ucar.nc2.dataset.EnhancementsImpl Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of cdm Show documentation
The newest version!
/*
 * Copyright (c) 1998-2018 John Caron and University Corporation for Atmospheric Research/Unidata
 * See LICENSE for license information.
 */
package ucar.nc2.dataset;

import ucar.nc2.*;
import ucar.nc2.constants.CDM;
import ucar.nc2.constants.CF;

import java.util.*;

/**
 * Implementation of Enhancements for coordinate systems and standard attribute handling.
 * Factored out so that it can be used as a 'mixin' in VariablesDS and StructureDS.
 * 
 * @author caron
 */
class EnhancementsImpl implements Enhancements {
  private Variable forVar;
  private String desc, units;
  private List coordSys; // dont allocate unless its used

  /**
   * Constructor when there's no underlying, existing Variable.
   * You can access units, description and coordSys.
   * All missing and scale/offset flags are false.
   * @param forVar the Variable to decorate.
   * @param units set unit string.
   * @param desc set description.
   */
  EnhancementsImpl( Variable forVar, String units, String desc) {
    this.forVar = forVar;
    this.units = units;
    this.desc = desc;
  }

  /**
   * Constructor.
   * @param forVar the Variable to decorate.
   */
  EnhancementsImpl( Variable forVar) {
    this.forVar = forVar;
  }

  /**
   * Get the list of Coordinate Systems for this variable.
   * Normally this is empty unless you use ucar.nc2.dataset.NetcdfDataset.
   * @return list of type ucar.nc2.dataset.CoordinateSystem; may be empty not null.
   */
  public List getCoordinateSystems() {
    return (coordSys == null) ? new ArrayList<>(0) : coordSys;
  }

  /** Add a CoordinateSystem to the dataset. */
  public void addCoordinateSystem( CoordinateSystem cs){
    if (cs == null)
      throw new RuntimeException("Attempted to add null CoordinateSystem to var " + forVar.getFullName());

    if (coordSys == null) coordSys = new ArrayList<>(5);
    coordSys.add(cs);
  }

  public void removeCoordinateSystem(ucar.nc2.dataset.CoordinateSystem p0) {
    if (coordSys != null)
      coordSys.remove( p0);
  }

  /** Set the Description for this Variable.
   * @param desc description
   */
  public void setDescription(String desc) { this.desc = desc; }

  /** Get the description of the Variable.
   *  Default is to look for attributes in this order: CDM.LONG_NAME, "description", "title", "standard_name".
   */
  public String getDescription() {
    if ((desc == null) && (forVar != null)) {
      Attribute att = forVar.findAttributeIgnoreCase( CDM.LONG_NAME);
      if ((att != null) && att.isString())
        desc = att.getStringValue();

      if (desc == null) {
        att = forVar.findAttributeIgnoreCase( "description");
        if ((att != null) && att.isString())
          desc = att.getStringValue();
      }

      if (desc == null) {
        att = forVar.findAttributeIgnoreCase( CDM.TITLE);
        if ((att != null) && att.isString())
          desc = att.getStringValue();
      }

      if (desc == null) {
        att = forVar.findAttributeIgnoreCase(CF.STANDARD_NAME);
        if ((att != null) && att.isString())
          desc = att.getStringValue();
      }
    }
    return (desc == null) ? null : desc.trim();
  }

  /** Set the Unit String for this Variable. Default is to use the CDM.UNITS attribute.
   * @param units  unit string
   */
  public void setUnitsString( String units) {
    this.units = units;
    forVar.addAttribute( new Attribute(CDM.UNITS, units));
  }

  /**
   * Get the Unit String for the Variable. May be set explicitly, else look for attribute CDM.UNITS.
   * @return the Unit String for the Variable, or null if none.
   */
  public String getUnitsString() {
    String result = units;
    if ((result == null) && (forVar != null)) {
      Attribute att = forVar.findAttribute( CDM.UNITS);
      if (att == null) att = forVar.findAttributeIgnoreCase( CDM.UNITS);
      if ((att != null) && att.isString())
        result = att.getStringValue();
    }
    return (result == null) ? null : result.trim();
  }
}