Fix #16485: Modal dialogs may occasionally be behind another dialog

From the [https://docs.oracle.com/en/java/javase/21/docs/api/java.desktop/java/awt/doc-files/Modality.html Modality] javadocs:
> * keeps its Z-order below the modal dialog that blocks it
> **Warning! ** Some window managers allow users to change the window Z-order in an arbitrary way — in that case the last requirement may not be met. 

The workaround is to set the blocking dialog as always on top.

git-svn-id: https://josm.openstreetmap.de/svn/trunk@18849 0c6e7542-c601-0410-84e7-c038aed88b3b

src/org/openstreetmap/josm/gui/ConditionalOptionPaneUtil.java

@@ -4,6 +4,7 @@
 import static org.openstreetmap.josm.tools.I18n.tr;
 
 import java.awt.Component;
+import java.awt.Dialog;
 import java.awt.GridBagLayout;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -14,6 +15,8 @@
 import javax.swing.JOptionPane;
 import javax.swing.JPanel;
 import javax.swing.JRadioButton;
+import javax.swing.event.AncestorEvent;
+import javax.swing.event.AncestorListener;
 
 import org.openstreetmap.josm.gui.widgets.JMultilineLabel;
 import org.openstreetmap.josm.spi.preferences.Config;
@@ -23,7 +26,7 @@
 /**
  * ConditionalOptionPaneUtil provides static utility methods for displaying modal message dialogs
  * which can be enabled/disabled by the user.
- *
+ * <p>
  * They wrap the methods provided by {@link JOptionPane}. Within JOSM you should use these
  * methods rather than the bare methods from {@link JOptionPane} because the methods provided
  * by ConditionalOptionPaneUtil ensure that a dialog window is always on top and isn't hidden by one of the
@@ -92,13 +95,13 @@ public static void endBulkOperation(final String prefKey) {
      * Displays an confirmation dialog with some option buttons given by <code>optionType</code>.
      * It is always on top even if there are other open windows like detached dialogs,
      * relation editors, history browsers and the like.
-     *
+     * <p>
      * Set <code>optionType</code> to {@link JOptionPane#YES_NO_OPTION} for a dialog with a YES and
      * a NO button.
-
+     * <p>
      * Set <code>optionType</code> to {@link JOptionPane#YES_NO_CANCEL_OPTION} for a dialog with a YES,
      * a NO and a CANCEL button
-     *
+     * <p>
      * Returns one of the constants JOptionPane.YES_OPTION, JOptionPane.NO_OPTION,
      * JOptionPane.CANCEL_OPTION or JOptionPane.CLOSED_OPTION depending on the action chosen by
      * the user.
@@ -132,13 +135,13 @@ public static int showOptionDialog(String preferenceKey, Component parent, Objec
      * Displays a confirmation dialog with some option buttons given by <code>optionType</code>.
      * It is always on top even if there are other open windows like detached dialogs,
      * relation editors, history browsers and the like.
-     *
+     * <p>
      * Set <code>optionType</code> to {@link JOptionPane#YES_NO_OPTION} for a dialog with a YES and
      * a NO button.
-
+     * <p>
      * Set <code>optionType</code> to {@link JOptionPane#YES_NO_CANCEL_OPTION} for a dialog with a YES,
      * a NO and a CANCEL button
-     *
+     * <p>
      * Replies true, if the selected option is equal to <code>trueOption</code>, otherwise false.
      * Replies true, if the dialog is not displayed because the respective preference option
      * <code>preferenceKey</code> is set to false and the user has previously chosen
@@ -180,7 +183,7 @@ private static boolean isYesOrNo(int returnCode) {
      * Displays an message in modal dialog with an OK button. Makes sure the dialog
      * is always on top even if there are other open windows like detached dialogs,
      * relation editors, history browsers and the like.
-     *
+     * <p>
      * If there is a preference with key <code>preferenceKey</code> and value <code>false</code>
      * the dialog is not show.
      *
@@ -283,6 +286,35 @@ public static class MessagePanel extends JPanel {
                 add(cbShowImmediateDialog, GBC.eol());
             }
             add(cbStandard, GBC.eol());
+
+            this.addAncestorListener(new AncestorListener() {
+                boolean wasAlwaysOnTop;
+                @Override
+                public void ancestorAdded(AncestorEvent event) {
+                    if (event.getAncestor() instanceof Dialog) {
+                        Dialog dialog = (Dialog) event.getAncestor();
+                        wasAlwaysOnTop = dialog.isAlwaysOnTop();
+                        if (dialog.isVisible() && dialog.isModal()) {
+                            dialog.setAlwaysOnTop(true);
+                        }
+                    }
+                }
+
+                @Override
+                public void ancestorRemoved(AncestorEvent event) {
+                    if (event.getAncestor() instanceof Dialog) {
+                        Dialog dialog = (Dialog) event.getAncestor();
+                        if (dialog.isVisible() && dialog.isModal()) {
+                            dialog.setAlwaysOnTop(wasAlwaysOnTop);
+                        }
+                    }
+                }
+
+                @Override
+                public void ancestorMoved(AncestorEvent event) {
+                    // Do nothing
+                }
+            });
         }
 
         NotShowAgain getNotShowAgain() {

src/org/openstreetmap/josm/gui/ExtendedDialog.java

@@ -459,6 +459,9 @@ public void setVisible(boolean visible) {
                 rememberWindowGeometry(new WindowGeometry(this));
             }
         }
+        if (visible && isModal()) {
+            this.setAlwaysOnTop(true);
+        }
         super.setVisible(visible);
 
         if (!visible && disposeOnClose) {

src/org/openstreetmap/josm/gui/HelpAwareOptionPane.java

@@ -218,11 +218,11 @@ public void actionPerformed(ActionEvent e) {
      * the dialog includes a "Help" button and launches the help browser if the user presses F1. If the
      * user clicks on the "Help" button the option dialog remains open and JOSM launches the help
      * browser.
-     *
+     * <p>
      * <code>helpTopic</code> is the trailing part of a JOSM online help URL, i.e. the part after the leading
-     * <code>https://josm.openstreetmap.de/wiki/Help</code>. It should start with a leading '/' and it
+     * {@code https://josm.openstreetmap.de/wiki/Help}. It should start with a leading '/' and it
      * may include an anchor after a '#'.
-     *
+     * <p>
      * <strong>Examples</strong>
      * <ul>
      *    <li>/Dialogs/RelationEditor</li>
@@ -350,6 +350,9 @@ public void actionPerformed(ActionEvent e) {
         if (helpTopic != null) {
             HelpUtil.setHelpContext(dialog.getRootPane(), helpTopic);
         }
+        if (dialog.isModal()) {
+            dialog.setAlwaysOnTop(true);
+        }
         dialog.setVisible(true);
     }
 
@@ -371,7 +374,7 @@ public static int showOptionDialog(Component parentComponent, Object msg, String
     /**
      * Run it in Event Dispatch Thread.
      * This version does not return anything, so it is more like {@code showMessageDialog}.
-     *
+     * <p>
      * It can be used, when you need to show a message dialog from a worker thread,
      * e.g. from {@code PleaseWaitRunnable}.
      *