Add MessageFormManager.kt

app/src/main/java/chat/rocket/android/layouthelper/chatroom/MessageFormManager.kt

+package chat.rocket.android.layouthelper.chatroom
+
+import chat.rocket.android.widget.message.MessageFormLayout
+
+class MessageFormManager(private val messageFormLayout: MessageFormLayout, val callback: MessageFormLayout.ExtraActionSelectionClickListener) {
+    private var sendMessageCallback: SendMessageCallback? = null
+
+    init {
+        messageFormLayout.setExtraActionSelectionClickListener(callback)
+        messageFormLayout.setSubmitTextListener(this::sendMessage)
+    }
+
+    fun setSendMessageCallback(sendMessageCallback: SendMessageCallback) {
+        this.sendMessageCallback = sendMessageCallback
+    }
+
+    fun onMessageSend() {
+        clearComposingText()
+    }
+
+    fun setEditMessage(message: String) {
+        clearComposingText()
+        messageFormLayout.setText(message)
+    }
+
+    fun clearComposingText() {
+        messageFormLayout.setText("")
+    }
+
+    fun enableComposingText(enable: Boolean) {
+        messageFormLayout.isEnabled = enable
+    }
+
+    private fun sendMessage(message: String) {
+        sendMessageCallback?.onSubmitText(message)
+    }
+
+    interface SendMessageCallback {
+        fun onSubmitText(messageText: String)
+    }
+}
\ No newline at end of file