Container's border now supports a title.

Fixes #22.
Fixes #19.

container/draw.go

@@ -75,7 +75,12 @@ func drawBorder(c *Container) error {
 		cOpts = append(cOpts, cell.FgColor(c.opts.inherited.borderColor))
 	}
 
-	if err := draw.Border(cvs, ar, draw.BorderLineStyle(c.opts.border), draw.BorderCellOpts(cOpts...)); err != nil {
+	if err := draw.Border(cvs, ar,
+		draw.BorderLineStyle(c.opts.border),
+		draw.BorderTitle(c.opts.borderTitle, draw.OverrunModeThreeDot, cOpts...),
+		draw.BorderTitleAlign(c.opts.borderTitleHAlign),
+		draw.BorderCellOpts(cOpts...),
+	); err != nil {
 		return err
 	}
 	return cvs.Apply(c.term)

container/draw_test.go

@@ -18,6 +18,7 @@ import (
 	"image"
 	"testing"
 
+	"github.com/mum4k/termdash/align"
 	"github.com/mum4k/termdash/canvas/testcanvas"
 	"github.com/mum4k/termdash/cell"
 	"github.com/mum4k/termdash/draw"
@@ -62,6 +63,145 @@ func TestDrawWidget(t *testing.T) {
 				return ft
 			},
 		},
+		{
+			desc:     "draws widget with container border and title aligned on the left",
+			termSize: image.Point{9, 5},
+			container: func(ft *faketerm.Terminal) *Container {
+				return New(
+					ft,
+					Border(draw.LineStyleLight),
+					BorderTitle("ab"),
+					BorderTitleAlignLeft(),
+					PlaceWidget(fakewidget.New(widgetapi.Options{})),
+				)
+			},
+			want: func(size image.Point) *faketerm.Terminal {
+				ft := faketerm.MustNew(size)
+				cvs := testcanvas.MustNew(ft.Area())
+				// Container border.
+				testdraw.MustBorder(
+					cvs,
+					cvs.Area(),
+					draw.BorderCellOpts(cell.FgColor(cell.ColorYellow)),
+					draw.BorderTitle(
+						"ab",
+						draw.OverrunModeThreeDot,
+						cell.FgColor(cell.ColorYellow),
+					),
+				)
+
+				// Fake widget border.
+				testdraw.MustBorder(cvs, image.Rect(1, 1, 8, 4))
+				testdraw.MustText(cvs, "(7,3)", image.Point{2, 2})
+				testcanvas.MustApply(cvs, ft)
+				return ft
+			},
+		},
+		{
+			desc:     "draws widget with container border and title aligned in the center",
+			termSize: image.Point{9, 5},
+			container: func(ft *faketerm.Terminal) *Container {
+				return New(
+					ft,
+					Border(draw.LineStyleLight),
+					BorderTitle("ab"),
+					BorderTitleAlignCenter(),
+					PlaceWidget(fakewidget.New(widgetapi.Options{})),
+				)
+			},
+			want: func(size image.Point) *faketerm.Terminal {
+				ft := faketerm.MustNew(size)
+				cvs := testcanvas.MustNew(ft.Area())
+				// Container border.
+				testdraw.MustBorder(
+					cvs,
+					cvs.Area(),
+					draw.BorderCellOpts(cell.FgColor(cell.ColorYellow)),
+					draw.BorderTitle(
+						"ab",
+						draw.OverrunModeThreeDot,
+						cell.FgColor(cell.ColorYellow),
+					),
+					draw.BorderTitleAlign(align.HorizontalCenter),
+				)
+
+				// Fake widget border.
+				testdraw.MustBorder(cvs, image.Rect(1, 1, 8, 4))
+				testdraw.MustText(cvs, "(7,3)", image.Point{2, 2})
+				testcanvas.MustApply(cvs, ft)
+				return ft
+			},
+		},
+		{
+			desc:     "draws widget with container border and title aligned on the right",
+			termSize: image.Point{9, 5},
+			container: func(ft *faketerm.Terminal) *Container {
+				return New(
+					ft,
+					Border(draw.LineStyleLight),
+					BorderTitle("ab"),
+					BorderTitleAlignRight(),
+					PlaceWidget(fakewidget.New(widgetapi.Options{})),
+				)
+			},
+			want: func(size image.Point) *faketerm.Terminal {
+				ft := faketerm.MustNew(size)
+				cvs := testcanvas.MustNew(ft.Area())
+				// Container border.
+				testdraw.MustBorder(
+					cvs,
+					cvs.Area(),
+					draw.BorderCellOpts(cell.FgColor(cell.ColorYellow)),
+					draw.BorderTitle(
+						"ab",
+						draw.OverrunModeThreeDot,
+						cell.FgColor(cell.ColorYellow),
+					),
+					draw.BorderTitleAlign(align.HorizontalRight),
+				)
+
+				// Fake widget border.
+				testdraw.MustBorder(cvs, image.Rect(1, 1, 8, 4))
+				testdraw.MustText(cvs, "(7,3)", image.Point{2, 2})
+				testcanvas.MustApply(cvs, ft)
+				return ft
+			},
+		},
+		{
+			desc:     "draws widget with container border and title that is trimmed",
+			termSize: image.Point{9, 5},
+			container: func(ft *faketerm.Terminal) *Container {
+				return New(
+					ft,
+					Border(draw.LineStyleLight),
+					BorderTitle("abcdefgh"),
+					BorderTitleAlignRight(),
+					PlaceWidget(fakewidget.New(widgetapi.Options{})),
+				)
+			},
+			want: func(size image.Point) *faketerm.Terminal {
+				ft := faketerm.MustNew(size)
+				cvs := testcanvas.MustNew(ft.Area())
+				// Container border.
+				testdraw.MustBorder(
+					cvs,
+					cvs.Area(),
+					draw.BorderCellOpts(cell.FgColor(cell.ColorYellow)),
+					draw.BorderTitle(
+						"abcdefgh",
+						draw.OverrunModeThreeDot,
+						cell.FgColor(cell.ColorYellow),
+					),
+					draw.BorderTitleAlign(align.HorizontalRight),
+				)
+
+				// Fake widget border.
+				testdraw.MustBorder(cvs, image.Rect(1, 1, 8, 4))
+				testdraw.MustText(cvs, "(7,3)", image.Point{2, 2})
+				testcanvas.MustApply(cvs, ft)
+				return ft
+			},
+		},
 		{
 			desc:     "draws widget without container border",
 			termSize: image.Point{9, 5},

container/options.go

@@ -54,7 +54,9 @@ type options struct {
 	vAlign align.Vertical
 
 	// border is the border around the container.
-	border draw.LineStyle
+	border            draw.LineStyle
+	borderTitle       string
+	borderTitleHAlign align.Horizontal
 }
 
 // inherited contains options that are inherited by child containers.
@@ -184,6 +186,34 @@ func Border(ls draw.LineStyle) Option {
 	})
 }
 
+// BorderTitle sets a text title within the border.
+func BorderTitle(title string) Option {
+	return option(func(c *Container) {
+		c.opts.borderTitle = title
+	})
+}
+
+// BorderTitleAlignLeft aligns the border title on the left.
+func BorderTitleAlignLeft() Option {
+	return option(func(c *Container) {
+		c.opts.borderTitleHAlign = align.HorizontalLeft
+	})
+}
+
+// BorderTitleAlignCenter aligns the border title in the center.
+func BorderTitleAlignCenter() Option {
+	return option(func(c *Container) {
+		c.opts.borderTitleHAlign = align.HorizontalCenter
+	})
+}
+
+// BorderTitleAlignRight aligns the border title on the right.
+func BorderTitleAlignRight() Option {
+	return option(func(c *Container) {
+		c.opts.borderTitleHAlign = align.HorizontalRight
+	})
+}
+
 // BorderColor sets the color of the border around the container.
 // This option is inherited to sub containers created by container splits.
 func BorderColor(color cell.Color) Option {