QGenericUnixThemes: Make DBus listener configurable

The DBus locations and signals QGenericUnixThemesDBusListener has
listened to, were hard coded.
While these hard codings were in line with the signals emitted by the
Linux systems officially supported by Qt, this approach has made it
impossible for Qt to react to (color) theme changes when they are
announced by other DBus signals.

This patch replaces hard coded signals with a QFlatMap member.
The member is populated with the DBus locations/signals currently
supported.

If the environment variable QT_QPA_DBUS_SIGNALS_SAVE contains a valid
file name, the default configuration is stored in a JSON file.
If the environment variable QT_QPA_DBUS_SIGNALS contains a valid file
name, the default configuration is replaced with its content.

While the patch doesn't change existing behavior, it adds the
possibility to customize alternative DBus signals to listen to.

Task-number: QTBUG-103093
Pick-to: 6.5
Change-Id: I37e085c74bf53eed5cda7ec0dd7105562df0ed21
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

0 files changed, 0 insertions, 0 deletions