TextEditor: restore addImport function

When given a "raw" class (no package), addImport will now iterate over
all elements in the core ImageJ packages looking for potential matches
to the requested class.

All potential matches will be added as imports (e.g. net.imglib2.ImgPlus
and net.imglib2.meta.ImgPlus will both be added). If there are no
matches, the class will be imported without a package.

Addresses http://fiji.sc/bugzilla/show_bug.cgi?id=817

Author: hinerm

src/main/java/net/imagej/ui/swing/script/TextEditor.java

@@ -59,6 +59,7 @@
 import java.io.Writer;
 import java.net.URL;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.Date;
@@ -107,6 +108,10 @@
 import org.fife.ui.rsyntaxtextarea.AbstractTokenMakerFactory;
 import org.fife.ui.rsyntaxtextarea.RSyntaxTextArea;
 import org.fife.ui.rsyntaxtextarea.TokenMakerFactory;
+import org.reflections.Reflections;
+import org.reflections.scanners.SubTypesScanner;
+import org.reflections.util.ClasspathHelper;
+import org.reflections.util.ConfigurationBuilder;
 import org.scijava.Context;
 import org.scijava.command.CommandService;
 import org.scijava.event.ContextDisposingEvent;
@@ -168,6 +173,7 @@ public class TextEditor extends JFrame implements ActionListener,
 	}
 
 	private static AbstractTokenMakerFactory tokenMakerFactory = null;
+	private static Reflections reflections = null;
 
 	private JTabbedPane tabbed;
 	private JMenuItem newFile, open, save, saveas, compileAndRun, compile,
@@ -2064,9 +2070,37 @@ public String getSelectedTextOrAsk(final String label) {
 	public String getSelectedClassNameOrAsk() {
 		String className = getSelectedTextOrAsk("Class name");
 		if (className != null) className = className.trim();
+
 		return className;
 	}
 
+	/**
+	 * Returns the static Reflections instance, constructing it
+	 * if it doesn't already exist. This is to limit the number of
+	 * classpath scans.
+	 *
+	 * @return static {@link Reflections} instance
+	 */
+	private static Reflections getReflections() {
+		if (reflections == null) {
+			synchronized(TextEditor.class) {
+				if (reflections == null) {
+					final Collection<URL> packages = new HashSet<>();
+					packages.addAll(ClasspathHelper.forPackage("net.imagej"));
+					packages.addAll(ClasspathHelper.forPackage("org.scijava"));
+					packages.addAll(ClasspathHelper.forPackage("net.imglib2"));
+					packages.addAll(ClasspathHelper.forPackage("io.scif"));
+					packages.addAll(ClasspathHelper.forPackage("sc.fiji"));
+					packages.addAll(ClasspathHelper.forPackage("ij"));
+					reflections = new Reflections(new ConfigurationBuilder().setUrls(
+						packages).setScanners(new SubTypesScanner(false)));
+				}
+			}
+		}
+
+		return reflections;
+	}
+
 	private static void append(final JTextArea textArea, final String text) {
 		final int length = textArea.getDocument().getLength();
 		textArea.insert(text, length);
@@ -2209,7 +2243,38 @@ private void updateGitDirectory() {
 
 	public void addImport(final String className) {
 		if (className != null) {
-			new TokenFunctions(getTextArea()).addImport(className.trim());
+
+			boolean addRaw = true;
+
+			// If there are NO package separators then this is a raw class name. Try
+			// and find matching packages
+
+			// NB: decided to only look for complete class names without packages.
+			// Matching "endsWith(className) can produce a plethora of false positives
+			// which we want to limit, because the current implementation imports
+			// all matches.
+			// Some alternatives to consider (including combinations):
+			//  - match *className
+			//  - match *className*
+			//  - match .className*
+			//  - if >1 match show list to the user to choose a "winner" to import
+			if (!className.contains(".")) {
+				final String packagedClass = "." + className;
+				final Reflections refl = TextEditor.getReflections();
+				final StringBuilder sb = new StringBuilder();
+
+				for (final String type : refl.getAllTypes()) {
+					// look for "blah.className"
+					if (type.endsWith(packagedClass)) {
+						addRaw = false;
+						new TokenFunctions(getTextArea()).addImport(type.trim());
+					}
+				}
+			}
+
+			// If there was a package separator or no matching packages, import the raw
+			// class.
+			if (addRaw) new TokenFunctions(getTextArea()).addImport(className.trim());
 		}
 	}