v0.2.54..v0.2.55 changeset ElementComparison.h

diff --git a/hoot-core/src/main/cpp/hoot/core/elements/ElementComparison.h b/hoot-core/src/main/cpp/hoot/core/elements/ElementComparison.h
new file mode 100644
index 0000000..9335c6c
--- /dev/null
+++ b/hoot-core/src/main/cpp/hoot/core/elements/ElementComparison.h
@@ -0,0 +1,85 @@
+/*
+ * This file is part of Hootenanny.
+ *
+ * Hootenanny is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * --------------------------------------------------------------------
+ *
+ * The following copyright notices are generated automatically. If you
+ * have a new notice to add, please use the format:
+ * " * @copyright Copyright ..."
+ * This will properly maintain the copyright information. DigitalGlobe
+ * copyrights will be updated automatically.
+ *
+ * @copyright Copyright (C) 2020 DigitalGlobe (http://www.digitalglobe.com/)
+ */
+#ifndef ELEMENT_COMPARISON_H
+#define ELEMENT_COMPARISON_H
+
+// Hoot
+#include <hoot/core/elements/OsmMap.h>
+#include <hoot/core/elements/ElementComparer.h>
+#include <hoot/core/schema/MetadataTags.h>
+
+namespace hoot
+{
+
+/**
+ * Allows for comparing elements within a collection
+ *
+ * @see ElementComparer
+ */
+class ElementComparison
+{
+public:
+
+  ElementComparison();
+  ElementComparison(ElementPtr element, const OsmMap& sourceMap,
+                    const bool ignoreElementId = false);
+
+  ElementPtr getElement() const { return _element; }
+
+  virtual bool operator==(const ElementComparison& elementComp) const;
+
+  virtual QString toString() const;
+
+  bool isNull() const { return !_element.get(); }
+
+  /**
+   * Wrapper around ElementHashVisitor::toHashString
+   */
+  QString toHashString() const { return _elementComparer.toHashString(_element); }
+
+protected:
+
+  // This isn't const due to ElementComparer needing to add the hash to it before comparison.
+  ElementPtr _element;
+  ElementComparer _elementComparer;
+};
+
+inline uint qHash(const ElementComparison& elementComp)
+{
+  // reuse the hash if its already there
+  const QString hashFromTag =
+    elementComp.getElement()->getTags().get(MetadataTags::HootHash()).trimmed();
+  if (!hashFromTag.isEmpty())
+  {
+    return qHash(hashFromTag);
+  }
+  return qHash(elementComp.toHashString());
+}
+
+}
+
+#endif // ELEMENT_COMPARISON_H