QQuickStyle: add API for managing style paths

In order to be able to use/refer to/select styles by name:

   - ./myapp -style Glossy
   - :/qtquickcontrols2.conf: [Controls] Style=Glossy
   - QT_QUICK_CONTROLS_STYLE=Glossy ./myapp

the style needs to be available in a place where QQC2 can find it
by the given name. Normally, QQC2 scans for available styles in the
QT_INSTALL_QML/QtQuick/Controls.2/ directory, where all the built-in
styles reside. However, 3rd party styles may want to install styles
into their own namespace, especially if they offer style-specific API.

If a style is installed elsewhere, QQC2 needs to be made aware of the
style path to make it possible to locate the style. Previously, the
QT_QUICK_CONTROLS_STYLE_PATH environment variable was the only way.
This adds proper C++ API, inspired by QQmlEngine's importPathList
and pluginPathList, to manage QQC2 style paths.

[ChangeLog][Controls][QQuickStyle] Added stylePathList() and
addStylePath() methods for managing the list of directories where
Qt Quick Controls 2 searches for available styles.

Task-number: QTBUG-67062
Change-Id: I1e85b5e09ba869483c0937ac61a0a2dcfc8e774e
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/auto/qquickstyle/tst_qquickstyle.cpp b/tests/auto/qquickstyle/tst_qquickstyle.cpp
index 4a34f24a..555e1686 100644
--- a/tests/auto/qquickstyle/tst_qquickstyle.cpp
+++ b/tests/auto/qquickstyle/tst_qquickstyle.cpp
@@ -151,8 +151,8 @@ void tst_QQuickStyle::availableStyles()
 {
     QString path = QFINDTESTDATA("data");
     QVERIFY(!path.isEmpty());
-    qputenv("QT_QUICK_CONTROLS_STYLE_PATH", path.toLocal8Bit());
 
+    QQuickStyle::addStylePath(path);
     QStringList paths = QQuickStylePrivate::stylePaths();
     QVERIFY(paths.contains(path));