vcl: migrate ImplLayoutRuns to own files

Wrote a set of unit tests for ImplLayoutRuns, and added ImplLayoutRuns
to vcl::text namespace.

Change-Id: Id6ae8882acb8e3d821bb38551e78019cbdcaa662
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/121204
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

1 files changed, 179 insertions, 0 deletions

diff --git a/vcl/source/text/ImplLayoutRuns.cxx b/vcl/source/text/ImplLayoutRuns.cxx
new file mode 100644
index 000000000000..a560e17e1b8b
--- /dev/null
+++ b/vcl/source/text/ImplLayoutRuns.cxx
@@ -0,0 +1,179 @@
+/* -*- 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 .
+ */
+
+#include <ImplLayoutRuns.hxx>
+
+void ImplLayoutRuns::AddPos( int nCharPos, bool bRTL )
+{
+    // check if charpos could extend current run
+    int nIndex = maRuns.size();
+    if( nIndex >= 2 )
+    {
+        int nRunPos0 = maRuns[ nIndex-2 ];
+        int nRunPos1 = maRuns[ nIndex-1 ];
+        if( ((nCharPos + int(bRTL)) == nRunPos1) && ((nRunPos0 > nRunPos1) == bRTL) )
+        {
+            // extend current run by new charpos
+            maRuns[ nIndex-1 ] = nCharPos + int(!bRTL);
+            return;
+        }
+        // ignore new charpos when it is in current run
+        if( (nRunPos0 <= nCharPos) && (nCharPos < nRunPos1) )
+            return;
+        if( (nRunPos1 <= nCharPos) && (nCharPos < nRunPos0) )
+            return;
+    }
+
+    // else append a new run consisting of the new charpos
+    maRuns.push_back( nCharPos + (bRTL ? 1 : 0) );
+    maRuns.push_back( nCharPos + (bRTL ? 0 : 1) );
+}
+
+void ImplLayoutRuns::AddRun( int nCharPos0, int nCharPos1, bool bRTL )
+{
+    if( nCharPos0 == nCharPos1 )
+        return;
+
+    // swap if needed
+    if( bRTL == (nCharPos0 < nCharPos1) )
+    {
+        int nTemp = nCharPos0;
+        nCharPos0 = nCharPos1;
+        nCharPos1 = nTemp;
+    }
+
+    if (maRuns.size() >= 2 && nCharPos0 == maRuns[maRuns.size() - 2] && nCharPos1 == maRuns[maRuns.size() - 1])
+    {
+        //this run is the same as the last
+        return;
+    }
+
+    // append new run
+    maRuns.push_back( nCharPos0 );
+    maRuns.push_back( nCharPos1 );
+}
+
+bool ImplLayoutRuns::PosIsInRun( int nCharPos ) const
+{
+    if( mnRunIndex >= static_cast<int>(maRuns.size()) )
+        return false;
+
+    int nMinCharPos = maRuns[ mnRunIndex+0 ];
+    int nEndCharPos = maRuns[ mnRunIndex+1 ];
+    if( nMinCharPos > nEndCharPos ) // reversed in RTL case
+    {
+        int nTemp = nMinCharPos;
+        nMinCharPos = nEndCharPos;
+        nEndCharPos = nTemp;
+    }
+
+    if( nCharPos < nMinCharPos )
+        return false;
+    if( nCharPos >= nEndCharPos )
+        return false;
+    return true;
+}
+
+bool ImplLayoutRuns::PosIsInAnyRun( int nCharPos ) const
+{
+    bool bRet = false;
+    int nRunIndex = mnRunIndex;
+
+    ImplLayoutRuns *pThis = const_cast<ImplLayoutRuns*>(this);
+
+    pThis->ResetPos();
+
+    for (size_t i = 0; i < maRuns.size(); i+=2)
+    {
+        bRet = PosIsInRun( nCharPos );
+        if( bRet )
+            break;
+        pThis->NextRun();
+    }
+
+    pThis->mnRunIndex = nRunIndex;
+    return bRet;
+}
+
+bool ImplLayoutRuns::GetNextPos( int* nCharPos, bool* bRightToLeft )
+{
+    // negative nCharPos => reset to first run
+    if( *nCharPos < 0 )
+        mnRunIndex = 0;
+
+    // return false when all runs completed
+    if( mnRunIndex >= static_cast<int>(maRuns.size()) )
+        return false;
+
+    int nRunPos0 = maRuns[ mnRunIndex+0 ];
+    int nRunPos1 = maRuns[ mnRunIndex+1 ];
+    *bRightToLeft = (nRunPos0 > nRunPos1);
+
+    if( *nCharPos < 0 )
+    {
+        // get first valid nCharPos in run
+        *nCharPos = nRunPos0;
+    }
+    else
+    {
+        // advance to next nCharPos for LTR case
+        if( !*bRightToLeft )
+            ++(*nCharPos);
+
+        // advance to next run if current run is completed
+        if( *nCharPos == nRunPos1 )
+        {
+            if( (mnRunIndex += 2) >= static_cast<int>(maRuns.size()) )
+                return false;
+            nRunPos0 = maRuns[ mnRunIndex+0 ];
+            nRunPos1 = maRuns[ mnRunIndex+1 ];
+            *bRightToLeft = (nRunPos0 > nRunPos1);
+            *nCharPos = nRunPos0;
+        }
+    }
+
+    // advance to next nCharPos for RTL case
+    if( *bRightToLeft )
+        --(*nCharPos);
+
+    return true;
+}
+
+bool ImplLayoutRuns::GetRun( int* nMinRunPos, int* nEndRunPos, bool* bRightToLeft ) const
+{
+    if( mnRunIndex >= static_cast<int>(maRuns.size()) )
+        return false;
+
+    int nRunPos0 = maRuns[ mnRunIndex+0 ];
+    int nRunPos1 = maRuns[ mnRunIndex+1 ];
+    *bRightToLeft = (nRunPos1 < nRunPos0) ;
+    if( !*bRightToLeft )
+    {
+        *nMinRunPos = nRunPos0;
+        *nEndRunPos = nRunPos1;
+    }
+    else
+    {
+        *nMinRunPos = nRunPos1;
+        *nEndRunPos = nRunPos0;
+    }
+    return true;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */