diff --git a/mainwindow.cpp b/mainwindow.cpp
index d3f36ae..0d4b922 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -35,14 +35,25 @@ void MainWindow::keyPressEvent(QKeyEvent* event)
 bool MainWindow::event(QEvent* event)
 {
     if (event->type() == QEvent::KeyPress || event->type() == QEvent::KeyRelease) {
-        // TODO: add checks for out of field and scroll
-        // TODO: change step from 1 pixel size to size of 1 cell
-        // TODO: faster moving
-
         QKeyEvent* keyEvent = static_cast<QKeyEvent*>(event);
         QPoint cursorPos = cursor().pos();
 
         auto cell = minesFieldWidget->getCellByMousePoint(minesFieldWidget->mapFromGlobal(cursorPos));
+        if (cell.x() <= 0) {
+            cell.setX(0);
+            minesFieldWidget->horizontalScrollPosChanged(-1);
+        } else if (cell.x() > minesFieldWidget->getViewport().cols - 1) {
+            cell.setX(minesFieldWidget->getViewport().cols - 1);
+            minesFieldWidget->horizontalScrollPosChanged(1);
+        }
+        if (cell.y() <= 0) {
+            cell.setY(0);
+            minesFieldWidget->verticalScrollPosChanged(-1);
+        } else if (cell.y() > minesFieldWidget->getViewport().rows - 1) {
+            cell.setY(minesFieldWidget->getViewport().rows - 1);
+            minesFieldWidget->verticalScrollPosChanged(1);
+        }
+
         qDebug() << cursorPos << "?" << cell.x() << ":" << cell.y();
 
         auto stepSize = minesFieldWidget->getCellSize() + minesFieldWidget->getBorderSize();
@@ -53,6 +64,11 @@ bool MainWindow::event(QEvent* event)
 
         auto key = keyEvent->key();
 
+        if (keyEvent->modifiers() & Qt::ControlModifier)
+            stepSize = QSize(stepSize.width() * 2, stepSize.height() * 2);
+        if (keyEvent->modifiers() & Qt::ShiftModifier)
+            stepSize = QSize(stepSize.width() * 4, stepSize.height() * 4);
+
         if (event->type() == QEvent::KeyPress) {
             if (key == Qt::Key_A)
                 cursorPos.setX(cursorPos.x() - stepSize.width());
diff --git a/minesfieldwidget.cpp b/minesfieldwidget.cpp
index 83adedc..62dfc7b 100644
--- a/minesfieldwidget.cpp
+++ b/minesfieldwidget.cpp
@@ -45,8 +45,7 @@ void MinesFieldWidget::paintEvent(QPaintEvent* event)
         return;
     }
 
-    if (!updatingMutex.tryLock())
-        return;
+    updatingMutex.lock();
 
     painter.drawPixmap(0, 0, pixmap);
 
@@ -290,6 +289,11 @@ QColor MinesFieldWidget::getCellColor(Cell::CellState cellState, int minesAround
     return color;
 }
 
+Viewport MinesFieldWidget::getViewport() const
+{
+    return viewport;
+}
+
 QSize MinesFieldWidget::getBorderSize() const
 {
     return borderSize;
diff --git a/minesfieldwidget.h b/minesfieldwidget.h
index 8cc4b9d..290e305 100644
--- a/minesfieldwidget.h
+++ b/minesfieldwidget.h
@@ -11,6 +11,13 @@
 #include <QWidget>
 #include <QtWidgets>
 
+struct Viewport {
+    long long x, y;
+    long width, height;
+    long start_col, start_row;
+    long cols, rows;
+};
+
 class MinesFieldWidgetUpdaterThread;
 
 class MinesFieldWidget : public QWidget {
@@ -38,6 +45,8 @@ class MinesFieldWidget : public QWidget {
 
     Point getCellByMousePoint(const QPoint& mousePoint);
     Point convertCellPointToAbsolute(const Point& point);
+    Viewport getViewport() const;
+
 signals:
 
 public slots:
@@ -66,14 +75,6 @@ private slots:
     QColor getCellColor(Cell::CellState cellState, int minesAroundCell);
 
     QPixmap pixmap;
-
-    struct Viewport {
-        long long x, y;
-        long width, height;
-        long start_col, start_row;
-        long cols, rows;
-    };
-
     Viewport viewport;
 
     QSize cellSize;
diff --git a/minesfieldwidgetupdaterthread.cpp b/minesfieldwidgetupdaterthread.cpp
index 9a96017..9ee31b9 100644
--- a/minesfieldwidgetupdaterthread.cpp
+++ b/minesfieldwidgetupdaterthread.cpp
@@ -47,7 +47,7 @@ void MinesFieldWidgetUpdaterThread::run()
             auto& cells = minesFieldWidget->field->getCells();
             const Cell& cell = cells.at(i);
 
-            int minesAroundCell = cell.minesAround(); // TODO: ?
+            int minesAroundCell = cell.minesAround();
             QColor color = minesFieldWidget->getCellColor(cell.cellState(), minesAroundCell);
 
             painter.fillRect((x - minesFieldWidget->viewport.start_col) * stepX + minesFieldWidget->borderSize.width(),