KeystrokeSupplementor.java

package glug.gui;

import static java.awt.event.InputEvent.CTRL_MASK;
import static java.awt.event.KeyEvent.VK_ADD;
import static java.awt.event.KeyEvent.VK_EQUALS;
import static java.awt.event.KeyEvent.VK_PLUS;
import static java.util.Arrays.asList;
import static javax.swing.JComponent.WHEN_IN_FOCUSED_WINDOW;
import static javax.swing.KeyStroke.getKeyStroke;

import javax.swing.InputMap;
import javax.swing.JComponent;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;

public class KeystrokeSupplementor {
	public void hackCtrlPlus(JComponent component) {		
		KeyStroke plusKeyOnNonEnglishKeyboards = getKeyStroke(VK_PLUS, CTRL_MASK);
		KeyStroke plusKeyOnEnglishKeyboards = getKeyStroke(VK_EQUALS, CTRL_MASK);
		KeyStroke plusKeyOnTheNumpad = getKeyStroke(VK_ADD, CTRL_MASK);
		
		supplementKeystokeMappingOn(component, plusKeyOnNonEnglishKeyboards, asList(plusKeyOnEnglishKeyboards, plusKeyOnTheNumpad));
	}
	
	public void hackCtrlMinus(JComponent component) {		
		KeyStroke minusKey = getKeyStroke(VK_EQUALS, CTRL_MASK);
		KeyStroke minusKeyOnTheNumpad = getKeyStroke(VK_ADD, CTRL_MASK);
		
		supplementKeystokeMappingOn(component, minusKey, asList(minusKeyOnTheNumpad));
	}

	private void supplementKeystokeMappingOn(JComponent component, KeyStroke keystrokeToSupplement, Iterable<KeyStroke> supplementalKeystrokes) {
		InputMap inputMap = SwingUtilities.getUIInputMap(component, WHEN_IN_FOCUSED_WINDOW);
		
		Object actionMapKey = inputMap.get(keystrokeToSupplement);
		
		for (KeyStroke supplementalKeystroke : supplementalKeystrokes) {
			inputMap.put(supplementalKeystroke, actionMapKey);
		}
	}
}