New class AutocompletionProvider to provide completions for class, pa…

…ckage

and fields and methods of imported classes.

src/main/java/org/scijava/ui/swing/script/AutocompletionProvider.java

@@ -0,0 +1,161 @@
+package org.scijava.ui.swing.script;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import javax.swing.text.JTextComponent;
+
+import org.fife.ui.autocomplete.BasicCompletion;
+import org.fife.ui.autocomplete.Completion;
+import org.fife.ui.autocomplete.DefaultCompletionProvider;
+import org.fife.ui.rsyntaxtextarea.RSyntaxTextArea;
+
+public class AutocompletionProvider extends DefaultCompletionProvider {
+
+	private final RSyntaxTextArea text_area;
+
+	public AutocompletionProvider(final RSyntaxTextArea text_area) {
+		this.text_area = text_area;
+		new Thread(new Runnable() {
+			@Override
+			public void run() {
+				ClassUtil.ensureCache();
+			}
+		}).start();
+	}
+
+	/**
+	 * Override parent implementation to allow letters, digits, the period and a space, to be able to match e.g.:
+	 * 
+	 * "from "
+	 * "from ij"
+	 * "from ij.Im"
+	 * etc.
+	 * 
+	 * @param c
+	 */
+	@Override
+	public boolean isValidChar(final char c) {
+		return Character.isLetterOrDigit(c) || '.' == c || ' ' == c;
+	}
+
+	static private final Pattern
+			fromImport = Pattern.compile("^(from[ \\t]+)([a-zA-Z][a-zA-Z0-9._]*)$"),
+			fastImport = Pattern.compile("^(from[ \\t]+)([a-zA-Z][a-zA-Z0-9._]*)[ \\t]+$"),
+			importStatement = Pattern.compile("^((from[ \\t]+([a-zA-Z0-9._]+)[ \\t]+|[ \\t]*)import(Class\\(|[ \\t]+))([a-zA-Z0-9_., \\t]*)$"),
+			simpleClassName = Pattern.compile("^(.*[ \\t]+|)([A-Z_][a-zA-Z0-9_]+)$"),
+			staticMethodOrField = Pattern.compile("^((.*[ \\t]+|)([A-Z_][a-zA-Z0-9_]*)\\.)([a-zA-Z0-9_]*)$");
+
+	private final List<Completion> asCompletionList(final Stream<String> stream, final String pre) {
+		return stream
+				.map((s) -> new BasicCompletion(AutocompletionProvider.this, pre + s))
+				.collect(Collectors.toList());
+	}
+
+	@Override
+	public List<Completion> getCompletionsImpl(final JTextComponent comp) {
+		// don't block
+		if (!ClassUtil.isCacheReady()) return Collections.emptyList();
+
+		final String text = this.getAlreadyEnteredText(comp);
+
+		// E.g. "from ij" to expand to a package name like ij or ij.gui or ij.plugin
+		final Matcher m1 = fromImport.matcher(text);
+		if (m1.find())
+			return asCompletionList(ClassUtil.findPackageNamesStartingWith(m1.group(2)), m1.group(1));
+
+		final Matcher m1f = fastImport.matcher(text);
+		if (m1f.find())
+			return asCompletionList(ClassUtil.findClassNamesForPackage(m1f.group(2)).map(s -> s.substring(m1f.group(2).length() + 1)),
+					m1f.group(0) + "import ");
+
+		// E.g. "from ij.gui import Roi, Po" to expand to PolygonRoi, PointRoi for Jython
+		// or e.g. "importClass(Package.ij" to expand to a fully qualified class name for Javascript
+		final Matcher m2 = importStatement.matcher(text);
+		if (m2.find()) {
+			String packageName = m2.group(3),
+					 className = m2.group(5); // incomplete or empty, or multiple separated by commas with the last one incomplete or empty
+
+			System.out.println("m2 matches className: " + className);
+			final String[] bycomma = className.split(",");
+			String precomma = "";
+			if (bycomma.length > 1) {
+				className = bycomma[bycomma.length -1].trim(); // last one
+				for (int i=0; i<bycomma.length -1; ++i)
+					precomma += bycomma[0] + ", ";
+			}
+			Stream<String> stream;
+			if (className.length() > 0)
+				stream = ClassUtil.findClassNamesStartingWith(null == packageName ? className : packageName + "." + className);
+			else
+				stream = ClassUtil.findClassNamesForPackage(packageName);
+			if (!m2.group(4).equals("Class(Package"))
+				stream = stream.map((s) -> s.substring(Math.max(0, s.lastIndexOf('.') + 1))); // simple class name for Jython
+			return asCompletionList(stream, m2.group(1) + precomma);
+		}
+
+		final Matcher m3 = simpleClassName.matcher(text);
+		if (m3.find())
+			return asCompletionList(ClassUtil.findSimpleClassNamesStartingWith(m3.group(2)).stream(), m3.group(1));
+
+		final Matcher m4 = staticMethodOrField.matcher(text);
+		if (m4.find()) {
+			try {
+				final String simpleClassName   = m4.group(3), // expected complete, e.g. ImagePlus
+							 methodOrFieldSeed = m4.group(4).toLowerCase(); // incomplete: e.g. "GR", a string to search for in the class declared fields or methods
+				// Scan the script, parse the imports, find first one matching
+				String packageName = null;
+				lines: for (final String line: text_area.getText().split("\n")) {
+					System.out.println(line);
+					final String[] comma = line.split(",");
+					final Matcher m = importStatement.matcher(comma[0]);
+					if (m.find()) {
+						final String first = m.group(5);
+						if (m.group(4).equals("Class(Package")) {
+							// Javascript import
+							final int lastdot = Math.max(0, first.lastIndexOf('.'));
+							if (simpleClassName.equals(first.substring(lastdot + 1))) {
+								packageName = first.substring(0, lastdot);
+								break lines;
+							}
+						} else {
+							// Jython import
+							comma[0] = first;
+							for (int i=0; i<comma.length; ++i)
+								if (simpleClassName.equals(comma[i].trim())) {
+									packageName = m.group(3);
+									break lines;
+								}
+						}
+					}
+				}
+				System.out.println("package name: " + packageName);
+				if (null != packageName) {
+					final Class<?> c = Class.forName(packageName + "." + simpleClassName);
+					final ArrayList<String> matches = new ArrayList<>();
+					for (final Field f: c.getFields()) {
+						if (Modifier.isStatic(f.getModifiers()) && f.getName().toLowerCase().startsWith(methodOrFieldSeed))
+							matches.add(f.getName());
+					}
+					for (final Method m: c.getMethods()) {
+						if (Modifier.isStatic(m.getModifiers()) && m.getName().toLowerCase().startsWith(methodOrFieldSeed))
+							matches.add(m.getName() + "(");
+					}
+					return asCompletionList(matches.stream(), m4.group(1));
+				}
+			} catch (Exception e) {
+				e.printStackTrace();
+			}
+		}
+
+		return Collections.emptyList();
+	}
+}