New camera viewfinder settings API.

There already was a control interface for the viewfinder settings
but no real public C++ API and a partial QML API.

This patch adds a new C++ API and improves the QML API.

Supported viewfinder settings are resolution, minimumFrameRate,
maximumFrameRate and pixelFormat. The camera can be queried for
the supported values for each of these settings.

A new control interface was created to match the new API.

Change-Id: I289fea038fe46277a5516c956a64280da09ed985
Reviewed-by: Andrew den Exter <andrew.den.exter@qinetic.com.au>

1 files changed, 34 insertions, 26 deletions

diff --git a/src/imports/multimedia/qdeclarativecameraviewfinder.cpp b/src/imports/multimedia/qdeclarativecameraviewfinder.cpp
index 66d4e1bbc..abb0b6290 100644
--- a/src/imports/multimedia/qdeclarativecameraviewfinder.cpp
+++ b/src/imports/multimedia/qdeclarativecameraviewfinder.cpp
@@ -42,68 +42,76 @@ QT_BEGIN_NAMESPACE
 QDeclarativeCameraViewfinder::QDeclarativeCameraViewfinder(QCamera *camera, QObject *parent)
     : QObject(parent)
     , m_camera(camera)
-    , m_control(0)
 {
-    if (QMediaService *service = m_camera->service())
-        m_control = service->requestControl<QCameraViewfinderSettingsControl *>();
+    connect(m_camera, &QCamera::statusChanged,
+            this, &QDeclarativeCameraViewfinder::_q_cameraStatusChanged);
 }
 
 QDeclarativeCameraViewfinder::~QDeclarativeCameraViewfinder()
 {
-    if (m_control) {
-        if (QMediaService *service = m_camera->service())
-            service->releaseControl(m_control);
-    }
 }
 
 QSize QDeclarativeCameraViewfinder::resolution() const
 {
-    return m_control
-            ? m_control->viewfinderParameter(QCameraViewfinderSettingsControl::Resolution).value<QSize>()
-            : QSize();
+    return m_settings.resolution();
 }
 
-void QDeclarativeCameraViewfinder::setResolution(const QSize &resolution)
+void QDeclarativeCameraViewfinder::setResolution(const QSize &res)
 {
-    if (m_control) {
-        m_control->setViewfinderParameter(
-                    QCameraViewfinderSettingsControl::Resolution, resolution);
+    if (res != m_settings.resolution()) {
+        m_settings = m_camera->viewfinderSettings();
+        m_settings.setResolution(res);
+        m_camera->setViewfinderSettings(m_settings);
         emit resolutionChanged();
     }
 }
 
 qreal QDeclarativeCameraViewfinder::minimumFrameRate() const
 {
-    return m_control
-            ? m_control->viewfinderParameter(QCameraViewfinderSettingsControl::MinimumFrameRate).value<qreal>()
-            : 0.0;
+    return m_settings.minimumFrameRate();
 }
 
 void QDeclarativeCameraViewfinder::setMinimumFrameRate(qreal frameRate)
 {
-    if (m_control) {
-        m_control->setViewfinderParameter(
-                    QCameraViewfinderSettingsControl::MinimumFrameRate, frameRate);
+    if (frameRate != minimumFrameRate()) {
+        m_settings = m_camera->viewfinderSettings();
+        m_settings.setMinimumFrameRate(frameRate);
+        m_camera->setViewfinderSettings(m_settings);
         emit minimumFrameRateChanged();
     }
 }
 
 qreal QDeclarativeCameraViewfinder::maximumFrameRate() const
 {
-    return m_control
-            ? m_control->viewfinderParameter(QCameraViewfinderSettingsControl::MaximumFrameRate).value<qreal>()
-            : 0.0;
+    return m_settings.maximumFrameRate();
 }
 
 void QDeclarativeCameraViewfinder::setMaximumFrameRate(qreal frameRate)
 {
-    if (m_control) {
-        m_control->setViewfinderParameter(
-                    QCameraViewfinderSettingsControl::MaximumFrameRate, frameRate);
+    if (frameRate != maximumFrameRate()) {
+        m_settings = m_camera->viewfinderSettings();
+        m_settings.setMaximumFrameRate(frameRate);
+        m_camera->setViewfinderSettings(m_settings);
         emit maximumFrameRateChanged();
     }
 }
 
+void QDeclarativeCameraViewfinder::_q_cameraStatusChanged(QCamera::Status status)
+{
+    // Settings values might change when the camera starts, for example if the settings are
+    // undefined, if unsupported values were set or if the settings conflict with capture settings.
+    if (status == QCamera::ActiveStatus) {
+        QCameraViewfinderSettings oldSettings = m_settings;
+        m_settings = m_camera->viewfinderSettings();
+        if (oldSettings.resolution() != m_settings.resolution())
+            emit resolutionChanged();
+        if (oldSettings.minimumFrameRate() != m_settings.minimumFrameRate())
+            emit minimumFrameRateChanged();
+        if (oldSettings.maximumFrameRate() != m_settings.maximumFrameRate())
+            emit maximumFrameRateChanged();
+    }
+}
+
 QT_END_NAMESPACE
 
 #include "moc_qdeclarativecameraviewfinder_p.cpp"