fix key repeat for Previous/Next Frame

https://forum.shotcut.org/t/keyboard-repeat-ignored/47633

Author: ddennedy

src/mainwindow.cpp

@@ -2586,7 +2586,7 @@ void MainWindow::keyPressEvent(QKeyEvent *event)
     switch (event->key()) {
     case Qt::Key_J:
         if (m_isKKeyPressed)
-            m_player->seek(m_player->position() - 1);
+            m_player->nextFrame();
         else
             m_player->rewind(false);
         break;
@@ -2597,7 +2597,7 @@ void MainWindow::keyPressEvent(QKeyEvent *event)
     case Qt::Key_L:
         if (event->modifiers() == Qt::NoModifier) {
             if (m_isKKeyPressed)
-                m_player->seek(m_player->position() + 1);
+                m_player->previousFrame();
             else
                 m_player->fastForward(false);
         }

src/player.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012-2024 Meltytech, LLC
+ * Copyright (c) 2012-2025 Meltytech, LLC
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -628,23 +628,13 @@ void Player::setupActions()
     action = new QAction(tr("Next Frame"), this);
     action->setProperty(Actions.hardKeyProperty, "K+L");
     action->setShortcut(QKeySequence(Qt::Key_Right));
-    connect(action, &QAction::triggered, this, [&]() {
-        if (MLT.producer()) {
-            pause(position() + 1);
-            seek(position() + 1);
-        }
-    });
+    connect(action, &QAction::triggered, this, &Player::nextFrame);
     Actions.add("playerNextFrameAction", action);
 
     action = new QAction(tr("Previous Frame"), this);
     action->setProperty(Actions.hardKeyProperty, "K+J");
     action->setShortcut(QKeySequence(Qt::Key_Left));
-    connect(action, &QAction::triggered, this, [&]() {
-        if (MLT.producer()) {
-            pause(position() - 1);
-            seek(position() - 1);
-        }
-    });
+    connect(action, &QAction::triggered, this, &Player::previousFrame);
     Actions.add("playerPreviousFrameAction", action);
 
     action = new QAction(tr("Forward One Second"), this);
@@ -1442,6 +1432,24 @@ void Player::onMuteButtonToggled(bool checked)
     m_volumePopup->hide();
 }
 
+void Player::nextFrame()
+{
+    if (MLT.producer() && m_requestedPosition != position() + 1) {
+        m_requestedPosition = position() + 1;
+        pause(m_requestedPosition);
+        seek(m_requestedPosition);
+    }
+}
+
+void Player::previousFrame()
+{
+    if (MLT.producer() && m_requestedPosition != position() - 1) {
+        m_requestedPosition = position() - 1;
+        pause(m_requestedPosition);
+        seek(m_requestedPosition);
+    }
+}
+
 void Player::setZoom(float factor, const QIcon &icon)
 {
     emit zoomChanged(factor);

src/player.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012-2024 Meltytech, LLC
+ * Copyright (c) 2012-2025 Meltytech, LLC
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -113,6 +113,8 @@ public slots:
     void showIdleStatus();
     void focusPositionSpinner() const;
     void onMuteButtonToggled(bool checked);
+    void nextFrame();
+    void previousFrame();
 
 protected:
     void resizeEvent(QResizeEvent *event) override;
@@ -172,6 +174,7 @@ public slots:
     DockToolBar *m_inSelectedToolBar;
     QHBoxLayout *m_toolRow1;
     QHBoxLayout *m_toolRow2;
+    int m_requestedPosition{0};
 
 private slots:
     void updateSelection();