allow current widget to dictate size of stacked widget for metatile/collision and events pages

include/ui/adjustingstackedwidget.h

@@ -0,0 +1,25 @@
+#ifndef ADJUSTINGSTACKEDWIDGET_H
+#define ADJUSTINGSTACKEDWIDGET_H
+
+#include <QStackedWidget>
+
+
+
+class AdjustingStackedWidget : public QStackedWidget
+{
+    Q_OBJECT
+
+public:
+    AdjustingStackedWidget(QWidget *parent = nullptr) : QStackedWidget(parent) {}
+
+    // override this to allow the stacked widget's current page to dictate size
+    virtual void setCurrentIndex(int index) {
+        QStackedWidget::setCurrentIndex(index);
+        for (int i = 0; i < this->count(); ++i) {
+            this->widget(i)->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored);
+        }
+        this->widget(index)->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);        
+    }
+};
+
+#endif // ADJUSTINGSTACKEDWIDGET_H