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  1. Qt
  2. QTBUG-76950

Removing a large amount of QML Map items takes a long time

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    Details

    • Platform/s:
      Windows
    • Commits:
      2bb07804f32e0c9cc7948a5cff0bcef81ae9d8c9 (qt/qtlocation/5.12) 60925ff5d4aaf211090b246618b492cf177cf21d (qt/qtlocation/5.13)

      Description

      I add ~25000 MapPolyline's to a QML Map.

      Instantiating these 25000 items (using a model) only takes a few seconds.
      When calling the slot clearMapItems of the QML Map, the operation takes about 2 to 3 minutes to complete.

      This is the top of the callstack where the minutes are being spent:

      Qt5Core.dll!QMetaObjectPrivate::disconnectHelper(QObjectPrivate::Connection * c, const QObject * receiver, int method_index, void * * slot, QMutex * senderMutex, QMetaObjectPrivate::DisconnectType disconnectType) Line 3390 C++
      Qt5Core.dll!QMetaObjectPrivate::disconnect(const QObject * sender, int signal_index, const QMetaObject * smeta, const QObject * receiver, int method_index, void * * slot, QMetaObjectPrivate::DisconnectType disconnectType) Line 3458 C++
      Qt5Core.dll!QObject::disconnect(const QObject * sender, const char * signal, const QObject * receiver, const char * method) Line 3032 C++
      Qt5Location.dll!QDeclarativeGeoMapItemBase::setMap(QDeclarativeGeoMap * quickMap, QGeoMap * map) Line 131 C++
      Qt5Location.dll!QDeclarativePolylineMapItem::setMap(QDeclarativeGeoMap * quickMap, QGeoMap * map) Line 769 C++
      > Qt5Location.dll!QDeclarativeGeoMap::removeMapItem_real(QDeclarativeGeoMapItemBase * ptr) Line 1981 C++
      Qt5Location.dll!QDeclarativeGeoMap::clearMapItems() Line 2011 C++

      Most of the time seems to being spent disconnecting each QML Polyline from the QML Map. Can't this be optimized?

        Attachments

        1. 76950_SlowClearMapItems.tar.gz
          2 kB
        2. main.cpp
          1 kB
        3. main.qml
          0.7 kB
        4. qml.qrc
          0.1 kB
        5. test.pro
          0.2 kB
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          Activity

            People

            Assignee:
            paangele Paolo Angelelli
            Reporter:
            pieterverberck Pieter Verberck
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              Dates

              Created:
              Updated:
              Resolved:

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