Converted symbology style from XML to SQlite

- Adds a python script, and the resulting default .db file
- Cannot SAVE new symbols into the DB still
Added the Grouping of symbols in Style Manager
- Can read groups from the DB and load them
- Limited to read-only operations

Author: Arunmozhi

resources/CMakeLists.txt

@@ -1,4 +1,4 @@
-INSTALL(FILES srs.db qgis.db qgis_help.db symbology-ng-style.xml spatialite.db customization.xml
+INSTALL(FILES srs.db qgis.db qgis_help.db symbology-ng-style.db spatialite.db customization.xml
         DESTINATION ${QGIS_DATA_DIR}/resources)
 
 ADD_SUBDIRECTORY(context_help)

resources/symbology-ng-style.db

@@ -0,0 +1,95 @@
+#!/usr/bin/python
+"""
+/***************************************************************************
+                               symbol_xml2db.py
+                              -------------------
+    begin                : 26-5-2012
+    copyright            : (C) 2012 by Arunmozhi
+    email                : aruntheguy at gmail dot com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program 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 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+    The script creates a sqlite3 Db for storing the symbols which will be
+    shipped with QGIS by default. It then converts symbols and colorramps
+    in the symbology_ng_style.xml to the database table entries.
+"""
+import sqlite3
+
+from xml.dom.minidom import parse, parseString
+
+xmlfile = "../resources/symbology-ng-style.xml"
+dbfile = "../resources/symbology-ng-style.db"
+
+_symbol = "CREATE TABLE symbol("\
+        "id INTEGER PRIMARY KEY,"\
+        "name TEXT UNIQUE,"\
+        "xml TEXT,"\
+        "groupid INTEGER)"
+
+_colorramp = "CREATE TABLE colorramp("\
+        "id INTEGER PRIMARY KEY,"\
+        "name TEXT,"\
+        "xml TEXT)"
+
+_tag = "CREATE TABLE tag("\
+        "id INTEGER PRIMARY KEY,"\
+        "name TEXT)"
+
+_tagmap = "CREATE TABLE tagmap("\
+        "tag_id INTEGER NOT NULL,"\
+        "symbol_id INTEGER)"
+
+_symgroup = "CREATE TABLE symgroup("\
+        "id INTEGER PRIMARY KEY,"\
+        "name TEXT,"\
+        "parent INTEGER)"
+
+create_tables = [ _symbol, _colorramp, _tag, _tagmap, _symgroup ]
+
+# Create the DB with required Schema
+conn = sqlite3.connect( dbfile )
+c = conn.cursor()
+print "Creating tables in the Database\n"
+for table in create_tables:
+    try:
+        c.execute( table )
+        print table
+    except sqlite3.OperationalError as e:
+        pass
+    conn.commit()
+
+# parse the XML file &  write symbol into DB
+dom = parse( xmlfile )
+symbols = dom.getElementsByTagName( "symbol" )
+for symbol in symbols:
+    symbol_name = symbol.getAttribute( "name" )
+    if '@' in symbol_name:
+        parts = symbol_name.split('@')
+        parent_name = parts[1]
+        layerno = int(parts[2])
+        c.execute( "SELECT xml FROM symbol WHERE name=(?)", (parent_name,) )
+        symdom = parseString( c.fetchone()[0] ).getElementsByTagName( 'symbol' )[0]
+        symdom.getElementsByTagName( "layer" )[ layerno ].appendChild( symbol )
+        c.execute( "UPDATE symbol SET xml=? WHERE name=?", ( symdom.toxml(), parent_name ))
+    else:
+        c.execute( "INSERT INTO symbol VALUES (?,?,?,?)", ( None, symbol_name, symbol.toxml(), None ) )
+conn.commit()
+
+
+# ColorRamps
+colorramps = dom.getElementsByTagName( "colorramp" )
+for ramp in colorramps:
+    ramp_name = ramp.getAttribute( "name" )
+    c.execute( "INSERT INTO colorramp VALUES (?,?,?)", ( None, ramp_name, ramp.toxml() ) )
+conn.commit()
+
+# Finally close the sqlite cursor
+c.close()

scripts/symbol_xml2db.py

@@ -516,12 +516,12 @@ const QString QgsApplication::svgPath()
 
 const QString QgsApplication::userStyleV2Path()
 {
-  return qgisSettingsDirPath() + QString( "symbology-ng-style.xml" );
+  return qgisSettingsDirPath() + QString( "symbology-ng-style.db" );
 }
 
 const QString QgsApplication::defaultStyleV2Path()
 {
-  return ABISYM( mPkgDataPath ) + QString( "/resources/symbology-ng-style.xml" );
+  return ABISYM( mPkgDataPath ) + QString( "/resources/symbology-ng-style.db" );
 }
 
 const QString QgsApplication::libraryPath()

src/core/qgsapplication.cpp

@@ -27,6 +27,9 @@
 #include <QDomElement>
 #include <QFile>
 #include <QTextStream>
+#include <QByteArray>
+
+#include <sqlite3.h>
 
 #define STYLE_CURRENT_VERSION  "0"
 
@@ -167,69 +170,71 @@ QStringList QgsStyleV2::colorRampNames()
   return mColorRamps.keys();
 }
 
-
-bool QgsStyleV2::load( QString filename )
+sqlite3* QgsStyleV2::openDB( QString filename )
 {
-  mErrorString = QString();
+  sqlite3 *db;
+  int rc;
 
-  // import xml file
-  QDomDocument doc( "style" );
-  QFile f( filename );
-  if ( !f.open( QFile::ReadOnly ) )
+  QByteArray namearray = filename.toUtf8();
+  rc = sqlite3_open( namearray.constData(), &db );
+  if ( rc )
   {
-    mErrorString = "Couldn't open the style file: " + filename;
-    return false;
+    mErrorString = "Couldn't open the style DB: " + QString( sqlite3_errmsg( db ) );
+    sqlite3_close( db );
+    return NULL;
   }
 
-  // parse the document
-  if ( !doc.setContent( &f ) )
-  {
-    mErrorString = "Couldn't parse the style file: " + filename;
-    f.close();
-    return false;
-  }
-  f.close();
+  return db;
+}
 
-  QDomElement docElem = doc.documentElement();
-  if ( docElem.tagName() != "qgis_style" )
-  {
-    mErrorString = "Incorrect root tag in style: " + docElem.tagName();
-    return false;
-  }
+bool QgsStyleV2::load( QString filename )
+{
+  mErrorString = QString();
 
-  // check for style version
-  QString version = docElem.attribute( "version" );
-  if ( version != STYLE_CURRENT_VERSION )
-  {
-    mErrorString = "Unknown style file version: " + version;
+  // Open the sqlite DB
+  sqlite3* db = openDB( filename );
+  if ( db == NULL )
     return false;
-  }
-
-  // load symbols
-  QDomElement symbolsElement = docElem.firstChildElement( "symbols" );
-  if ( !symbolsElement.isNull() )
+  // First create all the Main symbols
+  sqlite3_stmt *ppStmt;
+  const char *query = "SELECT * FROM symbol;";
+  int nError = sqlite3_prepare_v2( db, query, -1, &ppStmt, NULL );
+  while ( nError == SQLITE_OK && sqlite3_step( ppStmt ) == SQLITE_ROW )
   {
-    mSymbols = QgsSymbolLayerV2Utils::loadSymbols( symbolsElement );
+    QDomDocument doc;
+    QString symbol_name = QString( reinterpret_cast<const char*>( sqlite3_column_text( ppStmt, SymbolName ) ) );
+    QString xmlstring = QString( reinterpret_cast<const char*>( sqlite3_column_text( ppStmt, SymbolXML ) ) );
+    if( !doc.setContent( xmlstring ) )
+    {
+      QgsDebugMsg( "Cannot open symbol" + symbol_name );
+      continue;
+    }
+    QDomElement symElement = doc.documentElement();
+    QgsSymbolV2 *symbol = QgsSymbolLayerV2Utils::loadSymbol( symElement );
+    if ( symbol != NULL )
+      mSymbols.insert( symbol_name, symbol );
   }
+  sqlite3_finalize( ppStmt );
 
-  // load color ramps
-  QDomElement rampsElement = docElem.firstChildElement( "colorramps" );
-  QDomElement e = rampsElement.firstChildElement();
-  while ( !e.isNull() )
+  const char *rquery = "SELECT * FROM colorramp;";
+  nError = sqlite3_prepare_v2( db, rquery, -1, &ppStmt, NULL );
+  while ( nError == SQLITE_OK && sqlite3_step( ppStmt ) == SQLITE_ROW )
   {
-    if ( e.tagName() == "colorramp" )
+    QDomDocument doc;
+    QString ramp_name = QString( reinterpret_cast<const char*>( sqlite3_column_text( ppStmt, ColorrampName ) ) );
+    QString xmlstring = QString( reinterpret_cast<const char*>( sqlite3_column_text( ppStmt, ColorrampXML ) ) );
+    if( !doc.setContent( xmlstring ) )
     {
-      QgsVectorColorRampV2* ramp = QgsSymbolLayerV2Utils::loadColorRamp( e );
-      if ( ramp != NULL )
-        addColorRamp( e.attribute( "name" ), ramp );
+      QgsDebugMsg( "Cannot open symbol" + ramp_name );
+      continue;
     }
-    else
-    {
-      QgsDebugMsg( "unknown tag: " + e.tagName() );
-    }
-    e = e.nextSiblingElement();
+    QDomElement rampElement = doc.documentElement();
+    QgsVectorColorRampV2* ramp = QgsSymbolLayerV2Utils::loadColorRamp( rampElement );
+    if ( ramp != NULL )
+      addColorRamp( ramp_name, ramp );
   }
 
+  sqlite3_close( db );
   mFileName = filename;
   return true;
 }
@@ -242,6 +247,9 @@ bool QgsStyleV2::save( QString filename )
   if ( filename.isEmpty() )
     filename = mFileName;
 
+  // TODO evaluate the requirement of this function and change implementation accordingly
+
+  /*
   QDomDocument doc( "qgis_style" );
   QDomElement root = doc.createElement( "qgis_style" );
   root.setAttribute( "version", STYLE_CURRENT_VERSION );
@@ -271,6 +279,7 @@ bool QgsStyleV2::save( QString filename )
   QTextStream ts( &f );
   doc.save( ts, 2 );
   f.close();
+  */
 
   mFileName = filename;
   return true;
@@ -293,3 +302,68 @@ bool QgsStyleV2::renameColorRamp( QString oldName, QString newName )
   mColorRamps.insert( newName, mColorRamps.take( oldName ) );
   return true;
 }
+
+QgsSymbolGroupMap QgsStyleV2::groupNames( QString parent )
+{
+  QgsDebugMsg( "Request for groupNames for parent " + parent );
+  // get the name list from the sqlite db and return as a QStringList
+  sqlite3* db = openDB( mFileName );
+  if( db == NULL )
+  {
+    QgsDebugMsg( "Cannot open database for listing groups" );
+    return QgsSymbolGroupMap();
+  }
+  sqlite3_stmt *ppStmt;
+  int nError;
+  char *query;
+
+  if ( parent == "" || parent == QString() )
+  {
+    query = sqlite3_mprintf( "SELECT * FROM symgroup WHERE parent IS NULL;" );
+  }
+  else
+  {
+    QByteArray parentArray = parent.toUtf8();
+    char *subquery = sqlite3_mprintf( "SELECT * FROM symgroup WHERE name='%q';", parentArray.constData() );
+    nError = sqlite3_prepare_v2( db, subquery, -1, &ppStmt, NULL );
+    if ( nError == SQLITE_OK && sqlite3_step( ppStmt ) == SQLITE_ROW )
+    {
+      query = sqlite3_mprintf( "SELECT * FROM symgroup WHERE parent=%d;", sqlite3_column_int( ppStmt, SymgroupId ) );
+    }
+    sqlite3_finalize( ppStmt );
+  }
+
+  QgsSymbolGroupMap groupNames;
+
+  nError = sqlite3_prepare_v2( db, query, -1, &ppStmt, NULL );
+  while ( nError == SQLITE_OK && sqlite3_step( ppStmt ) == SQLITE_ROW )
+  {
+    QString group = QString( reinterpret_cast<const char*>( sqlite3_column_text( ppStmt, SymgroupName ) ) );
+    groupNames.insert( sqlite3_column_int( ppStmt, SymgroupId ), group );
+  }
+  sqlite3_finalize( ppStmt );
+  sqlite3_close( db );
+  return groupNames;
+}
+
+QStringList QgsStyleV2::symbolsOfGroup( int groupid )
+{
+  sqlite3 *db = openDB( mFileName );
+  if( db == NULL )
+  {
+    QgsDebugMsg( "Cannot Open Db for getting group symbols of groupid: " + groupid );
+    return QStringList();
+  }
+
+  QStringList symbols;
+  sqlite3_stmt *ppStmt;
+  char *query = sqlite3_mprintf( "SELECT name FROM symbol WHERE groupid=%d;", groupid );
+  int nErr = sqlite3_prepare_v2( db, query, -1, &ppStmt, NULL );
+  while ( nErr == SQLITE_OK && sqlite3_step( ppStmt ) == SQLITE_ROW )
+  {
+    QString symbol = QString( reinterpret_cast<const char*>( sqlite3_column_text( ppStmt, 0 ) ) );
+    symbols.append( symbol );
+  }
+
+  return symbols;
+}

src/core/symbology-ng/qgsstylev2.cpp

@@ -19,6 +19,8 @@
 #include <QMap>
 #include <QString>
 
+#include <sqlite3.h>
+
 #include "qgssymbollayerv2utils.h" // QgsStringMap
 
 class QgsSymbolV2;
@@ -29,6 +31,15 @@ class QDomDocument;
 class QDomElement;
 
 typedef QMap<QString, QgsVectorColorRampV2* > QgsVectorColorRampV2Map;
+typedef QMap<int, QString> QgsSymbolGroupMap;
+
+// Enumeraters representing sqlite DB  columns
+enum SymbolTable { SymbolId, SymbolName, SymbolXML, SymbolGroupId };
+enum SymgroupTable { SymgroupId, SymgroupName, SymgroupParent };
+enum TagTable { TagId, TagName };
+enum TagmapTable { TagmapTagId, TagmapSymbolId };
+enum ColorrampTable { ColorrampId, ColorrampName, ColorrampXML };
+
 
 class CORE_EXPORT QgsStyleV2
 {
@@ -65,6 +76,13 @@ class CORE_EXPORT QgsStyleV2
     //! return a list of names of symbols
     QStringList symbolNames();
 
+    //! return a map of all groupid and names for the given parent
+    //! Returns the First order groups when empty QString is passed
+    QgsSymbolGroupMap groupNames( QString parent = "" );
+
+    //! returns the symbolnames of a given groupid
+    QStringList symbolsOfGroup( int groupid );
+
 
     //! add color ramp to style. takes ramp's ownership
     bool addColorRamp( QString name, QgsVectorColorRampV2* colorRamp );
@@ -110,6 +128,9 @@ class CORE_EXPORT QgsStyleV2
     QString mFileName;
 
     static QgsStyleV2* mDefaultStyle;
+
+    //! Convinence function to open the DB and return a sqlite3 object
+    sqlite3* openDB( QString filename );
 };