When the modify annotation tool is used to select an annotation item,

show a panel in the layer styling dock allowing users to modify
the appearance of the annotation

python/gui/auto_generated/qgisinterface.sip.in

@@ -1569,6 +1569,13 @@ Any existing GPS connection used by the widget will be disconnect and replaced w
 is automatically registered within the :py:func:`QgsApplication.gpsConnectionRegistry()`.
 
 .. versionadded:: 3.16
+%End
+
+    virtual QgsMapToolModifyAnnotation *modifyAnnotationTool() = 0;
+%Docstring
+Returns the map tool used for modifying annotation layers.
+
+.. versionadded:: 3.22
 %End
 
   signals:

src/app/CMakeLists.txt

@@ -106,6 +106,8 @@ set(QGIS_APP_SRCS
   qgsmaptoolsvgannotation.cpp
   qgsmaptooltextannotation.cpp
 
+  annotations/qgsannotationitempropertieswidget.cpp
+
   decorations/qgsdecorationitem.cpp
   decorations/qgsdecorationtitle.cpp
   decorations/qgsdecorationtitledialog.cpp

src/app/annotations/qgsannotationitempropertieswidget.cpp

@@ -0,0 +1,153 @@
+/***************************************************************************
+    qgsannotationitempropertieswidget.cpp
+    ---------------------
+    begin                : December 2020
+    copyright            : (C) 2020 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 "qgsannotationitempropertieswidget.h"
+#include "qgsstyle.h"
+#include "qgsapplication.h"
+#include "qgsmaplayer.h"
+#include "qgsannotationlayer.h"
+#include "qgsannotationitemwidget.h"
+#include "qgsannotationitem.h"
+#include "qgsgui.h"
+#include "qgsannotationitemguiregistry.h"
+#include <QStackedWidget>
+#include <QHBoxLayout>
+
+QgsAnnotationItemPropertiesWidget::QgsAnnotationItemPropertiesWidget( QgsAnnotationLayer *layer, QgsMapCanvas *canvas, QWidget *parent )
+  : QgsMapLayerConfigWidget( layer, canvas, parent )
+{
+  mStack = new QStackedWidget();
+
+  setDockMode( true );
+
+  QHBoxLayout *l = new QHBoxLayout();
+  l->setContentsMargins( 0, 0, 0, 0 );
+  l->addWidget( mStack );
+  setLayout( l );
+
+  syncToLayer( layer );
+}
+
+void QgsAnnotationItemPropertiesWidget::syncToLayer( QgsMapLayer *layer )
+{
+  if ( layer == mLayer )
+    return;
+
+  mLayer = qobject_cast< QgsAnnotationLayer * >( layer );
+  if ( !mLayer )
+    return;
+
+  // check context
+  setItemId( mContext.annotationId() );
+}
+
+void QgsAnnotationItemPropertiesWidget::setContext( const QgsMapLayerConfigWidgetContext &context )
+{
+  QgsMapLayerConfigWidget::setContext( context );
+  setItemId( context.annotationId() );
+}
+
+void QgsAnnotationItemPropertiesWidget::setDockMode( bool dockMode )
+{
+  QgsMapLayerConfigWidget::setDockMode( dockMode );
+  if ( mItemWidget )
+    mItemWidget->setDockMode( dockMode );
+}
+
+void QgsAnnotationItemPropertiesWidget::apply()
+{
+  if ( !mLayer )
+    return;
+
+  mLayer->triggerRepaint();
+}
+
+void QgsAnnotationItemPropertiesWidget::onChanged()
+{
+  // set the annotation layer's item's properties to match the widget
+  std::unique_ptr< QgsAnnotationItem > newItem( mItemWidget->createItem() );
+
+  mLayer->replaceItem( mContext.annotationId(), newItem.release() );
+}
+
+void QgsAnnotationItemPropertiesWidget::setItemId( const QString &itemId )
+{
+  // try to retrieve matching item
+  bool setItem = false;
+  if ( QgsAnnotationItem *item = mLayer->item( itemId ) )
+  {
+    if ( mItemWidget )
+    {
+      setItem = mItemWidget->setItem( item );
+    }
+
+    if ( !setItem )
+    {
+      // create new item
+      mItemWidget = QgsGui::annotationItemGuiRegistry()->createItemWidget( item );
+
+      if ( mItemWidget )
+      {
+        setItem = true;
+
+        QWidget *prevWidget = mStack->currentWidget();
+        mStack->removeWidget( prevWidget );
+        delete prevWidget;
+
+        mStack->addWidget( mItemWidget );
+        connect( mItemWidget, &QgsAnnotationItemBaseWidget::itemChanged, this, &QgsAnnotationItemPropertiesWidget::onChanged );
+        mItemWidget->setDockMode( dockMode() );
+        connect( mItemWidget, &QgsPanelWidget::showPanel, this, &QgsPanelWidget::openPanel );
+      }
+    }
+  }
+
+  if ( !setItem )
+  {
+    // show a "no item" widget
+  }
+}
+
+//
+// QgsAnnotationItemPropertiesWidgetFactory
+//
+
+QgsAnnotationItemPropertiesWidgetFactory::QgsAnnotationItemPropertiesWidgetFactory( QObject *parent )
+  : QObject( parent )
+{
+  setIcon( QgsApplication::getThemeIcon( QStringLiteral( "propertyicons/symbology.svg" ) ) );
+  setTitle( tr( "Annotation" ) );
+}
+
+QgsMapLayerConfigWidget *QgsAnnotationItemPropertiesWidgetFactory::createWidget( QgsMapLayer *layer, QgsMapCanvas *canvas, bool, QWidget *parent ) const
+{
+  return new QgsAnnotationItemPropertiesWidget( qobject_cast< QgsAnnotationLayer * >( layer ), canvas, parent );
+}
+
+bool QgsAnnotationItemPropertiesWidgetFactory::supportLayerPropertiesDialog() const
+{
+  return false;
+}
+
+bool QgsAnnotationItemPropertiesWidgetFactory::supportsStyleDock() const
+{
+  return true;
+}
+
+bool QgsAnnotationItemPropertiesWidgetFactory::supportsLayer( QgsMapLayer *layer ) const
+{
+  return layer->type() == QgsMapLayerType::AnnotationLayer;
+}
+

src/app/annotations/qgsannotationitempropertieswidget.h

@@ -0,0 +1,68 @@
+/***************************************************************************
+    qgsannotationitempropertieswidget.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 QGSANNOTATIONITEMPROPERTIESWIDGET_H
+#define QGSANNOTATIONITEMPROPERTIESWIDGET_H
+
+#include "qgsmaplayerconfigwidget.h"
+#include "qgsmaplayerconfigwidgetfactory.h"
+
+class QgsAnnotationLayer;
+class QgsAnnotationItemBaseWidget;
+class QStackedWidget;
+
+class QgsAnnotationItemPropertiesWidget : public QgsMapLayerConfigWidget
+{
+    Q_OBJECT
+  public:
+
+    QgsAnnotationItemPropertiesWidget( QgsAnnotationLayer *layer, QgsMapCanvas *canvas, QWidget *parent );
+
+    void syncToLayer( QgsMapLayer *layer ) override;
+    void setContext( const QgsMapLayerConfigWidgetContext &context ) override;
+    void setDockMode( bool dockMode ) override;
+
+  public slots:
+    void apply() override;
+
+  private slots:
+
+    void onChanged();
+  private:
+
+    void setItemId( const QString &itemId );
+
+    QStackedWidget *mStack = nullptr;
+    QgsAnnotationLayer *mLayer = nullptr;
+    QgsAnnotationItemBaseWidget *mItemWidget = nullptr;
+
+};
+
+
+class QgsAnnotationItemPropertiesWidgetFactory : public QObject, public QgsMapLayerConfigWidgetFactory
+{
+    Q_OBJECT
+  public:
+    explicit QgsAnnotationItemPropertiesWidgetFactory( QObject *parent = nullptr );
+
+    QgsMapLayerConfigWidget *createWidget( QgsMapLayer *layer, QgsMapCanvas *canvas, bool dockWidget, QWidget *parent ) const override;
+    bool supportLayerPropertiesDialog() const override;
+    bool supportsStyleDock() const override;
+    bool supportsLayer( QgsMapLayer *layer ) const override;
+};
+
+
+
+#endif // QGSANNOTATIONITEMPROPERTIESWIDGET_H

src/app/maptools/qgsappmaptools.cpp

@@ -72,6 +72,7 @@
 #include "qgsmaptooleditmeshframe.h"
 #include "qgsspinbox.h"
 #include "qgssettingsregistrycore.h"
+#include "qgsmaptoolmodifyannotation.h"
 
 //
 // QgsStreamDigitizingSettingsAction
@@ -178,6 +179,7 @@ QgsAppMapTools::QgsAppMapTools( QgsMapCanvas *canvas, QgsAdvancedDigitizingDockW
   mTools.insert( Tool::RotateLabel, new QgsMapToolRotateLabel( canvas, cadDock ) );
   mTools.insert( Tool::ChangeLabelProperties, new QgsMapToolChangeLabelProperties( canvas, cadDock ) );
   mTools.insert( Tool::EditMeshFrame, new QgsMapToolEditMeshFrame( canvas ) );
+  mTools.insert( Tool::AnnotationEdit, new QgsMapToolModifyAnnotation( canvas, cadDock ) );
 
   mStreamDigitizingSettingsAction = new QgsStreamDigitizingSettingsAction();
 }

src/app/maptools/qgsappmaptools.h

@@ -113,7 +113,8 @@ class QgsAppMapTools
       ChangeLabelProperties,
       ReverseLine,
       TrimExtendFeature,
-      EditMeshFrame
+      EditMeshFrame,
+      AnnotationEdit
     };
 
     QgsAppMapTools( QgsMapCanvas *canvas, QgsAdvancedDigitizingDockWidget *cadDock );

src/app/qgisapp.cpp

@@ -104,6 +104,9 @@
 #include "qgsprovidersublayersdialog.h"
 #include "qgsmaplayerfactory.h"
 #include "qgsbrowserwidget.h"
+#include "annotations/qgsannotationitempropertieswidget.h"
+#include "qgsmaptoolmodifyannotation.h"
+#include "qgsannotationlayer.h"
 
 #include "qgsanalysis.h"
 #include "qgsgeometrycheckregistry.h"
@@ -1338,6 +1341,7 @@ QgisApp::QgisApp( QSplashScreen *splash, bool restorePlugins, bool skipVersionCh
   registerMapLayerPropertiesFactory( new QgsPointCloudLayer3DRendererWidgetFactory( this ) );
 #endif
   registerMapLayerPropertiesFactory( new QgsPointCloudElevationPropertiesWidgetFactory( this ) );
+  registerMapLayerPropertiesFactory( new QgsAnnotationItemPropertiesWidgetFactory( this ) );
 
   activateDeactivateLayerRelatedActions( nullptr ); // after members were created
 
@@ -1661,6 +1665,9 @@ QgisApp::QgisApp( QSplashScreen *splash, bool restorePlugins, bool skipVersionCh
   updateCrsStatusBar();
   endProfile();
 
+  connect( qobject_cast< QgsMapToolModifyAnnotation * >( mMapTools->mapTool( QgsAppMapTools::AnnotationEdit ) ), &QgsMapToolModifyAnnotation::itemSelected,
+           mMapStyleWidget, &QgsLayerStylingWidget::setAnnotationItem );
+
   // request notification of FileOpen events (double clicking a file icon in Mac OS X Finder)
   // should come after fileNewBlank to ensure project is properly set up to receive any data source files
   QgsApplication::setFileOpenEventReceiver( this );

src/app/qgisappinterface.cpp

@@ -47,7 +47,8 @@
 #include "qgslocatorwidget.h"
 #include "qgslocator.h"
 #include "qgsmessagebar.h"
-
+#include "qgsappmaptools.h"
+#include "qgsmaptoolmodifyannotation.h"
 
 QgisAppInterface::QgisAppInterface( QgisApp *_qgis )
   : qgis( _qgis )
@@ -907,3 +908,8 @@ QList<QgsMapDecoration *> QgisAppInterface::activeDecorations()
 {
   return qgis->activeDecorations();
 }
+
+QgsMapToolModifyAnnotation *QgisAppInterface::modifyAnnotationTool()
+{
+  return qobject_cast< QgsMapToolModifyAnnotation * >( qgis->mMapTools->mapTool( QgsAppMapTools::AnnotationEdit ) );
+}

src/app/qgisappinterface.h

@@ -322,6 +322,7 @@ class APP_EXPORT QgisAppInterface : public QgisInterface
     QgsLayerTreeRegistryBridge::InsertionPoint layerTreeInsertionPoint() override;
     void setGpsPanelConnection( QgsGpsConnection *connection ) override;
     QList<QgsMapDecoration *> activeDecorations() override;
+    virtual QgsMapToolModifyAnnotation *modifyAnnotationTool() override;
 
   private slots:
 

src/app/qgslayerstylingwidget.cpp

@@ -700,6 +700,17 @@ void QgsLayerStylingWidget::setCurrentPage( QgsLayerStylingWidget::Page page )
   }
 }
 
+void QgsLayerStylingWidget::setAnnotationItem( QgsAnnotationLayer *layer, const QString &itemId )
+{
+  mContext.setAnnotationId( itemId );
+  setLayer( layer );
+
+  if ( QgsMapLayerConfigWidget *configWidget = qobject_cast< QgsMapLayerConfigWidget * >( mWidgetStack->mainPanel() ) )
+  {
+    configWidget->setContext( mContext );
+  }
+}
+
 void QgsLayerStylingWidget::layerAboutToBeRemoved( QgsMapLayer *layer )
 {
   if ( layer == mCurrentLayer )

src/app/qgslayerstylingwidget.h

@@ -48,6 +48,7 @@ class QgsPointCloudLayer3DRendererWidget;
 class QgsMessageBar;
 class QgsVectorTileBasicRendererWidget;
 class QgsVectorTileBasicLabelingWidget;
+class QgsAnnotationLayer;
 
 class APP_EXPORT QgsLayerStyleManagerWidgetFactory : public QgsMapLayerConfigWidgetFactory
 {
@@ -129,6 +130,11 @@ class APP_EXPORT QgsLayerStylingWidget : public QWidget, private Ui::QgsLayerSty
      */
     void setCurrentPage( QgsLayerStylingWidget::Page page );
 
+    /**
+     * Sets an annotation item to show in the widget.
+     */
+    void setAnnotationItem( QgsAnnotationLayer *layer, const QString &itemId );
+
   private slots:
 
     void layerAboutToBeRemoved( QgsMapLayer *layer );

src/gui/qgisinterface.h

@@ -70,6 +70,7 @@ class QgsDevToolWidgetFactory;
 class QgsGpsConnection;
 class QgsApplicationExitBlockerInterface;
 class QgsAbstractMapToolHandler;
+class QgsMapToolModifyAnnotation;
 
 /**
  * \ingroup gui
@@ -1311,6 +1312,13 @@ class GUI_EXPORT QgisInterface : public QObject
      */
     virtual void setGpsPanelConnection( QgsGpsConnection *connection ) = 0;
 
+    /**
+     * Returns the map tool used for modifying annotation layers.
+     *
+     * \since QGIS 3.22
+     */
+    virtual QgsMapToolModifyAnnotation *modifyAnnotationTool() = 0;
+
   signals:
 
     /**