Clean up QQmlFileSelector

The global static map of file selectors is not thread safe. If you add a
file selector to engine A running in thread 1, you cannot at the same
time retrieve the file selector of engine B running in thread 2. Alas,
we only need the static map to discern file selectors from other URL
interceptors, and we only need to do this on QQmlFileSelector::get(),
which we don't use. Unfortunately it is public API, though.

Deprecate QQmlFileSelector::get() and add a different hack to discern
the interceptors for the case that it's still called. Also remove the
duplicate setExtraSelectors() method.

For this to work, we also add a method to QQmlApplicationEngine that
allows us to pass extra file selectors and delay the initialization of
QQmlApplicationEngine's QQmlFileSelector until the first file is loaded.

[ChangeLog][QML] QQmlFileSelector::get() is deprecated. You can use the
new method QQmlAplicationEngine::setExtraFileSelectors() to pass extra
selectors to QQmlApplicationEngine's internal QQmlFileSelector.
Manually created QQmlFileSelectors should be configured immediately
after creation, before they are used by the QQmlEngine.

Change-Id: Ia61a93777dc910b441a03ffb42d35a2a224c0e26
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

1 files changed, 3 insertions, 4 deletions

diff --git a/tools/qml/main.cpp b/tools/qml/main.cpp
index e8c471e22e..a38a3d599f 100644
--- a/tools/qml/main.cpp
+++ b/tools/qml/main.cpp
@@ -558,10 +558,9 @@ int main(int argc, char *argv[])
     QStringList customSelectors;
     for (const QString &selector : parser.values(selectorOption))
         customSelectors.append(selector);
-    if (!customSelectors.isEmpty()) {
-        QQmlFileSelector *selector =  QQmlFileSelector::get(&e);
-        selector->setExtraSelectors(customSelectors);
-    }
+
+    if (!customSelectors.isEmpty())
+        e.setExtraFileSelectors(customSelectors);
 
 #if defined(QT_GUI_LIB) && QT_CONFIG(opengl)
     if (qEnvironmentVariableIsSet("QSG_CORE_PROFILE") || qEnvironmentVariableIsSet("QML_CORE_PROFILE")) {