How to purge QMainWindow's geometry tag in Qt Designer UI files

Question

Qt Designer adds a geometry tag that contains the widget's default size in absolute units (pixels).

This is really annoying because if you edit a ui file on a 4k monitor all of your uis will (by default) display with massive white space on a lower DPI system.

If I manually delete this tag, my windows have the expected size on first-show, but manually editing every ui file each time I open them in Qt Designer feels wrong.

I'm using Qt 5.9.

What's the paradigmatic way to prevent Qt Designer from adding this XML tag?

In example.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>Example</class>
 <widget class="QMainWindow" name="Example">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>970</width>
    <height>1371</height>
   </rect>
  </property>

To "normalize" your UI on 4K monitor you can do: Simply put this before QApplication app object initialized: `QGuiApplication::setAttribute(Qt::AA_EnableHighDpiScaling); QApplication::setAttribute(Qt::AA_UseHighDpiPixmaps); QApplication app(argc, argv);` I could have put that in form of the answer but the question is more about Designer? — Alexander V, Aug 01 '17 at 17:44
Also: https://stackoverflow.com/questions/39823918/how-to-approach-development-of-new-qt-5-7-high-dpi-per-monitor-dpi-aware-applic/39824445#39824445 — Alexander V, Aug 01 '17 at 17:49
@AlexanderVX Yeah, that's different. The problem is that Qt Designer sets size hints that are specific to the DPI/resolution of the developer's machine. — Mikhail, Aug 01 '17 at 20:01
Why not to try smth like `mainwindow.setGeometry(screen.width() / 4, screen.height() / 4, screen.width() / 2, screen.height() / 2);` // so you will ensure it is proportional to the screen. And you can detect what screen it is on. — Alexander V, Aug 01 '17 at 20:20
@AlexanderVX On one hand that is not a bad idea, on the other hand the layout is "perfect' when I manually delete the line from the `ui` file. — Mikhail, Aug 01 '17 at 20:22
I guess nested layouts may help so that you avoid fixed things. — Alexander V, Aug 01 '17 at 20:27

score 6 · Accepted Answer · answered May 10 '18 at 18:26

I am able to remove the geometry tags in Qt Designer like this:

Open a new Main Window form
Select geometry in the Property Editor
Click the red arrow on the right

This will automatically resize the form - but manually resizing it won't reinstate the geometry tag. However, if the form has a menu-bar, it will also add a geometry tag for that. So select menubar in the Object Inspector and then repeat steps 2 and 3 above. After doing that, I get this output:

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralwidget"/>
  <widget class="QMenuBar" name="menubar"/>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

And after adding other widgets/menus/layouts and resizing the form, the geometry tags never reappear. This was all tested using Qt Designer 5.10.1 on Linux.

Yeah. This looks like the most reliable way. Seems that all children need to be "reset" to effectively loose those tags. — Mikhail, May 17 '18 at 00:24

score 1 · Answer 2 · answered May 13 '18 at 09:25

Assuming you are using qmake for your project:

One possible solution would be to create an intermediate "compiler" that first transforms the ui file to remove the geometry tag and that passes it to uic - this way you can at least automate the process of removing the geometry tags.

The code for the PRO-file would add a new compiler like this:

uiungeom_c.name = fix ui of ${QMAKE_FILE_IN}
uiungeom_c.input = RAW_FORMS
uiungeom_c.variable_out = FORMS
uiungeom_c.commands = /path/to/<some_command> ${QMAKE_FILE_IN} ${QMAKE_FILE_OUT}
uiungeom_c.output = ./.uifix/${QMAKE_FILE_BASE}.ui
uiungeom_c.CONFIG += target_predeps
QMAKE_EXTRA_COMPILERS += uiungeom_c

And change the FORMS in your pro file to RAW_FORMS, i.e.

RAW_FORMS += mainwindow.ui #...

This will run the <some_command> on all your ui-files and generate a copy of them without the geometry in your build folder in a subfolder. Those generated ui files are automatically passed to the FORMS variable and thus are now passed on to uic to create the header.

The tricky part here is the <some_command> - You would have to create some kind of script (bash, batch, python, XSLT-Transformation, ... - whatever you prefer) that takes the original xml file as input and removes the tag. XSLT-Transformations are propably the most elegant and reliable way, but also the most complicated - you can learn more about them at W3schools, but I would propably just use python, as it propably leads the the smallest and easiest to understand script.

(If you would like to see a basic sample in python that could do the job, I can fiddle one out later the day - just ask for it as a comment)

Welp. I don't use qmake, but yes, parsing XML is one strategy to remove the tag... — Mikhail, May 17 '18 at 00:13

score 1 · Answer 3 · answered May 15 '18 at 11:32

1

I don't have a solution to prevent Designer from writing this, I often find it simpler to just revert by code what has been done.

In this case I would suggest adding a call to setSize(sizeHint()) at the end of the constructor of your main window.

answered May 15 '18 at 11:32

Aurélien Gâteau

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How to purge QMainWindow's geometry tag in Qt Designer UI files

3 Answers3