Changed the selection behaviour of the attribute table. The repaintRequest signal is now only emitted if the mouse button is released and if the selected rows have changed. This minimises repaint events and allows to selecting multiple rows with mouse drag without generating a seperate repaint event for each new row

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@5706 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: mhugent

src/gui/qgsattributetable.cpp

@@ -50,6 +50,7 @@ QgsAttributeTable::QgsAttributeTable(QWidget * parent, const char *name):
   QObject::connect(this, SIGNAL(selectionChanged()), this, SLOT(handleChangedSelections()));
   connect(this, SIGNAL(contextMenuRequested(int, int, const QPoint&)), this, SLOT(popupMenu(int, int, const QPoint&)));
   connect(this, SIGNAL(valueChanged(int, int)), this, SLOT(storeChangedValue(int,int)));
+  connect(verticalHeader(), SIGNAL(released(int)), this, SLOT(rowClicked(int))); 
   setReadOnly(true);
   setFocus();
 }
@@ -128,7 +129,6 @@ void QgsAttributeTable::handleChangedSelections()
   //if there is no current selection, there is nothing to do
   if (currentSelection() == -1)
     {
-      emit repaintRequested();
       return;
     }
 
@@ -139,7 +139,9 @@ void QgsAttributeTable::handleChangedSelections()
       emit selected(text(index, 0).toInt());
     }
 
-  emit repaintRequested();
+  //don't send the signal repaintRequested() from here
+  //but in contentsMouseReleaseEvent() and rowClicked(int)
+  //todo: don't repaint in case of double clicks
 
 }
 
@@ -662,3 +664,41 @@ void QgsAttributeTable::showAllRows()
   for (int i = 0; i < numRows(); i++)
     showRow(i);
 }
+
+void QgsAttributeTable::rowClicked(int row)
+{
+  if(checkSelectionChanges())//only repaint the canvas if the selection has changed
+    {
+      emit repaintRequested();
+    }
+}
+
+void QgsAttributeTable::contentsMouseReleaseEvent(QMouseEvent* e)
+{
+  if(checkSelectionChanges())//only repaint the canvas if the selection has changed
+    {
+      emit repaintRequested();
+    }
+  Q3Table::contentsMouseReleaseEvent(e);
+}
+
+bool QgsAttributeTable::checkSelectionChanges()
+{
+  std::set<int> theCurrentSelection;
+  Q3TableSelection cselection;
+  cselection = selection(currentSelection());
+  for (int index = cselection.topRow(); index <= cselection.bottomRow(); index++)
+    {
+      theCurrentSelection.insert(index);
+    }
+
+  if(theCurrentSelection == mLastSelectedRows)
+    {
+      return false;
+    }
+  else
+    {
+      mLastSelectedRows = theCurrentSelection;
+      return true;
+    }
+}

src/gui/qgsattributetable.h

@@ -105,6 +105,7 @@ class QgsAttributeTable:public Q3Table
 
     public slots:
       void columnClicked(int col);
+      void rowClicked(int row);
     // Called when the user requests a popup menu
     void popupMenu(int row, int col, const QPoint& pos);
     // Called when the user chooses an item on the popup menu
@@ -132,6 +133,8 @@ class QgsAttributeTable:public Q3Table
     /**Nested map containing the changed attribute values. The int is the feature id, 
       the first QString the attribute name and the second QString the new value*/
     std::map<int,std::map<QString,QString> > mChangedValues;
+    /**Stors the numbers of the last selected rows. This is used to check for selection changes before emit repaintRequested()*/
+    std::set<int> mLastSelectedRows;
 
     /**Compares the content of two cells either alphanumeric or numeric. If 'ascending' is true, -1 means s1 is less, 0 equal, 1 greater. If 'ascending' is false, -1 means s1 is more, 0 equal, 1 greater. This method is used mainly to sort a column*/
     int compareItems(QString s1, QString s2, bool ascending, bool alphanumeric);
@@ -146,7 +149,10 @@ class QgsAttributeTable:public Q3Table
     void removeAttrColumn(const QString& name);
     /** puts attributes of feature to the chosen table row */
     void putFeatureInTable(int row, QgsFeature* fet);
-
+    void contentsMouseReleaseEvent(QMouseEvent* e);
+    /**This function compares the current selection and the selection of the last repaint. Returns true if there are differences in the selection.
+     Also, mLastSelectedRows is updated*/
+    bool checkSelectionChanges();
 signals:
 
     /**Is emitted when a row was selected*/