Can get older conversation messages

widgets/conversationwidget.cpp

@@ -24,6 +24,7 @@ ConversationWidget::ConversationWidget(const Conversation &conversation, const U
     //Initialize UI
     QString convTitle = ConversationsListHelper::getConversationDisplayName(conversation, list);
     ui->convName->setText(convTitle);
+    connect(ui->scrollArea->verticalScrollBar(), &QScrollBar::valueChanged, this, &ConversationWidget::messagesListScrolled);
 
     //Initalize helpers
     mConversationHelper = new ConversationHelper(this);
@@ -100,6 +101,11 @@ void ConversationWidget::sendMessage()
 
 void ConversationWidget::refreshTimeout()
 {
+    //Check if messages are already being loaded
+    if(mIsLoadingMessages)
+        return;
+
+    mIsLoadingMessages = true;
     mTimer->stop();
 
     //Get the latest message of the conversation
@@ -110,6 +116,7 @@ void ConversationWidget::getMessagesCallback(bool success, QList<ConversationMes
 {
     //Restart counter
     mTimer->start(CONVERSATION_MESSAGES_REFRESH_INTERVAL);
+    mIsLoadingMessages = false;
 
     if(!success){
         QMessageBox::warning(this, tr("Error while getting messages list"), tr("Could not refresh messages list!"));
@@ -117,8 +124,16 @@ void ConversationWidget::getMessagesCallback(bool success, QList<ConversationMes
     }
 
     //Stop now if the list of messages is empty
-    if(list.empty())
+    if(list.empty()){
+
+        //Check if we were loading older messages
+        if(mIsLoadingOlderMessages){
+            mGotOldestConversationMessage = true;
+            mIsLoadingOlderMessages = false;
+        }
+
         return;
+    }
 
     mMessages.append(list);
 
@@ -141,6 +156,10 @@ void ConversationWidget::getMessagesCallback(bool success, QList<ConversationMes
     //Scroll to the end of the widget if required
     if(list.at(list.count()-1).iD() == mMessages.getLastMessageID())
         QTimer::singleShot(1000, this, &ConversationWidget::scrollToBottom);
+
+    //Else we can check if we reached the top of the conversation
+    else if(list.count() < NUMBER_OF_OLDER_MESSAGES_TO_GET)
+        mGotOldestConversationMessage = true;
 }
 
 void ConversationWidget::scrollToBottom()
@@ -162,6 +181,27 @@ void ConversationWidget::sendMessageCallback(bool success)
     resetSendMessageForm();
 }
 
+void ConversationWidget::messagesListScrolled(int value)
+{
+    //Check if the user reached the top of the conversation
+    if(value > 0)
+        return; //Nothing to be done
+
+    //Check if the conversation does not contains any message yet
+    // or if we already retrieved the oldest message of the conversation
+    if(mMessages.count() == 0 || mGotOldestConversationMessage)
+        return;
+
+    //Check if messsages are already being loaded
+    if(mIsLoadingMessages)
+        return;
+    mIsLoadingMessages = true;
+    mIsLoadingOlderMessages = true;
+
+    //Get older messages
+    mConversationHelper->getOlderMessages(mConversation.iD(), mMessages.getOldestMessageID());
+}
+
 void ConversationWidget::on_sendMessageButton_clicked()
 {
     sendMessage();

widgets/conversationwidget.h

@@ -72,6 +72,13 @@ private slots:
      */
     void sendMessageCallback(bool success);
 
+    /**
+     * Slot called when the user scroll the conversation
+     *
+     * @param value The new scroll value
+     */
+    void messagesListScrolled(int value);
+
     void on_sendMessageButton_clicked();
 
     void on_messageContentInput_returnPressed();
@@ -105,6 +112,9 @@ private:
     Conversation mConversation;
     UsersList mUsersList;
     ConversationMessagesList mMessages;
+    bool mIsLoadingMessages = false;
+    bool mGotOldestConversationMessage = false;
+    bool mIsLoadingOlderMessages = false;
 };
 
 #endif // CONVERSATIONWIDGET_H