Add hotkeys D and U move DiffView down/up by half page

src/ui/DiffView/DiffView.cpp

@@ -15,6 +15,7 @@
 #include "CommentWidget.h"
 #include "ui/DiffTreeModel.h"
 #include "ui/DoubleTreeWidget.h"
+#include "ui/HotkeyManager.h"
 #include "git/Tree.h"
 #include <QScrollBar>
 #include <QPushButton>
@@ -47,6 +48,12 @@ bool copy(const QString &source, const QDir &targetDir) {
 
 } // namespace
 
+static Hotkey moveHalfPageDownHotKey = HotkeyManager::registerHotkey(
+    "d", "diffView/moveHalfPageDownHotKey", "DiffView/Move Half Page Down");
+
+static Hotkey moveHalfPageUpHotKey = HotkeyManager::registerHotkey(
+    "u", "diffView/moveHalfPageUpHotKey", "DiffView/Move Half Page Up");
+
 DiffView::DiffView(const git::Repository &repo, QWidget *parent)
     : QScrollArea(parent), mParent(parent) {
   setStyleSheet(DiffViewStyle::kStyleSheet);
@@ -84,6 +91,14 @@ DiffView::DiffView(const git::Repository &repo, QWidget *parent)
                 fetchMore();
             });
   }
+
+  QShortcut *shortcut = new QShortcut(this);
+  moveHalfPageDownHotKey.use(shortcut);
+  connect(shortcut, &QShortcut::activated, [this] { moveHalfPageDown(); });
+
+  shortcut = new QShortcut(this);
+  moveHalfPageUpHotKey.use(shortcut);
+  connect(shortcut, &QShortcut::activated, [this] { moveHalfPageUp(); });
 }
 
 DiffView::~DiffView() {}
@@ -513,3 +528,13 @@ void DiffView::indexChanged(const QStringList &paths) {
   //        }
   //    }
 }
+
+void DiffView::moveHalfPageDown() { moveRelative(height() / 2); }
+
+void DiffView::moveHalfPageUp() { moveRelative(-height() / 2); }
+
+void DiffView::moveRelative(int pixelsDown) {
+  int oldPosition = verticalScrollBar()->sliderPosition();
+  int newPosition = oldPosition + pixelsDown;
+  verticalScrollBar()->setSliderPosition(newPosition);
+}

src/ui/DiffView/DiffView.h

@@ -103,6 +103,9 @@ class DiffView : public QScrollArea, public EditorProvider {
   void diffTreeModelDataChanged(const QModelIndex &topLeft,
                                 const QModelIndex &bottomRight,
                                 const QVector<int> &roles);
+  void moveHalfPageDown();
+  void moveHalfPageUp();
+  void moveRelative(int pixelsDown);
 
 signals:
   void diagnosticAdded(TextEditor::DiagnosticKind kind);