<Swing Dev> A proposal for a behavior change about mnemonic key
Sean Chou
zhouyx at linux.vnet.ibm.com
Wed Jul 6 09:42:28 UTC 2011
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.ALT_MASK) == Event.ALT_MASK) {
> + /* 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.KEY_RELEASED){
> + 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 WHEN_IN_FOCUSED_WINDOW
> // bindings, but we give precedence to those bindings just
> // added. This is done so that JMenus WHEN_IN_FOCUSED_WINDOW
>
>
>
>
> 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(EXIT_ON_CLOSE);
>> }
>> public static void main(String[] args) {
>> new TestFocus();
>> }
>> }
>>
>>
>>
>>
>> --
>> Best Regards,
>> Sean Chou
>>
>>
>
>
> --
> Best Regards,
> Sean Chou
>
>
--
Best Regards,
Sean Chou
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