Add mapping for XQueryExtension

Author: lafoletc

CHANGES.md

@@ -14,6 +14,7 @@ Features
 * [#1239](https://github.com/java-native-access/jna/pull/1239): Improve performance of allocation of `c.s.j.Memory` objects - [@joerg1985](https://github.com/joerg1985).
 * [#1246](https://github.com/java-native-access/jna/pull/1246): Improve performance of `c.s.j.Structure#read` and `c.s.j.Structure#write` - [@joerg1985](https://github.com/joerg1985).
 * [#1260](https://github.com/java-native-access/jna/pull/1260): Add mapping for X11 generic events - [@lafoletc](https://github.com/lafoletc).
+* [#1265](https://github.com/java-native-access/jna/pull/1265): Add mapping for XQueryExtension - [@lafoletc](https://github.com/lafoletc).
 
 Bug Fixes
 ---------

contrib/platform/src/com/sun/jna/platform/unix/X11.java

@@ -285,6 +285,17 @@ class GC extends PointerType { }
     // TODO: define structure
     class XImage extends PointerType { }
 
+    /**
+     * The XQueryExtension function determines if the named extension is present.
+     * @param display Specifies the connection to the X server.
+     * @param name Specifies the extension name.
+     * @param major_opcode_return Returns the major opcode.
+     * @param first_event_return Returns the first event code, if any.
+     * @param first_error_return Returns the first error code, if any.
+     * @return if present
+     */
+    boolean XQueryExtension(Display display, String name, IntByReference major_opcode_return, IntByReference first_event_return, IntByReference first_error_return);
+
     /** Definition (incomplete) of the Xext library. */
     interface Xext extends Library {
         Xext INSTANCE = Native.load("Xext", Xext.class);

contrib/platform/test/com/sun/jna/platform/unix/X11Test.java

@@ -116,6 +116,24 @@ public void testXGetWMProtocols() {
         Assert.assertArrayEquals("Sent protocols were not equal to returned procols for XGetWMProtocols", sentAtoms, receivedAtoms);
     }
 
+    public void testXQueryExtension() {
+        final IntByReference opcode = new IntByReference(0);
+        final IntByReference first_event = new IntByReference(0);
+        final IntByReference first_error = new IntByReference(0);
+
+        // check if the XTEST extension is available
+        if (X11.INSTANCE.XQueryExtension(display, "XTEST", opcode, first_event, first_error)) {
+            // Opcode for extension should be assigned in range 128-255
+            Assert.assertTrue("Value for opcode should be between 128-255.", (opcode.getValue() & 0x80) > 0);
+            // No first_event defined for XTEST
+            Assert.assertEquals("Wrong value for first_event returned", 0, first_event.getValue());
+            // No first_error defined for XTEST
+            Assert.assertEquals("Wrong value for first_error returned", 0, first_error.getValue());
+        } else {
+            // XTEST extension is not supported by the X server
+        }
+    }
+
     public void testStructureFieldOrder() {
         StructureFieldOrderInspector.batchCheckStructureGetFieldOrder(X11.class, null, true);
     }