Detect Control-Plus and Control-Minus

Question

Hi,
I want to detect keyboard events in a swing application, with the Control key and the '+' or '-' keys pressed (the ones from the keyboard, not from the numpad).
This is to provide similar behaviour than Firefox for increasing and decreasing the font size.
I have an English keyboard, in which + is with = key, to be pressed with shift, and - can be pressed directly, without shift.
I've tried many ways to achieve this behaviour, but have not succeeded yet.
Platform is Java SE 1.6.0_07 on Red Hat Enterprise Linux 4 with Gnome.
import static java.awt.event.InputEvent.*;
import static java.awt.event.KeyEvent.*;
import static javax.swing.KeyStroke.getKeyStroke;
// Within some method in some class...
KeyStroke ctrlPlus, ctrlMinus;
// Menu items seem correct, but none of the combinations work for me
ctrlPlus  = getKeyStroke(Character.valueOf('+'), CTRL_DOWN_MASK); // menu item shows Ctrl-+
ctrlMinus = getKeyStroke(Character.valueOf('-'), CTRL_DOWN_MASK); // menu item shows Ctrl--
// Menu items seem a bit strange; Ctrl - works, but Ctrl + doesn't
ctrlPlus  = getKeyStroke(VK_PLUS , CTRL_DOWN_MASK); // menu item shows Ctrl-Plus
ctrlMinus = getKeyStroke(VK_MINUS, CTRL_DOWN_MASK); // menu item shows Ctrl-Minus
// None of these combinations work
ctrlPlus  = getKeyStroke("control +"); // menu item shows nothing
ctrlMinus = getKeyStroke("control -"); // menu item shows nothingIt seems I can get the desired behaviour with '+' and '-' of the numpad, but:
1. They are more weird than the normal '+' and '-' keys, which are the ones used by Firefox
2. The menu items show Ctrl-Numpad + and Ctrl-Numpad - as shortcuts, which are weird also
3. Not all keyboards have a numpad.
A solution would be very much appreciated... as well as rewarded with the dukes.

Answer 1

KeyStroke.getKeyStroke(KeyEvent.VK_EQUALS, KeyEvent.SHIFT_DOWN_MASK | KeyEvent.CTRL_DOWN_MASK)This works indeed with CTRL_DOWN_MASK alone (not tested with the other mask), thanks.
However, this solution has two drawbacks:
1. The accelerator string is shown as Ctrl-=, while I want Ctrl-+ to be shown
2. '+' key may not coincide with '=' in non-English keyboards (e.g. it doesn't coincide in Spanish keyboards)
I've found a solution that required a bit more work:
1. Create the actions with the keyStroke you want to be shown (in my case, Ctrl-- and Ctrl-+):
ctrlPlus  = getKeyStroke("ctrl typed +");  // Ctrl-+ is shown
ctrlMinus = getKeyStroke("ctrl typed -");  // Ctrl-- is shown
Action actionPlus = new AbstractAction() { ... };
actionPlus.setAccelerator(ctrlPlus);
Action actionMinus = new AbstractAction() { ... };
actionMinus.setAccelerator(ctrlMinus);2. Bind the keys you actually want to the corresponding action:
JComponent window = ...;  // root window
InputMap inputMap = window.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
ActionMap actionMap = window.getActionMap();
Object actionMapKeyPlus  = "ctrl+";
Object actionMapKeyMinus = "ctrl-";
inputMap.put(getKeyStroke(VK_EQUALS  , CTRL_DOWN_MASK), actionMapKeyPlus);  // + key in English keyboards
inputMap.put(getKeyStroke(VK_PLUS    , CTRL_DOWN_MASK), actionMapKeyPlus);  // + key in non-English keyboards
inputMap.put(getKeyStroke(VK_ADD     , CTRL_DOWN_MASK), actionMapKeyPlus);  // + key on the numpad
inputMap.put(getKeyStroke(VK_MINUS   , CTRL_DOWN_MASK), actionMapKeyMinus); // - key
inputMap.put(getKeyStroke(VK_SUBTRACT, CTRL_DOWN_MASK), actionMapKeyMinus); // - key on the numpad
actionMap.put(actionMapKeyPlus, actionPlus);
actionMap.put(actionMapKeyMinus, actionMinus);More complicated than expected, but at least works.
Thanks for the help.
God bless,
Jaime