TRD display use nullptr

Author: martenole

Detectors/TRD/qc/include/TRDQC/RawDisplay.h

@@ -31,7 +31,7 @@ namespace o2::trd
 class RawDisplay
 {
  public:
-  RawDisplay(RawDataSpan& dataspan, TVirtualPad* pad = NULL);
+  RawDisplay(RawDataSpan& dataspan, TVirtualPad* pad = nullptr);
   void drawDigits(std::string opt = "colz");
   void drawTracklets();
   void drawClusters();
@@ -60,7 +60,7 @@ class RawDisplay
 class MCMDisplay : public RawDisplay
 {
  public:
-  MCMDisplay(RawDataSpan& mcmdata, TVirtualPad* pad = NULL);
+  MCMDisplay(RawDataSpan& mcmdata, TVirtualPad* pad = nullptr);
 };
 
 } // namespace o2::trd

Detectors/TRD/qc/src/RawDisplay.cxx

@@ -79,7 +79,7 @@ MCMDisplay::MCMDisplay(RawDataSpan& mcmdata, TVirtualPad* pad)
   mFirstPad = mcmcol * constants::NCOLMCM - 1;
   mLastPad = (mcmcol + 1) * constants::NCOLMCM + 2;
 
-  if (pad == NULL) {
+  if (pad == nullptr) {
     mPad = new TCanvas(mName.c_str(), mDesc.c_str(), 800, 600);
   } else {
     mPad = pad;