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https://github.com/dantsu/escpos-thermalprinter-android
Useful library to help Android developpers to print with (Bluetooth, TCP, USB) ESC/POS thermal printer.
https://github.com/dantsu/escpos-thermalprinter-android
android android-library barcode bluetooth-printer escpos escpos-printer qrcode tcp-printer thermal-printer thermal-printing usb-printer
Last synced: 30 days ago
JSON representation
Useful library to help Android developpers to print with (Bluetooth, TCP, USB) ESC/POS thermal printer.
- Host: GitHub
- URL: https://github.com/dantsu/escpos-thermalprinter-android
- Owner: DantSu
- License: mit
- Created: 2020-04-07T06:42:00.000Z (over 4 years ago)
- Default Branch: master
- Last Pushed: 2024-05-14T13:06:50.000Z (6 months ago)
- Last Synced: 2024-10-14T11:02:28.657Z (30 days ago)
- Topics: android, android-library, barcode, bluetooth-printer, escpos, escpos-printer, qrcode, tcp-printer, thermal-printer, thermal-printing, usb-printer
- Language: Java
- Homepage:
- Size: 332 KB
- Stars: 1,209
- Watchers: 32
- Forks: 362
- Open Issues: 53
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE
Awesome Lists containing this project
README
[](https://jitpack.io/#DantSu/ESCPOS-ThermalPrinter-Android/3.3.0)
[](https://jitpack.io/#DantSu/ESCPOS-ThermalPrinter-Android/3.3.0)
[](https://jitpack.io/#DantSu/ESCPOS-ThermalPrinter-Android/3.3.0)
[](https://opensource.org/licenses/MIT)
# Android library for ESC/POS Thermal Printer
Useful library to help Android developers to print with (Bluetooth, TCP, USB) ESC/POS thermal printers.
## āØ Supporting
ā Star this repository to support this project. You will contribute to increase the visibility of this library š
## Table of contents
- [Android version](#android-version)
- [Tested printers](#tested-printers)
- [Test It !](#test-it-)
- [Installation](#installation)
- [Bluetooth](#bluetooth)
- [Bluetooth permission](#bluetooth-permission)
- [Bluetooth code example](#bluetooth-code-example)
- [TCP](#tcp)
- [TCP permission](#tcp-permission)
- [TCP code example](#tcp-code-example)
- [USB](#usb)
- [USB permission](#usb-permission)
- [USB code example](#usb-code-example)
- [Charset encoding](#charset-encoding)
- [Formatted text : syntax guide](#formatted-text--syntax-guide)
- [Class list](#class-list)
- [BluetoothPrintersConnections](#user-content-class--comdantsuescposprinterconnectionbluetoothbluetoothprintersconnections)
- [UsbPrintersConnections](#user-content-class--comdantsuescposprinterconnectionusbusbprintersconnections)
- [EscPosPrinter](#user-content-class--comdantsuescposprinterescposprinter)
- [PrinterTextParserImg](#user-content-class--comdantsuescposprintertextparserprintertextparserimg)
- [EscPosCharsetEncoding](#user-content-class--comdantsuescposprinterescposcharsetencoding)
- [Projects using this library](#projects-using-this-library)
- [Contributing](#contributing)
## Android version
Developed for SDK version 16 (Android 4.1 Jelly Bean) and above.
## Tested printers
1. [HOIN HOP H58 Thermal Printer ESC/POS](https://www.gearbest.com/printers/pp_662658.html).
2. [XPRINTER XP-P300](https://xprinter.vn/xprinter-xp-p300-may-in-hoa-don-di-dong-bluetooth/).
3. [MUNBYN IMP001](https://www.munbyn.com/collections/portable-receipt-printer/products/58mm-bluetooth-thermal-printer-imp001).
4. [JP-Q2 POS Terminal PDA](https://www.aliexpress.com/item/32971775060.html) (Embedded printer is configured as Bluetooth device)
5. [MUNBYN ITPP047](https://www.munbyn.com/products/munbyn-itpp047-wifi-thermal-printer) (tested over USB)
## Test it !
To test this library, it's pretty simple !
- Create a directory and open a terminal inside
- Run `git clone https://github.com/DantSu/ESCPOS-ThermalPrinter-Android.git .`
- Open the directory with Android Studio
- Test it !
## Installation
**Step 1.** Add the [JitPack](https://jitpack.io/#DantSu/ESCPOS-ThermalPrinter-Android/3.3.0) repository to your build file. Add it in your root `/build.gradle` at the end of repositories:
```
allprojects {
repositories {
...
maven { url 'https://jitpack.io' }
}
}
```
**Step 2.** Add the dependency in `/app/build.gradle` :
```
dependencies {
...
implementation 'com.github.DantSu:ESCPOS-ThermalPrinter-Android:3.3.0'
}
```
## Bluetooth
### Bluetooth permission
Be sure to have ``, ``, ``, `` in your `AndroidManifest.xml`.
Also, you have to check the bluetooth permission in your app like this :
```java
if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.S && ContextCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.BLUETOOTH}, MainActivity.PERMISSION_BLUETOOTH);
} else if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.S && ContextCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH_ADMIN) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.BLUETOOTH_ADMIN}, MainActivity.PERMISSION_BLUETOOTH_ADMIN);
} else if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.S && ContextCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH_CONNECT) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.BLUETOOTH_CONNECT}, MainActivity.PERMISSION_BLUETOOTH_CONNECT);
} else if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.S && ContextCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH_SCAN) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.BLUETOOTH_SCAN}, MainActivity.PERMISSION_BLUETOOTH_SCAN);
} else {
// Your code HERE
}
```
### Bluetooth code example
The code below is an example to write in your activity :
```java
EscPosPrinter printer = new EscPosPrinter(BluetoothPrintersConnections.selectFirstPaired(), 203, 48f, 32);
printer
.printFormattedText(
"[C]![]()
" + PrinterTextParserImg.bitmapToHexadecimalString(printer, this.getApplicationContext().getResources().getDrawableForDensity(R.drawable.logo, DisplayMetrics.DENSITY_MEDIUM))+"\n" +
"[L]\n" +
"[C]ORDER NĀ°045\n" +
"[L]\n" +
"[C]================================\n" +
"[L]\n" +
"[L]BEAUTIFUL SHIRT[R]9.99e\n" +
"[L] + Size : S\n" +
"[L]\n" +
"[L]AWESOME HAT[R]24.99e\n" +
"[L] + Size : 57/58\n" +
"[L]\n" +
"[C]--------------------------------\n" +
"[R]TOTAL PRICE :[R]34.98e\n" +
"[R]TAX :[R]4.23e\n" +
"[L]\n" +
"[C]================================\n" +
"[L]\n" +
"[L]Customer :\n" +
"[L]Raymond DUPONT\n" +
"[L]5 rue des girafes\n" +
"[L]31547 PERPETES\n" +
"[L]Tel : +33801201456\n" +
"[L]\n" +
"[C]831254784551\n" +
"[C]https://dantsu.com/"
);
```
Below a picture of the receipt printed with the code above :
## TCP
### TCP permission
Be sure to have `` in your `AndroidManifest.xml`.
### TCP code example
The code below is an example to write in your activity :
```java
new Thread(new Runnable() {
public void run() {
try {
EscPosPrinter printer = new EscPosPrinter(new TcpConnection("192.168.1.3", 9300, 15), 203, 48f, 32);
printer
.printFormattedText(
"[C]![]()
" + PrinterTextParserImg.bitmapToHexadecimalString(printer, getApplicationContext().getResources().getDrawableForDensity(R.drawable.logo, DisplayMetrics.DENSITY_MEDIUM)) + "\n" +
"[L]\n" +
"[C]ORDER NĀ°045\n" +
"[L]\n" +
"[C]================================\n" +
"[L]\n" +
"[L]BEAUTIFUL SHIRT[R]9.99e\n" +
"[L] + Size : S\n" +
"[L]\n" +
"[L]AWESOME HAT[R]24.99e\n" +
"[L] + Size : 57/58\n" +
"[L]\n" +
"[C]--------------------------------\n" +
"[R]TOTAL PRICE :[R]34.98e\n" +
"[R]TAX :[R]4.23e\n" +
"[L]\n" +
"[C]================================\n" +
"[L]\n" +
"[L]Customer :\n" +
"[L]Raymond DUPONT\n" +
"[L]5 rue des girafes\n" +
"[L]31547 PERPETES\n" +
"[L]Tel : +33801201456\n" +
"[L]\n" +
"[C]831254784551\n" +
"[C]https://dantsu.com/"
);
} catch (Exception e) {
e.printStackTrace();
}
}
}).start();
```
## USB
### USB permission
Be sure to have `` in your `AndroidManifest.xml`.
You have to check the USB permission in your app like this :
```java
private static final String ACTION_USB_PERMISSION = "com.android.example.USB_PERMISSION";
private final BroadcastReceiver usbReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (MainActivity.ACTION_USB_PERMISSION.equals(action)) {
synchronized (this) {
UsbManager usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
UsbDevice usbDevice = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
if (usbManager != null && usbDevice != null) {
// YOUR PRINT CODE HERE
}
}
}
}
}
};
public void printUsb() {
UsbConnection usbConnection = UsbPrintersConnections.selectFirstConnected(this);
UsbManager usbManager = (UsbManager) this.getSystemService(Context.USB_SERVICE);
if (usbConnection != null && usbManager != null) {
PendingIntent permissionIntent = PendingIntent.getBroadcast(
this,
0,
new Intent(MainActivity.ACTION_USB_PERMISSION),
android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.S ? PendingIntent.FLAG_MUTABLE : 0
);
IntentFilter filter = new IntentFilter(MainActivity.ACTION_USB_PERMISSION);
registerReceiver(this.usbReceiver, filter);
usbManager.requestPermission(usbConnection.getDevice(), permissionIntent);
}
}
```
### USB code example
The code below is an example to write in your activity :
```java
EscPosPrinter printer = new EscPosPrinter(new UsbConnection(usbManager, usbDevice), 203, 48f, 32);
printer
.printFormattedText(
"[C]![]()
" + PrinterTextParserImg.bitmapToHexadecimalString(printer, this.getApplicationContext().getResources().getDrawableForDensity(R.drawable.logo, DisplayMetrics.DENSITY_MEDIUM))+"\n" +
"[L]\n" +
"[C]ORDER NĀ°045\n" +
"[L]\n" +
"[C]================================\n" +
"[L]\n" +
"[L]BEAUTIFUL SHIRT[R]9.99e\n" +
"[L] + Size : S\n" +
"[L]\n" +
"[L]AWESOME HAT[R]24.99e\n" +
"[L] + Size : 57/58\n" +
"[L]\n" +
"[C]--------------------------------\n" +
"[R]TOTAL PRICE :[R]34.98e\n" +
"[R]TAX :[R]4.23e\n" +
"[L]\n" +
"[C]================================\n" +
"[L]\n" +
"[L]Customer :\n" +
"[L]Raymond DUPONT\n" +
"[L]5 rue des girafes\n" +
"[L]31547 PERPETES\n" +
"[L]Tel : +33801201456\n" +
"[L]\n" +
"[C]831254784551\n" +
"[C]https://dantsu.com/"
);
```
## Charset encoding
To change charset encoding of the printer, use `EscPosCharsetEncoding` class :
```java
EscPosPrinter printer = new EscPosPrinter(deviceConnection, 203, 48f, 32, new EscPosCharsetEncoding("windows-1252", 16));
```
`escPosCharsetId` may change with printer model.
[Follow this link to find `escPosCharsetId` that works with many printers](https://www.epson-biz.com/modules/ref_escpos/index.php?content_id=32)
## Formatted text : syntax guide
### New line
Use `\n` to create a new line of text.
### Text alignment and column separation
Add an alignment tag on a same line of text implicitly create a new column.
Column alignment tags :
- `[L]` : left side alignment
- `[C]` : center alignment
- `[R]` : right side alignment
Example :
- `[L]Some text` : One column aligned to left
- `[C]Some text` : One column aligned to center
- `[R]Some text` : One column aligned to right
- `[L]Some text[L]Some other text` : Two columns aligned to left. `Some other text` starts in the center of the paper.
- `[L]Some text[R]Some other text` : Two columns, first aligned to left, second aligned to right. `Some other text` is printed at the right of paper.
- `[L]Some[R]text[R]here` : Three columns.
- `[L][R]text[R]here` : Three columns. The first is empty but it takes a third of the available space.
### Font
#### Size
`` tag allows you to change the font size and color. Default size is `normal` / `black`.
- `Some text` : Normal size
- `Some text` : Double width of medium size
- `Some text` : Double height of medium size
- `Some text` : Double width and height of medium size
- `Some text` : 3 x width and height
- `Some text` : 4 x width and height
- `Some text` : 5 x width and height
- `Some text` : 6 x width and height
- `Some text` : 7 x width and height
- `Some text` : black text - white background
- `Some text` : white text - black background
- `Some text` : red text - white background (Not working on all printer)
- `Some text` : white text - red background (Not working on all printer)
#### Bold
`` tag allows you to change the font weight.
- `Some text`
#### Underline
`` tag allows you to underline the text.
- `Some text` text underlined
- `Some text` text double-strike (Not working on all printer)
### Image
`![]()
` tag allows you to print image. Inside the tag you need to write a hexadecimal string of an image.
Use `PrinterTextParserImg.bitmapToHexadecimalString` to convert `Drawable`, `BitmapDrawable` or `Bitmap` to hexadecimal string.
- `![]()
`hexadecimal string of an image``
**ā WARNING ā ** : This tag has several constraints :
- A line that contains `![]()
` can have only one alignment tag and it must be at the beginning of the line.
- `![]()
` must be directly preceded by nothing or an alignment tag (`[L][C][R]`).
- `` must be directly followed by a new line `\n`.
- You can't write text on a line that contains `![]()
`.
- Maximum height of printed image is 256px, If you want to print larger bitmap. Please refer to this solution: [#70](https://github.com/DantSu/ESCPOS-ThermalPrinter-Android/issues/70#issuecomment-714390014)
### Barcode
`` tag allows you to print a barcode. Inside the tag you need to write the code number to print.
- `451278452159` : **(12 numbers)**
Prints a EAN13 barcode (height: 10mm, width: ~70% printer width, text: displayed below).
- `4512784` : **(7 numbers)**
Prints a EAN8 barcode (height: 10mm, width: ~70% printer width, text: displayed below).
- `4512784521` : **(11 numbers)**
Prints a UPC-A barcode (height: 20mm, width: ~70% printer width, text: displayed below).
- `512789` : **(6 numbers)**
Prints a UPC-E barcode (height: 25mm, width: ~50mm, text: hidden).
- `DantSu` : **(string)**
Prints a barcode 128 (height: 10mm, width: ~40mm, text: displayed above).
**ā WARNING ā ** : This tag has several constraints :
- A line that contains `` can have only one alignment tag and it must be at the beginning of the line.
- `` must be directly preceded by nothing or an alignment tag (`[L][C][R]`).
- `` must be directly followed by a new line `\n`.
- You can't write text on a line that contains ``.
### QR Code
`` tag allows you to print a QR code. Inside the tag you need to write the QR code data.
- `https://dantsu.com/` :
Prints a QR code with a width and height of 20 millimeters.
- `123456789` :
Prints a QR code with a width and height of 25 millimeters.
**ā WARNING ā ** : This tag has several constraints :
- A line that contains `` can have only one alignment tag and it must be at the beginning of the line.
- `` must be directly preceded by nothing or an alignment tag (`[L][C][R]`).
- `` must be directly followed by a new line `\n`.
- You can't write text on a line that contains ``.
## Class list
### Class : `com.dantsu.escposprinter.connection.bluetooth.BluetoothPrintersConnections`
#### **Static** Method : `selectFirstPaired()`
Easy way to get the first bluetooth printer paired / connected.
- **return** `BluetoothConnection`
#### Method : `getList()`
Get a list of bluetooth printers.
- **return** `BluetoothConnection[]`
ā ļø If the arrray returned by `getList()` does not contain you printer or if `selectFirstPaired()` does not return your printer. Read this issue : https://github.com/DantSu/ESCPOS-ThermalPrinter-Android/issues/80#issuecomment-729759832
### Class : `com.dantsu.escposprinter.connection.tcp.TcpConnection`
#### Constructor : `TcpConnection(String address, int port[, int timeout])`
- **param** `String address` : Targeted ip address
- **param** `int port` : Targeted tcp port
- **param** `int timeout` *(optional)* : Connection timeout (default : 30)
### Class : `com.dantsu.escposprinter.connection.usb.UsbPrintersConnections`
#### **Static** Method : `selectFirstConnected()`
Easy way to get the first USB printer connected.
- **return** `UsbConnection`
#### Method : `getList()`
Get a list of USB printers.
- **return** `UsbConnection[]`
### Class : `com.dantsu.escposprinter.EscPosPrinter`
#### Constructor : `EscPosPrinter(DeviceConnection printer, int printerDpi, float printingWidthMM, int nbrCharactersPerLine [, EscPosCharsetEncoding charsetEncoding])`
- **param** `DeviceConnection printer` : Instance of a connected printer
- **param** `int printerDpi` : DPI of the connected printer
- **param** `float printerWidthMM` : Printing width in millimeters
- **param** `int printerNbrCharactersPerLine` : The maximum number of medium sized characters that can be printed on a line.
- **param** `EscPosCharsetEncoding charsetEncoding` *(optional)* : Set the charset encoding.
#### Method : `disconnectPrinter()`
Close the connection with the printer.
- **return** `Printer` : Fluent interface
#### Method : `getNbrCharactersPerLine()`
Get the maximum number of characters that can be printed on a line.
- **return** `int`
#### Method : `getPrinterWidthMM()`
Get the printing width in millimeters
- **return** `float`
#### Method : `getPrinterDpi()`
Get the printer DPI
- **return** `int`
#### Method : `getPrinterWidthPx()`
Get the printing width in dot
- **return** `int`
#### Method : `getPrinterCharSizeWidthPx()`
Get the number of dot that a printed character contain
- **return** `int`
#### Method : `mmToPx(float mmSize)`
Convert the mmSize variable from millimeters to dot.
- **param** `float mmSize` : Distance in millimeters to be converted
- **return** `int` : Dot size of mmSize.
#### Method : `useEscAsteriskCommand(boolean enable)`
Active "ESC *" command for image printing.
- **param** `boolean enable` : true to use "ESC *", false to use "GS v 0"
- **return** `Printer` : Fluent interface
#### Method : `printFormattedText(String text)`
Print a formatted text and feed paper (20 millimeters). Read the ["Formatted Text : Syntax guide" section](#formatted-text--syntax-guide) for more information about text formatting options.
- **param** `String text` : Formatted text to be printed.
- **return** `Printer` : Fluent interface
#### Method : `printFormattedTextAndCut(String text)`
Print a formatted text, feed paper (20 millimeters) and cut the paper. Read the ["Formatted Text : Syntax guide" section](#formatted-text--syntax-guide) for more information about text formatting options.
- **param** `String text` : Formatted text to be printed.
- **return** `Printer` : Fluent interface
#### Method : `printFormattedText(String text, float mmFeedPaper)`
Print a formatted text and feed paper (`mmFeedPaper` millimeters). Read the ["Formatted Text : Syntax guide" section](#formatted-text--syntax-guide) for more information about text formatting options.
- **param** `String text` : Formatted text to be printed.
- **param** `float mmFeedPaper` : Millimeter distance feed paper at the end.
- **return** `Printer` : Fluent interface
#### Method : `printFormattedTextAndCut(String text, float mmFeedPaper)`
Print a formatted text, feed paper (`mmFeedPaper` millimeters) and cut the paper. Read the ["Formatted Text : Syntax guide" section](#formatted-text--syntax-guide) for more information about text formatting options.
- **param** `String text` : Formatted text to be printed.
- **param** `float mmFeedPaper` : Millimeter distance feed paper at the end.
- **return** `Printer` : Fluent interface
#### Method : `printFormattedTextAndOpenCashBox(String text, float mmFeedPaper)`
Print a formatted text, feed paper (`mmFeedPaper` millimeters), cut the paper and open the cash box. Read the ["Formatted Text : Syntax guide" section](#formatted-text--syntax-guide) for more information about text formatting options.
- **param** `String text` : Formatted text to be printed.
- **param** `float mmFeedPaper` : Millimeter distance feed paper at the end.
- **return** `Printer` : Fluent interface
#### Method : `printFormattedText(String text, int dotsFeedPaper)`
Print a formatted text and feed paper (`dotsFeedPaper` dots). Read the ["Formatted Text : Syntax guide" section](#formatted-text--syntax-guide) for more information about text formatting options.
- **param** `String text` : Formatted text to be printed.
- **param** `int dotsFeedPaper` : Distance feed paper at the end.
- **return** `Printer` : Fluent interface
#### Method : `printFormattedTextAndCut(String text, int dotsFeedPaper)`
Print a formatted text, feed paper (`dotsFeedPaper` dots) and cut the paper. Read the ["Formatted Text : Syntax guide" section](#formatted-text--syntax-guide) for more information about text formatting options.
- **param** `String text` : Formatted text to be printed.
- **param** `int dotsFeedPaper` : Distance feed paper at the end.
- **return** `Printer` : Fluent interface
#### Method : `printFormattedTextAndOpenCashBox(String text, int dotsFeedPaper)`
Print a formatted text, feed paper (`dotsFeedPaper` dots), cut the paper and open the cash box. Read the ["Formatted Text : Syntax guide" section](#formatted-text--syntax-guide) for more information about text formatting options.
- **param** `String text` : Formatted text to be printed.
- **param** `int dotsFeedPaper` : Distance feed paper at the end.
- **return** `Printer` : Fluent interface
#### Method : `bitmapToBytes(Bitmap bitmap, boolean gradient)`
Convert Bitmap object to ESC/POS image.
- **param** `Bitmap bitmap` : Instance of Bitmap
- **param** `boolean gradient` : `false` Black and white image, `true` Grayscale image
- **return** `byte[]` : Bytes contain the image in ESC/POS command
### Class : `com.dantsu.escposprinter.textparser.PrinterTextParserImg`
#### **Static** Method : `bitmapToHexadecimalString(Printer printer, Drawable drawable [, boolean gradient])`
Convert Drawable instance to a hexadecimal string of the image data.
- **param** `Printer printer` : A Printer instance that will print the image.
- **param** `Drawable drawable` : Drawable instance to be converted.
- **param** `boolean gradient` *(optional)* : `false` Black and white image, `true` Grayscale image (Default : `true`)
- **return** `String` : A hexadecimal string of the image data. Empty string if Drawable cannot be cast to BitmapDrawable.
#### **Static** Method : `bitmapToHexadecimalString(Printer printer, BitmapDrawable bitmapDrawable [, boolean gradient])`
Convert BitmapDrawable instance to a hexadecimal string of the image data.
- **param** `Printer printer` : A Printer instance that will print the image.
- **param** `BitmapDrawable bitmapDrawable` : BitmapDrawable instance to be converted.
- **param** `boolean gradient` *(optional)* : `false` Black and white image, `true` Grayscale image (Default : `true`)
- **return** `String` : A hexadecimal string of the image data.
#### **Static** Method : `bitmapToHexadecimalString(Printer printer, Bitmap bitmap [, boolean gradient])`
Convert Bitmap instance to a hexadecimal string of the image data.
- **param** `Printer printer` : A Printer instance that will print the image.
- **param** `Bitmap bitmap` : Bitmap instance to be converted.
- **param** `boolean gradient` *(optional)* : `false` Black and white image, `true` Grayscale image (Default : `true`)
- **return** `String` : A hexadecimal string of the image data.
#### **Static** Method : `bytesToHexadecimalString(byte[] bytes)`
Convert byte array to a hexadecimal string of the image data.
- **param** `byte[] bytes` : Bytes contain the image in ESC/POS command.
- **return** `String` : A hexadecimal string of the image data.
#### **Static** Method : `hexadecimalStringToBytes(String hexString)`
Convert hexadecimal string of the image data to bytes ESC/POS command.
- **param** `String hexString` : Hexadecimal string of the image data.
- **return** `byte[]` : Bytes contain the image in ESC/POS command.
### Class : `com.dantsu.escposprinter.EscPosCharsetEncoding`
#### Constructor : `EscPosCharsetEncoding(String charsetName, int escPosCharsetId)`
- **param** `charsetName` Name of charset encoding (Ex: ISO-8859-1)
- **param** `escPosCharsetId` Id of charset encoding for your printer (Ex: 6)
## Projects using this library
- [AllInOneYT/react-native-thermal-printer : A React Native bridge](https://github.com/AllInOneYT/react-native-thermal-printer)
- [paystory-de/thermal-printer-cordova-plugin : A Cordova / Ionic bridge](https://github.com/paystory-de/thermal-printer-cordova-plugin)
- [asukiaaa/react-native-escpos-android : A React Native bridge](https://github.com/asukiaaa/react-native-escpos-android)
- [android_bluetooth_printer : A Flutter bridge](https://pub.dev/packages/android_bluetooth_printer)
## Contributing
Please fork this repository and contribute back using pull requests.
Any contributions, large or small, major features, bug fixes, are welcomed and appreciated but will be thoroughly reviewed