Android library for creating QR-codes with logo, custom pixel/eyes shapes, background image. Powered by ZXing.
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Try library features on live app example
I'll be glad, if you leave a positive review for it in Google Play 😊
Library is also available for:
To get a Git project into your build:
Step 1. Add the JitPack repository to your build file
allprojects {
repositories {
...
maven { url 'https://jitpack.io' }
}
}Or for gradle 7+ to settings.gradle file:
dependencyResolutionManagement {
repositories {
...
maven { url 'https://jitpack.io' }
}
}Step 2. Add the dependency.
dependencies {
implementation 'com.github.alexzhirkevich:custom-qr-generator:1.6.2'
// or new v2.0 alpha
implementation 'com.github.alexzhirkevich:custom-qr-generator:2.0.0-alpha01'
}
There are 2 types of QR code image - raster (deprecated) image and vector image.
| Raster (deprecated). Will be removed in v2.0 since all the available features were migrated to vector |
Vector | |
|---|---|---|
| Output image type | android.graphics.Bitmap |
android.graphics.drawable.Drawable |
| Size | ❌ Fixed | ✅ Dynamic. Based on View size |
| Speed | ❌ Slow (> 500 ms in average), so must be created in advance and only in background thread. Coroutines support included | ✅ Instant. All calculations performed during Drawable.setBounds, almost instantly |
You should use deprecated Raster QR codes only if you need extra customizability or special features like in this example.
Step 1. Create QR code data. There are multiple QR types: Plain Text, Url, Wi-Fi, Email, GeoPos, Profile Cards, Phone, etc.
val data = QrData.Url("https://example.com")Step 2. Define styling options.
val options = createQrVectorOptions {
padding = .125f
background {
drawable = ContextCompat
.getDrawable(context, R.drawable.frame)
}
logo {
drawable = ContextCompat
.getDrawable(context, R.drawable.logo)
size = .25f
padding = QrVectorLogoPadding.Natural(.2f)
shape = QrVectorLogoShape
.Circle
}
colors {
dark = QrVectorColor
.Solid(Color(0xff345288))
ball = QrVectorColor.Solid(
ContextCompat.getColor(context, R.color.your_color)
)
frame = QrVectorColor.LinearGradient(
colors = listOf(
0f to android.graphics.Color.RED,
1f to android.graphics.Color.BLUE,
),
orientation = QrVectorColor.LinearGradient
.Orientation.LeftDiagonal
)
}
shapes {
darkPixel = QrVectorPixelShape
.RoundCorners(.5f)
ball = QrVectorBallShape
.RoundCorners(.25f)
frame = QrVectorFrameShape
.RoundCorners(.25f)
}
}val options = QrVectorOptions.Builder()
.setPadding(.3f)
.setLogo(
QrVectorLogo(
drawable = ContextCompat
.getDrawable(context, R.drawable.logo),
size = .25f,
padding = QrVectorLogoPadding.Natural(.2f),
shape = QrVectorLogoShape
.Circle
)
)
.setBackground(
QrVectorBackground(
drawable = ContextCompat
.getDrawable(context, R.drawable.frame),
)
)
.setColors(
QrVectorColors(
dark = QrVectorColor
.Solid(Color(0xff345288)),
ball = QrVectorColor.Solid(
ContextCompat.getColor(context, R.color.your_color)
),
frame = QrVectorColor.LinearGradient(
colors = listOf(
0f to android.graphics.Color.RED,
1f to android.graphics.Color.BLUE,
),
orientation = QrVectorColor.LinearGradient
.Orientation.LeftDiagonal
)
)
)
.setShapes(
QrVectorShapes(
darkPixel = QrVectorPixelShape
.RoundCorners(.5f),
ball = QrVectorBallShape
.RoundCorners(.25f),
frame = QrVectorFrameShape
.RoundCorners(.25f),
)
)
.build()Step 3. Create QR code drawable:
val drawable : Drawable = QrCodeDrawable(data, options)To interop with Jetpack Compose, you can use this library (recommended) or convert Drawable to Bitmap (not recommended).
Step 4. Press ⭐ if you liked this lib
Deprecated (click to show). Will be removed in v2.0
Step 1. Create QR code data. There are multiple QR types: Plain Text, Url, Wi-Fi, Email, GeoPos, Profile Cards, Phone, etc.
val data = QrData.Url("https://example.com")Step 2. Define styling options using builder:
// Color(v : Long) and Long.toColor() functions take
// 0xAARRGGBB long and convert it to color int.
// Colors from android resources also can be used.
val options = QrOptions.Builder(1024)
.padding(.3f)
.background(
QrBackground(
drawable = ContextCompat
.getDrawable(context, R.drawable.frame),
)
)
.logo(
QrLogo(
drawable = ContextCompat
.getDrawable(context, R.drawable.logo),
size = .25f,
padding = QrLogoPadding.Accurate(.2f),
shape = QrLogoShape
.Circle
)
)
.colors(
QrColors(
dark = QrColor
.Solid(Color(0xff345288)),
highlighting = QrColor
.Solid(0xddffffff.toColor()),
)
)
.shapes(
QrElementsShapes(
darkPixel = QrPixelShape
.RoundCorners(),
ball = QrBallShape
.RoundCorners(.25f),
frame = QrFrameShape
.RoundCorners(.25f),
highlighting = QrBackgroundShape
.RoundCorners(.05f)
)
)
.build()Or using DSL:
val options = createQrOptions(1024, 1024, .3f) {
background {
drawable = ContextCompat
.getDrawable(context, R.drawable.frame)
}
logo {
drawable = ContextCompat
.getDrawable(context, R.drawable.logo)
size = .25f
padding = QrLogoPadding.Accurate(.2f)
shape = QrLogoShape
.Circle
}
colors {
dark = QrColor
.Solid(0xff345288.toColor())
highlighting = QrColor
.Solid(Color(0xddffffff))
}
shapes {
darkPixel = QrPixelShape
.RoundCorners()
ball = QrBallShape
.RoundCorners(.25f)
frame = QrFrameShape
.RoundCorners(.25f)
highlighting = QrBackgroundShape
.RoundCorners(.05f)
}
}Step 3. Create a QR code generator and pass your data and options into it:
val generator = QrCodeGenerator()
val bitmap = generator.generateQrCode(data, options)QrCodeGenerator is an interface, but also is a function, that returns generator instance.
generateQrCodeSuspend is always performed with Dispatchers.Default
//todo: don't use GlobalScope
GlobalScope.launch {
val bitmap = generator.generateQrCodeSuspend(data, options)
}Generator can work in parallel threads (different Default coroutine dispatchers).
By default generator works in SingleThread. To change it pass another ThreadPolicy to
QrCodeGenerator function.
For example:
val threadPolicy = when(Runtime.getRuntime().availableProcessors()){
in 1..3 -> ThreadPolicy.SingleThread
in 4..6 -> ThreadPolicy.DoubleThread
else -> ThreadPolicy.QuadThread
}
val generator = QrCodeGenerator(threadPolicy)
Shapes of QR code elements can be customized using android.graphics.Path.
For example, this is an implementation of circle pixels:
object Circle : QrVectorPixelShape {
override fun createPath(size: Float, neighbors: Neighbors): Path = Path().apply {
addCircle(size/2f, size/2f, size/2, Path.Direction.CW)
}
}Colors of QR code elements can be customized using android.graphics.Paint.
For example, this is an implementation of sweep gradient:
class SweepGradient(
val colors: List<Pair<Float, Int>>
) : QrVectorColor {
override fun createPaint(width: Float, height: Float): Paint =
Paint().apply {
shader = android.graphics.SweepGradient(
width / 2, height / 2,
colors.map { it.second }.toIntArray(),
colors.map { it.first }.toFloatArray()
)
}
}
Deprecated (click to show). Will be removed in v2.0
You can easily implement your own shapes and coloring for QR Code in 2 ways: using math formulas or by drawing on canvas. Second way is usually slower and uses a lot of memory but provides more freedom.
For example:
- Using math formulas:
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object Circle : QrPixelShape {
override fun invoke(
i: Int, j: Int, elementSize: Int, neighbors: Neighbors
): Boolean {
val center = elementSize/2.0
return sqrt((center-i).pow(2) + (center-j).pow(2)) < center
}
}
val options = createQrOptions(1024, .3f) {
shapes {
darkPixel = Circle
}
} |
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//It is not scannable. Don't create such colorful QR codes
object Pride : QrColor {
override fun invoke(
i: Int, j: Int, width : Int, height : Int
): Int {
return when(6f * j/height){
in 0f..1f -> Color.RED
in 1f..2f-> Color(0xffffa500)
in 2f..3f-> Color.YELLOW
in 3f..4f-> Color(0xff00A300)
in 4f..5f-> Color.BLUE
else -> Color(0xff800080)
}
}
}
val options = createQrOptions(1024) {
colors {
ball = Pride
}
} |
- By drawing on canvas:
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val options : QrOptions = createQrOptions(1024) {
shapes {
darkPixel = drawShape { canvas, drawPaint, erasePaint ->
val cx = canvas.width/2f
val cy = canvas.height/2f
val radius = minOf(cx,cy)
canvas.drawCircle(cx, cy, radius, drawPaint)
canvas.drawCircle(cx, cy, radius*2/2.5f, erasePaint)
canvas.drawCircle(cx, cy, radius/1.75f, drawPaint)
}
}
} |
drawShape is a generic function that can be used only inside a shapes or logo scope
and only to create properties of QrElementsShapes or QrLogoShape.
Usage with other type-parameters will cause an exception.
QrOptions with larger size!
This can cause shape quality issues.
You can also implement QrCanvasShape and cast it so necessary shape:
object Ring : QrCanvasShape {
override fun draw(
canvas: Canvas, drawPaint: Paint, erasePaint: Paint
) {
// ...
}
}
val ring : QrPixelShape = Ring
.toShapeModifier(elementSize = 48)
.asPixelShape()
// or automatically determine size with DSL
val ringPixelOptions : QrOptions = createQrOptions(1024){
shapes {
darkPixel = drawShape(Ring::draw)
}
}
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object CanvasColor : QrCanvasColor {
override fun draw(canvas: Canvas) = with(canvas) {
withRotation(135f, width/2f, height/2f) {
drawRect(-width / 2f, -height / 2f,
1.5f * width, height / 2f,
Paint().apply { color = Color.BLACK }
)
drawRect(-width / 2f, height / 2f,
1.5f * width.toFloat(), 1.5f * height.toFloat(),
Paint().apply { color = Color.DKGRAY }
)
}
}
}
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Using draw function inside colors scope you can colorize your code elements as you want.
It will be converted to a QrColor.
This is QrOptions of the code above:
val options = createQrOptions(1024, .2f) {
colors {
dark = QrColor.RadialGradient(
startColor = Color.GRAY,
endColor = Color.BLACK
)
ball = draw(CanvasColor::draw)
frame = draw {
withRotation(
180f, width / 2f,
height / 2f, CanvasColor::draw
)
}
symmetry = true
}
shapes {
darkPixel = QrPixelShape.RoundCorners()
frame = QrFrameShape.RoundCorners(
.25f, outer = false, inner = false
)
}
}- Some combinations of shapes are not compatible.
- If you create custom shapes, always test if they corrupt your qr code.
- Choose contrast colors for your code and dont't use too many of them at once.
- If you are using logo, make it smaller or apply next advice.
- Set
errorCorrectionLevelexplicitly toQrErrorCorrectionLevel.High
See Issue #6
You just need to resolve Drawable form file system. See this
See Issue #13
See Issue #19