enhanced performance of feature selection

git-svn-id: http://svn.osgeo.org/qgis/trunk@244 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/qgsattributetable.cpp

@@ -40,6 +40,14 @@ void QgsAttributeTable::columnClicked(int col)
 {
 	QApplication::setOverrideCursor(Qt::waitCursor);
 	sortColumn(col, true, true);
+	//clear and rebuild rowIdMap. Overwrite sortColumn later and sort rowIdMap there
+	rowIdMap.clear();
+	int id;
+	for(int i=0;i<numRows();i++)
+	{
+	    id=text(i,0).toInt();
+	    rowIdMap.insert(id,i);
+	}
 	clearSelection(true);
 	emit selectionRemoved();
 	emit repaintRequested();
@@ -89,18 +97,24 @@ void QgsAttributeTable::handleChangedSelections()
    
 }
 
+void QgsAttributeTable::insertFeatureId(int id)
+{
+    rowIdMap.insert(id,id+1);
+}
 
 void QgsAttributeTable::selectRowWithId(int id)
 {
     //brute force approach, add a solution with a hash table or a search tree later (and rebuild this structure every time the table is sorted)
-    for(int i=0;i<numRows();i++)
+    /*for(int i=0;i<numRows();i++)
     {
 	if(text(i,0).toInt()==id)
 	{
 	    selectRow(i);
 	    return;
 	}
-    }
+	}*/
+    QMap<int,int>::iterator it=rowIdMap.find(id);
+    selectRow(it.data());
 }
 
 	  

src/qgsattributetable.h

@@ -20,6 +20,7 @@
 #define QGSATTRIBUTETABLE_H
 
 #include <qtable.h>
+#include <qmap.h>
 
 /**
   *@author Gary E.Sherman
@@ -33,6 +34,8 @@ class QgsAttributeTable:public QTable
       QgsAttributeTable(QWidget * parent = 0, const char *name = 0);
       ~QgsAttributeTable();
 
+      /**Inserts the feature with the specified id into rowIdMap. This function has to be called (e.g. from QgsShapeFileLayer) when a row is inserted into the table*/
+      void insertFeatureId(int id);
       /**Selects the row which belongs to the feature with the specified id*/
       void selectRowWithId(int id);
 
@@ -43,6 +46,8 @@ class QgsAttributeTable:public QTable
       protected:
       /**Flag telling if the ctrl-button or the shift-button is pressed*/
       bool lockKeyPressed;
+      /**Search tree to find a row corresponding to a feature id*/
+      QMap<int,int> rowIdMap;
       void keyPressEvent(QKeyEvent* ev);
       void keyReleaseEvent(QKeyEvent* ev);
         signals:

src/qgsshapefilelayer.cpp

@@ -410,6 +410,7 @@ void QgsShapeFileLayer::table()
 	    
 	    //id-field
 	    tabledisplay->table()->setText(row,0,QString::number(fet->GetFID()));
+	    tabledisplay->table()->insertFeatureId(fet->GetFID());//insert the id into the search tree of qgsattributetable
 	    for (int i = 1; i < numFields+1; i++) {
 			// get the field values
 			QString val;