
+					ft,
+					Border(draw.LineStyleLight),
+					BorderColor(cell.ColorRed),
+				)
+			},
+			want: func(size image.Point) *faketerm.Terminal {
+				ft := faketerm.MustNew(size)
+				cvs := mustCanvas(image.Rect(0, 0, 4, 4))
+				mustBox(
+					cvs,
+					image.Rect(0, 0, 4, 4),
+					draw.LineStyleLight,
+					cell.FgColor(cell.ColorRed),
+				)
+				mustApply(cvs, ft)
+				return ft
+			},
+		},
 		// TODO(mum4k): Tests where widget removes children and vice versa.
 	}
 

container/options.go

@@ -3,6 +3,7 @@ package container
 // options.go defines container options.
 
 import (
+	"github.com/mum4k/termdash/cell"
 	"github.com/mum4k/termdash/draw"
 	"github.com/mum4k/termdash/widget"
 )
@@ -36,6 +37,8 @@ type options struct {
 
 	// border is the border around the container.
 	border draw.LineStyle
+	// borderColor is the color used for the border.
+	borderColor cell.Color
 }
 
 // option implements Option.
@@ -142,6 +145,13 @@ func Border(ls draw.LineStyle) Option {
 	})
 }
 
+// BorderColor sets the color of the border.
+func BorderColor(color cell.Color) Option {
+	return option(func(c *Container) {
+		c.opts.borderColor = color
+	})
+}
+
 // splitType identifies how a container is split.
 type splitType int
 

experimental/boxes/boxes.go

@@ -7,6 +7,7 @@ import (
 	"log"
 	"time"
 
+	"github.com/mum4k/termdash/cell"
 	"github.com/mum4k/termdash/container"
 	"github.com/mum4k/termdash/draw"
 	"github.com/mum4k/termdash/terminal/termbox"
@@ -54,6 +55,7 @@ func main() {
 							),
 							container.Bottom(
 								container.Border(draw.LineStyleLight),
+								container.BorderColor(cell.ColorYellow),
 							),
 						),
 					),

terminal/faketerm/diff.go

@@ -1,11 +1,25 @@
 package faketerm
 
+// diff.go provides functions that highlight differences between fake terminals.
+
 import (
 	"bytes"
+	"fmt"
+	"image"
 	"reflect"
+
+	"github.com/kylelemons/godebug/pretty"
+	"github.com/mum4k/termdash/cell"
 )
 
-// diff.go provides functions that highlight differences between fake terminals.
+// optDiff is used to display differences in cell options.
+type optDiff struct {
+	// point indicates the cell with the differing options.
+	point image.Point
+
+	got  *cell.Options
+	want *cell.Options
+}
 
 // Diff compares the two terminals, returning an empty string if there is not
 // difference. If a difference is found, returns a human readable description
@@ -21,20 +35,41 @@ func Diff(want, got *Terminal) string {
 	b.WriteString(got.String())
 	b.WriteString("  want:\n")
 	b.WriteString(want.String())
-	b.WriteString("  diff (unexpected cells highlighted with rune '࿃'):\n")
+	b.WriteString("  diff (unexpected cells highlighted with rune '࿃')\n")
+	b.WriteString("  note - this excludes cell options:\n")
 
 	size := got.Size()
+	var optDiffs []*optDiff
 	for row := 0; row < size.Y; row++ {
 		for col := 0; col < size.X; col++ {
-			r := got.BackBuffer()[col][row].Rune
+			gotCell := got.BackBuffer()[col][row]
-			if r != want.BackBuffer()[col][row].Rune {
+			wantCell := want.BackBuffer()[col][row]
+			r := gotCell.Rune
+			if r != wantCell.Rune {
 				r = '࿃'
 			} else if r == 0 {
 				r = ' '
 			}
 			b.WriteRune(r)
+
+			if !reflect.DeepEqual(gotCell.Opts, wantCell.Opts) {
+				optDiffs = append(optDiffs, &optDiff{
+					point: image.Point{col, row},
+					got:   gotCell.Opts,
+					want:  wantCell.Opts,
+				})
+			}
 		}
 		b.WriteRune('\n')
 	}
+
+	if len(optDiffs) > 0 {
+		b.WriteString("  Found differences in options on some of the cells:\n")
+		for _, od := range optDiffs {
+			if diff := pretty.Compare(od.want, od.got); diff != "" {
+				b.WriteString(fmt.Sprintf("cell %v, diff (-want +got):\n%s\n", od.point, diff))
+			}
+		}
+	}
 	return b.String()
 }