event dispatcher

core/src/main/kotlin/me/rhunk/snapenhance/EventDispatcher.kt

@@ -0,0 +1,37 @@
+package me.rhunk.snapenhance
+
+import me.rhunk.snapenhance.core.event.impl.OnSnapInteractionEvent
+import me.rhunk.snapenhance.core.event.impl.SendMessageWithContentEvent
+import me.rhunk.snapenhance.data.wrapper.impl.MessageContent
+import me.rhunk.snapenhance.data.wrapper.impl.SnapUUID
+import me.rhunk.snapenhance.hook.HookStage
+import me.rhunk.snapenhance.hook.hook
+import me.rhunk.snapenhance.manager.Manager
+
+class EventDispatcher(
+    private val context: ModContext
+) : Manager {
+    override fun init() {
+        context.classCache.conversationManager.hook("sendMessageWithContent", HookStage.BEFORE) { param ->
+            val messageContent = MessageContent(param.arg(1))
+            context.event.post(SendMessageWithContentEvent(messageContent))?.let {
+                if (it.canceled) {
+                    param.setResult(null)
+                }
+            }
+        }
+
+        context.classCache.snapManager.hook("onSnapInteraction", HookStage.BEFORE) { param ->
+            val conversationId = SnapUUID(param.arg(1))
+            val messageId = param.arg<Long>(2)
+            context.event.post(OnSnapInteractionEvent(
+                conversationId = conversationId,
+                messageId = messageId
+            ))?.let {
+                if (it.canceled) {
+                    param.setResult(null)
+                }
+            }
+        }
+    }
+}

core/src/main/kotlin/me/rhunk/snapenhance/ModContext.kt

@@ -14,6 +14,7 @@ import kotlinx.coroutines.asCoroutineDispatcher
 import me.rhunk.snapenhance.bridge.BridgeClient
 import me.rhunk.snapenhance.bridge.wrapper.TranslationWrapper
 import me.rhunk.snapenhance.core.config.ModConfig
+import me.rhunk.snapenhance.core.event.EventBus
 import me.rhunk.snapenhance.data.MessageSender
 import me.rhunk.snapenhance.database.DatabaseAccess
 import me.rhunk.snapenhance.features.Feature
@@ -41,6 +42,8 @@ class ModContext {
 
     private val modConfig = ModConfig()
     val config by modConfig
+    val event = EventBus(this)
+    val eventDispatcher = EventDispatcher(this)
 
     val translation = TranslationWrapper()
     val features = FeatureManager(this)

core/src/main/kotlin/me/rhunk/snapenhance/SnapEnhance.kt

@@ -99,6 +99,7 @@ class SnapEnhance {
             with(appContext) {
                 reloadConfig()
                 mappings.init()
+                eventDispatcher.init()
                 //if mappings aren't loaded, we can't initialize features
                 if (!mappings.areMappingsLoaded) return
                 features.init()

core/src/main/kotlin/me/rhunk/snapenhance/core/event/EventBus.kt

@@ -1,10 +1,12 @@
-package me.rhunk.snapenhance.event
+package me.rhunk.snapenhance.core.event
 
+import me.rhunk.snapenhance.Logger
 import me.rhunk.snapenhance.ModContext
 import kotlin.reflect.KClass
 
 abstract class Event {
     lateinit var context: ModContext
+    var canceled = false
 }
 
 interface IListener<T> {
@@ -23,12 +25,14 @@ class EventBus(
         subscribers[event]!!.add(listener)
     }
 
-    fun <T : Event> subscribe(event: KClass<T>, listener: (T) -> Unit) {
+    inline fun <T : Event> subscribe(event: KClass<T>, crossinline listener: (T) -> Unit): () -> Unit {
-        subscribe(event, object : IListener<T> {
+        val obj = object : IListener<T> {
             override fun handle(event: T) {
                 listener(event)
             }
-        })
+        }
+        subscribe(event, obj)
+        return { unsubscribe(event, obj) }
     }
 
     fun <T : Event> unsubscribe(event: KClass<T>, listener: IListener<T>) {
@@ -38,22 +42,22 @@ class EventBus(
         subscribers[event]!!.remove(listener)
     }
 
-    fun <T : Event> post(event: T) {
+    fun <T : Event> post(event: T): T? {
         if (!subscribers.containsKey(event::class)) {
-            return
+            return null
         }
 
         event.context = context
 
-        subscribers[event::class]!!.forEach { listener ->
+        subscribers[event::class]?.forEach { listener ->
             @Suppress("UNCHECKED_CAST")
-            try {
+            runCatching {
                 (listener as IListener<T>).handle(event)
-            } catch (t: Throwable) {
+            }.onFailure { t ->
-                println("Error while handling event ${event::class.simpleName} by ${listener::class.simpleName}")
+                Logger.error("Error while handling event ${event::class.simpleName} by ${listener::class.simpleName}", t)
-                t.printStackTrace()
             }
         }
+        return event
     }
 
     fun clear() {

core/src/main/kotlin/me/rhunk/snapenhance/core/event/impl/OnSnapInteractionEvent.kt

@@ -0,0 +1,9 @@
+package me.rhunk.snapenhance.core.event.impl
+
+import me.rhunk.snapenhance.core.event.Event
+import me.rhunk.snapenhance.data.wrapper.impl.SnapUUID
+
+class OnSnapInteractionEvent(
+    val conversationId: SnapUUID,
+    val messageId: Long
+) : Event()

core/src/main/kotlin/me/rhunk/snapenhance/core/event/impl/SendMessageWithContentEvent.kt

@@ -0,0 +1,8 @@
+package me.rhunk.snapenhance.core.event.impl
+
+import me.rhunk.snapenhance.core.event.Event
+import me.rhunk.snapenhance.data.wrapper.impl.MessageContent
+
+class SendMessageWithContentEvent(
+    val messageContent: MessageContent
+) : Event()

core/src/main/kotlin/me/rhunk/snapenhance/event/Events.kt

@@ -1,3 +0,0 @@
-package me.rhunk.snapenhance.event
-
-//TODO: addView event

core/src/main/kotlin/me/rhunk/snapenhance/features/impl/Messaging.kt

@@ -1,5 +1,6 @@
 package me.rhunk.snapenhance.features.impl
 
+import me.rhunk.snapenhance.core.event.impl.OnSnapInteractionEvent
 import me.rhunk.snapenhance.data.wrapper.impl.SnapUUID
 import me.rhunk.snapenhance.features.Feature
 import me.rhunk.snapenhance.features.FeatureLoadParams
@@ -72,9 +73,9 @@ class Messaging : Feature("Messaging", loadParams = FeatureLoadParams.ACTIVITY_C
         }
 
         //get last opened snap for media downloader
-        Hooker.hook(context.classCache.snapManager, "onSnapInteraction", HookStage.BEFORE) { param ->
+        context.event.subscribe(OnSnapInteractionEvent::class) { event ->
-            openedConversationUUID = SnapUUID(param.arg(1))
+            openedConversationUUID = event.conversationId
-            lastFocusedMessageId = param.arg(2)
+            lastFocusedMessageId = event.messageId
         }
 
         Hooker.hook(context.classCache.conversationManager, "fetchMessage", HookStage.BEFORE) { param ->

core/src/main/kotlin/me/rhunk/snapenhance/features/impl/privacy/PreventMessageSending.kt

@@ -1,6 +1,7 @@
 package me.rhunk.snapenhance.features.impl.privacy
 
 import me.rhunk.snapenhance.Logger
+import me.rhunk.snapenhance.core.event.impl.SendMessageWithContentEvent
 import me.rhunk.snapenhance.data.NotificationType
 import me.rhunk.snapenhance.data.wrapper.impl.MessageContent
 import me.rhunk.snapenhance.features.Feature
@@ -23,14 +24,13 @@ class PreventMessageSending : Feature("Prevent message sending", loadParams = Fe
             }
         }
 
-        context.classCache.conversationManager.hook("sendMessageWithContent", HookStage.BEFORE) { param ->
+        context.event.subscribe(SendMessageWithContentEvent::class) { event ->
-            val message = MessageContent(param.arg(1))
+            val contentType = event.messageContent.contentType
-            val contentType = message.contentType
+            val associatedType = NotificationType.fromContentType(contentType) ?: return@subscribe
-            val associatedType = NotificationType.fromContentType(contentType) ?: return@hook
 
             if (preventMessageSending.contains(associatedType.key)) {
                 Logger.debug("Preventing message sending for $associatedType")
-                param.setResult(null)
+                event.canceled = true
             }
         }
     }

core/src/main/kotlin/me/rhunk/snapenhance/features/impl/spying/PreventReadReceipts.kt

@@ -1,5 +1,6 @@
 package me.rhunk.snapenhance.features.impl.spying
 
+import me.rhunk.snapenhance.core.event.impl.OnSnapInteractionEvent
 import me.rhunk.snapenhance.data.wrapper.impl.SnapUUID
 import me.rhunk.snapenhance.features.Feature
 import me.rhunk.snapenhance.features.FeatureLoadParams
@@ -19,9 +20,10 @@ class PreventReadReceipts : Feature("PreventReadReceipts", loadParams = FeatureL
                 it.setResult(null)
             }
         }
-        Hooker.hook(context.classCache.snapManager, "onSnapInteraction", HookStage.BEFORE) {
+
-            if (isConversationInStealthMode(SnapUUID(it.arg(1) as Any))) {
+        context.event.subscribe(OnSnapInteractionEvent::class) { event ->
-                it.setResult(null)
+            if (isConversationInStealthMode(event.conversationId)) {
+                event.canceled = true
             }
         }
     }