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  1. JDK
  2. JDK-8154043

Fields not reachable anymore by tab-key, because of new tabbing behaviour of radio button groups.

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    • Subcomponent:
    • Introduced In Version:
    • Resolved In Build:
      b140
    • CPU:
      x86_64
    • OS:
      windows_7

      Backports

        Description

        FULL PRODUCT VERSION :
        JDK1.8.0_66

        ADDITIONAL OS VERSION INFORMATION :
        Window 7

        A DESCRIPTION OF THE PROBLEM :
        In one of the last JDK 1.8 versions the tabbing behaviour for radio button groups was changed.
        See e.g. https://bugs.openjdk.java.net/browse/JDK-8033699

        Now, under circumstances, some focusable fields are not reachable anymore.

        For example:

        <Radio Button 1> <Radio Button 2> <Textarea 1>
        <Radio Button 3> <Radio Button 4> <Textarea 2>
        <Radio Button 7> <Radio Button 6> <Textarea 3>

        The focus will always jump to "Textarea 3" if the user uses "tabs" at RadioButton1, RB3, RB7 or RB6.
        Textarea 1 and Textarea 2 are only reachable, if the user uses the cursor-keys to select RB2 or RB4 and presses thereafter the tab-key.

        The expected behaviour in current Java version for this example is: (some RB auf RB-Group) -> Textarea 1 -> Textarea 2 -> Testarea 3 -> back to start...
        The old expected behaviour before 1.8_40 was: RB1 -> RB2 -> Textarea 1 --> RB3 -> ...

        Currently the behaviour is nonpractical. The user could not tab to "Textarea 1" or "Textarea 2" in an easily comprehensible manner.

        Perhaps a property to switch to the old behaviour would be a workaround, because the new behaviour is not always the best idea...

        REGRESSION. Last worked in version 8u72

        ADDITIONAL REGRESSION INFORMATION:
        I suppose the bug results from a change in 1.8_4x
        JDK-8033699

        STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
        See source code example

        EXPECTED VERSUS ACTUAL BEHAVIOR :
        EXPECTED -
        The new expected behaviour for the example is: (some RB auf RB-Group) -> Textarea 1 -> Textarea 2 -> Testarea 3 -> back to start...
        ACTUAL -
        "Option 1" pressing Tab --> cursor Jumps to Textfield 2
        "Option 2" pressing Tab --> cursor Jumps to Textfield 1

        REPRODUCIBILITY :
        This bug can be reproduced always.

        ---------- BEGIN SOURCE ----------
        public class FocusCycleRootTest
        {
            public static void main(String[] args)
            {
                JFrame window = new JFrame("Test");
                window.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                 
                JPanel rootPanel = new JPanel();
                rootPanel.setLayout(new BorderLayout());
                 
                JPanel formPanel = new JPanel(new GridLayout(3, 3));
                formPanel.setFocusTraversalPolicy(new LayoutFocusTraversalPolicy());
                formPanel.setFocusCycleRoot(true);
                 
                JRadioButton option1 = new JRadioButton("Option 1", true);
                JRadioButton option2 = new JRadioButton("Option 2");
                JRadioButton option3 = new JRadioButton("Option 3");
                JRadioButton option4 = new JRadioButton("Option 4");
                 
                ButtonGroup radioButtonGroup = new ButtonGroup();
                radioButtonGroup.add(option1);
                radioButtonGroup.add(option2);
                radioButtonGroup.add(option3);
                radioButtonGroup.add(option4);
                 
                formPanel.add(option1);
                formPanel.add(option2);
                formPanel.add(new JTextField("1 - focusable, but not reachable"));
                formPanel.add(option3);
                formPanel.add(option4);
                formPanel.add(new JTextField("2 - focusable, great!"));
                formPanel.add(new JTextField("3 - another focusable textfield"));
                 
                rootPanel.add(formPanel, BorderLayout.CENTER);
                 
                JButton okButton = new JButton("OK");
                rootPanel.add(okButton, BorderLayout.SOUTH);
                 
                window.add(rootPanel);
                window.pack();
                window.setVisible(true);
            }
        }
        ---------- END SOURCE ----------

        CUSTOMER SUBMITTED WORKAROUND :
        I spent some time on debugging the java swing code and discovered the following cause:

        In SortingFocusTraversalPolicy the focus cycle is calculated.
        See getFocusTraversalCycle(aContainer) --> enumerateAndSortCycle()

        In this order the RadioButton entries are separately arranged.
        Later in BasicRadioButtonUI.class the method "containsInGroup" checks, whether the component belongs to a buttongroup. In this case the element behind the last buttongroup element will be taken. --> That is why the focus jumps from the first element to the element behind the last element of the radiobutton-group. But this is not correct, if there are other components between the radio button group elements, that do not belong to the radio-button group.

        Solution:
        The button group should be considered while sorting the focus-cycle. The containsInGroup check in BasicRadioButtonUI::getFocusTransferBaseComponent is to late to fix the focus behaviour.

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                Assignee:
                ssadetsky Semyon Sadetsky (Inactive)
                Reporter:
                webbuggrp Webbug Group
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                  Updated:
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