Merge pull request #35 from yeqown/issue-34

feat(image): support border width as output image parameters

README.md

@@ -19,6 +19,8 @@ QR code (abbreviated from Quick Response Code) is the trademark for a type of ma
 
 - [x] `WithLogoImage`, `WithLogoImageFilePNG`, `WithLogoImageFileJPEG` help you add an icon at the central of QR Code.
 
+- [x] `WithBorderWidth` allows to specify any width of 4 sides around the qrcode.
+
 ### Install
 
 ```sh
@@ -93,6 +95,12 @@ func WithBuiltinImageEncoder(format formatTyp) ImageOption
 // WithCustomImageEncoder to use custom image encoder to encode image.Image into
 // io.Writer
 func WithCustomImageEncoder(encoder ImageEncoder) ImageOption
+
+// WithBorderWidth specify the both 4 sides' border width. Notice that
+// WithBorderWidth(a) means all border width use this variable `a`,
+// WithBorderWidth(a, b) mean top/bottom equal to `a`, left/right equal to `b`.
+// WithBorderWidth(a, b, c, d) mean top, right, bottom, left.
+func WithBorderWidth(widths ...int) ImageOption
 ```
 
 use options in `New` and `NewWithConfig`. 

image.go

@@ -26,7 +26,10 @@ func drawAndSaveToFile(name string, m matrix.Matrix, opt *outputImageOptions) er
 	if err != nil {
 		return fmt.Errorf("could not create file: %v", err)
 	}
-	defer f.Close()
+
+	defer func(f *os.File) {
+		err = f.Close()
+	}(f)
 
 	return drawAndSave(f, m, opt)
 }
@@ -128,15 +131,16 @@ func drawAndSave(w io.Writer, m matrix.Matrix, imgOpt *outputImageOptions) (err
 //	return rgba
 //}
 
-// draw deal QRCode's matrix to be a image.Image
+// draw deal QRCode's matrix to be an image.Image
 func draw(mat matrix.Matrix, opt *outputImageOptions) image.Image {
 	if _debug {
 		fmt.Printf("matrix.Width()=%d, matrix.Height()=%d\n", mat.Width(), mat.Height())
 	}
 
+	top, right, bottom, left := opt.borderWidths[0], opt.borderWidths[1], opt.borderWidths[2], opt.borderWidths[3]
 	// w as image width, h as image height
-	w := mat.Width()*opt.qrBlockWidth() + 2*_defaultPadding
-	h := w
+	w := mat.Width()*opt.qrBlockWidth() + left + right
+	h := mat.Width()*opt.qrBlockWidth() + top + bottom
 	// rgba := image.NewRGBA(image.Rect(0, 0, w, h))
 	dc := gg.NewContext(w, h)
 
@@ -159,8 +163,8 @@ func draw(mat matrix.Matrix, opt *outputImageOptions) image.Image {
 	mat.Iterate(matrix.ROW, func(x int, y int, v matrix.State) {
 		// Draw the block
 		ctx.upperLeft = image.Point{
-			X: x*opt.qrBlockWidth() + _defaultPadding,
-			Y: y*opt.qrBlockWidth() + _defaultPadding,
+			X: x*opt.qrBlockWidth() + left,
+			Y: y*opt.qrBlockWidth() + top,
 		}
 		ctx.color = opt.stateRGBA(v)
 		// DONE(@yeqown): make this abstract to Shapes

image_option.go

@@ -17,6 +17,7 @@ func defaultOutputImageOption() *outputImageOptions {
 		qrWidth:      20,              //
 		shape:        _shapeRectangle, //
 		imageEncoder: jpegEncoder{},
+		borderWidths: [4]int{_defaultPadding, _defaultPadding, _defaultPadding, _defaultPadding},
 	}
 }
 
@@ -41,6 +42,9 @@ type outputImageOptions struct {
 	// imageEncoder specify which file format would be encoded the QR image.
 	imageEncoder ImageEncoder
 
+	// borderWidths indicates the border width of the output image. the order is
+	// top, right, bottom, left same as the WithBorder
+	borderWidths [4]int
 }
 
 func (oo *outputImageOptions) backgroundColor() color.Color {

image_option_api.go

@@ -152,7 +152,7 @@ func WithBuiltinImageEncoder(format formatTyp) ImageOption {
 	})
 }
 
-// WithBuiltinImageEncoder to use custom image encoder to encode image.Image into
+// WithCustomImageEncoder to use custom image encoder to encode image.Image into
 // io.Writer
 func WithCustomImageEncoder(encoder ImageEncoder) ImageOption {
 	return newFuncDialOption(func(oo *outputImageOptions) {
@@ -164,3 +164,30 @@ func WithCustomImageEncoder(encoder ImageEncoder) ImageOption {
 	})
 }
 
+// WithBorderWidth specify the both 4 sides' border width. Notice that
+// WithBorderWidth(a) means all border width use this variable `a`,
+// WithBorderWidth(a, b) mean top/bottom equal to `a`, left/right equal to `b`.
+// WithBorderWidth(a, b, c, d) mean top, right, bottom, left.
+func WithBorderWidth(widths ...int) ImageOption {
+	apply := func(arr *[4]int, top, right, bottom, left int) {
+		arr[0] = top
+		arr[1] = right
+		arr[2] = bottom
+		arr[3] = left
+	}
+
+	return newFuncDialOption(func(oo *outputImageOptions) {
+		n := len(widths)
+		switch n {
+		case 0:
+			apply(&oo.borderWidths, _defaultPadding, _defaultPadding, _defaultPadding, _defaultPadding)
+		case 1:
+			apply(&oo.borderWidths, widths[0], widths[0], widths[0], widths[0])
+		case 2, 3:
+			apply(&oo.borderWidths, widths[0], widths[1], widths[0], widths[1])
+		default:
+			// 4+
+			apply(&oo.borderWidths, widths[0], widths[1], widths[2], widths[3])
+		}
+	})
+}

image_option_api_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+
 	"github.com/yeqown/go-qrcode/matrix"
 )
 
@@ -69,3 +70,27 @@ func Test_defaultOutputOption(t *testing.T) {
 	oo2 := defaultOutputImageOption()
 	assert.NotEqual(t, oo2.bgColor, oo.bgColor)
 }
+
+func Test_WithBorderWidth(t *testing.T) {
+	oo := defaultOutputImageOption()
+
+	// zero parameter
+	WithBorderWidth().apply(oo)
+	assert.Equal(t, [4]int{_defaultPadding, _defaultPadding, _defaultPadding, _defaultPadding}, oo.borderWidths)
+
+	// one parameter
+	WithBorderWidth(1).apply(oo)
+	assert.Equal(t, [4]int{1, 1, 1, 1}, oo.borderWidths)
+
+	// two parameters
+	WithBorderWidth(1, 2).apply(oo)
+	assert.Equal(t, [4]int{1, 2, 1, 2}, oo.borderWidths)
+
+	// three parameters
+	WithBorderWidth(1, 2, 3).apply(oo)
+	assert.Equal(t, [4]int{1, 2, 1, 2}, oo.borderWidths)
+
+	// four parameters
+	WithBorderWidth(1, 2, 3, 4).apply(oo)
+	assert.Equal(t, [4]int{1, 2, 3, 4}, oo.borderWidths)
+}

qrcode_test.go

@@ -154,3 +154,19 @@ func Test_New_WithOutputOption_Shape(t *testing.T) {
 		t.Fail()
 	}
 }
+
+func Test_New_WithBorderWidth(t *testing.T) {
+	qrc, err := New("Test_New_WithOutputOption_Shape",
+		WithBorderWidth(10, 20, 30, 40),
+	)
+	if err != nil {
+		t.Errorf("could not generate QRCode: %v", err)
+		t.Fail()
+	}
+
+	// save file
+	if err = qrc.Save("./testdata/qrtest_border_width.jpeg"); err != nil {
+		t.Errorf("could not save image: %v", err)
+		t.Fail()
+	}
+}