Redesign API surface for MessageRenderer.kt

The class was exposing fields and Channel's, but this is breaking the principle of Encapsulation. These members are now deprecated, in favour of more standards functions and Flow as result.

The inputs now also require a message's id, in preparation of the support for multiple messages rendering

MAILAND-2332

app/src/main/java/ch/protonmail/android/activities/messageDetails/MessageRenderer.kt

@@ -32,6 +32,8 @@ import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.channels.actor
 import kotlinx.coroutines.channels.toList
 import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.consumeAsFlow
 import kotlinx.coroutines.newSingleThreadContext
 import kotlinx.coroutines.plus
 import me.proton.core.util.kotlin.DispatcherProvider
@@ -49,13 +51,20 @@ private const val DEBOUNCE_DELAY_MILLIS = 500L
 
 /**
  * A class that will inline the images in the message's body.
- * Implement [CoroutineScope] by the constructor scope
+ *
+ * ## Input
+ * For start the process, these functions must be called
+ * * [setMessageBody]
+ * * [setImagesAndStartProcess]
+ *
+ * ## Output
+ * The results will be delivered by [results]
+ *
+ *
+ * Implements [CoroutineScope] by the constructor scope
  *
  * @param scope [CoroutineScope] which this class inherit from, this should be our `ViewModel`s
  * scope, so when `ViewModel` is cleared all the coroutines for this class will be canceled
- *
- *
- * @author Davide Farella
  */
 internal class MessageRenderer(
     private val dispatchers: DispatcherProvider,
@@ -65,7 +74,17 @@ internal class MessageRenderer(
     scope: CoroutineScope
 ) : CoroutineScope by scope + dispatchers.Comp {
 
+    /**
+     * Emits the results of Inlining process
+     */
+    val results: Flow<RenderedMessage> get() =
+        renderedMessage.consumeAsFlow()
+
     /** The [String] html of the message body */
+    @set:Deprecated(
+        "Use 'setMessageBody' with relative messageId. This will be removed",
+        ReplaceWith("setMessageBody(messageId, messageBody!!)")
+    )
     var messageBody: String? = null
         set(value) {
             // Return if body is already set
@@ -82,7 +101,12 @@ internal class MessageRenderer(
     /** reference to the [Document] */
     private val document by lazy { documentParser(messageBody!!) }
 
+    // region Actors
     /** A [Channel] for receive new [EmbeddedImage] images to inline in [document] */
+    @Deprecated(
+        "Use 'setImagesAndStartProcess' with relative messageId. This will be private",
+        ReplaceWith("setImagesAndStartProcess(messageId, embeddedImages)")
+    )
     val images = actor<List<EmbeddedImage>> {
         for (embeddedImages in channel) {
             imageCompressor.send(embeddedImages)
@@ -93,6 +117,10 @@ internal class MessageRenderer(
     }
 
     /** A [Channel] that will emits message body [String] with inlined images */
+    @Deprecated(
+        "Use 'results'. This will be private",
+        ReplaceWith("results")
+    )
     val renderedMessage = Channel<RenderedMessage>()
 
     /** [List] for keep track of ids of the already inlined images across the threads */
@@ -216,6 +244,28 @@ internal class MessageRenderer(
     private val idsListUpdater = actor<String>(idsListContext) {
         for (id in channel) inlinedImageIds += id
     }
+    // endregion
+
+    /**
+     * Set the [messageBody] for the message with the given [messageId]
+     * The [messageBody] will be used when [setImagesAndStartProcess] is called for a message with the same [messageId]
+     *
+     * @param messageBody [String] representation of the HTML message's body
+     */
+    fun setMessageBody(messageId: String, messageBody: String) {
+
+    }
+
+    /**
+     * Set [EmbeddedImage]s to be inlined in the message with the given [messageId] and start the inlining process
+     * Result will be delivered through [renderedMessage]
+     *
+     * @throws IllegalStateException if no message body has been set for the message
+     *  @see setMessageBody
+     */
+    fun setImagesAndStartProcess(messageId: String, images: List<EmbeddedImage>) {
+
+    }
 
     /** @return [File] directory for the current message */
     private fun messageDirectory(messageId: String) = File(attachmentsDirectory, messageId)