[Qgis-developer] Using api to move features
Jordi Torres
jtorresfabra at gmail.com
Fri Jun 14 09:46:28 PDT 2013
HI,
2013/6/14 Marco Gomes <marco.gomes at edisoft.pt>
> Thank you Jordi for you help.****
>
> ** **
>
> I finally solve my problem and your algorithm work fine (beside a little
> slow refreshing….not sure if I could improve the refresh update to be
> quicker and not flicking…).****
>
> **
>
Yes, the refresh process is quite improved in the master version of Qgis,
it seems it now uses a backbuffer to render. I guess you are using 1.8 and
that's the reason of the flickering. I finally jumped to master branch and
I'm quite happy.
> **
>
> My problem, were in the figure id that I am using! In my application i set
> the figure id, during it's creation, but Qgis internally, modify it and
> remade the numeration starting by 1. Not sure if this is a good behavior or
> bug.****
>
> **
>
I think this is a feature, not a bug :). Shapefiles starts to indexing at
1.
Cheers.
**
>
> ** **
>
> *From:* Jordi Torres [mailto:jtorresfabra at gmail.com]
> *Sent:* Friday, June 14, 2013 12:39 PM
> *To:* Marco Gomes
> *Cc:* qgis-developer at lists.osgeo.org
> *Subject:* Re: [Qgis-developer] Using api to move features****
>
> ** **
>
> Hi Marco, ****
>
>
> I'm using categorized symbology too, the only difference I see is that
> I'm not calling
>
> categorizedSymbolRendererV2->startRender(QgsRenderContext(), symbolsLayer);
> ****
>
> nor ****
>
>
> categorizedSymbolRendererV2->renderFeature(feature, QgsRenderContext(),
> symbolsLayer->id().toInt(), false, false);****
>
> Maybe you can try a simple example with default simbology and see if it
> works ok, and then try to port it to your code. Anyway I'm new to qgis too,
> so not an expert here :)****
>
> Cheers. ****
>
> ** **
>
> 2013/6/14 Marco Gomes <marco.gomes at edisoft.pt>****
>
> Thank you Jordi!****
>
> ****
>
> But i am using a point memory layer as you mention but using special
> markers as defined below, and the code that you propose me, do not worked
> and my features with the symbols do not move. I need to have any kind of
> special consideration when moving feature points with marker symbols
> attached?****
>
> ****
>
> //create Vector layer in memory for adding iamge markers****
>
> QgsVectorLayer *symbolsLayer = new QgsVectorLayer("Point",
> "temporairy_points", "memory");****
>
> ****
>
> QgsVectorDataProvider *provider = symbolsLayer->dataProvider();****
>
> ****
>
> //create new feature****
>
> QgsFeature feature = QgsFeature();****
>
> ****
>
> QgsPoint point =
> ui.qgsMapCanvas->getCoordinateTransform()->toMapCoordinates(e->pos().x(),
> e->pos().y());****
>
> QgsGeometry *geometry = geometry->fromPoint(point); ****
>
> feature.setGeometry(geometry);****
>
> ****
>
> QgsSvgMarkerSymbolLayerV2 svgMarkersymbolLayerV2 = new
> QgsSvgMarkerSymbolLayerV2(QCoreApplication::applicationDirPath () +
> "/data/symbols/test.svg");****
>
> ****
>
> QgsSymbolLayerV2List symbolLayerV2List;****
>
> symbolLayerV2List.clear();****
>
> symbolLayerV2List.append(svgMarkersymbolLayerV2);****
>
> ****
>
> QgsMarkerSymbolV2 *markerSymbolV2 = new
> QgsMarkerSymbolV2(symbolLayerV2List);****
>
> ****
>
> QgsRendererCategoryV2 *rendererCategoryV2 = new QgsRendererCategoryV2(0,
> markerSymbolV2, "0");****
>
> ****
>
> QgsCategoryList categoryList;****
>
> categoryList.clear();****
>
> categoryList.append(*rendererCategoryV2);****
>
> ****
>
> QgsCategorizedSymbolRendererV2 *categorizedSymbolRendererV2 = new
> QgsCategorizedSymbolRendererV2("A", categoryList);****
>
> ****
>
> symbolsLayer->startEditing();****
>
> symbolsLayer->setRendererV2(categorizedSymbolRendererV2); **
> **
>
> symbolsLayer->addAttribute(QgsField("A", QVariant::String, "String", 4, 0,
> ""));****
>
> ****
>
> QList<QgsField> lstFields;****
>
> lstFields.insert(0, QgsField("A", QVariant::String, "String", 4, 0, ""));*
> ***
>
> provider->addAttributes(lstFields);****
>
> ****
>
> categorizedSymbolRendererV2->startRender(QgsRenderContext(), symbolsLayer);
> ****
>
> ****
>
> feature.clearAttributeMap();****
>
> QgsAttributeMap attributeMap;****
>
> attributeMap.insert(0, "0");****
>
> feature.setAttributeMap(attributeMap);****
>
> ****
>
> categorizedSymbolRendererV2->renderFeature(feature, QgsRenderContext(),
> symbolsLayer->id().toInt(), false, false);****
>
> ****
>
> QgsFeatureList qgsfeaturesList = QgsFeatureList();****
>
> qgsfeaturesList.append(feature);****
>
> provider->addFeatures(qgsfeaturesList);****
>
> ****
>
> symbolsLayer->updateExtents();****
>
> ****
>
> // Add the Vector Layer to the Layer Registry****
>
> QgsMapLayerRegistry::instance()->addMapLayer(symbolsLayer, false);****
>
> ****
>
> myLayerSet.prepend(QgsMapCanvasLayer(symbolsLayer, true));****
>
> ****
>
> // Set the Map Canvas Layer Set****
>
> ui.qgsMapCanvas->setLayerSet(myLayerSet);****
>
> ****
>
> ****
>
> ****
>
> *From:* qgis-developer-bounces at lists.osgeo.org [mailto:
> qgis-developer-bounces at lists.osgeo.org] *On Behalf Of *Jordi Torres
> *Sent:* Friday, June 14, 2013 11:54 AM
> *To:* qgis-developer at lists.osgeo.org
> *Subject:* Re: [Qgis-developer] Using api to move features****
>
> ****
>
> One more thing:****
>
>
> It should be _vectorLayer instead of _contactLayer in the last three lines.
> ****
>
> Cheers.****
>
> ****
>
> 2013/6/14 Jordi Torres <jtorresfabra at gmail.com>****
>
> OOPs forgot to send it to the list.****
>
> ****
>
> Hi Marco, ****
>
> This is working for me, don't know if is the best option:****
>
> //_vector Layer is a point layer in memory****
>
> _vectorLayer->startEditing();
> QgsGeometryMap m;****
>
> //Pass the feature id and the new x,y****
>
> m.insert(feature.id(),*QgsGeometry::fromPoint(QgsPoint(x,y)));
> _vectorLayer->dataProvider()->changeGeometryValues(m);
> _contactLayer->updateExtents();
> _contactLayer->commitChanges();****
>
> _contactLayer.triggerRepaint();****
>
> Hope it helps.****
>
> ****
>
> 2013/6/14 Marco Gomes <marco.gomes at edisoft.pt>****
>
> I am trying to move features in a Qt timer without success. What it is
> missing?****
>
> ****
>
> Below all my trials to make this work. ****
>
> ****
>
> //pointMarkersLayer->dataProvider()->changeGeometryValues(geomMap);
> ****
>
> //pointMarkersLayer->updateFeature(featureRoute_p);****
>
> ****
>
> ****
>
> //pointMarkersLayer->changeGeometry(featureRoute_p.id(), geometry);
> ****
>
> //pointMarkersLayer->moveVertex(finalPoint.x(), finalPoint.y(),
> featureRoute_p.id(), 0);****
>
> ****
>
> //pointMarkersLayer->changeGeometry(featureRoute_p.id(), geometry);
> ****
>
> //pointMarkersLayer->updateFeature(featureRoute_p);****
>
> //categorizedSymbolRendererV2->renderFeature(featureRoute_p,
> QgsRenderContext(), pointMarkersLayer->id().toInt(), false, false);****
>
> ****
>
> //pointMarkersLayer->startEditing();****
>
> //pointMarkersLayer->select(featureRoute_p.id(), false);****
>
> ****
>
> //featureRoute_p.setGeometry(QgsGeometry::fromPoint(finalPoint));**
> **
>
> //pointMarkersLayer->updateFeature(featureRoute_p);****
>
> ****
>
> //float dx = finalPoint.x() -
> featureRoute_p.geometry()->asPoint().x();****
>
> //float dy = finalPoint.y() -
> featureRoute_p.geometry()->asPoint().y();****
>
> ****
>
> //pointMarkersLayer->translateFeature(featureRoute_p.id(), dx, dy);
> ****
>
> ****
>
> ****
>
> _______________________________________________
> Qgis-developer mailing list
> Qgis-developer at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/qgis-developer****
>
>
>
>
> -- ****
>
> Jordi Torres****
>
>
>
> ****
>
> -- ****
>
> Jordi Torres****
>
>
>
>
> -- ****
>
> Jordi Torres****
>
>
> _______________________________________________
> Qgis-developer mailing list
> Qgis-developer at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/qgis-developer****
>
>
>
>
> -- ****
>
> Jordi Torres
>
> ****
>
--
Jordi Torres
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