feat: fit by width

Signed-off-by: Gary Wang <wzc782970009@gmail.com>

app/graphicsview.cpp

@@ -171,6 +171,31 @@ void GraphicsView::fitInView(const QRectF &rect, Qt::AspectRatioMode aspectRadio
     applyTransformationModeByScaleFactor();
 }
 
+void GraphicsView::fitByOrientation(Qt::Orientation ori, bool scaleDownOnly)
+{
+    resetScale();
+
+    QRectF viewRect = this->viewport()->rect().adjusted(2, 2, -2, -2);
+    QRectF imageRect = transform().mapRect(sceneRect());
+
+    qreal ratio;
+
+    if (ori == Qt::Horizontal) {
+        ratio = viewRect.width() / imageRect.width();
+    } else {
+        ratio = viewRect.height() / imageRect.height();
+    }
+
+    if (scaleDownOnly && ratio > 1) ratio = 1;
+
+    scale(ratio, ratio);
+    centerOn(imageRect.top(), 0);
+    m_enableFitInView = false;
+
+    applyTransformationModeByScaleFactor();
+    emit navigatorViewRequired(!isThingSmallerThanWindowWith(transform()), transform());
+}
+
 void GraphicsView::checkAndDoFitInView(bool markItOnAnyway)
 {
     if (!isThingSmallerThanWindowWith(transform())) {