[hist] reset kAxisRange bit when fully unzooming (root-project#18226)

When unzoom with mouse wheel, properly reset kAxisRange bit.
Adjust documentation

Author: ferdymercury

graf2d/gpad/src/TPad.cxx

@@ -2371,6 +2371,7 @@ void TPad::ExecuteEventAxis(Int_t event, Int_t px, Int_t py, TAxis *axis)
    Int_t nbd, inc, bin1, bin2, first, last;
    Double_t temp, xmin,xmax;
    Bool_t opaque  = gPad->OpaqueMoving();
+   bool resetAxisRange = false;
    static std::unique_ptr<TBox> zoombox;
    Double_t zbx1=0,zbx2=0,zby1=0,zby2=0;
 
@@ -2524,8 +2525,12 @@ void TPad::ExecuteEventAxis(Int_t event, Int_t px, Int_t py, TAxis *axis)
       bin2 = axis->GetLast()+inc;
       bin1 = TMath::Max(bin1, 1);
       bin2 = TMath::Min(bin2, axis->GetNbins());
+      resetAxisRange = (bin1 == 1 && axis->GetFirst() == 1 && bin2 == axis->GetNbins() && axis->GetLast() == axis->GetNbins());
       if (bin2>bin1) {
          axis->SetRange(bin1,bin2);
+      }
+      if (resetAxisRange) axis->ResetBit(TAxis::kAxisRange);
+      if (bin2>bin1) {
          gPad->Modified();
          gPad->Update();
       }

hist/hist/src/TAxis.cxx

@@ -457,7 +457,7 @@ const char *TAxis::GetBinLabel(Int_t bin) const
 ////////////////////////////////////////////////////////////////////////////////
 /// Return first bin on the axis
 /// i.e. 1 if no range defined
-/// NOTE: in some cases a zero is returned (see TAxis::SetRange)
+/// \note in some cases a zero is returned (see TAxis::SetRange)
 
 Int_t TAxis::GetFirst() const
 {
@@ -468,7 +468,7 @@ Int_t TAxis::GetFirst() const
 ////////////////////////////////////////////////////////////////////////////////
 /// Return last bin on the axis
 /// i.e. fNbins if no range defined
-/// NOTE: in some cases a zero is returned (see TAxis::SetRange)
+/// \note in some cases a zero is returned (see TAxis::SetRange)
 
 Int_t TAxis::GetLast() const
 {
@@ -1017,7 +1017,6 @@ void TAxis::ChangeLabelByValue(Double_t labValue, Double_t labAngle, Double_t la
    ml->SetText(labText);
 }
 
-
 ////////////////////////////////////////////////////////////////////////////////
 ///  Set the viewing range for the axis using bin numbers.
 ///
@@ -1061,10 +1060,8 @@ void TAxis::SetRange(Int_t first, Int_t last)
       fLast = std::min(last, nCells);
       SetBit(kAxisRange, true);
    }
-
 }
 
-
 ////////////////////////////////////////////////////////////////////////////////
 ///  Set the viewing range for the axis from `ufirst` to `ulast` (in user coordinates,
 ///  that is, the "natural" axis coordinates).

hist/histpainter/src/THistPainter.cxx

@@ -3641,12 +3641,16 @@ void THistPainter::ExecuteEvent(Int_t event, Int_t px, Int_t py)
          bin2 = xaxis->GetLast()+1;
          bin1 = TMath::Max(bin1, 1);
          bin2 = TMath::Min(bin2, xaxis->GetNbins());
+         const bool resetXaxisRange = bin1 == 1 && xaxis->GetFirst() == 1 && bin2 == xaxis->GetNbins() && xaxis->GetLast() == xaxis->GetNbins();
          if (bin2>bin1) xaxis->SetRange(bin1,bin2);
+         if (resetXaxisRange) xaxis->ResetBit(TAxis::kAxisRange);
          bin1 = yaxis->GetFirst()-1;
          bin2 = yaxis->GetLast()+1;
          bin1 = TMath::Max(bin1, 1);
          bin2 = TMath::Min(bin2, yaxis->GetNbins());
+         const bool resetYaxisRange = bin1 == 1 && yaxis->GetFirst() == 1 && bin2 == yaxis->GetNbins() && yaxis->GetLast() == yaxis->GetNbins();
          if (bin2>bin1) yaxis->SetRange(bin1,bin2);
+         if (resetYaxisRange) yaxis->ResetBit(TAxis::kAxisRange);
       }
       gPad->Modified();
       gPad->Update();