From a87e00e13654c1b3bcfd367142e69cfa29ca1a5f Mon Sep 17 00:00:00 2001
From: tstellanova <tstellanova+github@gmail.com>
Date: Thu, 22 Aug 2013 14:56:01 -0700
Subject: [PATCH] use a real component ID when we know what it is

---
 src/uas/QGCUASParamManager.cc | 33 ++++++++++++++++++++++++++++++++-
 src/uas/QGCUASParamManager.h  |  4 ++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/src/uas/QGCUASParamManager.cc b/src/uas/QGCUASParamManager.cc
index 788a227c2..1a967e79d 100644
--- a/src/uas/QGCUASParamManager.cc
+++ b/src/uas/QGCUASParamManager.cc
@@ -11,7 +11,8 @@ QGCUASParamManager::QGCUASParamManager(QObject *parent) :
     QObject(parent),
     mav(NULL),
     paramDataModel(this),
-    paramCommsMgr(NULL)
+    paramCommsMgr(NULL),
+    defaultComponentId(-1)
 {
 
 
@@ -57,6 +58,27 @@ void QGCUASParamManager::clearAllPendingParams()
     paramDataModel.clearAllPendingParams();
 }
 
+
+int QGCUASParamManager::getDefaultComponentId()
+{
+    int result = 0;
+
+    if (-1 != defaultComponentId)
+        return defaultComponentId;
+
+    QList<int> components = getComponentForParam("SYS_AUTOSTART");//TODO is this the best way to find the right component?
+
+    // Guard against multiple components responding - this will never show in practice
+    if (1 == components.count()) {
+        result = components.first();
+        defaultComponentId = result;
+    }
+
+    qDebug() << "Default compId: " << result;
+
+    return result;
+}
+
 QList<int> QGCUASParamManager::getComponentForParam(const QString& parameter) const
 {
     return paramDataModel.getComponentForOnboardParam(parameter);
@@ -95,6 +117,7 @@ void QGCUASParamManager::requestParameterListIfEmpty()
     if (mav) {
         int totalOnboard = paramDataModel.countOnboardParams();
         if (totalOnboard < 2) { //TODO arbitrary constant, maybe 0 is OK?
+            defaultComponentId = -1; //reset this ...we have no idea what the default component ID is
             requestParameterList();
         }
     }
@@ -108,6 +131,10 @@ void QGCUASParamManager::setParamDescriptions(const QMap<QString,QString>& param
 
 void QGCUASParamManager::setParameter(int compId, QString paramName, QVariant value)
 {
+    if ((0 == compId) || (-1 == compId)) {
+        //attempt to get an actual component ID
+        compId = getDefaultComponentId();
+    }
     paramDataModel.updatePendingParamWithValue(compId,paramName,value);
 }
 
@@ -121,6 +148,10 @@ void QGCUASParamManager::sendPendingParameters(bool persistAfterSend)
 
 void QGCUASParamManager::setPendingParam(int compId,  const QString& paramName,  const QVariant& value)
 {
+    if ((0 == compId) || (-1 == compId)) {
+        //attempt to get an actual component ID
+        compId = getDefaultComponentId();
+    }
     paramDataModel.updatePendingParamWithValue(compId,paramName,value);
 }
 
diff --git a/src/uas/QGCUASParamManager.h b/src/uas/QGCUASParamManager.h
index 6866b2b95..2c31136e2 100644
--- a/src/uas/QGCUASParamManager.h
+++ b/src/uas/QGCUASParamManager.h
@@ -23,6 +23,9 @@ public:
     /** @brief Get the known, confirmed value of a parameter */
     virtual bool getParameterValue(int component, const QString& parameter, QVariant& value) const;
 
+    /** @brief determine which component is the root component for the UAS and return its ID or 0 if unknown */
+    virtual int getDefaultComponentId();
+
     /**
      * @brief Get a list of all component IDs using this parameter name
      * @param parameter The string encoding the parameter name
@@ -122,6 +125,7 @@ protected:
     UASInterface*           mav;   ///< The MAV this manager is controlling
     UASParameterDataModel  paramDataModel;///< Shared data model of parameters
     UASParameterCommsMgr*   paramCommsMgr; ///< Shared comms mgr for parameters
+    int             defaultComponentId; ///< Cached default component ID
 
 };
 
-- 
2.22.0