Log and ignore missing flag definitions, and add placeholders for int…

…ernal GdkModifierType flags (fixes #155)

generator/src/main/java/io/github/jwharm/javagi/configuration/Patches.java

@@ -38,6 +38,7 @@ public class Patches {
             new GstAudioPatch(),
             new GstVideoPatch(),
             new GstBasePatch(),
+            new GdkPatch(),
             new GtkPatch(),
             new HarfBuzzPatch(),
             new PangoPatch(),

generator/src/main/java/io/github/jwharm/javagi/patches/GdkPatch.java

@@ -0,0 +1,64 @@
+/* Java-GI - Java language bindings for GObject-Introspection-based libraries
+ * Copyright (C) 2022-2024 Jan-Willem Harmannij
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+package io.github.jwharm.javagi.patches;
+
+import io.github.jwharm.javagi.gir.*;
+import io.github.jwharm.javagi.util.Patch;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import static java.util.Collections.emptyMap;
+
+public class GdkPatch implements Patch {
+    @Override
+    public GirElement patch(GirElement element, String namespace) {
+
+        if (!"Gdk".equals(namespace))
+            return element;
+
+        /*
+         * The GdkModifierType documentation states:
+         *   Note that GDK may add internal values to events which include
+         *   values outside of this enumeration. Your code should preserve and
+         *   ignore them.
+         *
+         * We preserve and ignore the internal flags in our Java EnumSet by
+         * adding placeholder "INTERNAL_n" flags for the missing ones.
+         */
+        if (element instanceof Bitfield bf
+                && "ModifierType".equals(bf.name())) {
+            var children = new ArrayList<>(bf.children());
+            Doc doc = new Doc(emptyMap(),
+                    "Internal flag. Your code should preserve and ignore this flag.");
+            for (int bit = 0; bit < 31; bit++) {
+                var value = Integer.toString(1 << bit);
+                if (bf.members().stream().noneMatch(m -> m.value().equals(value)))
+                    children.add(bit + 2, new Member(
+                            Map.of("name", "INTERNAL_" + bit, "value", value),
+                            List.of(doc)));
+            }
+            return element.withChildren(children);
+        }
+
+        return element;
+    }
+}

modules/glib/src/main/java/io/github/jwharm/javagi/interop/Interop.java

@@ -27,10 +27,12 @@
 import java.util.Arrays;
 import java.util.function.Function;
 
+import io.github.jwharm.javagi.Constants;
 import io.github.jwharm.javagi.base.Enumeration;
 import org.gnome.glib.GLib;
 
 import io.github.jwharm.javagi.base.*;
+import org.gnome.glib.LogLevelFlags;
 import org.gnome.glib.Type;
 
 import static java.lang.Long.max;
@@ -1345,7 +1347,9 @@ public static MemorySegment allocateNativeArray(MemorySegment[] array,
     }
 
     /**
-     * Create an EnumSet of class `cls` from the provided bitfield
+     * Create an EnumSet of class `cls` from the provided bitfield.
+     * Undefined flags are logged (with level
+     * {@link LogLevelFlags#LEVEL_WARNING}) and ignored.
      *
      * @param  <T>      an enum implementing the Java-GI Enumeration interface
      * @param  cls      the class of the enum
@@ -1361,8 +1365,19 @@ EnumSet<T> intToEnumSet(Class<T> cls,
         EnumSet<T> enumSet = EnumSet.noneOf(cls);
         int position = 0;
         while (n != 0) {
-            if ((n & 1) == 1)
-                enumSet.add(make.apply(1 << position));
+            if ((n & 1) == 1) {
+                // Gracefully handle undefined flags
+                try {
+                    T flag = make.apply(1 << position);
+                    enumSet.add(flag);
+                } catch (IllegalStateException e) {
+                    GLib.log(Constants.LOG_DOMAIN,
+                             LogLevelFlags.LEVEL_WARNING,
+                             "Unexpected flag %d in enum %s\n",
+                             n,
+                             cls == null ? "NULL" : cls.getName());
+                }
+            }
             position++;
             n >>= 1;
         }