store original proj4 representation of a CRS and use it to store a custom CRS

Author: leyan

src/core/qgscoordinatereferencesystem.cpp

@@ -277,6 +277,7 @@ QgsCoordinateReferenceSystem& QgsCoordinateReferenceSystem::operator=( const Qgs
     mIsValidFlag = srs.mIsValidFlag;
     mValidationHint = srs.mValidationHint;
     mWkt = srs.mWkt;
+    mProj4 = srs.mProj4;
     if ( mIsValidFlag )
     {
       OSRDestroySpatialReference( mCRS );
@@ -368,7 +369,7 @@ bool QgsCoordinateReferenceSystem::loadFromDb( QString db, QString expression, Q
                                        myPreparedStatement, 1 ) );
     mProjectionAcronym = QString::fromUtf8(( char * )sqlite3_column_text( myPreparedStatement, 2 ) );
     mEllipsoidAcronym = QString::fromUtf8(( char * )sqlite3_column_text( myPreparedStatement, 3 ) );
-    QString toProj4 = QString::fromUtf8(( char * )sqlite3_column_text( myPreparedStatement, 4 ) );
+    mProj4 = QString::fromUtf8(( char * )sqlite3_column_text( myPreparedStatement, 4 ) );
     mSRID = QString::fromUtf8(( char * )sqlite3_column_text( myPreparedStatement, 5 ) ).toLong();
     mAuthId = QString::fromUtf8(( char * )sqlite3_column_text( myPreparedStatement, 6 ) );
     mGeoFlag = QString::fromUtf8(( char * )sqlite3_column_text( myPreparedStatement, 7 ) ).toInt() != 0;
@@ -388,7 +389,7 @@ bool QgsCoordinateReferenceSystem::loadFromDb( QString db, QString expression, Q
 
     if ( !mIsValidFlag )
     {
-      setProj4String( toProj4 );
+      setProj4String( mProj4 );
     }
   }
   else
@@ -430,6 +431,7 @@ bool QgsCoordinateReferenceSystem::createFromWkt( const QString &theWkt )
 {
   mIsValidFlag = false;
   mWkt.clear();
+  mProj4.clear();
 
   if ( theWkt.isEmpty() )
   {
@@ -874,14 +876,16 @@ QString QgsCoordinateReferenceSystem::toProj4() const
   if ( !mIsValidFlag )
     return "";
 
-  QString toProj4;
-  char *proj4src = NULL;
-  OSRExportToProj4( mCRS, &proj4src );
-  toProj4 = proj4src;
-  CPLFree( proj4src );
-
+  if ( mProj4.isEmpty() )
+  {
+    QString toProj4;
+    char *proj4src = NULL;
+    OSRExportToProj4( mCRS, &proj4src );
+    mProj4 = proj4src;
+    CPLFree( proj4src );
+  }
   // Stray spaces at the end?
-  return toProj4.trimmed();
+  return mProj4.trimmed();
 }
 
 bool QgsCoordinateReferenceSystem::geographicFlag() const
@@ -916,6 +920,7 @@ void QgsCoordinateReferenceSystem::setDescription( QString theDescription )
 }
 void QgsCoordinateReferenceSystem::setProj4String( QString theProj4String )
 {
+  mProj4 = theProj4String;
   char *oldlocale = setlocale( LC_NUMERIC, NULL );
   /* the next setlocale() invalides the return of previous setlocale() */
   if ( oldlocale )
@@ -1462,6 +1467,12 @@ bool QgsCoordinateReferenceSystem::saveAsUserCRS( QString name )
 
   QString mySql;
 
+  QString proj4String=mProj4;
+  if ( proj4String.isEmpty() )
+  {
+    proj4String = toProj4();
+  }
+
   //if this is the first record we need to ensure that its srs_id is 10000. For
   //any rec after that sqlite3 will take care of the autonumering
   //this was done to support sqlite 3.0 as it does not yet support

src/core/qgscoordinatereferencesystem.h

@@ -465,6 +465,7 @@ class CORE_EXPORT QgsCoordinateReferenceSystem
 
     QString mValidationHint;
     mutable QString mWkt;
+    mutable QString mProj4;
 
     static bool loadIDs( QHash<int, QString> &wkts );
     static bool loadWkts( QHash<int, QString> &wkts, const char *filename );