refactor: DRY home button rect calculation in ViewCube

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>

src/ViewCube.cpp

@@ -9,6 +9,20 @@
 #include <QSvgRenderer>
 #include <QVector>
 
+namespace
+{
+QRect getHomeButtonRect(int widgetWidth) {
+    const int viewCubeSize = 150; // logical pixels
+    const int buttonSize = 24;
+    const int buttonOffsetX = 8;
+    const int buttonOffsetY = 0;
+
+    const int viewCubeX = widgetWidth - viewCubeSize;
+
+    return QRect(viewCubeX + buttonOffsetX, buttonOffsetY, buttonSize, buttonSize);
+}
+}
+
 ViewCube::ViewCube()
 {
     m_homeButtonRenderer = new QSvgRenderer(QString(":/icons/home.svg"));
@@ -220,14 +234,7 @@ void ViewCube::paint2D(QPainter& painter, int widgetWidth, int widgetHeight)
         return;
     }
 
-    int viewCubeSize = 150; // logical pixels
-    int buttonSize = 24;
-    int buttonMargin = -32;
-
-    int viewCubeX = widgetWidth - viewCubeSize;
-    int viewCubeY = 0;
-
-    m_homeButtonRect = QRect(viewCubeX - buttonMargin - buttonSize, viewCubeY, buttonSize, buttonSize);
+    m_homeButtonRect = getHomeButtonRect(widgetWidth);
 
     if (m_homeButtonRenderer && m_homeButtonRenderer->isValid()) {
         QImage image(m_homeButtonRect.size(), QImage::Format_ARGB32_Premultiplied);
@@ -249,12 +256,7 @@ bool ViewCube::handleMousePress(const QPoint& pos, int widgetWidth, int widgetHe
         return false;
     }
 
-    int viewCubeSize = 150;
-    int buttonSize = 24;
-    int buttonMargin = -32;
-    int viewCubeX = widgetWidth - viewCubeSize;
-    int viewCubeY = 0;
-    QRect homeButtonRect(viewCubeX - buttonMargin - buttonSize, viewCubeY, buttonSize, buttonSize);
+    QRect homeButtonRect = getHomeButtonRect(widgetWidth);
 
     return homeButtonRect.contains(pos);
 }