QGIS » QGIS Application

If the Raster Histogram tab was previously selected in the Raster Properties dialog and the user opens the dialog again, the histogram is refreshed twice, leading to needless processing and delay.

Specifically, in file src/app/qgsrasterlayerproperties.cpp the function QgsRasterLayerProperties::refreshHistogram() function gets called twice, once by the QgsRasterLayerProperties constructor, and once by the on_tabBar_currentChanged() slot.

The histogram tab gets activated by this call
tabBar->setCurrentIndex( settings.value( "/Windows/RasterLayerProperties/row" ).toInt() );

A simple fix is to disable the call in the constructor (around line 280 in the master branch), and leave it in the on_tabBar_currentChanged() slot.

QgsRasterLayerProperties::QgsRasterLayerProperties( QgsMapLayer* lyr, QgsMapCanvas* theCanvas, QWidget *parent, Qt::WFlags fl )
...

  setWindowTitle( tr( "Layer Properties - %1" ).arg( lyr->name() ) );
  // int myHistogramTab = 6;
  // if ( tabBar->currentIndex() == myHistogramTab )
  // {
  //   refreshHistogram();
  // }
  tableTransparency->horizontalHeader()->setResizeMode( 0, QHeaderView::Stretch );
  tableTransparency->horizontalHeader()->setResizeMode( 1, QHeaderView::Stretch );
} // QgsRasterLayerProperties ctor