<Swing Dev> A proposal for a behavior change about mnemonic key
Sean Chou
zhouyx at linux.vnet.ibm.com
Thu Sep 22 05:51:51 UTC 2011
Hi Pavel,
Your observation is right, but I can't agree with the conclusion. Windows
and
GTK behave differently about how to close an opened menu. Under GTK, press
"alt" can not close an opened menu, so, the "esc" is used to close it;
while
windows performs more friendly, when mnemonic key is pressed again, the
first
opened menu is closed automatically. This is totally about how to close an
opened menu, and it doesn't change the fact that menus with same mnemonic
key are iterated.
On the other side, swing implementation doesn't follow GTK's behavior
about
how to close the menu at all. Open the swingset2 and you can find its
behavior
is the same with windows. Press "alt+f" and then press "alt+l" will open the
"look and feel" menu instead of GTK's "alt+f", "esc", and "alt+l".
So, I think GTK's behavior about "use esc to close an opened menu" is not
user friendly and we can ignore it, while GTK's "iterate over menus with
same
mnemonic key" is better than current java implementation and we can add
this feature. And if a user wants to use GTK's key sequence "alt+f", "esc",
"alt+l", it is also functional.
So I think this enhancement will help keep the behavior same with both
these
platforms, how do you think?
2011/9/21 Pavel Porvatov <pavel.porvatov at oracle.com>
> **
> Hi Sean,
>
> I found out that Windows and GTK works in different ways (I used your
> apps):
>
> 1. When Alt+i is pressed several times:
> In Windows focus moves between items
> In Ubuntu focus stays at the initially selected item
>
> 2. When sequence Alt+i and Escape pressed several times
> In Windows the first menu item is selected
> In Ubuntu after every sequence the next item is selected
>
> In such case we should use different strategies for different platforms...
>
>
> Regards, Pavel
>
> Hi Pavel,
>
> I just tested linux gtk platform. With gtk2+, ubuntu linux with
> kernel 2.6.38, xfce, x86_32.
> I set four menus with mnemonic "i". Press "alt+i" will travel through four
> menus. The difference
> is that each menu must be closed with "esc" before "alt+i" opens the next
> one.
>
> So press "alt+i" opens "File", and press "esc" to close it;
> then press "alt+i" opens "Edit", and press "esc" to close it;
> ... for next menu with mnemonic "i"
>
> I attached the test application and its ui file. If it is blocked, please
> use
> this link:
> https://docs.google.com/leaf?id=0B8kRxsymP7imOGU1NjhiM2ItMGQ5Ni00NWNhLWJmMDQtZjZiZmQzN2U4ZGUw&hl=en_US
>
> Ubuntu x86_32 should work.
>
>
> So, I think both windows and linux gtk have supported traversal of same
> mnemonic keyed
> items already.
>
>
> 2011/9/14 Pavel Porvatov <pavel.porvatov at oracle.com>
>
> Hi Sean,
>
> Hi Pavel,
>
> Let's see if this time works. The attachement just contains the exe
> file written by C#, the application is very simple, I just drag a menu to
> the default WinForm in VS2003.
> Please change the extension from exe1 to exe after unzip as gmail
> doesn't allow exe file to be sent.
>
> Yes, I see. And what about other platforms/lafs? Your patch affects
> behavior of all lafs. So we must be sure, that such behavior is correct for
> every supported platform...
>
> Regards, Pavel
>
>
> 2011/9/13 Pavel Porvatov <pavel.porvatov at oracle.com>
>
> Hi Sean,
>
> I think the attached sample was removed because I didn't get any
> attachments...
>
> Regards, Pavel
>
> 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.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
>
>
>
>
> --
> Best Regards,
> Sean Chou
>
>
>
>
>
> --
> Best Regards,
> Sean Chou
>
>
>
>
>
> --
> Best Regards,
> Sean Chou
>
>
>
>
>
> --
> Best Regards,
> Sean Chou
>
>
>
--
Best Regards,
Sean Chou
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