Android: check for exceptions in some camera operations.

Not all camera operations are documented to raise exceptions, but they
actually might do so depending on the hardware/drivers.
Check for exceptions in all functions that could porentially fail
and react appropriately.

Task-number: QTBUG-49134
Change-Id: I633ca7f2e3aeb6532e1c445735e62135f52cf25f
Reviewed-by: Christian Stromme <christian.stromme@theqtcompany.com>

src/plugins/android/src/mediacapture/qandroidcamerasession.cpp

@@ -214,6 +214,8 @@ bool QAndroidCameraSession::open()
         connect(m_camera, SIGNAL(pictureCaptured(QByteArray)), this, SLOT(onCameraPictureCaptured(QByteArray)));
         connect(m_camera, SIGNAL(previewStarted()), this, SLOT(onCameraPreviewStarted()));
         connect(m_camera, SIGNAL(previewStopped()), this, SLOT(onCameraPreviewStopped()));
+        connect(m_camera, &AndroidCamera::previewFailedToStart, this, &QAndroidCameraSession::onCameraPreviewFailedToStart);
+        connect(m_camera, &AndroidCamera::takePictureFailed, this, &QAndroidCameraSession::onCameraTakePictureFailed);
 
         m_nativeOrientation = m_camera->getNativeOrientation();
 
@@ -554,6 +556,12 @@ void QAndroidCameraSession::cancelCapture()
     m_captureCanceled = true;
 }
 
+void QAndroidCameraSession::onCameraTakePictureFailed()
+{
+    emit imageCaptureError(m_currentImageCaptureId, QCameraImageCapture::ResourceError,
+                           tr("Failed to capture image"));
+}
+
 void QAndroidCameraSession::onCameraPictureExposed()
 {
     if (m_captureCanceled)
@@ -646,6 +654,27 @@ void QAndroidCameraSession::onCameraPreviewStarted()
     setReadyForCapture(true);
 }
 
+void QAndroidCameraSession::onCameraPreviewFailedToStart()
+{
+    if (m_status == QCamera::StartingStatus) {
+        Q_EMIT error(QCamera::CameraError, tr("Camera preview failed to start."));
+
+        AndroidMultimediaUtils::enableOrientationListener(false);
+        m_camera->setPreviewSize(QSize());
+        m_camera->setPreviewTexture(0);
+        if (m_videoOutput) {
+            m_videoOutput->stop();
+            m_videoOutput->reset();
+        }
+        m_previewStarted = false;
+
+        m_status = QCamera::LoadedStatus;
+        emit statusChanged(m_status);
+
+        setReadyForCapture(false);
+    }
+}
+
 void QAndroidCameraSession::onCameraPreviewStopped()
 {
     if (m_status == QCamera::StoppingStatus) {

src/plugins/android/src/mediacapture/qandroidcamerasession.h

@@ -112,11 +112,13 @@ private Q_SLOTS:
 
     void onApplicationStateChanged(Qt::ApplicationState state);
 
+    void onCameraTakePictureFailed();
     void onCameraPictureExposed();
     void onCameraPictureCaptured(const QByteArray &data);
     void onLastPreviewFrameFetched(const QByteArray &preview, int width, int height);
     void onNewPreviewFrame(const QByteArray &frame, int width, int height);
     void onCameraPreviewStarted();
+    void onCameraPreviewFailedToStart();
     void onCameraPreviewStopped();
 
 private:

src/plugins/android/src/wrappers/jni/androidcamera.cpp

@@ -224,12 +224,15 @@ public:
 Q_SIGNALS:
     void previewSizeChanged();
     void previewStarted();
+    void previewFailedToStart();
     void previewStopped();
 
     void autoFocusStarted();
 
     void whiteBalanceChanged();
 
+    void takePictureFailed();
+
     void lastPreviewFrameFetched(const QByteArray &preview, int width, int height);
 };
 
@@ -245,9 +248,11 @@ AndroidCamera::AndroidCamera(AndroidCameraPrivate *d, QThread *worker)
 
     connect(d, &AndroidCameraPrivate::previewSizeChanged, this, &AndroidCamera::previewSizeChanged);
     connect(d, &AndroidCameraPrivate::previewStarted, this, &AndroidCamera::previewStarted);
+    connect(d, &AndroidCameraPrivate::previewFailedToStart, this, &AndroidCamera::previewFailedToStart);
     connect(d, &AndroidCameraPrivate::previewStopped, this, &AndroidCamera::previewStopped);
     connect(d, &AndroidCameraPrivate::autoFocusStarted, this, &AndroidCamera::autoFocusStarted);
     connect(d, &AndroidCameraPrivate::whiteBalanceChanged, this, &AndroidCamera::whiteBalanceChanged);
+    connect(d, &AndroidCameraPrivate::takePictureFailed, this, &AndroidCamera::takePictureFailed);
     connect(d, &AndroidCameraPrivate::lastPreviewFrameFetched, this, &AndroidCamera::lastPreviewFrameFetched);
 }
 
@@ -1057,15 +1062,21 @@ void AndroidCameraPrivate::setFocusAreas(const QList<QRect> &areas)
 
 void AndroidCameraPrivate::autoFocus()
 {
+    QJNIEnvironmentPrivate env;
+
     m_camera.callMethod<void>("autoFocus",
                               "(Landroid/hardware/Camera$AutoFocusCallback;)V",
                               m_cameraListener.object());
-    emit autoFocusStarted();
+
+    if (!exceptionCheckAndClear(env))
+        emit autoFocusStarted();
 }
 
 void AndroidCameraPrivate::cancelAutoFocus()
 {
+    QJNIEnvironmentPrivate env;
     m_camera.callMethod<void>("cancelAutoFocus");
+    exceptionCheckAndClear(env);
 }
 
 bool AndroidCameraPrivate::isAutoExposureLockSupported()
@@ -1314,25 +1325,40 @@ void AndroidCameraPrivate::setJpegQuality(int quality)
 
 void AndroidCameraPrivate::startPreview()
 {
+    QJNIEnvironmentPrivate env;
+
     setupPreviewFrameCallback();
     m_camera.callMethod<void>("startPreview");
-    emit previewStarted();
+
+    if (exceptionCheckAndClear(env))
+        emit previewFailedToStart();
+    else
+        emit previewStarted();
 }
 
 void AndroidCameraPrivate::stopPreview()
 {
+    QJNIEnvironmentPrivate env;
+
     m_camera.callMethod<void>("stopPreview");
+
+    exceptionCheckAndClear(env);
     emit previewStopped();
 }
 
 void AndroidCameraPrivate::takePicture()
 {
+    QJNIEnvironmentPrivate env;
+
     m_camera.callMethod<void>("takePicture", "(Landroid/hardware/Camera$ShutterCallback;"
                                              "Landroid/hardware/Camera$PictureCallback;"
                                              "Landroid/hardware/Camera$PictureCallback;)V",
                                               m_cameraListener.object(),
                                               jobject(0),
                                               m_cameraListener.object());
+
+    if (exceptionCheckAndClear(env))
+        emit takePictureFailed();
 }
 
 void AndroidCameraPrivate::setupPreviewFrameCallback()

src/plugins/android/src/wrappers/jni/androidcamera.h

@@ -168,6 +168,7 @@ public:
 Q_SIGNALS:
     void previewSizeChanged();
     void previewStarted();
+    void previewFailedToStart();
     void previewStopped();
 
     void autoFocusStarted();
@@ -175,6 +176,7 @@ Q_SIGNALS:
 
     void whiteBalanceChanged();
 
+    void takePictureFailed();
     void pictureExposed();
     void pictureCaptured(const QByteArray &data);
     void lastPreviewFrameFetched(const QByteArray &preview, int width, int height);