Handle capture status retries when capturing images.

Allow plugin to validate parameter setting.

src/Camera/QGCCameraControl.cc

@@ -272,6 +272,7 @@ QGCCameraControl::takePhoto()
             0,                                          // Duration between two consecutive pictures (in seconds--ignored if single image)
             1);                                         // Number of images to capture total - 0 for unlimited capture
         _setPhotoStatus(PHOTO_CAPTURE_IN_PROGRESS);
+        _captureInfoRetries = 0;
         //-- Capture local image as well
         QString photoPath = qgcApp()->toolbox()->settingsManager()->appSettings()->savePath()->rawValue().toString() + QStringLiteral("/Photo");
         QDir().mkpath(photoPath);
@@ -384,6 +385,7 @@ QGCCameraControl::formatCard(int id)
 void
 QGCCameraControl::_requestCaptureStatus()
 {
+    qCDebug(CameraControlLog) << "_requestCaptureStatus()";
     _vehicle->sendMavCommand(
         _compID,                                // target component
         MAV_CMD_REQUEST_CAMERA_CAPTURE_STATUS,  // command id
@@ -445,16 +447,23 @@ QGCCameraControl::_mavCommandResult(int vehicleId, int component, int command, i
                 qCDebug(CameraControlLog) << "Command failed for" << command;
             }
             switch(command) {
+                case MAV_CMD_IMAGE_START_CAPTURE:
+                    if(++_captureInfoRetries < 5) {
+                        _captureStatusTimer.start(1000);
+                    } else {
+                        qCDebug(CameraControlLog) << "Giving up requesting capture status";
+                    }
+                    break;
                 case MAV_CMD_REQUEST_CAMERA_CAPTURE_STATUS:
                     if(++_captureInfoRetries < 3) {
-                        _requestCaptureStatus();
+                        _captureStatusTimer.start(500);
                     } else {
                         qCDebug(CameraControlLog) << "Giving up requesting capture status";
                     }
                     break;
                 case MAV_CMD_REQUEST_STORAGE_INFORMATION:
                     if(++_storageInfoRetries < 3) {
-                        _requestStorageInfo();
+                        QTimer::singleShot(500, this, &QGCCameraControl::_requestStorageInfo);
                     } else {
                         qCDebug(CameraControlLog) << "Giving up requesting storage status";
                     }
@@ -1349,3 +1358,12 @@ QGCCameraControl::incomingParameter(Fact* pFact, QVariant& newValue)
     Q_UNUSED(newValue);
     return true;
 }
+
+//-----------------------------------------------------------------------------
+bool
+QGCCameraControl::validateParameter(Fact* pFact, QVariant& newValue)
+{
+    Q_UNUSED(pFact);
+    Q_UNUSED(newValue);
+    return true;
+}

src/Camera/QGCCameraControl.h

@@ -161,6 +161,8 @@ public:
     virtual void        factChanged         (Fact* pFact);
     //-- Allow controller to modify or invalidate incoming parameter
     virtual bool        incomingParameter   (Fact* pFact, QVariant& newValue);
+    //-- Allow controller to modify or invalidate parameter change
+    virtual bool        validateParameter   (Fact* pFact, QVariant& newValue);
 
 signals:
     void    infoChanged                     ();

src/Camera/QGCCameraIO.cc

@@ -204,7 +204,9 @@ QGCCameraParamIO::handleParamAck(const mavlink_param_ext_ack_t& ack)
         //-- If UI changed and value was not set, restore UI
         QVariant val = _valueFromMessage(ack.param_value, ack.param_type);
         if(_fact->rawValue() != val) {
-            _fact->_containerSetRawValue(val);
+            if(_control->validateParameter(_fact, val)) {
+                _fact->_containerSetRawValue(val);
+            }
         }
     }
 }