From 0938ae91d87519ededfa09ac5cbc003e8937f274 Mon Sep 17 00:00:00 2001
From: Jakub Sobon <jakub.sobon@elohim.sk>
Date: Sun, 24 Feb 2019 15:44:13 -0500
Subject: [PATCH] Refactoring internal functions from align to
 internal/alignfor.

---
 align/align.go                           | 103 -------
 align/align_test.go                      | 347 +++-------------------
 container/container.go                   |   4 +-
 internal/alignfor/align.go               | 120 ++++++++
 internal/alignfor/align_test.go          | 351 +++++++++++++++++++++++
 internal/draw/border.go                  |   3 +-
 widgets/barchart/barchart.go             |   3 +-
 widgets/button/button.go                 |   3 +-
 widgets/donut/donut.go                   |   5 +-
 widgets/gauge/gauge.go                   |   4 +-
 widgets/linechart/internal/axes/label.go |   3 +-
 widgets/segmentdisplay/segmentdisplay.go |   6 +-
 12 files changed, 526 insertions(+), 426 deletions(-)
 create mode 100644 internal/alignfor/align.go
 create mode 100644 internal/alignfor/align_test.go

diff --git a/align/align.go b/align/align.go
index 8505c80..da4087f 100644
--- a/align/align.go
+++ b/align/align.go
@@ -15,14 +15,6 @@
 // Package align defines constants representing types of alignment.
 package align
 
-import (
-	"fmt"
-	"image"
-	"strings"
-
-	"github.com/mum4k/termdash/internal/runewidth"
-)
-
 // Horizontal indicates the type of horizontal alignment.
 type Horizontal int
 
@@ -76,98 +68,3 @@ const (
 	// VerticalBottom is bottom alignment along the vertical axis.
 	VerticalBottom
 )
-
-// hAlign aligns the given area in the rectangle horizontally.
-func hAlign(rect image.Rectangle, ar image.Rectangle, h Horizontal) (image.Rectangle, error) {
-	gap := rect.Dx() - ar.Dx()
-	switch h {
-	case HorizontalRight:
-		// Use gap from above.
-	case HorizontalCenter:
-		gap /= 2
-	case HorizontalLeft:
-		gap = 0
-	default:
-		return image.ZR, fmt.Errorf("unsupported horizontal alignment %v", h)
-	}
-
-	return image.Rect(
-		rect.Min.X+gap,
-		ar.Min.Y,
-		rect.Min.X+gap+ar.Dx(),
-		ar.Max.Y,
-	), nil
-}
-
-// vAlign aligns the given area in the rectangle vertically.
-func vAlign(rect image.Rectangle, ar image.Rectangle, v Vertical) (image.Rectangle, error) {
-	gap := rect.Dy() - ar.Dy()
-	switch v {
-	case VerticalBottom:
-		// Use gap from above.
-	case VerticalMiddle:
-		gap /= 2
-	case VerticalTop:
-		gap = 0
-	default:
-		return image.ZR, fmt.Errorf("unsupported vertical alignment %v", v)
-	}
-
-	return image.Rect(
-		ar.Min.X,
-		rect.Min.Y+gap,
-		ar.Max.X,
-		rect.Min.Y+gap+ar.Dy(),
-	), nil
-}
-
-// Rectangle aligns the area within the rectangle returning the
-// aligned area. The area must fall within the rectangle.
-func Rectangle(rect image.Rectangle, ar image.Rectangle, h Horizontal, v Vertical) (image.Rectangle, error) {
-	if !ar.In(rect) {
-		return image.ZR, fmt.Errorf("cannot align area %v inside rectangle %v, the area falls outside of the rectangle", ar, rect)
-	}
-
-	aligned, err := hAlign(rect, ar, h)
-	if err != nil {
-		return image.ZR, err
-	}
-	aligned, err = vAlign(rect, aligned, v)
-	if err != nil {
-		return image.ZR, err
-	}
-	return aligned, nil
-}
-
-// Text aligns the text within the given rectangle, returns the start point for the text.
-// For the purposes of the alignment this assumes that text will be trimmed if
-// it overruns the rectangle.
-// This only supports a single line of text, the text must not contain newlines.
-func Text(rect image.Rectangle, text string, h Horizontal, v Vertical) (image.Point, error) {
-	if strings.ContainsRune(text, '\n') {
-		return image.ZP, fmt.Errorf("the provided text contains a newline character: %q", text)
-	}
-
-	cells := runewidth.StringWidth(text)
-	var textLen int
-	if cells < rect.Dx() {
-		textLen = cells
-	} else {
-		textLen = rect.Dx()
-	}
-
-	textRect := image.Rect(
-		rect.Min.X,
-		rect.Min.Y,
-		// For the purposes of aligning the text, assume that it will be
-		// trimmed to the available space.
-		rect.Min.X+textLen,
-		rect.Min.Y+1,
-	)
-
-	aligned, err := Rectangle(rect, textRect, h, v)
-	if err != nil {
-		return image.ZP, err
-	}
-	return image.Point{aligned.Min.X, aligned.Min.Y}, nil
-}
diff --git a/align/align_test.go b/align/align_test.go
index 44b3d8b..a08c6c6 100644
--- a/align/align_test.go
+++ b/align/align_test.go
@@ -1,349 +1,76 @@
-// Copyright 2018 Google Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
 package align
 
-import (
-	"image"
-	"testing"
+import "testing"
 
-	"github.com/kylelemons/godebug/pretty"
-)
-
-func TestRectangle(t *testing.T) {
+func TestHorizontal(t *testing.T) {
 	tests := []struct {
-		desc    string
-		rect    image.Rectangle
-		area    image.Rectangle
-		hAlign  Horizontal
-		vAlign  Vertical
-		want    image.Rectangle
-		wantErr bool
+		desc  string
+		align Horizontal
+		want  string
 	}{
 		{
-			desc:    "area falls outside of the rectangle",
-			rect:    image.Rect(0, 0, 1, 1),
-			area:    image.Rect(1, 1, 2, 2),
-			hAlign:  HorizontalLeft,
-			vAlign:  VerticalTop,
-			wantErr: true,
+			desc:  "unknown",
+			align: Horizontal(-1),
+			want:  "HorizontalUnknown",
 		},
 		{
-			desc:    "unsupported horizontal alignment",
-			rect:    image.Rect(0, 0, 2, 2),
-			area:    image.Rect(0, 0, 1, 1),
-			hAlign:  Horizontal(-1),
-			vAlign:  VerticalTop,
-			wantErr: true,
+			desc:  "left",
+			align: HorizontalLeft,
+			want:  "HorizontalLeft",
 		},
 		{
-			desc:    "unsupported vertical alignment",
-			rect:    image.Rect(0, 0, 2, 2),
-			area:    image.Rect(0, 0, 1, 1),
-			hAlign:  HorizontalLeft,
-			vAlign:  Vertical(-1),
-			wantErr: true,
+			desc:  "center",
+			align: HorizontalCenter,
+			want:  "HorizontalCenter",
 		},
 		{
-			desc:   "nothing to align if the rectangles are equal",
-			rect:   image.Rect(0, 0, 2, 2),
-			area:   image.Rect(0, 0, 2, 2),
-			hAlign: HorizontalLeft,
-			vAlign: VerticalTop,
-			want:   image.Rect(0, 0, 2, 2),
-		},
-		{
-			desc:   "aligns top and left, area is zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(0, 0, 1, 1),
-			hAlign: HorizontalLeft,
-			vAlign: VerticalTop,
-			want:   image.Rect(0, 0, 1, 1),
-		},
-		{
-			desc:   "aligns top and center, area is zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(0, 0, 1, 1),
-			hAlign: HorizontalCenter,
-			vAlign: VerticalTop,
-			want:   image.Rect(1, 0, 2, 1),
-		},
-		{
-			desc:   "aligns top and right, area is zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(0, 0, 1, 1),
-			hAlign: HorizontalRight,
-			vAlign: VerticalTop,
-			want:   image.Rect(2, 0, 3, 1),
-		},
-		{
-			desc:   "aligns middle and left, area is zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(0, 0, 1, 1),
-			hAlign: HorizontalLeft,
-			vAlign: VerticalMiddle,
-			want:   image.Rect(0, 1, 1, 2),
-		},
-		{
-			desc:   "aligns middle and center, area is zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(0, 0, 1, 1),
-			hAlign: HorizontalCenter,
-			vAlign: VerticalMiddle,
-			want:   image.Rect(1, 1, 2, 2),
-		},
-		{
-			desc:   "aligns middle and right, area is zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(0, 0, 1, 1),
-			hAlign: HorizontalRight,
-			vAlign: VerticalMiddle,
-			want:   image.Rect(2, 1, 3, 2),
-		},
-		{
-			desc:   "aligns bottom and left, area is zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(0, 0, 1, 1),
-			hAlign: HorizontalLeft,
-			vAlign: VerticalBottom,
-			want:   image.Rect(0, 2, 1, 3),
-		},
-		{
-			desc:   "aligns bottom and center, area is zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(0, 0, 1, 1),
-			hAlign: HorizontalCenter,
-			vAlign: VerticalBottom,
-			want:   image.Rect(1, 2, 2, 3),
-		},
-		{
-			desc:   "aligns bottom and right, area is zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(0, 0, 1, 1),
-			hAlign: HorizontalRight,
-			vAlign: VerticalBottom,
-			want:   image.Rect(2, 2, 3, 3),
-		},
-		{
-			desc:   "aligns top and left, area isn't zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(0, 0, 1, 1),
-			hAlign: HorizontalLeft,
-			vAlign: VerticalTop,
-			want:   image.Rect(0, 0, 1, 1),
-		},
-		{
-			desc:   "aligns top and center, area isn't zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(1, 1, 2, 2),
-			hAlign: HorizontalCenter,
-			vAlign: VerticalTop,
-			want:   image.Rect(1, 0, 2, 1),
-		},
-		{
-			desc:   "aligns top and right, area isn't zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(1, 1, 2, 2),
-			hAlign: HorizontalRight,
-			vAlign: VerticalTop,
-			want:   image.Rect(2, 0, 3, 1),
-		},
-		{
-			desc:   "aligns middle and left, area isn't zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(1, 1, 2, 2),
-			hAlign: HorizontalLeft,
-			vAlign: VerticalMiddle,
-			want:   image.Rect(0, 1, 1, 2),
-		},
-		{
-			desc:   "aligns middle and center, area isn't zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(1, 1, 2, 2),
-			hAlign: HorizontalCenter,
-			vAlign: VerticalMiddle,
-			want:   image.Rect(1, 1, 2, 2),
-		},
-		{
-			desc:   "aligns middle and right, area isn't zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(1, 1, 2, 2),
-			hAlign: HorizontalRight,
-			vAlign: VerticalMiddle,
-			want:   image.Rect(2, 1, 3, 2),
-		},
-		{
-			desc:   "aligns bottom and left, area isn't zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(1, 1, 2, 2),
-			hAlign: HorizontalLeft,
-			vAlign: VerticalBottom,
-			want:   image.Rect(0, 2, 1, 3),
-		},
-		{
-			desc:   "aligns bottom and center, area isn't zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(1, 1, 2, 2),
-			hAlign: HorizontalCenter,
-			vAlign: VerticalBottom,
-			want:   image.Rect(1, 2, 2, 3),
-		},
-		{
-			desc:   "aligns bottom and right, area isn't zero based",
-			rect:   image.Rect(0, 0, 3, 3),
-			area:   image.Rect(1, 1, 2, 2),
-			hAlign: HorizontalRight,
-			vAlign: VerticalBottom,
-			want:   image.Rect(2, 2, 3, 3),
+			desc:  "right",
+			align: HorizontalRight,
+			want:  "HorizontalRight",
 		},
 	}
 
 	for _, tc := range tests {
 		t.Run(tc.desc, func(t *testing.T) {
-			got, err := Rectangle(tc.rect, tc.area, tc.hAlign, tc.vAlign)
-			if (err != nil) != tc.wantErr {
-				t.Errorf("Rectangle => unexpected error: %v, wantErr: %v", err, tc.wantErr)
-			}
-			if err != nil {
-				return
-			}
-
-			if diff := pretty.Compare(tc.want, got); diff != "" {
-				t.Errorf("Rectangle => unexpected diff (-want, +got):\n%s", diff)
+			if got := tc.align.String(); got != tc.want {
+				t.Errorf("String => %q, want %q", got, tc.want)
 			}
 		})
 	}
 }
 
-func TestText(t *testing.T) {
+func TestVertical(t *testing.T) {
 	tests := []struct {
-		desc    string
-		rect    image.Rectangle
-		text    string
-		hAlign  Horizontal
-		vAlign  Vertical
-		want    image.Point
-		wantErr bool
+		desc  string
+		align Vertical
+		want  string
 	}{
 		{
-			desc:    "fails when text contains newline",
-			rect:    image.Rect(0, 0, 3, 3),
-			text:    "a\nb",
-			wantErr: true,
+			desc:  "unknown",
+			align: Vertical(-1),
+			want:  "VerticalUnknown",
 		},
 		{
-			desc:   "aligns text top and left",
-			rect:   image.Rect(1, 1, 4, 4),
-			text:   "a",
-			hAlign: HorizontalLeft,
-			vAlign: VerticalTop,
-			want:   image.Point{1, 1},
+			desc:  "top",
+			align: VerticalTop,
+			want:  "VerticalTop",
 		},
 		{
-			desc:   "aligns text top and center",
-			rect:   image.Rect(1, 1, 4, 4),
-			text:   "a",
-			hAlign: HorizontalCenter,
-			vAlign: VerticalTop,
-			want:   image.Point{2, 1},
+			desc:  "middle",
+			align: VerticalMiddle,
+			want:  "VerticalMiddle",
 		},
 		{
-			desc:   "aligns text top and right",
-			rect:   image.Rect(1, 1, 4, 4),
-			text:   "a",
-			hAlign: HorizontalRight,
-			vAlign: VerticalTop,
-			want:   image.Point{3, 1},
-		},
-		{
-			desc:   "aligns text middle and left",
-			rect:   image.Rect(1, 1, 4, 4),
-			text:   "a",
-			hAlign: HorizontalLeft,
-			vAlign: VerticalMiddle,
-			want:   image.Point{1, 2},
-		},
-		{
-			desc:   "aligns half-width text rune middle and center",
-			rect:   image.Rect(1, 1, 4, 4),
-			text:   "a",
-			hAlign: HorizontalCenter,
-			vAlign: VerticalMiddle,
-			want:   image.Point{2, 2},
-		},
-		{
-			desc:   "aligns full-width text rune middle and center",
-			rect:   image.Rect(1, 1, 4, 4),
-			text:   "界",
-			hAlign: HorizontalCenter,
-			vAlign: VerticalMiddle,
-			want:   image.Point{1, 2},
-		},
-		{
-			desc:   "aligns text middle and right",
-			rect:   image.Rect(1, 1, 4, 4),
-			text:   "a",
-			hAlign: HorizontalRight,
-			vAlign: VerticalMiddle,
-			want:   image.Point{3, 2},
-		},
-		{
-			desc:   "aligns text bottom and left",
-			rect:   image.Rect(1, 1, 4, 4),
-			text:   "a",
-			hAlign: HorizontalLeft,
-			vAlign: VerticalBottom,
-			want:   image.Point{1, 3},
-		},
-		{
-			desc:   "aligns text bottom and center",
-			rect:   image.Rect(1, 1, 4, 4),
-			text:   "a",
-			hAlign: HorizontalCenter,
-			vAlign: VerticalBottom,
-			want:   image.Point{2, 3},
-		},
-		{
-			desc:   "aligns text bottom and right",
-			rect:   image.Rect(1, 1, 4, 4),
-			text:   "a",
-			hAlign: HorizontalRight,
-			vAlign: VerticalBottom,
-			want:   image.Point{3, 3},
-		},
-		{
-			desc:   "aligns text that is too long, assumes trimming",
-			rect:   image.Rect(1, 1, 4, 4),
-			text:   "abcd",
-			hAlign: HorizontalCenter,
-			vAlign: VerticalTop,
-			want:   image.Point{1, 1},
+			desc:  "bottom",
+			align: VerticalBottom,
+			want:  "VerticalBottom",
 		},
 	}
 
 	for _, tc := range tests {
 		t.Run(tc.desc, func(t *testing.T) {
-			got, err := Text(tc.rect, tc.text, tc.hAlign, tc.vAlign)
-			if (err != nil) != tc.wantErr {
-				t.Errorf("Text => unexpected error: %v, wantErr: %v", err, tc.wantErr)
-			}
-			if err != nil {
-				return
-			}
-
-			if diff := pretty.Compare(tc.want, got); diff != "" {
-				t.Errorf("Text => unexpected diff (-want, +got):\n%s", diff)
+			if got := tc.align.String(); got != tc.want {
+				t.Errorf("String => %q, want %q", got, tc.want)
 			}
 		})
 	}
diff --git a/container/container.go b/container/container.go
index 584135b..c45b81a 100644
--- a/container/container.go
+++ b/container/container.go
@@ -26,7 +26,7 @@ import (
 	"image"
 	"sync"
 
-	"github.com/mum4k/termdash/align"
+	"github.com/mum4k/termdash/internal/alignfor"
 	"github.com/mum4k/termdash/internal/area"
 	"github.com/mum4k/termdash/internal/event"
 	"github.com/mum4k/termdash/internal/widgetapi"
@@ -142,7 +142,7 @@ func (c *Container) widgetArea() (image.Rectangle, error) {
 	if wOpts.Ratio.X > 0 && wOpts.Ratio.Y > 0 {
 		adjusted = area.WithRatio(adjusted, wOpts.Ratio)
 	}
-	adjusted, err := align.Rectangle(c.usable(), adjusted, c.opts.hAlign, c.opts.vAlign)
+	adjusted, err := alignfor.Rectangle(c.usable(), adjusted, c.opts.hAlign, c.opts.vAlign)
 	if err != nil {
 		return image.ZR, err
 	}
diff --git a/internal/alignfor/align.go b/internal/alignfor/align.go
new file mode 100644
index 0000000..d19663a
--- /dev/null
+++ b/internal/alignfor/align.go
@@ -0,0 +1,120 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package alignfor provides functions that align elements.
+package alignfor
+
+import (
+	"fmt"
+	"image"
+	"strings"
+
+	"github.com/mum4k/termdash/align"
+	"github.com/mum4k/termdash/internal/runewidth"
+)
+
+// hAlign aligns the given area in the rectangle horizontally.
+func hAlign(rect image.Rectangle, ar image.Rectangle, h align.Horizontal) (image.Rectangle, error) {
+	gap := rect.Dx() - ar.Dx()
+	switch h {
+	case align.HorizontalRight:
+		// Use gap from above.
+	case align.HorizontalCenter:
+		gap /= 2
+	case align.HorizontalLeft:
+		gap = 0
+	default:
+		return image.ZR, fmt.Errorf("unsupported horizontal alignment %v", h)
+	}
+
+	return image.Rect(
+		rect.Min.X+gap,
+		ar.Min.Y,
+		rect.Min.X+gap+ar.Dx(),
+		ar.Max.Y,
+	), nil
+}
+
+// vAlign aligns the given area in the rectangle vertically.
+func vAlign(rect image.Rectangle, ar image.Rectangle, v align.Vertical) (image.Rectangle, error) {
+	gap := rect.Dy() - ar.Dy()
+	switch v {
+	case align.VerticalBottom:
+		// Use gap from above.
+	case align.VerticalMiddle:
+		gap /= 2
+	case align.VerticalTop:
+		gap = 0
+	default:
+		return image.ZR, fmt.Errorf("unsupported vertical alignment %v", v)
+	}
+
+	return image.Rect(
+		ar.Min.X,
+		rect.Min.Y+gap,
+		ar.Max.X,
+		rect.Min.Y+gap+ar.Dy(),
+	), nil
+}
+
+// Rectangle aligns the area within the rectangle returning the
+// aligned area. The area must fall within the rectangle.
+func Rectangle(rect image.Rectangle, ar image.Rectangle, h align.Horizontal, v align.Vertical) (image.Rectangle, error) {
+	if !ar.In(rect) {
+		return image.ZR, fmt.Errorf("cannot align area %v inside rectangle %v, the area falls outside of the rectangle", ar, rect)
+	}
+
+	aligned, err := hAlign(rect, ar, h)
+	if err != nil {
+		return image.ZR, err
+	}
+	aligned, err = vAlign(rect, aligned, v)
+	if err != nil {
+		return image.ZR, err
+	}
+	return aligned, nil
+}
+
+// Text aligns the text within the given rectangle, returns the start point for the text.
+// For the purposes of the alignment this assumes that text will be trimmed if
+// it overruns the rectangle.
+// This only supports a single line of text, the text must not contain newlines.
+func Text(rect image.Rectangle, text string, h align.Horizontal, v align.Vertical) (image.Point, error) {
+	if strings.ContainsRune(text, '\n') {
+		return image.ZP, fmt.Errorf("the provided text contains a newline character: %q", text)
+	}
+
+	cells := runewidth.StringWidth(text)
+	var textLen int
+	if cells < rect.Dx() {
+		textLen = cells
+	} else {
+		textLen = rect.Dx()
+	}
+
+	textRect := image.Rect(
+		rect.Min.X,
+		rect.Min.Y,
+		// For the purposes of aligning the text, assume that it will be
+		// trimmed to the available space.
+		rect.Min.X+textLen,
+		rect.Min.Y+1,
+	)
+
+	aligned, err := Rectangle(rect, textRect, h, v)
+	if err != nil {
+		return image.ZP, err
+	}
+	return image.Point{aligned.Min.X, aligned.Min.Y}, nil
+}
diff --git a/internal/alignfor/align_test.go b/internal/alignfor/align_test.go
new file mode 100644
index 0000000..276fcd1
--- /dev/null
+++ b/internal/alignfor/align_test.go
@@ -0,0 +1,351 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package alignfor
+
+import (
+	"image"
+	"testing"
+
+	"github.com/kylelemons/godebug/pretty"
+	"github.com/mum4k/termdash/align"
+)
+
+func TestRectangle(t *testing.T) {
+	tests := []struct {
+		desc    string
+		rect    image.Rectangle
+		area    image.Rectangle
+		hAlign  align.Horizontal
+		vAlign  align.Vertical
+		want    image.Rectangle
+		wantErr bool
+	}{
+		{
+			desc:    "area falls outside of the rectangle",
+			rect:    image.Rect(0, 0, 1, 1),
+			area:    image.Rect(1, 1, 2, 2),
+			hAlign:  align.HorizontalLeft,
+			vAlign:  align.VerticalTop,
+			wantErr: true,
+		},
+		{
+			desc:    "unsupported horizontal alignment",
+			rect:    image.Rect(0, 0, 2, 2),
+			area:    image.Rect(0, 0, 1, 1),
+			hAlign:  align.Horizontal(-1),
+			vAlign:  align.VerticalTop,
+			wantErr: true,
+		},
+		{
+			desc:    "unsupported vertical alignment",
+			rect:    image.Rect(0, 0, 2, 2),
+			area:    image.Rect(0, 0, 1, 1),
+			hAlign:  align.HorizontalLeft,
+			vAlign:  align.Vertical(-1),
+			wantErr: true,
+		},
+		{
+			desc:   "nothing to align if the rectangles are equal",
+			rect:   image.Rect(0, 0, 2, 2),
+			area:   image.Rect(0, 0, 2, 2),
+			hAlign: align.HorizontalLeft,
+			vAlign: align.VerticalTop,
+			want:   image.Rect(0, 0, 2, 2),
+		},
+		{
+			desc:   "aligns top and left, area is zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(0, 0, 1, 1),
+			hAlign: align.HorizontalLeft,
+			vAlign: align.VerticalTop,
+			want:   image.Rect(0, 0, 1, 1),
+		},
+		{
+			desc:   "aligns top and center, area is zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(0, 0, 1, 1),
+			hAlign: align.HorizontalCenter,
+			vAlign: align.VerticalTop,
+			want:   image.Rect(1, 0, 2, 1),
+		},
+		{
+			desc:   "aligns top and right, area is zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(0, 0, 1, 1),
+			hAlign: align.HorizontalRight,
+			vAlign: align.VerticalTop,
+			want:   image.Rect(2, 0, 3, 1),
+		},
+		{
+			desc:   "aligns middle and left, area is zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(0, 0, 1, 1),
+			hAlign: align.HorizontalLeft,
+			vAlign: align.VerticalMiddle,
+			want:   image.Rect(0, 1, 1, 2),
+		},
+		{
+			desc:   "aligns middle and center, area is zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(0, 0, 1, 1),
+			hAlign: align.HorizontalCenter,
+			vAlign: align.VerticalMiddle,
+			want:   image.Rect(1, 1, 2, 2),
+		},
+		{
+			desc:   "aligns middle and right, area is zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(0, 0, 1, 1),
+			hAlign: align.HorizontalRight,
+			vAlign: align.VerticalMiddle,
+			want:   image.Rect(2, 1, 3, 2),
+		},
+		{
+			desc:   "aligns bottom and left, area is zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(0, 0, 1, 1),
+			hAlign: align.HorizontalLeft,
+			vAlign: align.VerticalBottom,
+			want:   image.Rect(0, 2, 1, 3),
+		},
+		{
+			desc:   "aligns bottom and center, area is zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(0, 0, 1, 1),
+			hAlign: align.HorizontalCenter,
+			vAlign: align.VerticalBottom,
+			want:   image.Rect(1, 2, 2, 3),
+		},
+		{
+			desc:   "aligns bottom and right, area is zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(0, 0, 1, 1),
+			hAlign: align.HorizontalRight,
+			vAlign: align.VerticalBottom,
+			want:   image.Rect(2, 2, 3, 3),
+		},
+		{
+			desc:   "aligns top and left, area isn't zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(0, 0, 1, 1),
+			hAlign: align.HorizontalLeft,
+			vAlign: align.VerticalTop,
+			want:   image.Rect(0, 0, 1, 1),
+		},
+		{
+			desc:   "aligns top and center, area isn't zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(1, 1, 2, 2),
+			hAlign: align.HorizontalCenter,
+			vAlign: align.VerticalTop,
+			want:   image.Rect(1, 0, 2, 1),
+		},
+		{
+			desc:   "aligns top and right, area isn't zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(1, 1, 2, 2),
+			hAlign: align.HorizontalRight,
+			vAlign: align.VerticalTop,
+			want:   image.Rect(2, 0, 3, 1),
+		},
+		{
+			desc:   "aligns middle and left, area isn't zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(1, 1, 2, 2),
+			hAlign: align.HorizontalLeft,
+			vAlign: align.VerticalMiddle,
+			want:   image.Rect(0, 1, 1, 2),
+		},
+		{
+			desc:   "aligns middle and center, area isn't zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(1, 1, 2, 2),
+			hAlign: align.HorizontalCenter,
+			vAlign: align.VerticalMiddle,
+			want:   image.Rect(1, 1, 2, 2),
+		},
+		{
+			desc:   "aligns middle and right, area isn't zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(1, 1, 2, 2),
+			hAlign: align.HorizontalRight,
+			vAlign: align.VerticalMiddle,
+			want:   image.Rect(2, 1, 3, 2),
+		},
+		{
+			desc:   "aligns bottom and left, area isn't zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(1, 1, 2, 2),
+			hAlign: align.HorizontalLeft,
+			vAlign: align.VerticalBottom,
+			want:   image.Rect(0, 2, 1, 3),
+		},
+		{
+			desc:   "aligns bottom and center, area isn't zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(1, 1, 2, 2),
+			hAlign: align.HorizontalCenter,
+			vAlign: align.VerticalBottom,
+			want:   image.Rect(1, 2, 2, 3),
+		},
+		{
+			desc:   "aligns bottom and right, area isn't zero based",
+			rect:   image.Rect(0, 0, 3, 3),
+			area:   image.Rect(1, 1, 2, 2),
+			hAlign: align.HorizontalRight,
+			vAlign: align.VerticalBottom,
+			want:   image.Rect(2, 2, 3, 3),
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.desc, func(t *testing.T) {
+			got, err := Rectangle(tc.rect, tc.area, tc.hAlign, tc.vAlign)
+			if (err != nil) != tc.wantErr {
+				t.Errorf("Rectangle => unexpected error: %v, wantErr: %v", err, tc.wantErr)
+			}
+			if err != nil {
+				return
+			}
+
+			if diff := pretty.Compare(tc.want, got); diff != "" {
+				t.Errorf("Rectangle => unexpected diff (-want, +got):\n%s", diff)
+			}
+		})
+	}
+}
+
+func TestText(t *testing.T) {
+	tests := []struct {
+		desc    string
+		rect    image.Rectangle
+		text    string
+		hAlign  align.Horizontal
+		vAlign  align.Vertical
+		want    image.Point
+		wantErr bool
+	}{
+		{
+			desc:    "fails when text contains newline",
+			rect:    image.Rect(0, 0, 3, 3),
+			text:    "a\nb",
+			wantErr: true,
+		},
+		{
+			desc:   "aligns text top and left",
+			rect:   image.Rect(1, 1, 4, 4),
+			text:   "a",
+			hAlign: align.HorizontalLeft,
+			vAlign: align.VerticalTop,
+			want:   image.Point{1, 1},
+		},
+		{
+			desc:   "aligns text top and center",
+			rect:   image.Rect(1, 1, 4, 4),
+			text:   "a",
+			hAlign: align.HorizontalCenter,
+			vAlign: align.VerticalTop,
+			want:   image.Point{2, 1},
+		},
+		{
+			desc:   "aligns text top and right",
+			rect:   image.Rect(1, 1, 4, 4),
+			text:   "a",
+			hAlign: align.HorizontalRight,
+			vAlign: align.VerticalTop,
+			want:   image.Point{3, 1},
+		},
+		{
+			desc:   "aligns text middle and left",
+			rect:   image.Rect(1, 1, 4, 4),
+			text:   "a",
+			hAlign: align.HorizontalLeft,
+			vAlign: align.VerticalMiddle,
+			want:   image.Point{1, 2},
+		},
+		{
+			desc:   "aligns half-width text rune middle and center",
+			rect:   image.Rect(1, 1, 4, 4),
+			text:   "a",
+			hAlign: align.HorizontalCenter,
+			vAlign: align.VerticalMiddle,
+			want:   image.Point{2, 2},
+		},
+		{
+			desc:   "aligns full-width text rune middle and center",
+			rect:   image.Rect(1, 1, 4, 4),
+			text:   "界",
+			hAlign: align.HorizontalCenter,
+			vAlign: align.VerticalMiddle,
+			want:   image.Point{1, 2},
+		},
+		{
+			desc:   "aligns text middle and right",
+			rect:   image.Rect(1, 1, 4, 4),
+			text:   "a",
+			hAlign: align.HorizontalRight,
+			vAlign: align.VerticalMiddle,
+			want:   image.Point{3, 2},
+		},
+		{
+			desc:   "aligns text bottom and left",
+			rect:   image.Rect(1, 1, 4, 4),
+			text:   "a",
+			hAlign: align.HorizontalLeft,
+			vAlign: align.VerticalBottom,
+			want:   image.Point{1, 3},
+		},
+		{
+			desc:   "aligns text bottom and center",
+			rect:   image.Rect(1, 1, 4, 4),
+			text:   "a",
+			hAlign: align.HorizontalCenter,
+			vAlign: align.VerticalBottom,
+			want:   image.Point{2, 3},
+		},
+		{
+			desc:   "aligns text bottom and right",
+			rect:   image.Rect(1, 1, 4, 4),
+			text:   "a",
+			hAlign: align.HorizontalRight,
+			vAlign: align.VerticalBottom,
+			want:   image.Point{3, 3},
+		},
+		{
+			desc:   "aligns text that is too long, assumes trimming",
+			rect:   image.Rect(1, 1, 4, 4),
+			text:   "abcd",
+			hAlign: align.HorizontalCenter,
+			vAlign: align.VerticalTop,
+			want:   image.Point{1, 1},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.desc, func(t *testing.T) {
+			got, err := Text(tc.rect, tc.text, tc.hAlign, tc.vAlign)
+			if (err != nil) != tc.wantErr {
+				t.Errorf("Text => unexpected error: %v, wantErr: %v", err, tc.wantErr)
+			}
+			if err != nil {
+				return
+			}
+
+			if diff := pretty.Compare(tc.want, got); diff != "" {
+				t.Errorf("Text => unexpected diff (-want, +got):\n%s", diff)
+			}
+		})
+	}
+}
diff --git a/internal/draw/border.go b/internal/draw/border.go
index 833bd8c..b97d2c2 100644
--- a/internal/draw/border.go
+++ b/internal/draw/border.go
@@ -22,6 +22,7 @@ import (
 
 	"github.com/mum4k/termdash/align"
 	"github.com/mum4k/termdash/cell"
+	"github.com/mum4k/termdash/internal/alignfor"
 	"github.com/mum4k/termdash/internal/canvas"
 	"github.com/mum4k/termdash/linestyle"
 )
@@ -120,7 +121,7 @@ func drawTitle(c *canvas.Canvas, border image.Rectangle, opt *borderOptions) err
 		border.Max.X-1, // One space for the top right corner char.
 		border.Min.Y+1,
 	)
-	start, err := align.Text(available, opt.title, opt.titleHAlign, align.VerticalTop)
+	start, err := alignfor.Text(available, opt.title, opt.titleHAlign, align.VerticalTop)
 	if err != nil {
 		return err
 	}
diff --git a/widgets/barchart/barchart.go b/widgets/barchart/barchart.go
index e65e5d1..dd4cbdd 100644
--- a/widgets/barchart/barchart.go
+++ b/widgets/barchart/barchart.go
@@ -24,6 +24,7 @@ import (
 
 	"github.com/mum4k/termdash/align"
 	"github.com/mum4k/termdash/cell"
+	"github.com/mum4k/termdash/internal/alignfor"
 	"github.com/mum4k/termdash/internal/area"
 	"github.com/mum4k/termdash/internal/canvas"
 	"github.com/mum4k/termdash/internal/draw"
@@ -139,7 +140,7 @@ func (bc *BarChart) drawText(cvs *canvas.Canvas, i int, text string, color cell.
 		barCol = image.Rect(r.Min.X, cvs.Area().Min.Y, r.Max.X, cvs.Area().Max.Y)
 	}
 
-	start, err := align.Text(barCol, text, align.HorizontalCenter, align.VerticalBottom)
+	start, err := alignfor.Text(barCol, text, align.HorizontalCenter, align.VerticalBottom)
 	if err != nil {
 		return err
 	}
diff --git a/widgets/button/button.go b/widgets/button/button.go
index 8944709..80fe486 100644
--- a/widgets/button/button.go
+++ b/widgets/button/button.go
@@ -24,6 +24,7 @@ import (
 
 	"github.com/mum4k/termdash/align"
 	"github.com/mum4k/termdash/cell"
+	"github.com/mum4k/termdash/internal/alignfor"
 	"github.com/mum4k/termdash/internal/button"
 	"github.com/mum4k/termdash/internal/canvas"
 	"github.com/mum4k/termdash/internal/draw"
@@ -142,7 +143,7 @@ func (b *Button) Draw(cvs *canvas.Canvas) error {
 	}
 
 	textAr := image.Rect(buttonAr.Min.X+1, buttonAr.Min.Y, buttonAr.Dx()-1, buttonAr.Max.Y)
-	start, err := align.Text(textAr, b.text, align.HorizontalCenter, align.VerticalMiddle)
+	start, err := alignfor.Text(textAr, b.text, align.HorizontalCenter, align.VerticalMiddle)
 	if err != nil {
 		return err
 	}
diff --git a/widgets/donut/donut.go b/widgets/donut/donut.go
index b88c7eb..254fdc1 100644
--- a/widgets/donut/donut.go
+++ b/widgets/donut/donut.go
@@ -23,6 +23,7 @@ import (
 	"sync"
 
 	"github.com/mum4k/termdash/align"
+	"github.com/mum4k/termdash/internal/alignfor"
 	"github.com/mum4k/termdash/internal/canvas"
 	"github.com/mum4k/termdash/internal/canvas/braille"
 	"github.com/mum4k/termdash/internal/draw"
@@ -173,9 +174,9 @@ func (d *Donut) drawText(cvs *canvas.Canvas, mid image.Point, holeR int) error {
 	}
 
 	ar := image.Rect(first.X, first.Y, first.X+cells+2, first.Y+1)
-	start, err := align.Text(ar, t, align.HorizontalCenter, align.VerticalMiddle)
+	start, err := alignfor.Text(ar, t, align.HorizontalCenter, align.VerticalMiddle)
 	if err != nil {
-		return fmt.Errorf("align.Text => %v", err)
+		return fmt.Errorf("alignfor.Text => %v", err)
 	}
 	if err := draw.Text(cvs, t, start, draw.TextMaxX(start.X+needCells), draw.TextCellOpts(d.opts.textCellOpts...)); err != nil {
 		return fmt.Errorf("draw.Text => %v", err)
diff --git a/widgets/gauge/gauge.go b/widgets/gauge/gauge.go
index d22641d..314fd75 100644
--- a/widgets/gauge/gauge.go
+++ b/widgets/gauge/gauge.go
@@ -22,8 +22,8 @@ import (
 	"image"
 	"sync"
 
-	"github.com/mum4k/termdash/align"
 	"github.com/mum4k/termdash/cell"
+	"github.com/mum4k/termdash/internal/alignfor"
 	"github.com/mum4k/termdash/internal/area"
 	"github.com/mum4k/termdash/internal/canvas"
 	"github.com/mum4k/termdash/internal/draw"
@@ -200,7 +200,7 @@ func (g *Gauge) drawText(cvs *canvas.Canvas, progress image.Rectangle) error {
 		return err
 	}
 
-	cur, err := align.Text(ar, trimmed, g.opts.hTextAlign, g.opts.vTextAlign)
+	cur, err := alignfor.Text(ar, trimmed, g.opts.hTextAlign, g.opts.vTextAlign)
 	if err != nil {
 		return err
 	}
diff --git a/widgets/linechart/internal/axes/label.go b/widgets/linechart/internal/axes/label.go
index c99522a..5e13ba2 100644
--- a/widgets/linechart/internal/axes/label.go
+++ b/widgets/linechart/internal/axes/label.go
@@ -21,6 +21,7 @@ import (
 	"image"
 
 	"github.com/mum4k/termdash/align"
+	"github.com/mum4k/termdash/internal/alignfor"
 )
 
 // LabelOrientation represents the orientation of text labels.
@@ -115,7 +116,7 @@ func rowLabel(scale *YScale, y int, labelWidth int) (*Label, error) {
 	}
 
 	ar := rowLabelArea(y, labelWidth)
-	pos, err := align.Text(ar, v.Text(), align.HorizontalRight, align.VerticalMiddle)
+	pos, err := alignfor.Text(ar, v.Text(), align.HorizontalRight, align.VerticalMiddle)
 	if err != nil {
 		return nil, fmt.Errorf("unable to align the label value: %v", err)
 	}
diff --git a/widgets/segmentdisplay/segmentdisplay.go b/widgets/segmentdisplay/segmentdisplay.go
index 97fd735..5a4ad19 100644
--- a/widgets/segmentdisplay/segmentdisplay.go
+++ b/widgets/segmentdisplay/segmentdisplay.go
@@ -23,7 +23,7 @@ import (
 	"image"
 	"sync"
 
-	"github.com/mum4k/termdash/align"
+	"github.com/mum4k/termdash/internal/alignfor"
 	"github.com/mum4k/termdash/internal/attrrange"
 	"github.com/mum4k/termdash/internal/canvas"
 	"github.com/mum4k/termdash/internal/segdisp/sixteen"
@@ -188,9 +188,9 @@ func (sd *SegmentDisplay) Draw(cvs *canvas.Canvas) error {
 	}
 
 	text := sd.buff.String()
-	aligned, err := align.Rectangle(cvs.Area(), segAr.needArea(), sd.opts.hAlign, sd.opts.vAlign)
+	aligned, err := alignfor.Rectangle(cvs.Area(), segAr.needArea(), sd.opts.hAlign, sd.opts.vAlign)
 	if err != nil {
-		return fmt.Errorf("align.Rectangle => %v", err)
+		return fmt.Errorf("alignfor.Rectangle => %v", err)
 	}
 
 	optRange, err := sd.wOptsTracker.ForPosition(0) // Text options for the current byte.