[remote EPT] [point cloud] fix UI freeze bug (#42965)

* fix UI freeze bug

* fix spelling

* fix spelling

* refactor a bit of the code

* rename getPointCloudBlock to pointCloudBlock

* use a feedback object instead of cancelled callback

* do not use QMetaObject::Connection

* Qgs3DRenderContext doesn't need to be QObject

* remove Q_OBJECT

python/3d/auto_generated/qgspointcloudlayer3drenderer.sip.in

@@ -11,7 +11,6 @@
 
 
 
-
 class QgsPointCloudLayer3DRenderer : QgsAbstract3DRenderer
 {
 %Docstring(signature="appended")

src/3d/qgspointcloudlayer3drenderer.cpp

@@ -27,20 +27,14 @@
 #include "qgspointcloud3dsymbol.h"
 #include "qgspointcloudlayerelevationproperties.h"
 
-#include "qgis.h"
-
 QgsPointCloud3DRenderContext::QgsPointCloud3DRenderContext( const Qgs3DMapSettings &map, const QgsCoordinateTransform &coordinateTransform, std::unique_ptr<QgsPointCloud3DSymbol> symbol, double zValueScale, double zValueFixedOffset )
   : Qgs3DRenderContext( map )
   , mSymbol( std::move( symbol ) )
   , mZValueScale( zValueScale )
   , mZValueFixedOffset( zValueFixedOffset )
   , mCoordinateTransform( coordinateTransform )
+  , mFeedback( new QgsFeedback )
 {
-  auto callback = []()->bool
-  {
-    return false;
-  };
-  mIsCanceledCallback = callback;
 }
 
 void QgsPointCloud3DRenderContext::setAttributes( const QgsPointCloudAttributeCollection &attributes )
@@ -71,6 +65,18 @@ void QgsPointCloud3DRenderContext::setCoordinateTransform( const QgsCoordinateTr
   mCoordinateTransform = coordinateTransform;
 }
 
+bool QgsPointCloud3DRenderContext::isCanceled() const
+{
+  return mFeedback->isCanceled();
+}
+
+void QgsPointCloud3DRenderContext::cancelRendering() const
+{
+  mFeedback->cancel();
+}
+// ---------
+
+
 QgsPointCloudLayer3DRendererMetadata::QgsPointCloudLayer3DRendererMetadata()
   : Qgs3DRendererAbstractMetadata( QStringLiteral( "pointcloud" ) )
 {

src/3d/qgspointcloudlayer3drenderer.h

@@ -22,7 +22,7 @@
 #include "qgs3drendererregistry.h"
 #include "qgsabstract3drenderer.h"
 #include "qgsmaplayerref.h"
-
+#include "qgsfeedback.h"
 #include <QObject>
 
 class QgsPointCloudLayer;
@@ -151,14 +151,15 @@ class _3D_NO_EXPORT QgsPointCloud3DRenderContext : public Qgs3DRenderContext
     double zValueFixedOffset() const { return mZValueFixedOffset; }
 
     /**
-     * Sets the function to call to test if the rendering is canceled.
+     * Returns TRUE if the rendering is canceled.
      */
-    void setIsCanceledCallback( const std::function< bool() > &callback ) { mIsCanceledCallback = callback; }
+    bool isCanceled() const;
 
     /**
-     * Returns TRUE if the rendering is canceled.
+     * Cancels rendering.
+     * \see isCanceled()
      */
-    bool isCanceled() const { return mIsCanceledCallback(); }
+    void cancelRendering() const;
 
     /**
      * Sets the coordinate transform used to transform points from layer CRS to the map CRS
@@ -170,6 +171,10 @@ class _3D_NO_EXPORT QgsPointCloud3DRenderContext : public Qgs3DRenderContext
      */
     QgsCoordinateTransform coordinateTransform() const { return mCoordinateTransform; }
 
+    /**
+     * Returns the feedback object used to cancel rendering and check if rendering was canceled.
+     */
+    QgsFeedback *feedback() const { return mFeedback.get(); }
   private:
 #ifdef SIP_RUN
     QgsPointCloudRenderContext( const QgsPointCloudRenderContext &rh );
@@ -180,9 +185,7 @@ class _3D_NO_EXPORT QgsPointCloud3DRenderContext : public Qgs3DRenderContext
     double mZValueScale = 1.0;
     double mZValueFixedOffset = 0;
     QgsCoordinateTransform mCoordinateTransform;
-
-    std::function< bool() > mIsCanceledCallback;
-
+    std::unique_ptr<QgsFeedback> mFeedback;
 };
 
 

src/3d/qgspointcloudlayerchunkloader_p.cpp

@@ -52,7 +52,6 @@ QgsPointCloudLayerChunkLoader::QgsPointCloudLayerChunkLoader( const QgsPointClou
   , mFactory( factory )
   , mContext( factory->mMap, coordinateTransform, std::move( symbol ), zValueScale, zValueOffset )
 {
-  mContext.setIsCanceledCallback( [this] { return mCanceled; } );
 
   QgsPointCloudIndex *pc = mFactory->mPointCloudIndex;
   mContext.setAttributes( pc->attributes() );
@@ -84,7 +83,7 @@ QgsPointCloudLayerChunkLoader::QgsPointCloudLayerChunkLoader( const QgsPointClou
   {
     QgsEventTracing::ScopedEvent e( QStringLiteral( "3D" ), QStringLiteral( "PC chunk load" ) );
 
-    if ( mCanceled )
+    if ( mContext.isCanceled() )
     {
       QgsDebugMsgLevel( QStringLiteral( "canceled" ), 2 );
       return;
@@ -104,13 +103,14 @@ QgsPointCloudLayerChunkLoader::~QgsPointCloudLayerChunkLoader()
   if ( mFutureWatcher && !mFutureWatcher->isFinished() )
   {
     disconnect( mFutureWatcher, &QFutureWatcher<void>::finished, this, &QgsChunkQueueJob::finished );
+    mContext.cancelRendering();
     mFutureWatcher->waitForFinished();
   }
 }
 
 void QgsPointCloudLayerChunkLoader::cancel()
 {
-  mCanceled = true;
+  mContext.cancelRendering();
 }
 
 Qt3DCore::QEntity *QgsPointCloudLayerChunkLoader::createEntity( Qt3DCore::QEntity *parent )

src/3d/qgspointcloudlayerchunkloader_p.h

@@ -104,7 +104,6 @@ class QgsPointCloudLayerChunkLoader : public QgsChunkLoader
     const QgsPointCloudLayerChunkLoaderFactory *mFactory;
     std::unique_ptr<QgsPointCloud3DSymbolHandler> mHandler;
     QgsPointCloud3DRenderContext mContext;
-    bool mCanceled = false;
     QFutureWatcher<void> *mFutureWatcher = nullptr;
 };
 

src/3d/symbols/qgspointcloud3dsymbol_p.cpp

@@ -25,6 +25,8 @@
 #include "qgscolorramptexture.h"
 #include "qgs3dmapsettings.h"
 #include "qgspointcloudindex.h"
+#include "qgspointcloudblockrequest.h"
+#include "qgsfeedback.h"
 
 #include <Qt3DRender/QGeometryRenderer>
 #include <Qt3DRender/QAttribute>
@@ -225,6 +227,34 @@ void QgsPointCloud3DSymbolHandler::makeEntity( Qt3DCore::QEntity *parent, const
   // cppcheck-suppress memleak
 }
 
+QgsPointCloudBlock *QgsPointCloud3DSymbolHandler::pointCloudBlock( QgsPointCloudIndex *pc, const IndexedPointCloudNode &n, const QgsPointCloudRequest &request, const QgsPointCloud3DRenderContext &context )
+{
+  QgsPointCloudBlock *block = nullptr;
+  if ( pc->accessType() == QgsPointCloudIndex::AccessType::Local )
+  {
+    block = pc->nodeData( n, request );
+  }
+  else if ( pc->accessType() == QgsPointCloudIndex::AccessType::Remote )
+  {
+    bool loopAborted = false;
+    QEventLoop loop;
+    QgsPointCloudBlockRequest *req = pc->asyncNodeData( n, request );
+    QObject::connect( req, &QgsPointCloudBlockRequest::finished, &loop, &QEventLoop::quit );
+    QObject::connect( context.feedback(), &QgsFeedback::canceled, &loop, [ & ]()
+    {
+      loopAborted = true;
+      loop.quit();
+    } );
+    loop.exec();
+
+    if ( !loopAborted )
+      block = req->block();
+  }
+  return block;
+}
+
+//
+
 QgsSingleColorPointCloud3DSymbolHandler::QgsSingleColorPointCloud3DSymbolHandler()
   : QgsPointCloud3DSymbolHandler()
 {
@@ -246,7 +276,7 @@ void QgsSingleColorPointCloud3DSymbolHandler::processNode( QgsPointCloudIndex *p
 
   QgsPointCloudRequest request;
   request.setAttributes( attributes );
-  std::unique_ptr<QgsPointCloudBlock> block( pc->nodeData( n, request ) );
+  std::unique_ptr<QgsPointCloudBlock> block( pointCloudBlock( pc, n, request, context ) );
   if ( !block )
     return;
 
@@ -369,7 +399,7 @@ void QgsColorRampPointCloud3DSymbolHandler::processNode( QgsPointCloudIndex *pc,
 
   QgsPointCloudRequest request;
   request.setAttributes( attributes );
-  std::unique_ptr<QgsPointCloudBlock> block( pc->nodeData( n, request ) );
+  std::unique_ptr<QgsPointCloudBlock> block( pointCloudBlock( pc, n, request, context ) );
   if ( !block )
     return;
 
@@ -474,7 +504,7 @@ void QgsRGBPointCloud3DSymbolHandler::processNode( QgsPointCloudIndex *pc, const
 
   QgsPointCloudRequest request;
   request.setAttributes( attributes );
-  std::unique_ptr<QgsPointCloudBlock> block( pc->nodeData( n, request ) );
+  std::unique_ptr<QgsPointCloudBlock> block( pointCloudBlock( pc, n, request, context ) );
   if ( !block )
     return;
 
@@ -637,7 +667,7 @@ void QgsClassificationPointCloud3DSymbolHandler::processNode( QgsPointCloudIndex
 
   QgsPointCloudRequest request;
   request.setAttributes( attributes );
-  std::unique_ptr<QgsPointCloudBlock> block( pc->nodeData( n, request ) );
+  std::unique_ptr<QgsPointCloudBlock> block( pointCloudBlock( pc, n, request, context ) );
   if ( !block )
     return;
 

src/3d/symbols/qgspointcloud3dsymbol_p.h

@@ -64,6 +64,7 @@ class QgsPointCloud3DSymbolHandler // : public QgsFeature3DHandler
 
     void makeEntity( Qt3DCore::QEntity *parent, const QgsPointCloud3DRenderContext &context, PointData &out, bool selected );
     virtual Qt3DRender::QGeometry *makeGeometry( Qt3DCore::QNode *parent, const QgsPointCloud3DSymbolHandler::PointData &data, unsigned int byteStride ) = 0;
+    QgsPointCloudBlock *pointCloudBlock( QgsPointCloudIndex *pc, const IndexedPointCloudNode &node, const QgsPointCloudRequest &request, const QgsPointCloud3DRenderContext &context );
 
     // outputs
     PointData outNormal;  //!< Features that are not selected