Implemented saving and restoring app settings

EpcQrCodeJavaFxApp/src/main/kotlin/net/codinux/banking/epcqrcode/windows/main/AppSettings.kt

@@ -0,0 +1,11 @@
+package net.codinux.banking.epcqrcode.windows.main
+
+
+open class AppSettings(
+    open var receiver: String = "",
+    open var iban: String = "",
+    open var bic: String = "",
+    open var amount: Double? = null,
+    open var reference: String = "",
+    open var destinationFile: String = ""
+)

EpcQrCodeJavaFxApp/src/main/kotlin/net/codinux/banking/epcqrcode/windows/main/MainWindow.kt

@@ -16,6 +16,7 @@ import java.io.File
 import java.text.DecimalFormat
 import java.text.ParsePosition
 import net.codinux.banking.epcqrcode.*
+import net.dankito.utils.serialization.JacksonJsonSerializer
 
 
 class MainWindow : View(FX.messages["application.title"]) {
@@ -25,6 +26,8 @@ class MainWindow : View(FX.messages["application.title"]) {
 
         private val DecimalFormat = DecimalFormat( "#.0" )
 
+        private val AppSettingsFile = File("settings.json")
+
         private val logger = LoggerFactory.getLogger(MainWindow::class.java)
     }
 
@@ -52,10 +55,15 @@ class MainWindow : View(FX.messages["application.title"]) {
     private var generatedQrCodeBytes: ByteArray? = null // couldn't find no working way to get image bytes from image -> also saving pure bytes in memory (what a waste)
 
 
+    private val serializer = JacksonJsonSerializer()
+
+
     init {
         selectedDestinationFile.addListener { _, _, newValue ->
             isDestinationFileSelected.value = newValue.isNotBlank()
         }
+
+        deserializeAppSettings()
     }
 
 
@@ -217,6 +225,8 @@ class MainWindow : View(FX.messages["application.title"]) {
                 alert.show()
             }
         }
+
+        saveSettings() // TODO: actually a side effect
     }
 
 
@@ -235,6 +245,8 @@ class MainWindow : View(FX.messages["application.title"]) {
         generatedQrCodeImage.value = generateQrCode(qrCodeContent)
 
         currentStage?.sizeToScene()
+
+        saveSettings() // TODO: actually a side effect
     }
 
     private fun map(amount: String): Double? {
@@ -253,4 +265,36 @@ class MainWindow : View(FX.messages["application.title"]) {
         return null
     }
 
+
+    private fun saveSettings() {
+        try {
+            val appSettings = AppSettings(receiver.value, iban.value, bic.value, map(amount.value), reference.value,
+                selectedDestinationFile.value)
+
+            serializer.serializeObject(appSettings, AppSettingsFile)
+        } catch (e: Exception) {
+            logger.error("Could not save AppSettings", e) // TODO: show message to user?
+        }
+    }
+
+    private fun deserializeAppSettings() {
+        try {
+            serializer.deserializeObject(AppSettingsFile, AppSettings::class.java)?.let { appSettings ->
+                receiver.value = appSettings.receiver
+                iban.value = appSettings.iban
+                bic.value = appSettings.bic
+
+                appSettings.amount?.let {
+                    amount.value = DecimalFormat.format(it)
+                }
+
+                reference.value = appSettings.reference
+
+                selectedDestinationFile.value = appSettings.destinationFile
+            }
+        } catch (e: Exception) {
+            logger.error("Could not deserialize AppSettings", e) // TODO: show message to user?
+        }
+    }
+
 }