Works now for the default case

src/app/qgsattributetabledialog.cpp

@@ -715,8 +715,9 @@ void QgsAttributeTableDialog::filterQueryChanged( const QString& query )
 
     QSettings settings;
     QString nullValue = settings.value( "qgis/nullValue", "NULL" ).toString();
+    QString value = mCurrentSearchWidgetWrapper->value().toString();
 
-    if ( mFilterQuery->displayText() == nullValue )
+    if (  value == nullValue )
     {
       str = QString( "%1 IS NULL" ).arg( QgsExpression::quotedColumnRef( fieldName ) );
     }
@@ -726,9 +727,9 @@ void QgsAttributeTableDialog::filterQueryChanged( const QString& query )
             .arg( QgsExpression::quotedColumnRef( fieldName ) )
             .arg( numeric ? "=" : sensString )
             .arg( numeric
-                  ? mFilterQuery->displayText().replace( "'", "''" )
+                  ? value.replace( "'", "''" )
                   :
-                  "%" + mFilterQuery->displayText().replace( "'", "''" ) + "%" ); // escape quotes
+                  "%" + value.replace( "'", "''" ) + "%" ); // escape quotes
     }
   }
 
@@ -738,7 +739,8 @@ void QgsAttributeTableDialog::filterQueryChanged( const QString& query )
 
 void QgsAttributeTableDialog::filterQueryAccepted()
 {
-  if ( mFilterQuery->text().isEmpty() )
+  if ( (mFilterQuery->isVisible() && mFilterQuery->text().isEmpty()) ||
+          (mCurrentSearchWidgetWrapper->widget()->isVisible() && mCurrentSearchWidgetWrapper->value().toString().isEmpty() ))
   {
     filterShowAll();
     return;
@@ -753,6 +755,10 @@ void QgsAttributeTableDialog::setFilterExpression( QString filterString )
   mFilterButton->setPopupMode( QToolButton::MenuButtonPopup );
   mCbxCaseSensitive->setVisible( false );
   mFilterQuery->setVisible( true );
+  if ( mCurrentSearchWidgetWrapper != 0 ) 
+  {
+    mCurrentSearchWidgetWrapper->widget()->setVisible( false );
+  }
   mApplyFilterButton->setVisible( true );
   mMainView->setFilterMode( QgsAttributeTableFilterModel::ShowFilteredList );
 

src/gui/editorwidgets/core/qgsdefaultsearchwidgetwrapper.cpp

@@ -28,17 +28,18 @@ QgsDefaultSearchWidgetWrapper::QgsDefaultSearchWidgetWrapper( QgsVectorLayer* vl
 
 QVariant QgsDefaultSearchWidgetWrapper::value()
 {
-    return QString("foo");
+    return mLineEdit->text();
 }
 
 QWidget* QgsDefaultSearchWidgetWrapper::createWidget( QWidget* parent )
 {
     return new QgsFilterLineEdit( parent );
 }
 
-void QgsDefaultSearchWidgetWrapper::initWidget( QWidget* editor )
+void QgsDefaultSearchWidgetWrapper::initWidget( QWidget* widget )
 {
-    connect( mLineEdit, SIGNAL( textChanged( QString ) ), this, SLOT( valueChanged( QString ) ) );
+    mLineEdit = qobject_cast<QgsFilterLineEdit*>( widget );
+    connect( widget, SIGNAL( textChanged( QString ) ), this, SLOT( valueChanged( QString ) ) );
 }
 
 void QgsDefaultSearchWidgetWrapper::setValue( const QVariant& value )