Merge pull request #21 from tillhub/develop

v1.6.0 improvements and simplification of interface

buildSrc/src/main/java/ConfigData.kt

@@ -5,8 +5,7 @@ object ConfigData {
     const val applicationId = "de.tillhub.printengine"
     const val minSdkVersion = 21
     const val targetSdkVersion = 34
-    const val versionCode = 17
-    const val versionName = "1.5.0"
+    const val versionName = "1.6.0"
 
     val JAVA_VERSION = JavaVersion.VERSION_17
     val JVM_TARGET = JAVA_VERSION.toString()

src/main/java/de/tillhub/printengine/PrintService.kt

@@ -1,25 +1,12 @@
 package de.tillhub.printengine
 
-import de.tillhub.printengine.data.PrinterConnectionState
 import de.tillhub.printengine.data.PrinterResult
+import de.tillhub.printengine.data.PrinterState
 import kotlinx.coroutines.flow.StateFlow
-import timber.log.Timber
 
 abstract class PrintService {
     abstract var printController: PrinterController?
-    abstract val printerConnectionState: StateFlow<PrinterConnectionState>
-
-    @Suppress("TooGenericExceptionCaught")
-    inline fun <T> withPrinterOrDefault(default: T, body: (PrinterController) -> T): T {
-        return printController?.let {
-            try {
-                body(it)
-            } catch (e: Exception) {
-                Timber.e(e)
-                default
-            }
-        } ?: default
-    }
+    abstract val printerState: StateFlow<PrinterState>
 
     @Suppress("TooGenericExceptionCaught")
     inline fun <T> withPrinterCatching(body: (PrinterController) -> T): PrinterResult<T> {

src/main/java/de/tillhub/printengine/Printer.kt

@@ -1,38 +1,22 @@
 package de.tillhub.printengine
 
 import de.tillhub.printengine.data.PrintJob
-import de.tillhub.printengine.data.PrinterConnectionState
 import de.tillhub.printengine.data.PrinterState
-import de.tillhub.printengine.data.PrintingIntensity
 import de.tillhub.printengine.data.PrinterResult
 import de.tillhub.printengine.data.PrinterInfo
+import de.tillhub.printengine.data.PrinterSettings
 import de.tillhub.printengine.data.PrintingPaperSpec
 import kotlinx.coroutines.flow.StateFlow
 
 /**
  * Represents one printer and allows to manage the printers connection issue print commands.
  */
 interface Printer {
-    fun setEnabled(enabled: Boolean)
-    fun observeConnection(): StateFlow<PrinterConnectionState>
+    val settings: PrinterSettings
     fun observePrinterState(): StateFlow<PrinterState>
-    fun setPrintingIntensity(intensity: PrintingIntensity)
     suspend fun getPrinterInfo(): PrinterResult<PrinterInfo>
-
     suspend fun startPrintJob(job: PrintJob): PrinterResult<Unit>
 
-    /**
-     *  Due to the distance between the paper hatch and the print head,
-     *  the paper needs to be fed out automatically
-     *  But if the Api does not support it, it will be replaced by printing three lines
-     */
-    suspend fun feedPaper(): PrinterResult<Unit>
-
-    /**
-     *  Printer cuts paper and throws exception on machines without a cutter
-     */
-    suspend fun cutPaper(): PrinterResult<Unit>
-
     companion object {
         val DEFAULT_PRINTER_WIDTH = PrintingPaperSpec.PAX_PAPER_56MM.characterCount
     }

src/main/java/de/tillhub/printengine/PrinterImpl.kt

@@ -3,22 +3,24 @@ package de.tillhub.printengine
 import de.tillhub.printengine.analytics.PrintAnalytics
 import de.tillhub.printengine.data.PrintCommand
 import de.tillhub.printengine.data.PrintJob
-import de.tillhub.printengine.data.PrinterConnectionState
 import de.tillhub.printengine.data.PrinterInfo
 import de.tillhub.printengine.data.PrinterResult
+import de.tillhub.printengine.data.PrinterSettings
 import de.tillhub.printengine.data.PrinterState
-import de.tillhub.printengine.data.PrintingIntensity
 import de.tillhub.printengine.data.doOnError
+import de.tillhub.printengine.dispatcher.DispatcherProvider
+import de.tillhub.printengine.dispatcher.DispatcherProviderImp
 import de.tillhub.printengine.pax.PaxPrintService
 import de.tillhub.printengine.sunmi.SunmiPrintService
 import de.tillhub.printengine.verifone.VerifonePrintService
-import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.withContext
 import timber.log.Timber
 
 class PrinterImpl(
     private val printService: PrintService,
-    private val analytics: PrintAnalytics?
+    private val analytics: PrintAnalytics?,
+    private val dispatcherProvider: DispatcherProvider = DispatcherProviderImp()
 ) : Printer {
 
     init {
@@ -29,88 +31,62 @@ class PrinterImpl(
         }
     }
 
-    private var enabled: Boolean = true
-    private var printingIntensity: PrintingIntensity = PrintingIntensity.DEFAULT
-
-    override fun setEnabled(enabled: Boolean) {
-        this.enabled = enabled
+    override val settings: PrinterSettings by lazy {
+        PrinterSettings()
     }
 
-    override fun observeConnection(): StateFlow<PrinterConnectionState> = printService.printerConnectionState
-
-    override fun observePrinterState(): StateFlow<PrinterState> =
-        printService.withPrinterOrDefault(default = MutableStateFlow(PrinterState.Error.Unknown)) {
-            it.observePrinterState()
-        }
-
-    override fun setPrintingIntensity(intensity: PrintingIntensity) {
-        printingIntensity = intensity
-    }
+    override fun observePrinterState(): StateFlow<PrinterState> = printService.printerState
 
     override suspend fun getPrinterInfo(): PrinterResult<PrinterInfo> =
-        printService.withPrinterCatching {
-            it.getPrinterInfo().let { info ->
-                PrinterInfo(
-                    info.serialNumber,
-                    info.deviceModel,
-                    info.printerVersion,
-                    info.printerPaperSpec,
-                    info.printingFontType,
-                    info.printerHead,
-                    info.printedDistance,
-                    info.serviceVersion
-                )
+        withContext(dispatcherProvider.iO()) {
+            printService.withPrinterCatching {
+                it.getPrinterInfo().let { info ->
+                    PrinterInfo(
+                        info.serialNumber,
+                        info.deviceModel,
+                        info.printerVersion,
+                        info.printerPaperSpec,
+                        info.printingFontType,
+                        info.printerHead,
+                        info.printedDistance,
+                        info.serviceVersion
+                    )
+                }
+            }.doOnError {
+                logWarning("getting printer info")
             }
-        }.doOnError {
-            logWarning("getting printer info")
         }
 
     override suspend fun startPrintJob(job: PrintJob): PrinterResult<Unit> =
-        printService.withPrinterCatching { controller ->
-            logInfo(
-                """receipt: START #################
+        withContext(dispatcherProvider.iO()) {
+            printService.withPrinterCatching { controller ->
+                logInfo(
+                    """receipt: START #################
                    |${job.description}
                    |receipt END #################
                    |""".trimMargin()
-            )
-            if (enabled && job.isNotEmpty) {
-                controller.setIntensity(printingIntensity)
-                controller.setFontSize(controller.getPrinterInfo().printingFontType)
-                job.commands.forEach { command ->
-                    when (command) {
-                        is PrintCommand.Barcode -> controller.printBarcode(command.barcode)
-                        is PrintCommand.Image -> controller.printImage(command.image)
-                        is PrintCommand.QrCode -> controller.printQr(command.code)
-                        is PrintCommand.RawData -> controller.sendRawData(command.data)
-                        is PrintCommand.Text -> controller.printText(command.text)
-                        PrintCommand.CutPaper -> controller.cutPaper()
-                        PrintCommand.FeedPaper -> controller.feedPaper()
+                )
+                if (settings.enabled && job.isNotEmpty) {
+                    controller.setIntensity(settings.printingIntensity)
+                    controller.setFontSize(controller.getPrinterInfo().printingFontType)
+                    job.commands.forEach { command ->
+                        when (command) {
+                            is PrintCommand.Barcode -> controller.printBarcode(command.barcode)
+                            is PrintCommand.Image -> controller.printImage(command.image)
+                            is PrintCommand.QrCode -> controller.printQr(command.code)
+                            is PrintCommand.RawData -> controller.sendRawData(command.data)
+                            is PrintCommand.Text -> controller.printText(command.text)
+                            PrintCommand.CutPaper -> controller.cutPaper()
+                            PrintCommand.FeedPaper -> controller.feedPaper()
+                        }
                     }
+                    controller.start()
+                    analytics?.logPrintReceipt(job.description)
                 }
-                controller.start()
-                analytics?.logPrintReceipt(job.description)
-            }
-        }.doOnError {
-            logWarning("printing job '${job.description}'")
-            analytics?.logErrorPrintReceipt("printing text '${job.description}'")
-        }
-
-    override suspend fun feedPaper(): PrinterResult<Unit> =
-        printService.withPrinterCatching {
-            if (enabled) {
-                it.feedPaper()
-            }
-        }.doOnError {
-            logWarning("feeding paper")
-        }
-
-    override suspend fun cutPaper(): PrinterResult<Unit> =
-        printService.withPrinterCatching {
-            if (enabled) {
-                it.cutPaper()
+            }.doOnError {
+                logWarning("printing job '${job.description}'")
+                analytics?.logErrorPrintReceipt("printing text '${job.description}'")
             }
-        }.doOnError {
-            logWarning("cutting paper")
         }
 
     private fun logInfo(message: String) {

src/main/java/de/tillhub/printengine/data/PrintCommand.kt

@@ -8,6 +8,14 @@ sealed class PrintCommand {
     data class Barcode(val barcode: String) : PrintCommand()
     data class QrCode(val code: String) : PrintCommand()
     data class RawData(val data: RawPrinterData) : PrintCommand()
+    /**
+     *  Due to the distance between the paper hatch and the print head,
+     *  the paper needs to be fed out automatically
+     *  But if the Api does not support it, it will be replaced by printing three lines
+     */
     object FeedPaper : PrintCommand()
+    /**
+     *  Printer cuts paper and throws exception on machines without a cutter
+     */
     object CutPaper : PrintCommand()
 }

src/main/java/de/tillhub/printengine/data/PrinterSettings.kt

@@ -0,0 +1,6 @@
+package de.tillhub.printengine.data
+
+data class PrinterSettings(
+    var enabled: Boolean = true,
+    var printingIntensity: PrintingIntensity = PrintingIntensity.DEFAULT
+)

src/main/java/de/tillhub/printengine/data/PrinterState.kt

@@ -4,20 +4,26 @@ package de.tillhub.printengine.data
  * State of the [Printer] in case a connection is established.
  */
 sealed class PrinterState {
+    /** Trying to find supported printer */
+    object CheckingForPrinter : PrinterState()
+
     /** The printer works normally / printer is running */
     object Connected : PrinterState()
 
     /** Preparing printer / printer found but still initializing */
     object Preparing : PrinterState()
 
-    /** Printer was not detected / does not exist */
-    object PrinterNotDetected : PrinterState()
-
     /** Printer found but operating */
     object Busy : PrinterState()
 
     /** Printer error */
     sealed class Error : PrinterState() {
+        /** Connection to printer has lost */
+        object ConnectionLost : Error()
+
+        /** Printer was not detected / does not exist */
+        object NotAvailable : PrinterState()
+
         /** Abnormal communication / printer hardware interface is abnormal */
         object AbnormalCommunication : Error()
 
@@ -48,23 +54,27 @@ sealed class PrinterState {
         /** Unknown error state */
         object Unknown : Error()
 
-        /**
-         * Pax A920 specific
-         */
-
-        object FormatPrintDataPacketError : Error()
+        /** Print job cannot continue, but could be resumed later. */
+        object PrintingUnfinished : Error()
 
         object Malfunctions : Error()
 
-        object PrintingUnfinished : Error()
+        /**
+         * Pax A920 specific
+         */
+        sealed class Pax : Error() {
+            object FormatPrintDataPacketError : Pax()
 
-        object NotInstalledFontLibrary : Error()
+            object NotInstalledFontLibrary : Pax()
 
-        object DataPackageTooLong : Error()
+            object DataPackageTooLong : Pax()
+        }
 
         /**
          * Verifone specific
          */
-        object InternalError : Error()
+        sealed class Verifone : Error() {
+            object InternalError : Verifone()
+        }
     }
 }

src/main/java/de/tillhub/printengine/dispatcher/DispatcherProvider.kt

@@ -0,0 +1,7 @@
+package de.tillhub.printengine.dispatcher
+
+import kotlinx.coroutines.CoroutineDispatcher
+
+interface DispatcherProvider {
+    fun iO(): CoroutineDispatcher
+}

src/main/java/de/tillhub/printengine/dispatcher/DispatcherProviderImp.kt

@@ -0,0 +1,8 @@
+package de.tillhub.printengine.dispatcher
+
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.Dispatchers
+
+class DispatcherProviderImp : DispatcherProvider {
+    override fun iO(): CoroutineDispatcher = Dispatchers.IO
+}