#14524 Histogram: Start a user-defined bin range at the data range

Initialize the min and max cutoffs to the data range of the selected result
when the bin range mode is set to User Defined. The previous fixed default of
[0..1] excluded most values for results like PERMX.

The data range is computed by the same statistics query as the histogram,
respecting the selected time step and an active visible-cells filter, but
without custom binning so min and max are the range of the data.

ApplicationLibCode/ProjectDataModel/Histogram/RimHistogramDataSource.cpp

@@ -109,6 +109,14 @@ void RimHistogramDataSource::resetBinRange()
     m_binRangeMax  = m_binRangeMax.defaultValue();
 }
 
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+std::optional<std::pair<double, double>> RimHistogramDataSource::dataRange() const
+{
+    return std::nullopt;
+}
+
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------
@@ -142,6 +150,16 @@ void RimHistogramDataSource::fieldChangedByUi( const caf::PdmFieldHandle* change
     {
         resetBinRange();
     }
+
+    // Start a user-defined range at the data range: the default [0..1] could exclude most values
+    if ( changedField == &m_binRangeMode && m_binRangeMode() == BinRangeMode::USER_DEFINED )
+    {
+        if ( auto range = dataRange() )
+        {
+            m_binRangeMin = range->first;
+            m_binRangeMax = range->second;
+        }
+    }
 }
 
 //--------------------------------------------------------------------------------------------------