Widget with maximum size does not follow AlignHCenter - qt

Question

I have a vertical layout with a label and a QGraphicsView. I have set the maximum size of the QGraphicsView, and set the horizontal alignment to AlignHCenter, but it still seems to appear on the left rather than cenetered? Here is a demo ui file:
<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<class>Form</class>
<widget class="QWidget" name="Form">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>400</width>
<height>300</height>
</rect>
</property>
<property name="windowTitle">
<string>Form</string>
</property>
<layout class="QVBoxLayout" name="verticalLayout">
<item>
<widget class="QLabel" name="label">
<property name="text">
<string>TextLabel</string>
</property>
<property name="alignment">
<set>Qt::AlignCenter</set>
</property>
</widget>
</item>
<item>
<widget class="QGraphicsView" name="graphicsView">
<property name="sizePolicy">
<sizepolicy hsizetype="Expanding" vsizetype="Expanding">
<horstretch>0</horstretch>
<verstretch>0</verstretch>
</sizepolicy>
</property>
<property name="maximumSize">
<size>
<width>100</width>
<height>100</height>
</size>
</property>
</widget>
</item>
</layout>
</widget>
<resources/>
<connections/>
</ui>
If I change the Horizontal alignment of the label, it behaves as I'd expect (Left moves it to the left and AlignHCenter moves it to the center), but the QGraphicsView does not follow that behavior - it is always on the left.
How would I centered this fixed size QGraphicsView?

Answer 1

If you wrap the QGraphicsView in a QHBoxLayout as shown then it will appear centered like you expect. You can insert a horizontal spacer on the left or right if you want it aligned to either side.
The alignment property controls its behavior when the QGraphicsView has a scrollbar, not its relative position in the QLayout.
<item>
<layout class="QHBoxLayout" name="horizontalLayout">
<item>
<widget class="QGraphicsView" name="graphicsView">
<property name="sizePolicy">
<sizepolicy hsizetype="Expanding" vsizetype="Expanding">
<horstretch>0</horstretch>
<verstretch>0</verstretch>
</sizepolicy>
</property>
<property name="maximumSize">
<size>
<width>100</width>
<height>100</height>
</size>
</property>
</widget>
</item>
</layout>
</item>