tdf#118418 implement scrollSubstringTo() for gtk

Define & use new accessibility scroll type compatible with IAccessible2
and extend the XAccessibleText interface to require scrollSubstringTo().

Co-authored-by: Martin Pieuchot <mpi@grenadille.net>
Change-Id: Id3b2e8616892d7dcbfb41a14b72a8a457fd1dbf6
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/89851
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

3 files changed, 109 insertions, 0 deletions

diff --git a/offapi/UnoApi_offapi.mk b/offapi/UnoApi_offapi.mk
index 8f4079009f12..61262689343b 100644
--- a/offapi/UnoApi_offapi.mk
+++ b/offapi/UnoApi_offapi.mk
@@ -1621,6 +1621,7 @@ $(eval $(call gb_UnoApi_add_idlfiles,offapi,com/sun/star/accessibility,\
 	AccessibleRelation \
 	AccessibleRelationType \
 	AccessibleRole \
+	AccessibleScrollType \
 	AccessibleStateType \
 	AccessibleTableModelChange \
 	AccessibleTableModelChangeType \
diff --git a/offapi/com/sun/star/accessibility/AccessibleScrollType.idl b/offapi/com/sun/star/accessibility/AccessibleScrollType.idl
new file mode 100644
index 000000000000..fd096b09b3d9
--- /dev/null
+++ b/offapi/com/sun/star/accessibility/AccessibleScrollType.idl
@@ -0,0 +1,81 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#ifndef __com_sun_star_accessibility_AccessibleScrollType_idl__
+#define __com_sun_star_accessibility_AccessibleScrollType_idl__
+
+module com { module sun { module star { module accessibility {
+
+/** Scroll types
+
+    <p>Describes the type of scrolling that are available for the methods of
+    the XAccessibleScrollableText interface.</p>
+
+    @since LibreOffice 7.0
+*/
+enum AccessibleScrollType
+{
+    /**
+        Scroll the top left corner of the object or string such that the
+        top left corner is within the top level window.
+    */
+    SCROLL_TOP_LEFT,
+
+    /**
+        Scroll the bottom right corner of the object or string such that the
+        bottom right corner is within the top level window.
+    */
+    SCROLL_BOTTOM_RIGHT,
+
+    /**
+        Scroll the top edge of the object or string such that the top edge is
+        within the top level window.
+    */
+    SCROLL_TOP_EDGE,
+
+    /**
+        Scroll the bottom edge of the object or string such that the bottom
+        edge is within the top level window.
+    */
+    SCROLL_BOTTOM_EDGE,
+
+    /**
+        Scroll the left edge of the object or string such that the left edge
+        is within the top level window.
+    */
+    SCROLL_LEFT_EDGE,
+
+    /**
+        Scroll the right edge of the object or string such that the right edge
+        is within the top level window.
+    */
+    SCROLL_RIGHT_EDGE,
+
+    /**
+        Scroll the object or string such that as much as possible of the
+        object or string is within the top level window.
+    */
+    SCROLL_ANYWHERE
+};
+
+}; }; }; };
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/offapi/com/sun/star/accessibility/XAccessibleText.idl b/offapi/com/sun/star/accessibility/XAccessibleText.idl
index 7e90f2d8a463..98af06445733 100644
--- a/offapi/com/sun/star/accessibility/XAccessibleText.idl
+++ b/offapi/com/sun/star/accessibility/XAccessibleText.idl
@@ -491,6 +491,33 @@ interface XAccessibleText : ::com::sun::star::uno::XInterface
     boolean copyText ([in] long nStartIndex, [in] long nEndIndex)
         raises (::com::sun::star::lang::IndexOutOfBoundsException);
 
+    /** Scroll the specified text to make it visible on screen.
+
+        @param nStartIndex
+            Start index of the text to scroll.
+            The valid range is 0..length.
+
+        @param nEndIndex
+            End index of the text to scroll.
+            The valid range is nStartIndex..length.
+
+        @param aScrollType
+            Type of scroll to perform.  See AccessibleScrollType for the
+            complete list.
+
+        @return
+            Returns `TRUE` if the specified text has been scrolled
+            successfully.
+
+        @throws ::com::sun::star::lang::IndexOutOfBoundsException
+            if the indices are invalid
+
+        @since LibreOffice 7.0
+    */
+    boolean
+        scrollSubstringTo ([in] long nStartIndex, [in] long nEndIndex,
+            [in] AccessibleScrollType aScrollType)
+        raises (::com::sun::star::lang::IndexOutOfBoundsException);
 };
 
 }; }; }; };