[FEATURE] new OpenStreetMap data access API and GUI

The idea is to replace the current OSM provider+plugin by this new code. Differences from old code:
- read-only access - without editing and upload support
- no special provider (using SpatiaLite provider)
- underlying OSM topology accessible from API
- download using Overpass API: fast, customizable, nearly unlimited download
- OSM XML files have to be first imported to a Sqlite3 database, then SpatiaLite layers can be exported

Author: wonder-sk

src/analysis/CMakeLists.txt

@@ -37,6 +37,10 @@ SET(QGIS_ANALYSIS_SRCS
   vector/qgsgeometryanalyzer.cpp
   vector/qgszonalstatistics.cpp
   vector/qgsoverlayanalyzer.cpp
+  openstreetmap/qgsosmbase.cpp
+  openstreetmap/qgsosmdatabase.cpp
+  openstreetmap/qgsosmdownload.cpp
+  openstreetmap/qgsosmimport.cpp
 )
 
 INCLUDE_DIRECTORIES(BEFORE raster)
@@ -64,6 +68,8 @@ IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
 ENDIF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
 
 SET(QGIS_ANALYSIS_MOC_HDRS
+  openstreetmap/qgsosmdownload.h
+  openstreetmap/qgsosmimport.h
 )
 
 QT4_WRAP_CPP(QGIS_ANALYSIS_MOC_SRCS ${QGIS_ANALYSIS_MOC_HDRS})
@@ -85,6 +91,10 @@ SET(QGIS_ANALYSIS_HDRS
   interpolation/qgsgridfilewriter.h
   interpolation/qgsidwinterpolator.h
   interpolation/qgstininterpolator.h
+  openstreetmap/qgsosmbase.h
+  openstreetmap/qgsosmdatabase.h
+  openstreetmap/qgsosmdownload.h
+  openstreetmap/qgsosmimport.h
 )
 
 INCLUDE_DIRECTORIES(

src/analysis/openstreetmap/qgsosmbase.cpp

@@ -0,0 +1,3 @@
+#include "qgsosmbase.h"
+
+// nothing here now

src/analysis/openstreetmap/qgsosmbase.h

@@ -0,0 +1,130 @@
+#ifndef OSMBASE_H
+#define OSMBASE_H
+
+#include <QString>
+
+#include "qgspoint.h"
+
+#include <sqlite3.h>
+
+typedef qint64 QgsOSMId;
+
+class QgsOSMDatabase;
+
+struct QgsOSMElementID
+{
+  enum Type { Invalid, Node, Way, Relation };
+
+  Type type;
+  QgsOSMId id;
+};
+
+
+/**
+Elements (also data primitives) are the basic components in OpenStreetMap from which everything else
+is defined. These consist of Nodes (which define a point in space), Ways (which define a linear features
+and areas), and Relations - with an optional role - which are sometimes used to define the relation
+between other elements. All of the above can have one of more associated tags.
+*/
+class ANALYSIS_EXPORT QgsOSMElement
+{
+  public:
+    QgsOSMElement() { mElemID.type = QgsOSMElementID::Invalid; mElemID.id = 0; }
+    QgsOSMElement( QgsOSMElementID::Type t, QgsOSMId id ) { mElemID.type = t; mElemID.id = id; }
+
+    bool isValid() const { return mElemID.type != QgsOSMElementID::Invalid; }
+
+    QgsOSMDatabase* database() const;
+
+    // fetched automatically from DB
+    QgsOSMElementID elemID() const { return mElemID; }
+    int id() const { return mElemID.id; }
+    //QString username() const;
+    //QDateTime timestamp() const;
+    //int version() const;
+
+  private:
+    QgsOSMElementID mElemID;
+};
+
+
+
+/**
+A node is one of the core elements in the OpenStreetMap data model. It consists of a single geospatial
+point using a latitude and longitude. A third optional dimension, altitude, can be recorded; key:ele
+and a node can also be defined at a particular layer=* or level=*. Nodes can be used to define standalone
+point features or be used to define the path of a way.
+*/
+class ANALYSIS_EXPORT QgsOSMNode : public QgsOSMElement
+{
+  public:
+    QgsOSMNode() : mPoint() {}
+    QgsOSMNode( QgsOSMId id, const QgsPoint& point ) : QgsOSMElement( QgsOSMElementID::Node, id ), mPoint( point ) {}
+
+    QgsPoint point() const { return mPoint; }
+
+    // fetched on-demand
+    QList<QgsOSMElementID> ways() const; // where the node participates?
+    QList<QgsOSMElementID> relations() const;
+
+  private:
+    QgsPoint mPoint;
+};
+
+
+/**
+A way is an ordered list of nodes which normally also has at least one tag or is included within
+a Relation. A way can have between 2 and 2,000 nodes, although it's possible that faulty ways with zero
+or a single node exist. A way can be open or closed. A closed way is one whose last node on the way
+is also the first on that way. A closed way may be interpreted either as a closed polyline, or an area,
+or both.
+*/
+class ANALYSIS_EXPORT QgsOSMWay : public QgsOSMElement
+{
+  public:
+    QgsOSMWay() {}
+    QgsOSMWay( QgsOSMId id, const QList<QgsOSMId> nodes ) : QgsOSMElement( QgsOSMElementID::Way, id ), mNodes( nodes ) {}
+
+    QList<QgsOSMId> nodes() const { return mNodes; }
+
+    // fetched on-demand
+    //QList<OSMElementID> relations() const;
+
+  private:
+    QList<QgsOSMId> mNodes;
+};
+
+
+#if 0
+/**
+A relation is one of the core data elements that consists of one or more tags and also an ordered list
+of one or more nodes and/or ways as members which is used to define logical or geographic relationships
+between other elements. A member of a relation can optionally have a role which describe the part that
+a particular feature plays within a relation.
+*/
+class ANALYSIS_EXPORT QgsOSMRelation : public QgsOSMElement
+{
+  public:
+    QString relationType() const;
+
+    QList< QPair<QgsOSMElementID, QString> > members() const;
+};
+#endif
+
+
+class ANALYSIS_EXPORT QgsOSMTags
+{
+  public:
+    QgsOSMTags() {}
+
+    int count() const { return mMap.count(); }
+    QList<QString> keys() const { return mMap.keys(); }
+    bool contains( const QString& k ) const { return mMap.contains( k ); }
+    void insert( const QString& k, const QString& v ) { mMap.insert( k, v ); }
+    QString value( const QString& k ) const { return mMap.value( k ); }
+
+  private:
+    QMap<QString, QString> mMap;
+};
+
+#endif // OSMBASE_H