[processing] Add an algorithm which transfers all items from the

main annotation layer in a project to a secondary annotation layer

Useful for moving items created in the main layer to a secondary
layer, so that the item placement can be adjusted within the
layer stack

src/analysis/CMakeLists.txt

@@ -39,6 +39,7 @@ set(QGIS_ANALYSIS_SRCS
   processing/qgsalgorithmaffinetransform.cpp
   processing/qgsalgorithmaggregate.cpp
   processing/qgsalgorithmangletonearest.cpp
+  processing/qgsalgorithmannotations.cpp
   processing/qgsalgorithmapplylayerstyle.cpp
   processing/qgsalgorithmarraytranslatedfeatures.cpp
   processing/qgsalgorithmaspect.cpp

src/analysis/processing/qgsalgorithmannotations.cpp

@@ -0,0 +1,92 @@
+/***************************************************************************
+                         qgsalgorithmannotations.cpp
+                         ------------------------------
+    begin                : September 2021
+    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 "qgsalgorithmannotations.h"
+#include "qgsannotationlayer.h"
+
+///@cond PRIVATE
+
+QString QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm::name() const
+{
+  return QStringLiteral( "transferannotationsfrommain" );
+}
+
+QString QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm::displayName() const
+{
+  return QObject::tr( "Transfer annotations from main layer" );
+}
+
+QStringList QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm::tags() const
+{
+  return QObject::tr( "annotations,drawing,cosmetic,objects" ).split( ',' );
+}
+
+QString QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm::group() const
+{
+  return QObject::tr( "Cartography" );
+}
+
+QString QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm::groupId() const
+{
+  return QStringLiteral( "cartography" );
+}
+
+QgsProcessingAlgorithm::Flags QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm::flags() const
+{
+  return QgsProcessingAlgorithm::flags() | QgsProcessingAlgorithm::FlagNoThreading | QgsProcessingAlgorithm::FlagRequiresProject;
+}
+
+
+QString QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm::shortHelpString() const
+{
+  return QObject::tr( "Transfer all annotations from the main annotation layer in a project to a new annotation layer." );
+}
+
+QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm *QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm::createInstance() const
+{
+  return new QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm();
+}
+
+void QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm::initAlgorithm( const QVariantMap & )
+{
+  addParameter( new QgsProcessingParameterString( QStringLiteral( "LAYER_NAME" ), QObject::tr( "New layer name" ), QObject::tr( "Annotations" ) ) );
+
+  addOutput( new QgsProcessingOutputMapLayer( QStringLiteral( "OUTPUT" ), QObject::tr( "New annotation layer" ) ) );
+}
+
+QVariantMap QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback * )
+{
+  if ( !context.project() )
+    throw QgsProcessingException( QObject::tr( "No project available." ) );
+
+  QgsAnnotationLayer *main = context.project()->mainAnnotationLayer();
+  if ( !main )
+    throw QgsProcessingException( QObject::tr( "Could not load main annotation layer for project." ) );
+
+  std::unique_ptr< QgsAnnotationLayer > newLayer( main->clone() );
+  newLayer->setName( parameterAsString( parameters, QStringLiteral( "LAYER_NAME" ), context ) );
+  main->clear();
+
+  QVariantMap outputs;
+  outputs.insert( QStringLiteral( "OUTPUT" ), newLayer->id() );
+
+  context.project()->addMapLayer( newLayer.release() );
+
+  return outputs;
+}
+
+///@endcond

src/analysis/processing/qgsalgorithmannotations.h

@@ -0,0 +1,55 @@
+/***************************************************************************
+                         qgsalgorithmannotations.h
+                         ------------------------------
+    begin                : September 2021
+    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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSALGORITHMANNOTATIONS_H
+#define QGSALGORITHMANNOTATIONS_H
+
+#define SIP_NO_FILE
+
+#include "qgis_sip.h"
+#include "qgsprocessingalgorithm.h"
+
+///@cond PRIVATE
+
+/**
+ * Native transfer annotations from main annotation layer algorithm
+ */
+class QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm : public QgsProcessingAlgorithm
+{
+
+  public:
+
+    QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm() = default;
+    void initAlgorithm( const QVariantMap &configuration = QVariantMap() ) override;
+    QString name() const override;
+    QString displayName() const override;
+    QStringList tags() const override;
+    QString group() const override;
+    QString groupId() const override;
+    Flags flags() const override;
+    QString shortHelpString() const override;
+    QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm *createInstance() const override SIP_FACTORY;
+
+  protected:
+
+    QVariantMap processAlgorithm( const QVariantMap &parameters,
+                                  QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
+};
+
+///@endcond PRIVATE
+
+#endif // QGSALGORITHMANNOTATIONS_H

src/analysis/processing/qgsnativealgorithms.cpp

@@ -23,6 +23,7 @@
 #include "qgsalgorithmaffinetransform.h"
 #include "qgsalgorithmaggregate.h"
 #include "qgsalgorithmangletonearest.h"
+#include "qgsalgorithmannotations.h"
 #include "qgsalgorithmapplylayerstyle.h"
 #include "qgsalgorithmarraytranslatedfeatures.h"
 #include "qgsalgorithmaspect.h"
@@ -477,6 +478,7 @@ void QgsNativeAlgorithms::loadAlgorithms()
   addAlgorithm( new QgsTaperedBufferAlgorithm() );
   addAlgorithm( new QgsTinMeshCreationAlgorithm() );
   addAlgorithm( new QgsTransectAlgorithm() );
+  addAlgorithm( new QgsTransferAnnotationsFromMainAnnotationLayerAlgorithm() );
   addAlgorithm( new QgsTransformAlgorithm() );
   addAlgorithm( new QgsTranslateAlgorithm() );
   addAlgorithm( new QgsTruncateTableAlgorithm() );

tests/src/analysis/testqgsprocessingalgs.cpp

@@ -61,6 +61,8 @@
 #include "qgsmarkersymbol.h"
 #include "qgsfillsymbol.h"
 #include "qgsalgorithmgpsbabeltools.h"
+#include "qgsannotationlayer.h"
+#include "qgsannotationmarkeritem.h"
 
 class TestQgsProcessingAlgs: public QObject
 {
@@ -189,6 +191,7 @@ class TestQgsProcessingAlgs: public QObject
     void convertGpsData();
     void downloadGpsData();
     void uploadGpsData();
+    void transferMainAnnotationLayer();
 
   private:
 
@@ -6915,6 +6918,31 @@ void TestQgsProcessingAlgs::uploadGpsData()
   feedback.errors.clear();
 }
 
+void TestQgsProcessingAlgs::transferMainAnnotationLayer()
+{
+  std::unique_ptr< QgsProcessingAlgorithm > alg( QgsApplication::processingRegistry()->createAlgorithmById( QStringLiteral( "native:transferannotationsfrommain" ) ) );
+  QVERIFY( alg != nullptr );
+
+  QgsProject p;
+  p.mainAnnotationLayer()->addItem( new QgsAnnotationMarkerItem( QgsPoint( 1, 2 ) ) );
+
+  std::unique_ptr< QgsProcessingContext > context = std::make_unique< QgsProcessingContext >();
+  context->setProject( &p );
+  QgsProcessingFeedback feedback;
+  QVariantMap results;
+  bool ok = false;
+
+  QVariantMap parameters;
+  parameters.insert( QStringLiteral( "LAYER_NAME" ), QStringLiteral( "my annotations" ) );
+  results = alg->run( parameters, *context, &feedback, &ok );
+  QVERIFY( ok );
+
+  QCOMPARE( p.mainAnnotationLayer()->items().size(), 0 );
+  QgsAnnotationLayer *newLayer = qobject_cast< QgsAnnotationLayer * >( p.mapLayer( results.value( QStringLiteral( "OUTPUT" ) ).toString() ) );
+  QCOMPARE( newLayer->name(), QStringLiteral( "my annotations" ) );
+  QCOMPARE( newLayer->items().size(), 1 );
+}
+
 void TestQgsProcessingAlgs::exportMeshTimeSeries()
 {
   std::unique_ptr< QgsProcessingAlgorithm > alg( QgsApplication::processingRegistry()->createAlgorithmById( QStringLiteral( "native:meshexporttimeseries" ) ) );