Fix binary incompatible change in the LOK API + add unit test.

Change-Id: I53cb40ea351bf56b1a299857a59ae4bf7c6b6dc3
Reviewed-on: https://gerrit.libreoffice.org/46272Reviewed-by: Marco Cecchetti <mrcekets@gmail.com>
Tested-by: Marco Cecchetti <mrcekets@gmail.com>
Tested-by: Jenkins <ci@libreoffice.org>

desktop/qa/desktop_lib/test_desktop_lib.cxx

@@ -116,6 +116,7 @@ public:
     void testCommentsCallbacksWriter();
     void testRunMacro();
     void testExtractParameter();
+    void testABI();
 
     CPPUNIT_TEST_SUITE(DesktopLOKTest);
     CPPUNIT_TEST(testGetStyles);
@@ -158,6 +159,7 @@ public:
     CPPUNIT_TEST(testCommentsCallbacksWriter);
     CPPUNIT_TEST(testRunMacro);
     CPPUNIT_TEST(testExtractParameter);
+    CPPUNIT_TEST(testABI);
     CPPUNIT_TEST_SUITE_END();
 
     uno::Reference<lang::XComponent> mxComponent;
@@ -2230,6 +2232,68 @@ void DesktopLOKTest::testExtractParameter()
     comphelper::LibreOfficeKit::setActive(false);
 }
 
+namespace {
+
+size_t documentClassOffset(int i)
+{
+    return sizeof(static_cast<struct _LibreOfficeKitDocumentClass*>(nullptr)->nSize) + i * sizeof(void*);
+}
+
+}
+
+void DesktopLOKTest::testABI()
+{
+    // STABLE ABI, NEVER CHANGE (unless there's a very good reason, agreed by ESC, etc.)
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(0), offsetof(struct _LibreOfficeKitDocumentClass, destroy));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(1), offsetof(struct _LibreOfficeKitDocumentClass, saveAs));
+
+    // Unstable ABI, but still think twice before changing this
+    // Eg. can't you add your new member at the end of the struct instead of
+    // in the middle?  The thing you are changing - is it already part of some
+    // release?
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(2), offsetof(struct _LibreOfficeKitDocumentClass, getDocumentType));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(3), offsetof(struct _LibreOfficeKitDocumentClass, getParts));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(4), offsetof(struct _LibreOfficeKitDocumentClass, getPartPageRectangles));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(5), offsetof(struct _LibreOfficeKitDocumentClass, getPart));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(6), offsetof(struct _LibreOfficeKitDocumentClass, setPart));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(7), offsetof(struct _LibreOfficeKitDocumentClass, getPartName));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(8), offsetof(struct _LibreOfficeKitDocumentClass, setPartMode));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(9), offsetof(struct _LibreOfficeKitDocumentClass, paintTile));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(10), offsetof(struct _LibreOfficeKitDocumentClass, getTileMode));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(11), offsetof(struct _LibreOfficeKitDocumentClass, getDocumentSize));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(12), offsetof(struct _LibreOfficeKitDocumentClass, initializeForRendering));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(13), offsetof(struct _LibreOfficeKitDocumentClass, registerCallback));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(14), offsetof(struct _LibreOfficeKitDocumentClass, postKeyEvent));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(15), offsetof(struct _LibreOfficeKitDocumentClass, postMouseEvent));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(16), offsetof(struct _LibreOfficeKitDocumentClass, postUnoCommand));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(17), offsetof(struct _LibreOfficeKitDocumentClass, setTextSelection));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(18), offsetof(struct _LibreOfficeKitDocumentClass, getTextSelection));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(19), offsetof(struct _LibreOfficeKitDocumentClass, paste));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(20), offsetof(struct _LibreOfficeKitDocumentClass, setGraphicSelection));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(21), offsetof(struct _LibreOfficeKitDocumentClass, resetSelection));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(22), offsetof(struct _LibreOfficeKitDocumentClass, getCommandValues));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(23), offsetof(struct _LibreOfficeKitDocumentClass, setClientZoom));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(24), offsetof(struct _LibreOfficeKitDocumentClass, setClientVisibleArea));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(25), offsetof(struct _LibreOfficeKitDocumentClass, createView));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(26), offsetof(struct _LibreOfficeKitDocumentClass, destroyView));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(27), offsetof(struct _LibreOfficeKitDocumentClass, setView));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(28), offsetof(struct _LibreOfficeKitDocumentClass, getView));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(29), offsetof(struct _LibreOfficeKitDocumentClass, getViewsCount));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(30), offsetof(struct _LibreOfficeKitDocumentClass, renderFont));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(31), offsetof(struct _LibreOfficeKitDocumentClass, getPartHash));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(32), offsetof(struct _LibreOfficeKitDocumentClass, paintPartTile));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(33), offsetof(struct _LibreOfficeKitDocumentClass, getViewIds));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(34), offsetof(struct _LibreOfficeKitDocumentClass, setOutlineState));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(35), offsetof(struct _LibreOfficeKitDocumentClass, paintWindow));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(36), offsetof(struct _LibreOfficeKitDocumentClass, postWindow));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(37), offsetof(struct _LibreOfficeKitDocumentClass, postWindowKeyEvent));
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(38), offsetof(struct _LibreOfficeKitDocumentClass, postWindowMouseEvent));
+
+    // Extending is fine, update this, and add new assert for the offsetof the
+    // new method
+    CPPUNIT_ASSERT_EQUAL(documentClassOffset(39), sizeof(struct _LibreOfficeKitDocumentClass));
+}
+
 CPPUNIT_TEST_SUITE_REGISTRATION(DesktopLOKTest);
 
 CPPUNIT_PLUGIN_IMPLEMENT();

include/LibreOfficeKit/LibreOfficeKit.h

@@ -228,9 +228,6 @@ struct _LibreOfficeKitDocumentClass
     /// @see lok::Document::setVisibleArea).
     void (*setClientVisibleArea) (LibreOfficeKitDocument* pThis, int nX, int nY, int nWidth, int nHeight);
 
-    /// @see lok::Document::setOutlineState).
-    void (*setOutlineState) (LibreOfficeKitDocument* pThis, bool bColumn, int nLevel, int nIndex, bool bHidden);
-
     /// @see lok::Document::createView().
     int (*createView) (LibreOfficeKitDocument* pThis);
     /// @see lok::Document::destroyView().
@@ -270,6 +267,9 @@ struct _LibreOfficeKitDocumentClass
                        int* pArray,
                        size_t nSize);
 
+    /// @see lok::Document::setOutlineState).
+    void (*setOutlineState) (LibreOfficeKitDocument* pThis, bool bColumn, int nLevel, int nIndex, bool bHidden);
+
     /// Paints window with given id to the buffer
     /// @see lok::Document::paintWindow().
     void (*paintWindow) (LibreOfficeKitDocument* pThis, unsigned nWindowId,