1 files changed, 33 insertions, 0 deletions
diff --git a/app/src/main/java/net/taler/merchantpos/order/OrderManager.kt b/app/src/main/java/net/taler/merchantpos/order/OrderManager.kt
index 124e73a..449d741 100644
--- a/app/src/main/java/net/taler/merchantpos/order/OrderManager.kt
+++ b/app/src/main/java/net/taler/merchantpos/order/OrderManager.kt
@@ -8,6 +8,7 @@ import androidx.lifecycle.Transformations.map
 import com.fasterxml.jackson.core.type.TypeReference
 import com.fasterxml.jackson.databind.ObjectMapper
 import net.taler.merchantpos.Amount.Companion.fromString
+import net.taler.merchantpos.CombinedLiveData
 import net.taler.merchantpos.config.ConfigurationReceiver
 import net.taler.merchantpos.order.RestartState.DISABLED
 import net.taler.merchantpos.order.RestartState.ENABLED
@@ -40,6 +41,13 @@ class OrderManager(private val mapper: ObjectMapper) : ConfigurationReceiver {
     private val mRestartState = MutableLiveData<RestartState>().apply { value = DISABLED }
     internal val restartState: LiveData<RestartState> = mRestartState
 
+    private val mSelectedOrderLine = MutableLiveData<OrderLine>()
+
+    internal val modifyOrderAllowed =
+        CombinedLiveData(restartState, mSelectedOrderLine) { restartState, selectedOrderLine ->
+            restartState != DISABLED && selectedOrderLine != null
+        }
+
     @Suppress("BlockingMethodInNonBlockingContext") // run on Dispatchers.Main
     override suspend fun onConfigurationReceived(json: JSONObject, currency: String): Boolean {
         // parse categories
@@ -105,6 +113,14 @@ class OrderManager(private val mapper: ObjectMapper) : ConfigurationReceiver {
     }
 
     @UiThread
+    internal fun removeProduct(product: ConfigProduct) {
+        val order = mOrder.value ?: throw IllegalStateException()
+        val modifiedOrder = order - product
+        mOrder.value = modifiedOrder
+        mRestartState.value = if (modifiedOrder.products.isEmpty()) DISABLED else ENABLED
+    }
+
+    @UiThread
     internal fun restartOrUndo() {
         if (restartState.value == UNDO) {
             mOrder.value = undoOrder
@@ -117,4 +133,21 @@ class OrderManager(private val mapper: ObjectMapper) : ConfigurationReceiver {
         }
     }
 
+    @UiThread
+    fun selectOrderLine(orderLine: OrderLine?) {
+        mSelectedOrderLine.value = orderLine
+    }
+
+    @UiThread
+    fun increaseSelectedOrderLine() {
+        val orderLine = mSelectedOrderLine.value ?: throw IllegalStateException()
+        addProduct(orderLine.first)
+    }
+
+    @UiThread
+    fun decreaseSelectedOrderLine() {
+        val orderLine = mSelectedOrderLine.value ?: throw IllegalStateException()
+        removeProduct(orderLine.first)
+    }
+
 }