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src/widget/form/chatform.cpp

@@ -143,6 +143,8 @@ void ChatForm::onSendTriggered()
             rec = Core::getInstance()->sendMessage(f->getFriendID(), qt_msg);
 
         registerReceipt(rec, id, ma);
+        
+        msgEdit->setLastMessage(msg); //set last message only when sending it
     }
 
     msgEdit->clear();

src/widget/tool/chattextedit.cpp

@@ -16,6 +16,7 @@
 
 #include "chattextedit.h"
 #include <QKeyEvent>
+#include <QDebug>
 
 ChatTextEdit::ChatTextEdit(QWidget *parent) :
     QTextEdit(parent)
@@ -31,9 +32,31 @@ void ChatTextEdit::keyPressEvent(QKeyEvent * event)
         emit enterPressed();
     else if (key == Qt::Key_Tab)
         emit tabPressed();
+    else if (key == Qt::Key_Up && this->toPlainText().isEmpty())
+    {
+        this->setText(lastMessage);
+        this->setFocus();
+    }
+    else if (key == Qt::Key_Up && !this->toPlainText().isEmpty())
+    {
+        currentMessage = this->toPlainText();
+        this->setText(lastMessage);
+    }
+    else if (key == Qt::Key_Down && !currentMessage.isEmpty())
+    {
+        this->setPlainText(currentMessage);
+        currentMessage.clear();
+    }
+    else if (key == Qt::Key_Down)
+        this->clear();
     else
     {
         emit keyPressed();
         QTextEdit::keyPressEvent(event);
     }
 }
+
+void ChatTextEdit::setLastMessage(QString lm)
+{
+    lastMessage = lm;
+}

src/widget/tool/chattextedit.h

@@ -25,13 +25,16 @@ class ChatTextEdit : public QTextEdit
 public:
     explicit ChatTextEdit(QWidget *parent = 0);
     virtual void keyPressEvent(QKeyEvent * event) override;
-
+    void setLastMessage(QString lm);
+    
 signals:
     void enterPressed();
     void tabPressed();
     void keyPressed();
-
-public slots:
+    
+private:
+    QString lastMessage,
+            currentMessage;
 
 };