vasilito
cf12defd28
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent) Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
91 lines
4.1 KiB
C++
91 lines
4.1 KiB
C++
/*
|
|
This file is part of the KDE libraries
|
|
SPDX-FileCopyrightText: 2014 Thomas Lübking <thomas.luebking@gmail.com>
|
|
|
|
SPDX-License-Identifier: LGPL-2.0-or-later
|
|
*/
|
|
|
|
#include "kstyleextensions.h"
|
|
|
|
#include <QWidget>
|
|
|
|
namespace KStyleExtensions
|
|
{
|
|
/*
|
|
Custom Style Element runtime extension:
|
|
We reserve one StyleHint to let the effective style inform widgets whether it supports certain
|
|
string based style elements.
|
|
As this could lead to number conflicts (i.e. an app utilizing one of the hints itself for other
|
|
purposes) there're various safety mechanisms to rule out such interference.
|
|
|
|
1) It's most unlikely that a widget in some 3rd party app will accidentally call a general
|
|
QStyle/KStyle styleHint() or draw*() and (unconditionally) expect a valid return, however:
|
|
a. The StyleHint is not directly above Qt's custom base, assuming most 3rd party apps would
|
|
- in case - make use of such
|
|
b. In order to be accepted, the StyleHint query must pass a widget with a perfectly matching
|
|
name, containing the typical element prefix ("CE_", etc.) and being supported by the current
|
|
style
|
|
c. Instead using Qt's fragile qstyleoption_cast on the QStyleOption provided to the StyleHint
|
|
query, try to dump out a string and hope for the best, we now manipulate the widgets
|
|
objectName().
|
|
Plain Qt dependent widgets can do that themselves and if a widget uses KStyle's
|
|
convenience access functions, it won't notice this at all
|
|
|
|
2) The key problem is that a common KDE widget will run into an apps custom style which will then
|
|
falsely respond to the styleHint() call with an invalid value.
|
|
To prevent this, supporting styles *must* set a Q_CLASSINFO "X-KDE-CustomElements".
|
|
|
|
3) If any of the above traps snaps, the returned id is 0 - the QStyle default, indicating
|
|
that this element is not supported by the current style.
|
|
|
|
Obviously, this contains the "diminished clean" action to (temporarily) manipulate the
|
|
objectName() of a const QWidget* - but this happens completely inside KStyle or the widget, if
|
|
it does not make use of KStyles static convenience functions.
|
|
My biggest worry here would be, that in a multithreaded environment a thread (usually not being
|
|
owner of the widget) does something crucially relying on the widgets name property...
|
|
This however would also have to happen during the widget construction or stylechanges, when
|
|
the functions in doubt will typically be called.
|
|
So this is imho unlikely causing any trouble, ever.
|
|
*/
|
|
|
|
/// @private Prevent kapidox's doxygen config to pick up this namespace variable
|
|
static const QStyle::StyleHint SH_KCustomStyleElement = (QStyle::StyleHint)0xff000001;
|
|
/// @private Prevent kapidox's doxygen config to pick up this namespace variable
|
|
static const int X_KdeBase = 0xff000000;
|
|
|
|
/*
|
|
The functions called by widgets that request custom element support, passed to the effective style.
|
|
Collected in a static inline function due to similarity.
|
|
*/
|
|
|
|
/// @private Prevent kapidox's doxygen config to pick up this namespace method
|
|
static inline int customStyleElement(QStyle::StyleHint type, const QString &element, QWidget *widget)
|
|
{
|
|
if (!widget || widget->style()->metaObject()->indexOfClassInfo("X-KDE-CustomElements") < 0) {
|
|
return 0;
|
|
}
|
|
|
|
const QString originalName = widget->objectName();
|
|
widget->setObjectName(element);
|
|
const int id = widget->style()->styleHint(type, nullptr, widget);
|
|
widget->setObjectName(originalName);
|
|
return id;
|
|
}
|
|
|
|
QStyle::StyleHint customStyleHint(const QString &element, const QWidget *widget)
|
|
{
|
|
return (QStyle::StyleHint)customStyleElement(SH_KCustomStyleElement, element, const_cast<QWidget *>(widget));
|
|
}
|
|
|
|
QStyle::ControlElement customControlElement(const QString &element, const QWidget *widget)
|
|
{
|
|
return (QStyle::ControlElement)customStyleElement(SH_KCustomStyleElement, element, const_cast<QWidget *>(widget));
|
|
}
|
|
|
|
QStyle::SubElement customSubElement(const QString &element, const QWidget *widget)
|
|
{
|
|
return (QStyle::SubElement)customStyleElement(SH_KCustomStyleElement, element, const_cast<QWidget *>(widget));
|
|
}
|
|
|
|
}
|