Reset the measure value after change the scope param

DSView/pv/data/analogsnapshot.cpp

@@ -76,6 +76,7 @@ void AnalogSnapshot::init_all()
     _ring_sample_count = 0;
     _memory_failed = false;
     _last_ended = true;
+
     for (unsigned int i = 0; i < _channel_num; i++) {
         for (unsigned int level = 0; level < ScaleStepCount; level++) {
             _envelope_levels[i][level].length = 0;
@@ -103,7 +104,6 @@ void AnalogSnapshot::clear()
     free_data();
     free_envelop();
     init_all();
-    _have_data = false;
 }
 
 void AnalogSnapshot::first_payload(const sr_datafeed_analog &analog, uint64_t total_sample_count, GSList *channels)
@@ -179,8 +179,6 @@ void AnalogSnapshot::append_payload(
 	// Generate the first mip-map from the data
     if (analog.num_samples != 0) // guarantee new samples to compute
         append_payload_to_envelope_levels();
-
-    _have_data = true;
 }
 
 void AnalogSnapshot::append_data(void *data, uint64_t samples, uint16_t pitch)

DSView/pv/data/dsosnapshot.cpp

@@ -99,7 +99,6 @@ void DsoSnapshot::clear()
     free_data();
     free_envelop();
     init_all();
-    _have_data  = false;
     _envelope_en = false;
 }
 
@@ -224,8 +223,6 @@ void DsoSnapshot::append_payload(const sr_datafeed_dso &dso)
         // Generate the first mip-map from the data
         if (_envelope_en)
             append_payload_to_envelope_levels(dso.samplerate_tog);
-
-        _have_data = true;
     }
 }
 

DSView/pv/data/logicsnapshot.cpp

@@ -109,7 +109,6 @@ void LogicSnapshot::clear()
     std::lock_guard<std::mutex> lock(_mutex);
     free_data();
     init_all();
-    _have_data = false;
 }
 
 void LogicSnapshot::first_payload(const sr_datafeed_logic &logic, uint64_t total_sample_count, GSList *channels, bool able_free)
@@ -202,8 +201,6 @@ void LogicSnapshot::append_payload(const sr_datafeed_logic &logic)
     std::lock_guard<std::mutex> lock(_mutex);
 
     append_cross_payload(logic);
-
-    _have_data = true;
 }
 
 void LogicSnapshot::append_cross_payload(const sr_datafeed_logic &logic)

DSView/pv/data/snapshot.cpp

@@ -43,7 +43,6 @@ Snapshot::Snapshot(int unit_size, uint64_t total_sample_count, unsigned int chan
     _last_ended = true;
     _unit_bytes = 1;
     _unit_pitch = 0;
-    _have_data = false;
 }
 
 Snapshot::~Snapshot()

DSView/pv/data/snapshot.h

@@ -67,7 +67,7 @@ public:
     }
 
     inline bool have_data(){
-        return _have_data;
+        return !empty();
     }
 
     inline double samplerate(){
@@ -106,7 +106,6 @@ protected:
     uint16_t    _unit_pitch;
     bool        _memory_failed;
     bool        _last_ended;
-    bool        _have_data;
     double      _samplerate;
 };
 

DSView/pv/view/dsosignal.cpp

@@ -521,6 +521,10 @@ QString DsoSignal::get_measure(enum DSO_MEASURE_TYPE type)
     const QString mNone = "--";
     QString mString;
 
+    if (_data->empty()){
+        return mNone;
+    }
+
     if (_mValid) {
         const int hw_offset = get_hw_offset();