Merge pull request #3618 from nyalldawson/true_north

[composer] Allow syncing pictures to true north (fixes #192)

Author: nyalldawson

ci/travis/linux/blacklist.txt

@@ -1,4 +1,3 @@
-PyQgsComposerPicture
 PyQgsJSONUtils
 PyQgsLocalServer
 PyQgsPalLabelingServer

python/core/composer/qgscomposerpicture.sip

@@ -30,6 +30,13 @@ class QgsComposerPicture: QgsComposerItem
       Unknown
     };
 
+    //! Method for syncing rotation to a map's North direction
+    enum NorthMode
+    {
+      GridNorth, /*!< Align to grid north */
+      TrueNorth, /*!< Align to true north */
+    };
+
     QgsComposerPicture( QgsComposition *composition /TransferThis/);
     ~QgsComposerPicture();
 
@@ -109,6 +116,38 @@ class QgsComposerPicture: QgsComposerItem
      */
     bool useRotationMap() const;
 
+     /**
+     * Returns the mode used to align the picture to a map's North.
+     * @see setNorthMode()
+     * @see northOffset()
+     * @note added in QGIS 2.18
+     */
+    NorthMode northMode() const;
+
+    /**
+     * Sets the mode used to align the picture to a map's North.
+     * @see northMode()
+     * @see setNorthOffset()
+     * @note added in QGIS 2.18
+     */
+    void setNorthMode( NorthMode mode );
+
+    /**
+     * Returns the offset added to the picture's rotation from a map's North.
+     * @see setNorthOffset()
+     * @see northMode()
+     * @note added in QGIS 2.18
+     */
+    double northOffset() const;
+
+    /**
+     * Sets the offset added to the picture's rotation from a map's North.
+     * @see northOffset()
+     * @see setNorthMode()
+     * @note added in QGIS 2.18
+     */
+    void setNorthOffset( double offset );
+
     /** Returns the resize mode used for drawing the picture within the composer
      * item's frame.
      * @returns resize mode of picture

python/core/core.sip

@@ -21,6 +21,7 @@
 %Include qgsaggregatecalculator.sip
 %Include qgsattributetableconfig.sip
 %Include qgsattributeeditorelement.sip
+%Include qgsbearingutils.sip
 %Include qgsbrowsermodel.sip
 %Include qgsclipper.sip
 %Include qgscolorramp.sip

python/core/qgsbearingutils.sip

@@ -0,0 +1,21 @@
+/**
+ * \class QgsBearingUtils
+ * \ingroup core
+ * Utilities for calculating bearings and directions.
+ * \note Added in version 2.18
+*/
+class QgsBearingUtils
+{
+%TypeHeaderCode
+#include <qgsbearingutils.h>
+%End
+  public:
+
+    /**
+     * Returns the direction to true north from a specified point and for a specified
+     * coordinate reference system. The returned value is in degrees clockwise from
+     * vertical. An exception will be thrown if the bearing could not be calculated.
+     */
+    static double bearingTrueNorth( const QgsCoordinateReferenceSystem& crs,
+                                    const QgsPoint& point );
+};

src/app/composer/qgscomposerpicturewidget.cpp

@@ -45,6 +45,13 @@ QgsComposerPictureWidget::QgsComposerPictureWidget( QgsComposerPicture* picture
   mOutlineColorButton->setColorDialogTitle( tr( "Select outline color" ) );
   mOutlineColorButton->setContext( "composer" );
 
+  mNorthTypeComboBox->blockSignals( true );
+  mNorthTypeComboBox->addItem( tr( "Grid north" ), QgsComposerPicture::GridNorth );
+  mNorthTypeComboBox->addItem( tr( "True north" ), QgsComposerPicture::TrueNorth );
+  mNorthTypeComboBox->blockSignals( false );
+  mPictureRotationOffsetSpinBox->setClearValue( 0.0 );
+  mPictureRotationSpinBox->setClearValue( 0.0 );
+
   //add widget for general composer item properties
   QgsComposerItemWidget* itemPropertiesWidget = new QgsComposerItemWidget( this, picture );
   mainLayout->addWidget( itemPropertiesWidget );
@@ -270,6 +277,8 @@ void QgsComposerPictureWidget::on_mRotationFromComposerMapCheckBox_stateChanged(
     mPicture->setRotationMap( -1 );
     mPictureRotationSpinBox->setEnabled( true );
     mComposerMapComboBox->setEnabled( false );
+    mNorthTypeComboBox->setEnabled( false );
+    mPictureRotationOffsetSpinBox->setEnabled( false );
     mPicture->setPictureRotation( mPictureRotationSpinBox->value() );
   }
   else
@@ -278,6 +287,8 @@ void QgsComposerPictureWidget::on_mRotationFromComposerMapCheckBox_stateChanged(
     int mapId = map ? map->id() : -1;
     mPicture->setRotationMap( mapId );
     mPictureRotationSpinBox->setEnabled( false );
+    mNorthTypeComboBox->setEnabled( true );
+    mPictureRotationOffsetSpinBox->setEnabled( true );
     mComposerMapComboBox->setEnabled( true );
   }
   mPicture->endCommand();
@@ -325,6 +336,8 @@ void QgsComposerPictureWidget::setGuiElementValues()
     mPictureLineEdit->blockSignals( true );
     mComposerMapComboBox->blockSignals( true );
     mRotationFromComposerMapCheckBox->blockSignals( true );
+    mNorthTypeComboBox->blockSignals( true );
+    mPictureRotationOffsetSpinBox->blockSignals( true );
     mResizeModeComboBox->blockSignals( true );
     mAnchorPointComboBox->blockSignals( true );
     mFillColorButton->blockSignals( true );
@@ -345,13 +358,19 @@ void QgsComposerPictureWidget::setGuiElementValues()
       mRotationFromComposerMapCheckBox->setCheckState( Qt::Checked );
       mPictureRotationSpinBox->setEnabled( false );
       mComposerMapComboBox->setEnabled( true );
+      mNorthTypeComboBox->setEnabled( true );
+      mPictureRotationOffsetSpinBox->setEnabled( true );
     }
     else
     {
       mRotationFromComposerMapCheckBox->setCheckState( Qt::Unchecked );
       mPictureRotationSpinBox->setEnabled( true );
       mComposerMapComboBox->setEnabled( false );
+      mNorthTypeComboBox->setEnabled( false );
+      mPictureRotationOffsetSpinBox->setEnabled( false );
     }
+    mNorthTypeComboBox->setCurrentIndex( mNorthTypeComboBox->findData( mPicture->northMode() ) );
+    mPictureRotationOffsetSpinBox->setValue( mPicture->northOffset() );
 
     mResizeModeComboBox->setCurrentIndex(( int )mPicture->resizeMode() );
     //disable picture rotation for non-zoom modes
@@ -379,6 +398,8 @@ void QgsComposerPictureWidget::setGuiElementValues()
     mPictureRotationSpinBox->blockSignals( false );
     mPictureLineEdit->blockSignals( false );
     mComposerMapComboBox->blockSignals( false );
+    mNorthTypeComboBox->blockSignals( false );
+    mPictureRotationOffsetSpinBox->blockSignals( false );
     mResizeModeComboBox->blockSignals( false );
     mAnchorPointComboBox->blockSignals( false );
     mFillColorButton->blockSignals( false );
@@ -655,6 +676,22 @@ void QgsComposerPictureWidget::on_mOutlineWidthSpinBox_valueChanged( double d )
   mPicture->update();
 }
 
+void QgsComposerPictureWidget::on_mPictureRotationOffsetSpinBox_valueChanged( double d )
+{
+  mPicture->beginCommand( tr( "Picture North offset changed" ), QgsComposerMergeCommand::ComposerPictureNorthOffset );
+  mPicture->setNorthOffset( d );
+  mPicture->endCommand();
+  mPicture->update();
+}
+
+void QgsComposerPictureWidget::on_mNorthTypeComboBox_currentIndexChanged( int index )
+{
+  mPicture->beginCommand( tr( "Picture North mode changed" ) );
+  mPicture->setNorthMode( static_cast< QgsComposerPicture::NorthMode >( mNorthTypeComboBox->itemData( index ).toInt() ) );
+  mPicture->endCommand();
+  mPicture->update();
+}
+
 void QgsComposerPictureWidget::resizeEvent( QResizeEvent * event )
 {
   Q_UNUSED( event );

src/app/composer/qgscomposerpicturewidget.h

@@ -70,6 +70,8 @@ class QgsComposerPictureWidget: public QgsComposerItemBaseWidget, private Ui::Qg
     void on_mFillColorButton_colorChanged( const QColor& color );
     void on_mOutlineColorButton_colorChanged( const QColor& color );
     void on_mOutlineWidthSpinBox_valueChanged( double d );
+    void on_mPictureRotationOffsetSpinBox_valueChanged( double d );
+    void on_mNorthTypeComboBox_currentIndexChanged( int index );
 
   private:
     QgsComposerPicture* mPicture;

src/core/CMakeLists.txt

@@ -85,6 +85,7 @@ SET(QGIS_CORE_SRCS
   qgsaggregatecalculator.cpp
   qgsattributetableconfig.cpp
   qgsattributeeditorelement.cpp
+  qgsbearingutils.cpp
   qgsbrowsermodel.cpp
   qgscachedfeatureiterator.cpp
   qgscacheindex.cpp
@@ -600,6 +601,7 @@ SET(QGIS_CORE_HDRS
   qgsannotation.h
   qgsattributetableconfig.h
   qgsattributeeditorelement.h
+  qgsbearingutils.h
   qgscachedfeatureiterator.h
   qgscacheindex.h
   qgscacheindexfeatureid.h

src/core/composer/qgscomposeritemcommand.h

@@ -118,6 +118,7 @@ class CORE_EXPORT QgsComposerMergeCommand: public QgsComposerItemCommand
       ComposerPictureRotation,
       ComposerPictureFillColor,
       ComposerPictureOutlineColor,
+      ComposerPictureNorthOffset,
       // composer scalebar
       ScaleBarLineWidth,
       ScaleBarHeight,

src/core/composer/qgscomposerpicture.cpp

@@ -29,6 +29,8 @@
 #include "qgssymbollayerutils.h"
 #include "qgssvgcache.h"
 #include "qgslogger.h"
+#include "qgsbearingutils.h"
+#include "qgsmapsettings.h"
 
 #include <QDomDocument>
 #include <QDomElement>
@@ -46,6 +48,8 @@ QgsComposerPicture::QgsComposerPicture( QgsComposition *composition )
     , mMode( Unknown )
     , mPictureRotation( 0 )
     , mRotationMap( nullptr )
+    , mNorthMode( GridNorth )
+    , mNorthOffset( 0.0 )
     , mResizeMode( QgsComposerPicture::Zoom )
     , mPictureAnchor( UpperLeft )
     , mSvgFillColor( QColor( 255, 255, 255 ) )
@@ -63,6 +67,8 @@ QgsComposerPicture::QgsComposerPicture()
     , mMode( Unknown )
     , mPictureRotation( 0 )
     , mRotationMap( nullptr )
+    , mNorthMode( GridNorth )
+    , mNorthOffset( 0.0 )
     , mResizeMode( QgsComposerPicture::Zoom )
     , mPictureAnchor( UpperLeft )
     , mSvgFillColor( QColor( 255, 255, 255 ) )
@@ -408,6 +414,43 @@ void QgsComposerPicture::remotePictureLoaded()
   mLoaded = true;
 }
 
+void QgsComposerPicture::updateMapRotation()
+{
+  if ( !mRotationMap )
+    return;
+
+  // take map rotation
+  double rotation = mRotationMap->mapRotation();
+
+  // handle true north
+  switch ( mNorthMode )
+  {
+    case GridNorth:
+      break; // nothing to do
+
+    case TrueNorth:
+    {
+      QgsPoint center = mRotationMap->currentMapExtent()->center();
+      QgsCoordinateReferenceSystem crs = mComposition->mapSettings().destinationCrs();
+
+      try
+      {
+        double bearing = QgsBearingUtils::bearingTrueNorth( crs, center );
+        rotation += bearing;
+      }
+      catch ( QgsException& e )
+      {
+        Q_UNUSED( e );
+        QgsDebugMsg( QString( "Caught exception %1" ).arg( e.what() ) );
+      }
+      break;
+    }
+  }
+
+  rotation += mNorthOffset;
+  setPictureRotation( rotation );
+}
+
 void QgsComposerPicture::loadPicture( const QString &path )
 {
   if ( path.startsWith( "http" ) )
@@ -633,7 +676,8 @@ void QgsComposerPicture::setRotationMap( int composerMapId )
 
   if ( composerMapId == -1 ) //disable rotation from map
   {
-    QObject::disconnect( mRotationMap, SIGNAL( mapRotationChanged( double ) ), this, SLOT( setPictureRotation( double ) ) );
+    disconnect( mRotationMap, SIGNAL( mapRotationChanged( double ) ), this, SLOT( updateMapRotation() ) );
+    disconnect( mRotationMap, SIGNAL( extentChanged() ), this, SLOT( updateMapRotation() ) );
     mRotationMap = nullptr;
   }
 
@@ -644,10 +688,12 @@ void QgsComposerPicture::setRotationMap( int composerMapId )
   }
   if ( mRotationMap )
   {
-    QObject::disconnect( mRotationMap, SIGNAL( mapRotationChanged( double ) ), this, SLOT( setPictureRotation( double ) ) );
+    disconnect( mRotationMap, SIGNAL( mapRotationChanged( double ) ), this, SLOT( updateMapRotation() ) );
+    disconnect( mRotationMap, SIGNAL( extentChanged() ), this, SLOT( updateMapRotation() ) );
   }
   mPictureRotation = map->mapRotation();
-  QObject::connect( map, SIGNAL( mapRotationChanged( double ) ), this, SLOT( setPictureRotation( double ) ) );
+  connect( map, SIGNAL( mapRotationChanged( double ) ), this, SLOT( updateMapRotation() ) );
+  connect( map, SIGNAL( extentChanged() ), this, SLOT( updateMapRotation() ) );
   mRotationMap = map;
   update();
   emit pictureRotationChanged( mPictureRotation );
@@ -722,6 +768,8 @@ bool QgsComposerPicture::writeXml( QDomElement& elem, QDomDocument & doc ) const
   {
     composerPictureElem.setAttribute( "mapId", mRotationMap->id() );
   }
+  composerPictureElem.setAttribute( "northMode", mNorthMode );
+  composerPictureElem.setAttribute( "northOffset", mNorthOffset );
 
   _writeXml( composerPictureElem, doc );
   elem.appendChild( composerPictureElem );
@@ -788,6 +836,9 @@ bool QgsComposerPicture::readXml( const QDomElement& itemElem, const QDomDocumen
   }
 
   //rotation map
+  mNorthMode = static_cast< NorthMode >( itemElem.attribute( "northMode", "0" ).toInt() );
+  mNorthOffset = itemElem.attribute( "northOffset", "0" ).toDouble();
+
   int rotationMapId = itemElem.attribute( "mapId", "-1" ).toInt();
   if ( rotationMapId == -1 )
   {
@@ -798,10 +849,12 @@ bool QgsComposerPicture::readXml( const QDomElement& itemElem, const QDomDocumen
 
     if ( mRotationMap )
     {
-      QObject::disconnect( mRotationMap, SIGNAL( mapRotationChanged( double ) ), this, SLOT( setRotation( double ) ) );
+      disconnect( mRotationMap, SIGNAL( mapRotationChanged( double ) ), this, SLOT( updateMapRotation() ) );
+      disconnect( mRotationMap, SIGNAL( extentChanged() ), this, SLOT( updateMapRotation() ) );
     }
     mRotationMap = mComposition->getComposerMapById( rotationMapId );
-    QObject::connect( mRotationMap, SIGNAL( mapRotationChanged( double ) ), this, SLOT( setRotation( double ) ) );
+    connect( mRotationMap, SIGNAL( mapRotationChanged( double ) ), this, SLOT( updateMapRotation() ) );
+    connect( mRotationMap, SIGNAL( extentChanged() ), this, SLOT( updateMapRotation() ) );
   }
 
   refreshPicture();
@@ -822,6 +875,18 @@ int QgsComposerPicture::rotationMap() const
   }
 }
 
+void QgsComposerPicture::setNorthMode( QgsComposerPicture::NorthMode mode )
+{
+  mNorthMode = mode;
+  updateMapRotation();
+}
+
+void QgsComposerPicture::setNorthOffset( double offset )
+{
+  mNorthOffset = offset;
+  updateMapRotation();
+}
+
 void QgsComposerPicture::setPictureAnchor( QgsComposerItem::ItemPositionMode anchor )
 {
   mPictureAnchor = anchor;