ttools: Modify the way that DataGeom works with PlotLayers.

DataGeom is now OK to use if it only has some coordinates, i.e. it
might specify a point, or a line, or a plane or whatever.
It has a new hasPosition() method to report which of these it's doing.
This means that non-point-plotting layers (such as spectrogram) can use
the DataGeom machinery to report ranges.  Users of DataGeom have to
be a bit more careful now.

Rename Plotter.getDataGeoms to getPointDataGeoms, to emphasise
that these ones must be full-point (hasPosition=true) instances.

Also add PlotLayer.extendCoordinateRanges which gives you the chance to
report non-point-like range extensions (like a spectrogram channel array).

topcat/src/main/uk/ac/starlink/topcat/plot2/CubePlotWindow.java

@@ -36,7 +36,8 @@ private static class CubePlotTypeGui
             return new CubeAxisControl( false, stack );
         }
         public PositionCoordPanel createPositionCoordPanel() {
-            return new SimplePositionCoordPanel( PLOT_TYPE.getDataGeoms()[ 0 ],
+            return new SimplePositionCoordPanel( PLOT_TYPE
+                                                .getPointDataGeoms()[ 0 ],
                                                  true );
         }
     }

topcat/src/main/uk/ac/starlink/topcat/plot2/PlanePlotWindow.java

@@ -37,7 +37,8 @@ private static class PlanePlotTypeGui
             return new PlaneAxisControl( stack );
         }
         public PositionCoordPanel createPositionCoordPanel() {
-            return new SimplePositionCoordPanel( PLOT_TYPE.getDataGeoms()[ 0 ],
+            return new SimplePositionCoordPanel( PLOT_TYPE
+                                                .getPointDataGeoms()[ 0 ],
                                                  true );
         }
     }

topcat/src/main/uk/ac/starlink/topcat/plot2/SpherePlotWindow.java

@@ -37,7 +37,8 @@ private static class SpherePlotTypeGui
             return new CubeAxisControl( true, stack );
         }
         public PositionCoordPanel createPositionCoordPanel() {
-            return new SimplePositionCoordPanel( PLOT_TYPE.getDataGeoms()[ 0 ],
+            return new SimplePositionCoordPanel( PLOT_TYPE
+                                                .getPointDataGeoms()[ 0 ],
                                                  true );
         }
     }

topcat/src/main/uk/ac/starlink/topcat/plot2/StackPlotWindow.java

@@ -480,7 +480,8 @@ private void identifyPoint( Point point ) {
             PlotLayer layer = visibleLayers[ il ];
             DataGeom geom = layer.getDataGeom();
             DataSpec dataSpec = layer.getDataSpec();
-            if ( dataSpec != null && geom != null ) {
+            if ( dataSpec != null &&
+                 geom != null && geom.hasPosition() ) {
                 cloudMap.put( new PointCloud( geom, dataSpec ), layer );
             }
         }
@@ -498,6 +499,7 @@ private void identifyPoint( Point point ) {
 
             /* Iterate over each visible point in the layer. */
             DataGeom geom = layer.getDataGeom();
+            assert geom != null && geom.hasPosition();
             DataSpec dataSpec = layer.getDataSpec();
             TopcatModel tcModel = getTopcatModel( dataSpec );
             TupleSequence tseq = dataStore.getTupleSequence( dataSpec );
@@ -604,6 +606,9 @@ private void highlightRow( TopcatModel tcModel, long irow ) {
     private static double[] getDataPos( PlotLayer layer, long irow,
                                         DataStore dataStore ) {
         DataGeom geom = layer.getDataGeom();
+        if ( geom == null || ! geom.hasPosition() ) {
+            return null;
+        }
         double[] dpos = new double[ geom.getDataDimCount() ];
         TupleSequence tseq = dataStore.getTupleSequence( layer.getDataSpec() );
 
@@ -654,7 +659,8 @@ public Map<TopcatModel,BitSet> getItem() {
                     DataGeom geom = layer.getDataGeom();
                     DataSpec dataSpec = layer.getDataSpec();
                     TopcatModel tcModel = tcModels[ il ];
-                    if ( tcModel != null && geom != null ) {
+                    if ( tcModel != null &&
+                         geom != null && geom.hasPosition() ) {
                         if ( ! maskMap.containsKey( tcModel ) ) {
                             int nrow =
                                 Tables.checkedLongToInt( tcModel.getDataModel()

ttools/src/main/uk/ac/starlink/ttools/plot2/DataGeom.java

@@ -28,11 +28,23 @@ public interface DataGeom {
      */
     Coord[] getPosCoords();
 
+    /**
+     * Indicates whether the values read by the <code>readDataPos</code>
+     * method correspond to a point position in the data space.
+     * If true, a successful read will result in a position array
+     * with a definite value for each coordinate.  If false, some of
+     * the coordinates may be NaN.  A false return value would be
+     * appropriate for instance if each tuple row for the plot layer
+     * represented by this geom corresponds to a line rather than a
+     * point in the data space.
+     *
+     * @return   true iff this geom represents point positions
+     */
+    boolean hasPosition();
+
     /**
      * Determines the base positional coordinates in data space
      * for the current row of a supplied tuple sequence.
-     * The positional coordinates are assumed to start at column
-     * zero of the supplied tuple sequence.
      *
      * <p>An array of (at least) {@link #getDataDimCount} elements is
      * supplied, and on success the data space coordinate values of the

ttools/src/main/uk/ac/starlink/ttools/plot2/PlotLayer.java

@@ -5,12 +5,14 @@
 import uk.ac.starlink.ttools.plot.Range;
 import uk.ac.starlink.ttools.plot.Style;
 import uk.ac.starlink.ttools.plot2.data.DataSpec;
+import uk.ac.starlink.ttools.plot2.data.DataStore;
 import uk.ac.starlink.ttools.plot2.paper.PaperType;
 
 /**
  * Represents a layered element of the plot.
  * When combined with certain other information it can draw data or
- * other graphical elements onto a Surface.
+ * other graphical elements onto a Surface, and report on the surface
+ * region covered by such graphics.
  *
  * @author   Mark Taylor
  * @since    11 Feb 2013
@@ -35,12 +37,33 @@ public interface PlotLayer {
     /**
      * Returns the data geometry used by this layer.
      * This can be used in conjunction with the DataSpec to determine the
-     * base positions in data space of all the points plotted.
+     * base positions in data space of what has been plotted.
+     * Depending on the nature of the returned object, these positions may
+     * be actual points in the data space, or some higher-dimensional object.
+     * If null is returned, no such information is available.
      *
-     * @return  data geom
+     * @return  data geom, or null
      */
     DataGeom getDataGeom();
 
+    /**
+     * Gives this layer a chance to adjust the coordinate ranges
+     * assembled during data ranging.  Supplied is an array of range
+     * objects, each corresponding to one of the data position dimensions
+     * (it has <code>surface.getDataDimCount</code> elements).
+     * If this layer needs to adjust these ranges beyond what is implied
+     * by the result of <code>getDataGeom</code>, it may be done here.
+     * The implementation may or may not need to acquire
+     * a tuple sequence from the supplied <code>dataStore</code>.
+     *
+     * <p>In many cases (especially for point-plotting type layers)
+     * the implementation of this method will be a no-operation.
+     *
+     * @param   ranges   array of data space dimension ranges, may be adjusted
+     * @param   dataStore   data storage object
+     */
+    void extendCoordinateRanges( Range[] ranges, DataStore dataStore );
+
     /**
      * Returns the data spec that defines the data used by this layer.
      * May be null if no tabular data is required.

ttools/src/main/uk/ac/starlink/ttools/plot2/PlotType.java

@@ -18,13 +18,15 @@ public interface PlotType {
 
     /**
      * Returns a list of one or more geometry variants which describe
-     * how user-supplied coordinates map to the data space.
+     * how user-supplied point coordinates map to the data space.
+     * The geoms returned from this method will return true from their
+     * {@link DataGeom#hasPosition} method.
      * If multiple values are returned, the first one may be used as some kind
      * of default.
      *
      * @return   data geom option list
      */
-    DataGeom[] getDataGeoms();
+    DataGeom[] getPointDataGeoms();
 
     /**
      * Returns an object that can construct the plot surface including

ttools/src/main/uk/ac/starlink/ttools/plot2/PlotUtil.java

@@ -149,28 +149,48 @@ public void paintPicture( Graphics2D g2 ) {
     }
 
     /**
-     * Determines range information for each of the coordinates of the
-     * data positions in a PointCloud.
+     * Determines range information for a set of layers which have
+     * Cartesian (or similar) coordinates.
      *
-     * @param   cloud  point cloud
-     * @param   nDataDim  dimensionality of data points in the point cloud
+     * @param   layers   plot layers
+     * @param   nDataDim  dimensionality of data points
      * @param   dataStore  data storage
      * @return   nDataDim-element array of ranges, each containing the
      *           range of data position coordinate values for
      *           the corresponding dimension
      */
     @Slow
-    public static Range[] readCoordinateRanges( PointCloud cloud, int nDataDim,
+    public static Range[] readCoordinateRanges( PlotLayer[] layers,
+                                                int nDataDim,
                                                 DataStore dataStore ) {
+
+        /* Set up an array of range objects, one for each data dimension. */
         Range[] ranges = new Range[ nDataDim ];
         for ( int idim = 0; idim < nDataDim; idim++ ) {
             ranges[ idim ] = new Range();
-        }                      
+        }
+
+        /* Create a point cloud containing all the point positions
+         * represented by the supplied layers.  If there are several
+         * layers using the same basic positions, this should combine
+         * them efficiently. */
+        PointCloud cloud = new PointCloud( layers, true );
+
+        /* Iterate over the represented points to mark out the basic
+         * range of data positions covered by the layers. */
         for ( double[] dpos : cloud.createDataPosIterable( dataStore ) ) {
             for ( int idim = 0; idim < nDataDim; idim++ ) {
                 ranges[ idim ].submit( dpos[ idim ] );
-            }       
+            }
+        }
+
+        /* If any of the layers wants to supply non-data-position points
+         * to mark out additional space, take account of those too. */
+        for ( int il = 0; il < layers.length; il++ ) {
+            layers[ il ].extendCoordinateRanges( ranges, dataStore );
         }
+
+        /* Return the ranges. */
         return ranges;
     }
 

ttools/src/main/uk/ac/starlink/ttools/plot2/Plotter.java

@@ -84,21 +84,23 @@ public interface Plotter<S extends Style> {
      * <code>dataGeom.getPosCoords</code> and
      * {@link #getExtraCoords}.
      *
-     * <p>The <code>dataGeom</code> (and probably <code>dataSpec</code>)
+     * <p>The <code>pointDataGeom</code>
      * parameter is only used if {@link #hasPosition} returns true,
-     * otherwise the plot is dataless and those parameters are ignored.
+     * otherwise the plot does not have point positions.
      *
      * <p>It is legal to supply null for any of the parameters;
      * if insufficient data is supplied to generate a plot, then
      * the method should return null.
      *
      * <p>Creating a layer should be cheap; layers may be created and not used.
      *
-     * @param   dataGeom  indicates base position coordinates and their
-     *                    mapping to the data space
+     * @param   pointDataGeom  indicates base position coordinates and their
+     *                    mapping to points in the data space;
+     *                    if non-null, the data geom's
+     *                    {@link DataGeom#hasPosition} method will return true 
      * @param   dataSpec  specifies the data required for the plot
      * @param   style   data style as obtained from <code>createStyle</code>
      * @return   new plot layer, or null if no drawing will take place
      */
-    PlotLayer createLayer( DataGeom dataGeom, DataSpec dataSpec, S style );
+    PlotLayer createLayer( DataGeom pointDataGeom, DataSpec dataSpec, S style );
 }

ttools/src/main/uk/ac/starlink/ttools/plot2/geom/CubeDataGeom.java

@@ -34,6 +34,10 @@ public int getDataDimCount() {
         return 3;
     }
 
+    public boolean hasPosition() {
+        return true;
+    }
+
     public String getVariantName() {
         return "Cartesian";
     }

ttools/src/main/uk/ac/starlink/ttools/plot2/geom/CubePlotType.java

@@ -56,7 +56,7 @@ private CubePlotType() {
         }
     }
 
-    public DataGeom[] getDataGeoms() {
+    public DataGeom[] getPointDataGeoms() {
         return dataGeoms_;
     }
 

ttools/src/main/uk/ac/starlink/ttools/plot2/geom/CubeSurfaceFactory.java

@@ -11,7 +11,6 @@
 import uk.ac.starlink.ttools.plot2.Captioner;
 import uk.ac.starlink.ttools.plot2.PlotLayer;
 import uk.ac.starlink.ttools.plot2.PlotUtil;
-import uk.ac.starlink.ttools.plot2.PointCloud;
 import uk.ac.starlink.ttools.plot2.Subrange;
 import uk.ac.starlink.ttools.plot2.Surface;
 import uk.ac.starlink.ttools.plot2.SurfaceFactory;
@@ -317,8 +316,7 @@ public CubeAspect createAspect( Profile profile, ConfigMap config,
     }
 
     public Range[] readRanges( PlotLayer[] layers, DataStore dataStore ) {
-        return PlotUtil.readCoordinateRanges( new PointCloud( layers, true ),
-                                              3, dataStore );
+        return PlotUtil.readCoordinateRanges( layers, 3, dataStore );
     }
 
     public CubeAspect pan( Surface surface, Point pos0, Point pos1 ) {

ttools/src/main/uk/ac/starlink/ttools/plot2/geom/PlaneDataGeom.java

@@ -35,6 +35,10 @@ public int getDataDimCount() {
         return 2;
     }
 
+    public boolean hasPosition() {
+        return true;
+    }
+
     public String getVariantName() {
         return "Cartesian";
     }

ttools/src/main/uk/ac/starlink/ttools/plot2/geom/PlanePlotType.java

@@ -55,7 +55,7 @@ private PlanePlotType() {
         };
     }
 
-    public DataGeom[] getDataGeoms() {
+    public DataGeom[] getPointDataGeoms() {
         return dataGeoms_;
     }
 

ttools/src/main/uk/ac/starlink/ttools/plot2/geom/PlaneSurfaceFactory.java

@@ -9,7 +9,6 @@
 import uk.ac.starlink.ttools.plot2.Captioner;
 import uk.ac.starlink.ttools.plot2.PlotLayer;
 import uk.ac.starlink.ttools.plot2.PlotUtil;
-import uk.ac.starlink.ttools.plot2.PointCloud;
 import uk.ac.starlink.ttools.plot2.Subrange;
 import uk.ac.starlink.ttools.plot2.Surface;
 import uk.ac.starlink.ttools.plot2.SurfaceFactory;
@@ -178,8 +177,7 @@ public PlaneAspect createAspect( Profile profile, ConfigMap config,
     }
 
     public Range[] readRanges( PlotLayer[] layers, DataStore dataStore ) {
-        return PlotUtil.readCoordinateRanges( new PointCloud( layers, true ),
-                                              2, dataStore );
+        return PlotUtil.readCoordinateRanges( layers, 2, dataStore );
     }
 
     public PlaneAspect pan( Surface surface, Point pos0, Point pos1 ) {

ttools/src/main/uk/ac/starlink/ttools/plot2/geom/SkyDataGeom.java

@@ -36,6 +36,10 @@ public int getDataDimCount() {
         return 3;
     }
 
+    public boolean hasPosition() {
+        return true;
+    }
+
     public String getVariantName() {
         return variantName_;
     }

ttools/src/main/uk/ac/starlink/ttools/plot2/geom/SkyPlotType.java

@@ -47,7 +47,7 @@ private SkyPlotType() {
         };
     }
 
-    public DataGeom[] getDataGeoms() {
+    public DataGeom[] getPointDataGeoms() {
         return dataGeoms_;
     }
 

ttools/src/main/uk/ac/starlink/ttools/plot2/geom/SphereDataGeom.java

@@ -34,6 +34,10 @@ public int getDataDimCount() {
         return 3;
     }
 
+    public boolean hasPosition() {
+        return true;
+    }
+
     public String getVariantName() {
         return "Polar";
     }

ttools/src/main/uk/ac/starlink/ttools/plot2/geom/SpherePlotType.java

@@ -43,7 +43,7 @@ private SpherePlotType() {
         dataGeoms_ = new DataGeom[] { SphereDataGeom.INSTANCE };
     }
 
-    public DataGeom[] getDataGeoms() {
+    public DataGeom[] getPointDataGeoms() {
         return dataGeoms_;
     }
 

ttools/src/main/uk/ac/starlink/ttools/plot2/layer/AbstractPlotLayer.java

@@ -2,6 +2,7 @@
 
 import java.util.HashMap;
 import java.util.Map;
+import uk.ac.starlink.ttools.plot.Range;
 import uk.ac.starlink.ttools.plot.Style;
 import uk.ac.starlink.ttools.plot2.AuxReader;
 import uk.ac.starlink.ttools.plot2.AuxScale;
@@ -10,6 +11,7 @@
 import uk.ac.starlink.ttools.plot2.PlotLayer;
 import uk.ac.starlink.ttools.plot2.Plotter;
 import uk.ac.starlink.ttools.plot2.data.DataSpec;
+import uk.ac.starlink.ttools.plot2.data.DataStore;
 
 /**
  * Partial PlotLayer implementation.
@@ -54,6 +56,12 @@ public DataGeom getDataGeom() {
         return geom_;
     }
 
+    /**
+     * This implementation does nothing.
+     */
+    public void extendCoordinateRanges( Range[] ranges, DataStore dataStore ) {
+    }
+
     public DataSpec getDataSpec() {
         return dataSpec_;
     }