topcat: added a little plus sign to control action icons

Plot2 actions which add items to a stack of controls now have a little
plus sign added to their action icons.  Also reword the names and
descriptions slightly.  This (hopefully) makes it clearer what those
actions are there for.

topcat/src/main/uk/ac/starlink/topcat/ResourceIcon.java

@@ -5,6 +5,7 @@
 import java.awt.Graphics;
 import java.awt.Image;
 import java.awt.MediaTracker;
+import java.awt.image.BufferedImage;
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
 import java.io.ByteArrayOutputStream;
@@ -244,6 +245,7 @@ public class ResourceIcon implements Icon {
         NAV_HELP = makeIcon( "navhelp.gif" ),
         NAV_DEC = makeIcon( "navdec1.gif" ),
         SMALL_CLOSE = makeIcon( "x9.gif" ),
+        ADD_CONTROL = makeIcon( "addlayer4.png" ),
 
         /* Datanode (hierarchy browser) icons. */
         COLLAPSED = makeIcon( "handle1.gif" ),
@@ -373,6 +375,42 @@ private Icon readBaseIcon() {
         return icon;
     }
 
+    /**
+     * Paints a stack of icons on top of each other and returns the result.
+     * Later elements obscure earlier ones
+     *
+     * @param  icons  icon array
+     * @return  combination
+     */
+    public static ImageIcon combineIcons( Icon[] icons ) {
+        int width = 0;
+        int height = 0;
+        for ( int i = 0; i < icons.length; i++ ) {
+            width = Math.max( width, icons[ i ].getIconWidth() );
+            height = Math.max( height, icons[ i ].getIconHeight() );
+        }
+        BufferedImage image =
+            new BufferedImage( width, height, BufferedImage.TYPE_INT_ARGB );
+        Component c = null;
+        Graphics g = image.createGraphics();
+        for ( int i = 0; i < icons.length; i++ ) {
+            icons[ i ].paintIcon( c, g, 0, 0 );
+        }
+        g.dispose();
+        return new ImageIcon( image );
+    }
+
+    /**
+     * Doctors an icon representing a control to look like it means adding
+     * that control.  Currently, it puts a little plus sign in the corner.
+     *
+     * @param  baseIcon  standard sized (24x24) base icon
+     * @return  doctored icon
+     */
+    public static ImageIcon toAddIcon( Icon baseIcon ) {
+        return combineIcons( new Icon[] { baseIcon, ADD_CONTROL } );
+    }
+
     /**
      * Returns a full-size TOPCAT logo for display.
      *

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

@@ -96,7 +96,7 @@ public GangControlManager( ControlStack stack, PlotType plotType,
         if ( ! plotterMap_.get( 1 ).isEmpty() ) {
             final Icon icon1 = ResourceIcon.PLOT_DATA;
             stackActList.add( new LayerControlAction(
-                                  "Add Position Plot", icon1,
+                                  "Add Position Control", icon1,
                                   "Add a new positional plot control"
                                   + " to the stack", stack_ ) {
                 public LayerControl createLayerControl() {
@@ -109,7 +109,7 @@ public LayerControl createLayerControl() {
         if ( ! plotterMap_.get( 2 ).isEmpty() ) {
             final Icon icon2 = ResourceIcon.PLOT_PAIR;
             stackActList.add( new LayerControlAction(
-                                  "Add Pair Plot", icon2,
+                                  "Add Pair Control", icon2,
                                   "Add a new pair position plot control"
                                   + " to the stack", stack_ ) {
                 public LayerControl createLayerControl() {

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

@@ -4,6 +4,7 @@
 import javax.swing.Action;
 import javax.swing.Icon;
 import uk.ac.starlink.topcat.BasicAction;
+import uk.ac.starlink.topcat.ResourceIcon;
 import uk.ac.starlink.topcat.TopcatListener;
 import uk.ac.starlink.ttools.plot2.Plotter;
 import uk.ac.starlink.ttools.plot2.data.CoordGroup;
@@ -25,13 +26,15 @@ public abstract class LayerControlAction extends BasicAction {
      * Constructs a LayerControlAction from name, icon and description.
      *
      * @param   name   action name
-     * @param   icon   action icon
+     * @param   layerIcon   icon representing the type of layer the action
+     *                      will add; it may get doctored to generate the
+     *                      icon for this action
      * @param   descrip  action description
      * @param   stack   plot stack
      */
-    public LayerControlAction( String name, Icon icon, String descrip,
+    public LayerControlAction( String name, Icon layerIcon, String descrip,
                                ControlStack stack ) {
-        super( name, icon, descrip );
+        super( name, ResourceIcon.toAddIcon( layerIcon ), descrip );
         stack_ = stack;
     }
 
@@ -42,7 +45,7 @@ public LayerControlAction( String name, Icon icon, String descrip,
      * @param  stack    plot stack
      */
     public LayerControlAction( Plotter plotter, ControlStack stack ) {
-        this( "Add " + plotter.getPlotterName() + " Layer",
+        this( "Add " + plotter.getPlotterName() + " Control",
               plotter.getPlotterIcon(),
               "Add a new " + plotter.getPlotterName().toLowerCase()
                            + " layer control to the stack",

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

@@ -16,6 +16,7 @@
 import javax.swing.JToolBar;
 import javax.swing.event.ListSelectionEvent;
 import javax.swing.event.ListSelectionListener;
+import uk.ac.starlink.topcat.ResourceIcon;
 import uk.ac.starlink.topcat.TopcatListener;
 import uk.ac.starlink.ttools.plot2.Plotter;
 import uk.ac.starlink.ttools.plot2.config.ConfigKey;
@@ -278,7 +279,8 @@ private class SingleFormAction extends AbstractAction {
          * @param  plotter   object that generates plot layers
          */
         public SingleFormAction( Plotter plotter ) {
-            super( plotter.getPlotterName(), plotter.getPlotterIcon() );
+            super( plotter.getPlotterName(),
+                   ResourceIcon.toAddIcon( plotter.getPlotterIcon() ) );
             putValue( SHORT_DESCRIPTION,
                       "Add new " + plotter.getPlotterName() + " form" );
             plotter_ = plotter;
@@ -304,7 +306,8 @@ private class ModeFormAction extends AbstractAction {
          * @param  form   common form
          */
         public ModeFormAction( ModePlotter[] plotters, ModePlotter.Form form ) {
-            super( form.getFormName(), form.getFormIcon() );
+            super( form.getFormName(),
+                   ResourceIcon.toAddIcon( form.getFormIcon() ) );
             putValue( SHORT_DESCRIPTION,
                       "Add new " + form.getFormName() + " form" );
             plotters_ = plotters;

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

@@ -343,7 +343,7 @@ public void modelChanged( TopcatEvent evt ) {
 
         /* Action for deleting a control from the stack. */
         Action removeAction =
-            stack_.createRemoveAction( "Remove Current Layer",
+            stack_.createRemoveAction( "Remove Current Control",
                                        "Delete the current layer control"
                                      + " from the stack" );