From c0319d1cfb056c2e26f436357cdfdb3bdecd10f0 Mon Sep 17 00:00:00 2001
From: Maurice Kalinowski <maurice.kalinowski@qt.io>
Date: Fri, 20 May 2016 14:21:42 +0200
Subject: winrt: focus action has to happen in the xaml thread

Otherwise it will cause asserts and/or crashes.

Change-Id: If8af4202395ae573b280744343dd853346a8c160
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>
---
 src/plugins/winrt/qwinrtcameracontrol.cpp | 90 +++++++++++++++++--------------
 1 file changed, 51 insertions(+), 39 deletions(-)

diff --git a/src/plugins/winrt/qwinrtcameracontrol.cpp b/src/plugins/winrt/qwinrtcameracontrol.cpp
index 5c41987a0..cc80c0e7d 100644
--- a/src/plugins/winrt/qwinrtcameracontrol.cpp
+++ b/src/plugins/winrt/qwinrtcameracontrol.cpp
@@ -1121,46 +1121,54 @@ bool QWinRTCameraControl::setFocus(QCameraFocus::FocusModes modes)
     if (d->status == QCamera::UnloadedStatus)
         return false;
 
-    ComPtr<IFocusSettings> focusSettings;
-    ComPtr<IInspectable> focusSettingsObject;
-    HRESULT hr = RoActivateInstance(HString::MakeReference(RuntimeClass_Windows_Media_Devices_FocusSettings).Get(), &focusSettingsObject);
-    Q_ASSERT_SUCCEEDED(hr);
-    hr = focusSettingsObject.As(&focusSettings);
-    Q_ASSERT_SUCCEEDED(hr);
-    FocusMode mode;
-    if (modes.testFlag(QCameraFocus::ContinuousFocus)) {
-        mode = FocusMode_Continuous;
-    } else if (modes.testFlag(QCameraFocus::AutoFocus)
-               || modes.testFlag(QCameraFocus::MacroFocus)
-               || modes.testFlag(QCameraFocus::InfinityFocus)) {
-        // The Macro and infinity focus modes are only supported in auto focus mode on WinRT.
-        // QML camera focus doesn't support combined focus flags settings. In the case of macro
-        // and infinity Focus modes, the auto focus setting is applied.
-        mode = FocusMode_Single;
-    } else {
-        emit error(QCamera::NotSupportedFeatureError, QStringLiteral("Unsupported camera focus modes."));
-        return false;
-    }
-    hr = focusSettings->put_Mode(mode);
-    Q_ASSERT_SUCCEEDED(hr);
-    AutoFocusRange range = AutoFocusRange_Normal;
-    if (modes.testFlag(QCameraFocus::MacroFocus))
-        range = AutoFocusRange_Macro;
-    else if (modes.testFlag(QCameraFocus::InfinityFocus))
-        range = AutoFocusRange_FullRange;
-    hr = focusSettings->put_AutoFocusRange(range);
-    Q_ASSERT_SUCCEEDED(hr);
-    hr = focusSettings->put_WaitForFocus(true);
-    Q_ASSERT_SUCCEEDED(hr);
-    hr = focusSettings->put_DisableDriverFallback(false);
-    Q_ASSERT_SUCCEEDED(hr);
+    bool result = false;
+    HRESULT hr = QEventDispatcherWinRT::runOnXamlThread([modes, &result, d, this]() {
+        ComPtr<IFocusSettings> focusSettings;
+        ComPtr<IInspectable> focusSettingsObject;
+        HRESULT hr = RoActivateInstance(HString::MakeReference(RuntimeClass_Windows_Media_Devices_FocusSettings).Get(), &focusSettingsObject);
+        Q_ASSERT_SUCCEEDED(hr);
+        hr = focusSettingsObject.As(&focusSettings);
+        Q_ASSERT_SUCCEEDED(hr);
+        FocusMode mode;
+        if (modes.testFlag(QCameraFocus::ContinuousFocus)) {
+            mode = FocusMode_Continuous;
+        } else if (modes.testFlag(QCameraFocus::AutoFocus)
+                   || modes.testFlag(QCameraFocus::MacroFocus)
+                   || modes.testFlag(QCameraFocus::InfinityFocus)) {
+            // The Macro and infinity focus modes are only supported in auto focus mode on WinRT.
+            // QML camera focus doesn't support combined focus flags settings. In the case of macro
+            // and infinity Focus modes, the auto focus setting is applied.
+            mode = FocusMode_Single;
+        } else {
+            emit error(QCamera::NotSupportedFeatureError, QStringLiteral("Unsupported camera focus modes."));
+            result = false;
+            return S_OK;
+        }
+        hr = focusSettings->put_Mode(mode);
+        Q_ASSERT_SUCCEEDED(hr);
+        AutoFocusRange range = AutoFocusRange_Normal;
+        if (modes.testFlag(QCameraFocus::MacroFocus))
+            range = AutoFocusRange_Macro;
+        else if (modes.testFlag(QCameraFocus::InfinityFocus))
+            range = AutoFocusRange_FullRange;
+        hr = focusSettings->put_AutoFocusRange(range);
+        Q_ASSERT_SUCCEEDED(hr);
+        hr = focusSettings->put_WaitForFocus(true);
+        Q_ASSERT_SUCCEEDED(hr);
+        hr = focusSettings->put_DisableDriverFallback(false);
+        Q_ASSERT_SUCCEEDED(hr);
 
-    ComPtr<IFocusControl2> focusControl2;
-    hr = d->focusControl.As(&focusControl2);
+        ComPtr<IFocusControl2> focusControl2;
+        hr = d->focusControl.As(&focusControl2);
+        Q_ASSERT_SUCCEEDED(hr);
+        hr = focusControl2->Configure(focusSettings.Get());
+        result = SUCCEEDED(hr);
+        RETURN_OK_IF_FAILED("Failed to configure camera focus control");
+        return S_OK;
+    });
     Q_ASSERT_SUCCEEDED(hr);
-    hr = focusControl2->Configure(focusSettings.Get());
-    RETURN_FALSE_IF_FAILED("Failed to configure camera focus control");
-    return true;
+    Q_UNUSED(hr); // Silence release build
+    return result;
 }
 
 bool QWinRTCameraControl::setFocusPoint(const QPointF &focusPoint)
@@ -1224,7 +1232,11 @@ bool QWinRTCameraControl::focus()
     if (!d->focusControl || status == AsyncStatus::Started)
         return false;
 
-    hr = d->focusControl->FocusAsync(&d->focusOperation);
+    QEventDispatcherWinRT::runOnXamlThread([&d, &hr]() {
+        hr = d->focusControl->FocusAsync(&d->focusOperation);
+        Q_ASSERT_SUCCEEDED(hr);
+        return S_OK;
+    });
     const long errorCode = HRESULT_CODE(hr);
     if (errorCode == ERROR_OPERATION_IN_PROGRESS
         || errorCode == ERROR_WRITE_PROTECT) {
-- 
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