1 files changed, 131 insertions, 0 deletions
diff --git a/sc/inc/fstalgorithm.hxx b/sc/inc/fstalgorithm.hxx
new file mode 100644
index 000000000..f3f189184
--- /dev/null
+++ b/sc/inc/fstalgorithm.hxx
@@ -0,0 +1,131 @@
+/* -*- 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/.
+ */
+
+#pragma once
+
+#include <mdds/flat_segment_tree.hpp>
+#include <vector>
+
+namespace sc {
+
+template<typename Key, typename Span>
+void buildSpan(
+    std::vector<Span>& rSpans,
+    typename mdds::flat_segment_tree<Key,bool>::const_iterator it,
+    typename mdds::flat_segment_tree<Key,bool>::const_iterator itEnd, const Key* pStart )
+{
+    Key nLastPos = it->first;
+    bool bLastVal = it->second;
+    for (++it; it != itEnd; ++it)
+    {
+        Key nThisPos = it->first;
+        bool bThisVal = it->second;
+
+        if (bLastVal)
+        {
+            Key nIndex1 = nLastPos;
+            Key nIndex2 = nThisPos-1;
+
+            if (!pStart || *pStart < nIndex1)
+                rSpans.push_back(Span(nIndex1, nIndex2));
+            else if (*pStart <= nIndex2)
+                rSpans.push_back(Span(*pStart, nIndex2));
+        }
+
+        nLastPos = nThisPos;
+        bLastVal = bThisVal;
+    }
+}
+
+template<typename Key, typename Val, typename Span>
+void buildSpanWithValue(
+    std::vector<Span>& rSpans,
+    typename mdds::flat_segment_tree<Key,Val>::const_iterator it,
+    typename mdds::flat_segment_tree<Key,Val>::const_iterator itEnd )
+{
+    Key nLastPos = it->first;
+    Val nLastVal = it->second;
+    for (++it; it != itEnd; ++it)
+    {
+        Key nThisPos = it->first;
+        Val nThisVal = it->second;
+
+        if (nLastVal)
+        {
+            Key nIndex1 = nLastPos;
+            Key nIndex2 = nThisPos-1;
+            rSpans.push_back(Span(nIndex1, nIndex2, nLastVal));
+        }
+
+        nLastPos = nThisPos;
+        nLastVal = nThisVal;
+    }
+}
+
+/**
+ * Convert a flat_segment_tree structure whose value type is boolean, into
+ * an array of ranges that corresponds with the segments that have a 'true'
+ * value.
+ */
+template<typename Key, typename Span>
+std::vector<Span> toSpanArray( const mdds::flat_segment_tree<Key,bool>& rTree )
+{
+    typedef mdds::flat_segment_tree<Key,bool> FstType;
+
+    std::vector<Span> aSpans;
+
+    typename FstType::const_iterator it = rTree.begin(), itEnd = rTree.end();
+    buildSpan<Key,Span>(aSpans, it, itEnd, nullptr);
+    return aSpans;
+}
+
+/**
+ * Convert a flat_segment_tree structure into an array of ranges with
+ * values.  Only those ranges whose value is evaluated to be true will be
+ * included.  The value type must be something that supports bool operator.
+ * The span type must support a constructor that takes a start key, an end
+ * key and a value in this order.
+ */
+template<typename Key, typename Val, typename Span>
+std::vector<Span> toSpanArrayWithValue( const mdds::flat_segment_tree<Key,Val>& rTree )
+{
+    typedef mdds::flat_segment_tree<Key,Val> FstType;
+
+    std::vector<Span> aSpans;
+
+    typename FstType::const_iterator it = rTree.begin(), itEnd = rTree.end();
+    buildSpanWithValue<Key,Val,Span>(aSpans, it, itEnd);
+    return aSpans;
+}
+
+template<typename Key, typename Span>
+std::vector<Span> toSpanArray( const mdds::flat_segment_tree<Key,bool>& rTree, Key nStartPos )
+{
+    typedef mdds::flat_segment_tree<Key,bool> FstType;
+
+    std::vector<Span> aSpans;
+    if (!rTree.is_tree_valid())
+        return aSpans;
+
+    bool bThisVal = false;
+    std::pair<typename FstType::const_iterator, bool> r =
+        rTree.search_tree(nStartPos, bThisVal);
+
+    if (!r.second)
+        // Tree search failed.
+        return aSpans;
+
+    typename FstType::const_iterator it = r.first, itEnd = rTree.end();
+    buildSpan<Key,Span>(aSpans, it, itEnd, &nStartPos);
+    return aSpans;
+}
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */