[FEATURE][gps] Allow showing a bearing line from the GPS location

pointed in the GPS's direction Allows users to view a "current path" directional line as they navigate using a GPS
qgis · Dec 10, 2019 · e262056 · e262056
1 parent 9356cd8
commit e262056
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Showing 6 changed files with 424 additions and 319 deletions.
diff --git a/src/app/gps/qgsgpsbearingitem.cpp b/src/app/gps/qgsgpsbearingitem.cpp
@@ -32,6 +32,8 @@ QgsGpsBearingItem::QgsGpsBearingItem( QgsMapCanvas *mapCanvas )
   mSymbol->setColor( QColor( 255, 0, 0 ) );
   mWgs84CRS = QgsCoordinateReferenceSystem::fromOgcWmsCrs( QStringLiteral( "EPSG:4326" ) );
 
+  setZValue( 199 );
+
   connect( mMapCanvas, &QgsMapCanvas::rotationChanged, this, &QgsGpsBearingItem::updateLine );
   connect( mMapCanvas, &QgsMapCanvas::extentsChanged, this, &QgsGpsBearingItem::updateLine );
 }

diff --git a/src/app/gps/qgsgpsbearingitem.h b/src/app/gps/qgsgpsbearingitem.h
@@ -27,7 +27,7 @@ class QgsLineSymbol;
  * \ingroup app
  * A canvas item for showing the bearing of the GPS device
  */
-class QgsGpsBearingItem : public QObject, QgsMapCanvasLineSymbolItem
+class QgsGpsBearingItem : public QObject, public QgsMapCanvasLineSymbolItem
 {
     Q_OBJECT
 

diff --git a/src/app/gps/qgsgpsinformationwidget.cpp b/src/app/gps/qgsgpsinformationwidget.cpp
@@ -41,6 +41,8 @@
 #include "qgsmapcanvas.h"
 #include "qgsmessagebar.h"
 #include "qgsbearingutils.h"
+#include "qgsgpsbearingitem.h"
+#include "qgssymbollayerutils.h"
 
 // QWT Charting widget
 
@@ -93,8 +95,6 @@ QgsGpsInformationWidget::QgsGpsInformationWidget( QgsMapCanvas *mapCanvas, QWidg
   mLastNmeaPosition.lat = nmea_degree2radian( 0.0 );
   mLastNmeaPosition.lon = nmea_degree2radian( 0.0 );
 
-  mMapMarker = nullptr;
-  mRubberBand = nullptr;
   populateDevices();
   QWidget *mpHistogramWidget = mStackedWidget->widget( 1 );
 #ifndef WITH_QWTPOLAR
@@ -191,8 +191,31 @@ QgsGpsInformationWidget::QgsGpsInformationWidget( QgsMapCanvas *mapCanvas, QWidg
 
   mBtnTrackColor->setAllowOpacity( true );
   mBtnTrackColor->setColorDialogTitle( tr( "Track Color" ) );
-  // Restore state
+
+  mBearingLineStyleButton->setSymbolType( QgsSymbol::Line );
+
   QgsSettings mySettings;
+
+  QDomDocument doc;
+  QDomElement elem;
+  QString symbolXml = mySettings.value( QStringLiteral( "gps/bearingLineSymbol" ) ).toString();
+  if ( !symbolXml.isEmpty() )
+  {
+    doc.setContent( symbolXml );
+    elem = doc.documentElement();
+    std::unique_ptr< QgsLineSymbol > bearingSymbol( QgsSymbolLayerUtils::loadSymbol<QgsLineSymbol>( elem, QgsReadWriteContext() ) );
+    if ( bearingSymbol )
+      mBearingLineStyleButton->setSymbol( bearingSymbol.release() );
+  }
+
+  connect( mBearingLineStyleButton, &QgsSymbolButton::changed, this, [ = ]
+  {
+    if ( mMapBearingItem )
+      mMapBearingItem->setSymbol( std::unique_ptr< QgsSymbol >( mBearingLineStyleButton->clonedSymbol< QgsLineSymbol >() ) );
+  } );
+
+  // Restore state
+
   mGroupShowMarker->setChecked( mySettings.value( QStringLiteral( "gps/showMarker" ), "true" ).toBool() );
   mSliderMarkerSize->setValue( mySettings.value( QStringLiteral( "gps/markerSize" ), "12" ).toInt() );
   mSpinTrackWidth->setValue( mySettings.value( QStringLiteral( "gps/trackWidth" ), "2" ).toInt() );
@@ -254,6 +277,7 @@ QgsGpsInformationWidget::QgsGpsInformationWidget( QgsMapCanvas *mapCanvas, QWidg
     radRecenterWhenNeeded->setChecked( true );
   }
   mRotateMapCheckBox->setChecked( mySettings.value( QStringLiteral( "gps/rotateMap" ), false ).toBool() );
+  mShowBearingLineCheck->setChecked( mySettings.value( QStringLiteral( "gps/showBearingLine" ), false ).toBool() );
 
   mWgs84CRS = QgsCoordinateReferenceSystem::fromOgcWmsCrs( QStringLiteral( "EPSG:4326" ) );
 
@@ -363,6 +387,7 @@ QgsGpsInformationWidget::~QgsGpsInformationWidget()
   }
 
   delete mMapMarker;
+  delete mMapBearingItem;
   delete mRubberBand;
 
 #ifdef WITH_QWTPOLAR
@@ -420,6 +445,12 @@ QgsGpsInformationWidget::~QgsGpsInformationWidget()
     mySettings.setValue( QStringLiteral( "gps/panMode" ), "none" );
   }
   mySettings.setValue( QStringLiteral( "gps/rotateMap" ), mRotateMapCheckBox->isChecked() );
+  mySettings.setValue( QStringLiteral( "gps/showBearingLine" ), mShowBearingLineCheck->isChecked() );
+
+  QDomDocument doc;
+  QDomElement elem = QgsSymbolLayerUtils::saveSymbol( QStringLiteral( "Symbol" ), mBearingLineStyleButton->symbol(), doc, QgsReadWriteContext() );
+  doc.appendChild( elem );
+  mySettings.setValue( QStringLiteral( "gps/bearingLineSymbol" ), doc.toString() );
 }
 
 void QgsGpsInformationWidget::mSpinTrackWidth_valueChanged( int value )
@@ -603,6 +634,11 @@ void QgsGpsInformationWidget::disconnectGps()
     delete mMapMarker;
     mMapMarker = nullptr;
   }
+  if ( mMapBearingItem )
+  {
+    delete mMapBearingItem;
+    mMapBearingItem = nullptr;
+  }
   mGPSPlainTextEdit->appendPlainText( tr( "Disconnected…" ) );
   mConnectButton->setChecked( false );
   mConnectButton->setText( tr( "&Connect" ) );
@@ -866,17 +902,44 @@ void QgsGpsInformationWidget::displayGPSInformation( const QgsGpsInformation &in
     }
   } // mLastGpsPosition != myNewCenter
 
-  if ( mRotateMapCheckBox->isChecked() && !std::isnan( info.direction ) )
+  if ( !std::isnan( info.direction ) )
   {
+    double trueNorth = 0;
     try
     {
-      const double trueNorth = QgsBearingUtils::bearingTrueNorth( mMapCanvas->mapSettings().destinationCrs(), QgsProject::instance()->transformContext(), mMapCanvas->mapSettings().visibleExtent().center() );
-      mMapCanvas->setRotation( trueNorth - info.direction );
+      trueNorth = QgsBearingUtils::bearingTrueNorth( mMapCanvas->mapSettings().destinationCrs(), QgsProject::instance()->transformContext(), mMapCanvas->mapSettings().visibleExtent().center() );
     }
     catch ( QgsException & )
     {
-      mMapCanvas->setRotation( - info.direction );
+
+    }
+
+    if ( mRotateMapCheckBox->isChecked() )
+    {
+      mMapCanvas->setRotation( trueNorth - info.direction );
     }
+
+    if ( mShowBearingLineCheck )
+    {
+      if ( ! mMapBearingItem )
+      {
+        mMapBearingItem = new QgsGpsBearingItem( mMapCanvas );
+        mMapBearingItem->setSymbol( std::unique_ptr< QgsSymbol >( mBearingLineStyleButton->clonedSymbol< QgsLineSymbol >() ) );
+      }
+
+      mMapBearingItem->setGpsPosition( myNewCenter );
+      mMapBearingItem->setGpsBearing( info.direction - trueNorth );
+    }
+    else if ( mMapBearingItem )
+    {
+      delete mMapBearingItem;
+      mMapBearingItem = nullptr;
+    }
+  }
+  else if ( mMapBearingItem )
+  {
+    delete mMapBearingItem;
+    mMapBearingItem = nullptr;
   }
 
   // new marker position after recentering
@@ -1382,9 +1445,8 @@ void QgsGpsInformationWidget::cboDistanceThresholdEdited()
   setDistanceThreshold( mCboDistanceThreshold->currentText().toUInt() );
 }
 
-void QgsGpsInformationWidget::timestampFormatChanged( int index )
+void QgsGpsInformationWidget::timestampFormatChanged( int )
 {
-  Q_UNUSED( index );
   QgsSettings().setValue( QStringLiteral( "gps/timestampFormat" ), mCboTimestampFormat->currentData( ).toInt() );
   const bool enabled { static_cast<Qt::TimeSpec>( mCboTimestampFormat->currentData( ).toInt() ) == Qt::TimeSpec::TimeZone };
   mCboTimeZones->setEnabled( enabled );

diff --git a/src/app/gps/qgsgpsinformationwidget.h b/src/app/gps/qgsgpsinformationwidget.h
@@ -37,6 +37,7 @@ class QgsGpsTrackerThread;
 struct QgsGpsInformation;
 class QgsMapCanvas;
 class QgsFeature;
+class QgsGpsBearingItem;
 
 class QFile;
 class QColor;
@@ -102,6 +103,8 @@ class APP_EXPORT QgsGpsInformationWidget: public QWidget, private Ui::QgsGpsInfo
     QgsGpsConnection *mNmea = nullptr;
     QgsMapCanvas *mMapCanvas = nullptr;
     QgsGpsMarker *mMapMarker = nullptr;
+    QgsGpsBearingItem *mMapBearingItem = nullptr;
+
     QwtPlot *mPlot = nullptr;
     QwtPlotCurve *mCurve = nullptr;
 #ifdef WITH_QWTPOLAR

diff --git a/src/app/gps/qgsgpsmarker.cpp b/src/app/gps/qgsgpsmarker.cpp
@@ -30,6 +30,7 @@ QgsGpsMarker::QgsGpsMarker( QgsMapCanvas *mapCanvas )
   mSize = 16;
   mWgs84CRS = QgsCoordinateReferenceSystem::fromOgcWmsCrs( QStringLiteral( "EPSG:4326" ) );
   mSvg.load( QStringLiteral( ":/images/north_arrows/gpsarrow2.svg" ) );
+  setZValue( 200 );
 }
 
 void QgsGpsMarker::setSize( int size )