Fix QSettings problems:
- Reopen file in ReadOnly mode if it was open in ReadWrite mode
and is being read. This is needed for stupid QSettings which
opens file in ReadWrite mode just to call readAll() on it.
- Implement setSize(0)
<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<class>MainWindow</class>
<widget class="QMainWindow" name="MainWindow">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>600</width>
<height>400</height>
</rect>
</property>
<property name="windowTitle">
<string>MainWindow</string>
</property>
<widget class="QWidget" name="centralWidget">
<layout class="QGridLayout" name="gridLayout" rowstretch="3,1">
<item row="1" column="2">
<widget class="QPlainTextEdit" name="plainTextEdit"/>
</item>
<item row="0" column="0" rowspan="2">
<layout class="QVBoxLayout" name="verticalLayout">
<item>
<widget class="QPushButton" name="pbUndo">
<property name="text">
<string>Undo</string>
</property>
</widget>
</item>
<item>
<spacer name="verticalSpacer">
<property name="orientation">
<enum>Qt::Vertical</enum>
</property>
<property name="sizeHint" stdset="0">
<size>
<width>20</width>
<height>40</height>
</size>
</property>
</spacer>
</item>
<item>
<widget class="QPushButton" name="pbSave">
<property name="text">
<string>Save</string>
</property>
</widget>
</item>
<item>
<widget class="QPushButton" name="pbLoad">
<property name="text">
<string>Load</string>
</property>
</widget>
</item>
<item>
<widget class="QSpinBox" name="sbBytes">
<property name="readOnly">
<bool>true</bool>
</property>
<property name="buttonSymbols">
<enum>QAbstractSpinBox::NoButtons</enum>
</property>
<property name="suffix">
<string> bytes</string>
</property>
<property name="maximum">
<number>999999</number>
</property>
</widget>
</item>
</layout>
</item>
<item row="0" column="2">
<widget class="DrawMapWidget" name="drawMapWidget" native="true"/>
</item>
</layout>
</widget>
</widget>
<layoutdefault spacing="6" margin="11"/>
<customwidgets>
<customwidget>
<class>DrawMapWidget</class>
<extends>QWidget</extends>
<header>drawmapwidget.h</header>
<container>1</container>
</customwidget>
</customwidgets>
<resources/>
<connections/>
</ui>