Add unit test for scalebar decoration map width calculations

qgis · Jan 19, 2021 · 81c5770 · 81c5770
1 parent 4caecdc
commit 81c5770
Show file tree

Hide file tree

Showing 3 changed files with 101 additions and 0 deletions.
diff --git a/src/app/decorations/qgsdecorationscalebar.h b/src/app/decorations/qgsdecorationscalebar.h
@@ -79,6 +79,7 @@ class APP_EXPORT QgsDecorationScaleBar: public QgsDecorationItem
     double mapWidth( const QgsMapSettings &settings ) const;
 
     friend class QgsDecorationScaleBarDialog;
+    friend class TestQgsDecorationScalebar;
 };
 
 #endif
diff --git a/tests/src/app/CMakeLists.txt b/tests/src/app/CMakeLists.txt
@@ -61,6 +61,7 @@ ADD_QGIS_TEST(qgisappclipboard testqgisappclipboard.cpp)
 ADD_QGIS_TEST(appdockwidgets testqgisappdockwidgets.cpp)
 ADD_QGIS_TEST(attributetabletest testqgsattributetable.cpp)
 ADD_QGIS_TEST(applocatorfilters testqgsapplocatorfilters.cpp)
+ADD_QGIS_TEST(decorationscalebar testqgsdecorationscalebar.cpp)
 ADD_QGIS_TEST(fieldcalculatortest testqgsfieldcalculator.cpp)
 ADD_QGIS_TEST(maptooladdfeatureline testqgsmaptooladdfeatureline.cpp)
 ADD_QGIS_TEST(maptooladdfeaturepoint testqgsmaptooladdfeaturepoint.cpp)

diff --git a/tests/src/app/testqgsdecorationscalebar.cpp b/tests/src/app/testqgsdecorationscalebar.cpp
@@ -0,0 +1,99 @@
+/***************************************************************************
+     testqgsdecorationscalebar.cpp
+     ----------------------
+    Date                 : 2021-01-19
+    Copyright            : (C) 2021 by Nyall Dawson
+    Email                : nyall dot dawson 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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+#include "qgstest.h"
+#include "qgisapp.h"
+#include "qgsapplication.h"
+#include "qgsmapsettings.h"
+#include "qgsdecorationscalebar.h"
+
+class TestQgsDecorationScalebar : public QObject
+{
+    Q_OBJECT
+  public:
+    TestQgsDecorationScalebar();
+
+  private slots:
+    void initTestCase();// will be called before the first testfunction is executed.
+    void cleanupTestCase();// will be called after the last testfunction was executed.
+    void init() {} // will be called before each testfunction is executed.
+    void cleanup() {} // will be called after every testfunction.
+    void mapWidth();
+
+  private:
+    QgisApp *mQgisApp = nullptr;
+};
+
+TestQgsDecorationScalebar::TestQgsDecorationScalebar() = default;
+
+//runs before all tests
+void TestQgsDecorationScalebar::initTestCase()
+{
+  qDebug() << "TestQgisAppClipboard::initTestCase()";
+  // init QGIS's paths - true means that all path will be inited from prefix
+  QgsApplication::init();
+  QgsApplication::initQgis();
+
+  // Set up the QgsSettings environment
+  QCoreApplication::setOrganizationName( QStringLiteral( "QGIS" ) );
+  QCoreApplication::setOrganizationDomain( QStringLiteral( "qgis.org" ) );
+  QCoreApplication::setApplicationName( QStringLiteral( "QGIS-TEST" ) );
+
+  mQgisApp = new QgisApp();
+
+  // enforce C locale because the tests expect it
+  // (decimal separators / thousand separators)
+  QLocale::setDefault( QLocale::c() );
+}
+
+//runs after all tests
+void TestQgsDecorationScalebar::cleanupTestCase()
+{
+  QgsApplication::exitQgis();
+}
+
+void TestQgsDecorationScalebar::mapWidth()
+{
+  QgsProject::instance()->setCrs( QgsCoordinateReferenceSystem( QStringLiteral( "EPSG:3857" ) ) );
+  QgsMapSettings settings;
+  settings.setDestinationCrs( QgsCoordinateReferenceSystem( QStringLiteral( "EPSG:3857" ) ) );
+  settings.setOutputSize( QSize( 800, 400 ) );
+  // same aspect ratio as output size
+  settings.setExtent( QgsRectangle( 16700000, -4210000, 16708000, -4206000 ) );
+
+  // unknown units, no conversion
+  QgsDecorationScaleBar scalebar;
+  QGSCOMPARENEAR( scalebar.mapWidth( settings ), 8000, 0.000001 );
+
+  // Cartesian measure
+  QgsProject::instance()->setEllipsoid( QString() );
+  scalebar.mSettings.setUnits( QgsUnitTypes::DistanceMiles );
+  QGSCOMPARENEAR( scalebar.mapWidth( settings ), 4.97097, 0.0001 );
+
+#if PROJ_VERSION_MAJOR>=6
+  // ellipsoidal measure
+  QgsProject::instance()->setEllipsoid( QStringLiteral( "EPSG:7030" ) );
+  QGSCOMPARENEAR( scalebar.mapWidth( settings ), 4.060337, 0.0001 );
+  QgsProject::instance()->setEllipsoid( QString() );
+#endif
+
+  // with non-uniform output size vs extent aspect ratio
+  settings.setExtent( QgsRectangle( 16700000, -4212000, 16708000, -4204000 ) );
+  QGSCOMPARENEAR( scalebar.mapWidth( settings ), 9.941939, 0.0001 );
+  settings.setExtent( settings.visibleExtent() );
+  QGSCOMPARENEAR( scalebar.mapWidth( settings ), 9.941939, 0.0001 );
+}
+
+QGSTEST_MAIN( TestQgsDecorationScalebar )
+#include "testqgsdecorationscalebar.moc"