WinRT: Add Windows UI Automation support

Adds support to accessibility tools and programmatic UI control to the
WinRT platform through Windows UI Automation, using the AutomationPeer API.

[ChangeLog][winrt][feature] Added support to Windows UI Automation to the
WinRT QPA, allowing Qt-based UWP applications to operate with accessibility
and programmatic UI control tools.

Change-Id: If0a8edbebc7c16c4896d749f2d7e11809b4b37b3
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@qt.io>

1 files changed, 22 insertions, 0 deletions

diff --git a/src/corelib/kernel/qeventdispatcher_winrt.cpp b/src/corelib/kernel/qeventdispatcher_winrt.cpp
index 33753ed507..600c6c38fd 100644
--- a/src/corelib/kernel/qeventdispatcher_winrt.cpp
+++ b/src/corelib/kernel/qeventdispatcher_winrt.cpp
@@ -43,6 +43,8 @@
 #include <QtCore/QThread>
 #include <QtCore/QHash>
 #include <QtCore/QMutex>
+#include <QtCore/QSemaphore>
+#include <QtCore/QSharedPointer>
 #include <QtCore/qfunctions_winrt.h>
 #include <private/qabstracteventdispatcher_p.h>
 #include <private/qcoreapplication_p.h>
@@ -293,6 +295,26 @@ HRESULT QEventDispatcherWinRT::runOnXamlThread(const std::function<HRESULT ()> &
     return QWinRTFunctions::await(op);
 }
 
+HRESULT QEventDispatcherWinRT::runOnMainThread(const std::function<HRESULT()> &delegate, int timeout)
+{
+    if (QThread::currentThread() == QCoreApplication::instance()->thread())
+        return delegate();
+
+    auto semaphore = QSharedPointer<QSemaphore>(new QSemaphore);
+    auto ptrSemaphore = new QSharedPointer<QSemaphore>(semaphore);
+    auto result = QSharedPointer<HRESULT>(new HRESULT);
+    auto ptrResult = new QSharedPointer<HRESULT>(result);
+
+    QMetaObject::invokeMethod(QCoreApplication::instance(), [delegate, ptrSemaphore, ptrResult]() {
+        **ptrResult = delegate();
+        delete ptrResult;
+        (*ptrSemaphore)->release();
+        delete ptrSemaphore;
+    }, nullptr);
+
+    return semaphore->tryAcquire(1, timeout) ? *result : E_FAIL;
+}
+
 bool QEventDispatcherWinRT::processEvents(QEventLoop::ProcessEventsFlags flags)
 {
     Q_D(QEventDispatcherWinRT);