wrote viewer resizing container

app/widget/viewer/viewersizer.cpp

@@ -9,23 +9,29 @@ ViewerSizer::ViewerSizer(QWidget *parent) :
 
 void ViewerSizer::SetWidget(QWidget *widget)
 {
-  if (widget_ != nullptr) {
-    widget_->setParent(nullptr);
-
-    disconnect(widget_, SIGNAL(SizeChanged(int, int)), this, SLOT(SizeChangedSlot(int, int)));
-  }
+  // Delete any previous widgets occupying this space
+  delete widget_;
 
   widget_ = widget;
 
   if (widget_ != nullptr) {
     widget_->setParent(this);
 
-    connect(widget_, SIGNAL(SizeChanged(int, int)), this, SLOT(SizeChangedSlot(int, int)));
-
     UpdateSize();
   }
 }
 
+void ViewerSizer::SetChildSize(int width, int height)
+{
+  if (height == 0) {
+    aspect_ratio_ = 0;
+  } else {
+    aspect_ratio_ = static_cast<double>(width) / static_cast<double>(height);
+  }
+
+  UpdateSize();
+}
+
 void ViewerSizer::resizeEvent(QResizeEvent *event)
 {
   QWidget::resizeEvent(event);
@@ -39,6 +45,7 @@ void ViewerSizer::UpdateSize()
     return;
   }
 
+  // If the aspect ratio is 0, the widget is always hidden
   if (qIsNull(aspect_ratio_)) {
     widget_->setVisible(false);
     return;
@@ -48,22 +55,19 @@ void ViewerSizer::UpdateSize()
 
   double our_aspect_ratio = static_cast<double>(width()) / static_cast<double>(height());
 
+  QPoint child_pos;
   QSize child_size = size();
 
   if (our_aspect_ratio > aspect_ratio_) {
     // This container is wider than the image, scale by height
     child_size.setWidth(qRound(child_size.height() * aspect_ratio_));
+    child_pos.setX(width() / 2 - child_size.width() / 2);
   } else {
     // This container is taller than the image, scale by width
     child_size.setHeight(qRound(child_size.width() / aspect_ratio_));
+    child_pos.setY(height() / 2 - child_size.height() / 2);
   }
 
   widget_->resize(child_size);
-}
-
-void ViewerSizer::SizeChangedSlot(int width, int height)
-{
-  aspect_ratio_ = static_cast<double>(width) / static_cast<double>(height);
-
-  UpdateSize();
+  widget_->move(child_pos);
 }