A proposal for a behavior change about mnemonic key (original) (raw)

Sean Chou zhouyx at linux.vnet.ibm.com
Tue Sep 13 09:48:16 UTC 2011

Hi Pavel,

I found C# Form application treats Mnemonics in menu in this way. I attached the sample application. Press alt+i will iterate over three menu.

2011/9/13 Pavel Porvatov <pavel.porvatov at oracle.com>

** Hi Sean,

Hi, Thanks. So is there any one can give me a suggestion about what shall I do if we want these feature ? Thanks again. First of all you should file a bug (RFE actually). BTW: before reviewing the fix I'd like to ask about OS behavior when there are several components with the same mnemonic. How Windows XP/Vista/7 and Linux (Gnome/KDE) manage the described situation? Regards, Pavel

2011/7/6 Jean-Remi Desjardins <jeanremi.desjardins at gmail.com> I think that sounds like a great idea! Regards, Jean-Rémi Desjardins Sent from my iPhone (so don't expect me to be too verbose) On 2011-07-06, at 5:42 AM, Sean Chou <zhouyx at linux.vnet.ibm.com> wrote: Hi, Is there anybody interested in this feature? Or any other comments? 2011/4/21 Sean Chou <zhouyx at linux.vnet.ibm.com> Hi, I have a simple patch to demo the new behavior. With the patch, the focus will go through the radiobuttons with mnemonic key Y when alt+y is pressed instead of select the last. The patch is as follows: diff -r 554adcfb615e src/share/classes/javax/swing/KeyboardManager.java --- a/src/share/classes/javax/swing/KeyboardManager.java Wed Mar 16 15:01:07 2011 -0700 +++ b/src/share/classes/javax/swing/KeyboardManager.java Thu Mar 17 14:57:14 2011 +0800 @@ -251,6 +251,93 @@ } } else if ( tmp instanceof Vector) { //more than one comp registered for this Vector v = (Vector)tmp; + + /* The below code is added to make sure the focus is not always + transferred to the last component in the vector when + more than one component have the same mnemonic + */ + if ((e.getModifiers() & Event.ALTMASK) == Event.ALTMASK) { + /* Mnemonic key should transfer the focus only, do not select. + * The following code works in this way: + * 1. If only one component in the vector is visible, fireBinding on it. + * 2. If multi-components in the vector are visible, move the focus to next component. + * 2.1 If the next component is not a JAbstractButton, fireBinding on it. + * 2.2 If the next component is a JMenu, which is a JAbstractButton, fireBinding + * on it to open the menu. + * 2.3 If the next component is another JAbstractButton like JRadioButton. Request + * focus on it instead of fireBinding. To AVOID SELECTION & CLICK of the button. + * 3. If the code is triggered by release event, fireBinding on current focus component + * instead of move focus. + * 4. Further consideration: there may be more swing control like JMenu, or customized + * controls, which may break this behavior. + */ + // This has alt as it's modifier so this could be a mnemonic + Component focusOwner = KeyboardFocusManager.getCurrentKeyboardFocusManager().getFocusOwner(); + { + // If only one visible component, invoke it. + int visibleComponentCounter = 0; + int nextFocus = 0; + for (int i = 0; i < v.size(); i++){_ _+ JComponent c = (JComponent) v.elementAt(i);_ _+ if (c.isShowing() && c.isEnabled()){_ _+ visibleComponentCounter++ ;_ _+ nextFocus = i;_ _+ }_ _+ }_ _+ if (visibleComponentCounter == 1){_ _+ JComponent tmpc = (JComponent) v.elementAt(nextFocus);_ _+ fireBinding(tmpc, ks, e, pressed);_ _+ if (e.isConsumed())_ _+ return true;_ _+ }_ _+ // If multi-components are visible, do not select the button, just move the focus._ _+ for (int counter = v.size() - 1; counter >= 0; counter--) { + JComponent c = (JComponent) v.elementAt(counter); + if (c.isShowing() && c.isEnabled()) { + if ((c == focusOwner) + || (c instanceof JLabel && ((JLabel) c).getLabelFor() == focusOwner)) { + if (e.getID() == KeyEvent.KEYRELEASED){ + nextFocus = counter; + break; + } + nextFocus = (counter - 1 + v.size()) % v.size(); + break; + } + } + } + for (; nextFocus >= 0; nextFocus--) { + JComponent c = (JComponent) v.elementAt(nextFocus); + if (c.isShowing() && c.isEnabled()) { + break; + } + } + if (nextFocus >= 0) { + JComponent tmpc = (JComponent) v.elementAt(nextFocus); + // Next is the hack for this accessibility: + // For general Buttons, do not press them, but request focus only. + // For special buttons like JMenu, needs press. + // If it is not a button, let the component handles by itself. + if (!(tmpc instanceof javax.swing.AbstractButton)){ + fireBinding(tmpc, ks, e, pressed); + if (e.isConsumed()) + return true; + } + if (tmpc instanceof JMenu ) { + fireBinding(tmpc, ks, e, pressed); + tmpc.requestFocusInWindow(); + if (e.isConsumed()) + return true; + } else { + boolean result = tmpc.requestFocusInWindow(); + e.consume(); + return result; + } + } + // If it is not handled here, default behavior is selecting the last. + } + } + + // There is no well defined order for WHENINFOCUSEDWINDOW // bindings, but we give precedence to those bindings just // added. This is done so that JMenus WHENINFOCUSEDWINDOW

2011/4/1 Sean Chou <zhouyx at linux.vnet.ibm.com> Hi all, In daily use, we may encounter a problem of mnemonic key: there may be several controls want the same key to be set as mnemonic key. It is not common but it does exist. Current openjdk implementation allows users to set a same mnemonic key for different controls; but during the execution, when the mnemonic key is pressed, the last control always gets the action. Users are not able to touch other controls with that mnemonic key. This may confuse them. If all the controls with the same mnemonic key can be accessed through, for example, when the mnemonic key is pressed, the focus is moved to the last control, and when the mnemonic key is pressed again, the focus is moved to the second control with that mnemonic, it will give user the choice to select other controls. Here is an example for the case: package test; import java.awt.BorderLayout; import java.awt.Container; import javax.swing.ButtonGroup; import javax.swing.JFrame; import javax.swing.JRadioButton; public class TestFocus extends JFrame { public TestFocus() { Container pane = getContentPane(); pane.setLayout(new BorderLayout()); JRadioButton btn1,btn2,btn3; btn1 = new JRadioButton("Yes"); btn1.setMnemonic('Y'); btn2 = new JRadioButton("Yup"); btn2.setMnemonic('Y'); btn3 = new JRadioButton("No"); btn3.setMnemonic('N'); btn3.setSelected(true); ButtonGroup group = new ButtonGroup(); group.add(btn1); group.add(btn2); group.add(btn3); pane.add(btn1,BorderLayout.NORTH); pane.add(btn2,BorderLayout.CENTER); pane.add(btn3,BorderLayout.SOUTH); setSize(200,200); setVisible(true); setDefaultCloseOperation(EXITONCLOSE); } public static void main(String[] args) { new TestFocus(); } } -- Best Regards, Sean Chou -- Best Regards, Sean Chou -- Best Regards, Sean Chou -- Best Regards, Sean Chou

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