commit 2a8a2d228d
Author: Matthias Koefferlein <matthias@koefferlein.de>
Date: Fri Feb 26 23:54:08 2021 +0100
One more fix.
commit 8c4d76505c
Author: Matthias Koefferlein <matthias@koefferlein.de>
Date: Fri Feb 26 23:03:07 2021 +0100
More patches for uitools-less build for CentOS 8
commit 2ac28292b8
Author: Matthias Koefferlein <matthias@koefferlein.de>
Date: Fri Feb 26 22:52:27 2021 +0100
First steps for fixing build on CentOS 8 without uitools
* #730: providing a new Qt module named QtUiTools for QUiLoader class support.
* Fixed a compile error on Mac
* Added QtUiTools to some more places
* Fixed a linker issue in the QtUiTools Python lib
* On occasion fixed a infinite recursion problem in the debugger
The recursion happened because by mistake I instantiated a
QApplication inside an in-application Python script. This
crashed the debugger due to infinite recursion. This is not
a real use case but to prevent similar issues, a recursion
sentinel was added.
* Removed QCoreApplication#notify from script bindings
Reasoning: "notify" made standalone scripts using QApplication and
QUiLoader virtually impossible.
Problem description:
- When a QApplication object is instantiated, e.g. in Python, the Qt binding
will install reimplementation hooks as the object may be dynamically
extended.
- A notify is virtual this means the *every* "notify" call in the application
is routed through the interpreter.
- For one thing this will slow down the application
- But as "notify" is called a zillion times this has more than this side effect.
- Specifically "notify" is called from within the QWidget constructor to
indicate a new widget. Then, if a QDialog for example is instatiated, it's
base class constructor will call "notify" when the object isn't ready yet.
- This has another severe side effect: as the object isn't ready yet, it gets
registered in the Python space with the wrong class and QDialog is not visible
as such.
To mitigate these problems, the most efficient solution is to disable "notify"
in general. There is hardly any use case in a script environment (in C++,
apart from hacking the only reasonable use case is exception handling, but
this does not apply to scripts). For providing the call functionality of
"notify" you should better use "postEvent" or "sendEvent" anyway.
So farewell QCoreApplication.notify ...
* Fixed python test for QtUiTools module
* Fixed UiTools test on Qt4 - QUiLoader needs an application object
Co-authored-by: Kazunari Sekigawa <kazunari.sekigawa@gmail.com>
Matthias Koefferlein