ttools: CombinationConfigKey may optionally allow null value

The null value will be used to indicate 2-axis zooming for cube surface.
Starlink · Nov 7, 2013 · f771745 · f771745
1 parent 1459ae6
commit f771745
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Showing 3 changed files with 34 additions and 14 deletions.
diff --git a/ttools/src/main/uk/ac/starlink/ttools/plot2/config/CombinationConfigKey.java b/ttools/src/main/uk/ac/starlink/ttools/plot2/config/CombinationConfigKey.java
@@ -21,6 +21,7 @@ public class CombinationConfigKey extends ConfigKey<boolean[]> {
 
     private final int nopt_;
     private final String[] optNames_;
+    private final boolean nullPermitted_;
 
     /**
      * Constructs an instance with a specified default.
@@ -29,40 +30,58 @@ public class CombinationConfigKey extends ConfigKey<boolean[]> {
      * @param   dflt  default array of selection flags
      * @param   optNames  labels for each of the options that may be selected,
      *                    same length as <code>dflt</code>
+     * @param   nullPermitted  true iff null is an acceptable value for
+     *                         this key
      */
     public CombinationConfigKey( ConfigMeta meta, boolean[] dflt,
-                                 String[] optNames ) {
+                                 String[] optNames, boolean nullPermitted ) {
         super( meta, boolean[].class, dflt );
         optNames_ = optNames;
+        nullPermitted_ = nullPermitted;
         nopt_ = optNames.length;
-        if ( dflt.length != nopt_ ) {
-            throw new IllegalArgumentException( "Array length mismatch" );
+        if ( dflt == null ) {
+            if ( ! nullPermitted ) {
+                throw new NullPointerException();
+            }
+        }
+        else {
+            if ( dflt.length != nopt_ ) {
+                throw new IllegalArgumentException( "Array length mismatch" );
+            }
         }
     }
 
     /**
-     * Constructs an instance where all the default inclusion flags are true.
+     * Constructs an instance where all the default inclusion flags are true
+     * and a null value is not permitted.
      *
      * @param   meta  metadata
      * @param   optNames  labels for each of the options that may be selected,
      */
     public CombinationConfigKey( ConfigMeta meta, String[] optNames ) {
-        this( meta, createTrueArray( optNames.length ), optNames );
+        this( meta, createTrueArray( optNames.length ), optNames, false );
     }
 
     public boolean[] stringToValue( String txt ) throws ConfigException {
-        boolean[] value = new boolean[ nopt_ ];
-        for ( int ic = 0; ic < txt.length(); ic++ ) {
-            value[ optCharToIndex( txt.charAt( ic ) ) ] = true;
+        if ( nullPermitted_ && ( txt == null || txt.trim().length() == 0 ) ) {
+            return null;
+        }
+        else {
+            boolean[] value = new boolean[ nopt_ ];
+            for ( int ic = 0; ic < txt.length(); ic++ ) {
+                value[ optCharToIndex( txt.charAt( ic ) ) ] = true;
+            }
+            return value;
         }
-        return value;
     }
 
     public String valueToString( boolean[] opts ) {
         StringBuffer sbuf = new StringBuffer();
-        for ( int io = 0; io < nopt_; io++ ) {
-            if ( opts[ io ] ) {
-                sbuf.append( optIndexToChar( io ) );
+        if ( opts != null ) {
+            for ( int io = 0; io < nopt_; io++ ) {
+                if ( opts[ io ] ) {
+                    sbuf.append( optIndexToChar( io ) );
+                }
             }
         }
         return sbuf.toString();

diff --git a/ttools/src/main/uk/ac/starlink/ttools/plot2/geom/CubeNavigator.java b/ttools/src/main/uk/ac/starlink/ttools/plot2/geom/CubeNavigator.java
@@ -30,7 +30,8 @@ public class CubeNavigator implements Navigator<CubeAspect> {
     /** Config key to select which axes zoom will operate on. */
     public static final ConfigKey<boolean[]> ZOOMAXES_KEY =
         new CombinationConfigKey( new ConfigMeta( "zoomaxes", "Zoom Axes" ),
-                                  new String[] { "X", "Y", "Z" } );
+                                  new boolean[] { true, true, true },
+                                  new String[] { "X", "Y", "Z" }, true );
 
     /**
      * Constructor.

diff --git a/ttools/src/main/uk/ac/starlink/ttools/plot2/geom/TimeNavigator.java b/ttools/src/main/uk/ac/starlink/ttools/plot2/geom/TimeNavigator.java
@@ -130,7 +130,7 @@ private static class AxisCombinationConfigKey extends CombinationConfigKey {
         AxisCombinationConfigKey( ConfigMeta meta,
                                   boolean tDflt, boolean yDflt) {
             super( meta, new boolean[] { tDflt, yDflt },
-                   new String[] { "Time", "Y" } );
+                   new String[] { "Time", "Y" }, false );
         }
 
         /**