martinselva / thermalprinter

Android library that simplifies communication with thermal printers via Bluetooth

ThermalPrinter

Android library for communication with thermal printers via Bluetooth. This library is only compatible with androidx.

Installation

Add jitpack.io to your root build.gradle:

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

Finally add the dependency to your app build.gradle:

dependencies {
    implementation "com.github.isradeleon:ThermalPrinter:1.0.3"
}

Usage

This library includes the code for the bluetooth connection. All you need to do is first to start the ConnectBluetoothActivity:

override fun onCreate(savedInstanceState: Bundle?) {
    ...

    startActivityForResult(
        Intent(this, ConnectBluetoothActivity::class.java),
        ConnectBluetoothActivity.CONNECT_BLUETOOTH
    )
}

You'll get Activity.RESULT_OK if the device was successfully connected via bluetooth:

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)

    if(resultCode == Activity.RESULT_OK && requestCode == ConnectBluetoothActivity.CONNECT_BLUETOOTH){
        // ThermalPrinter is ready
        ThermalPrinter.instance
            .write("Hello world", PrintAlignment.CENTER, PrintFont.LARGE)
            .fillLineWith('-')
            .write("Let's eat","some tacos")
            .write("Price","0.5 USD")
            .writeImage(BitmapFactory.decodeResource(getResources(), R.drawable.panda))
            .print()
    }
}

If you want to set or modify the BluetoothSocket by yourself, you can do it with the BluetoothConnection class. ThermalPrinter uses this socket to send all its commands to the printer.

ThermalPrinter methods

Method	Description
print()	Prints all the written content
write(text: String)	Writes text to thermal printer
write(text: String, alignment: PrintAlignment)	Writes text and sets the text alignment
write(text: String, alignment: PrintAlignment, font: PrintFont)	Writes text, sets text alignment and font size
write(key: String, value: String)	Writes a line with key value pair
write(key: String, value: String, separator: Char)	Writes a line with key value pair and fills space with separator
writeImage(bitmap: Bitmap)	Writes an image to thermal printer. Image must be black and white format
newLine()	Writes a new line to thermal printer
fillLineWith(char: Char)	Writes a line filled with the specified char

Result

Credits

This library uses Thermal Printer in Android code for image printing.

License

This library is licensed under MIT license. View license.