# QgsSdkApp.pro
QT += core gui xml svg

void QgsSdkApp::on_actionShp_Layer_triggered()
{QString filePath = QFileDialog::getOpenFileName(this, tr("Open ESRI Shapefile"), tr(""), tr("ESRI Shapefile (*.shp)"));QFileInfo fileInfo(filePath);if (fileInfo.exists()){QString fileName = fileInfo.baseName();addVectorLayer(filePath, fileName, "ogr");}
}

QgsVectorLayer *QgsSdkApp::addVectorLayer(const QString &vectorLayerPath, const QString &name, const QString &providerKey, bool guiWarning)
{QgsVectorLayer* vectorLayer = new QgsVectorLayer(uri, layerName, providerKey);mMapLayerList.append(vectorLayer);mMapCanvas->setLayers(mMapLayerList);if (mMapLayerList.size() == 1){QgsMapLayer* firstLayer = mMapLayerList.first();QgsRectangle extent = mMapCanvas->mapSettings().layerExtentToOutputExtent(firstLayer, firstLayer->extent());mMapCanvas->setExtent(extent);}mMapCanvas->refresh();
}

QgsVectorLayer *QgsSdkApp::addVectorLayer(const QString &vectorLayerPath, const QString &name, const QString &providerKey, bool guiWarning)
{QString baseName = QgsMapLayer::formatLayerName( name );/* Eliminate the need to instantiate the layer based on provider type.The caller is responsible for cobbling together the needed information toopen the layer*/QgsDebugMsg( "Creating new vector layer using " + vectorLayerPath+ " with baseName of " + baseName+ " and providerKey of " + providerKey );// if the layer needs authentication, ensure the master password is setbool authok = true;QRegExp rx( "authcfg=([a-z]|[A-Z]|[0-9]){7}" );if ( rx.indexIn( vectorLayerPath ) != -1 ){authok = false;if ( !QgsAuthGuiUtils::isDisabled( messageBar(), messageTimeout() ) ){authok = QgsApplication::authManager()->setMasterPassword( true );}}// create the layerQgsVectorLayer::LayerOptions options { QgsProject::instance()->transformContext() };// Default style is loaded later in this methodoptions.loadDefaultStyle = false;QgsVectorLayer *layer = new QgsVectorLayer( vectorLayerPath, baseName, providerKey, options );if ( authok && layer && layer->isValid() ){QStringList sublayers = layer->dataProvider()->subLayers();QgsDebugMsg( QStringLiteral( "got valid layer with %1 sublayers" ).arg( sublayers.count() ) );// If the newly created layer has more than 1 layer of data available, we show the// sublayers selection dialog so the user can select the sublayers to actually load.if ( sublayers.count() > 1 &&! vectorLayerPath.contains( QStringLiteral( "layerid=" ) ) &&! vectorLayerPath.contains( QStringLiteral( "layername=" ) ) ){QList< QgsMapLayer * > addedLayers = askUserForOGRSublayers( layer );// The first layer loaded is not useful in that case. The user can select it in// the list if he wants to load it.delete layer;layer = addedLayers.isEmpty() ? nullptr : qobject_cast< QgsVectorLayer * >( addedLayers.at( 0 ) );for ( QgsMapLayer *l : addedLayers )askUserForDatumTransform( l->crs(), QgsProject::instance()->crs(), l );}else{// Register this layer with the layers registryQList<QgsMapLayer *> myList;//set friendly name for datasources with only one layerQStringList sublayers = layer->dataProvider()->subLayers();if ( !sublayers.isEmpty() ){setupVectorLayer( vectorLayerPath, sublayers, layer,providerKey, options );}myList << layer;QgsProject::instance()->addMapLayers( myList );askUserForDatumTransform( layer->crs(), QgsProject::instance()->crs(), layer );bool ok;layer->loadDefaultStyle( ok );layer->loadDefaultMetadata( ok );}}else{if ( guiWarning ){QString message = layer->dataProvider() ? layer->dataProvider()->error().message( QgsErrorMessage::Text ) : tr( "Invalid provider" );QString msg = tr( "The layer %1 is not a valid layer and can not be added to the map. Reason: %2" ).arg( vectorLayerPath, message );visibleMessageBar()->pushMessage( tr( "Layer is not valid" ), msg, Qgis::Critical, messageTimeout() );}delete layer;return nullptr;}// Let render() do its own cursor management//  QApplication::restoreOverrideCursor();return layer;
}

QList<QgsMapLayer *> QgsSdkApp::askUserForOGRSublayers(QgsVectorLayer *layer)
{QList<QgsMapLayer *> result;if ( !layer ){layer = qobject_cast<QgsVectorLayer *>( activeLayer() );if ( !layer || layer->providerType() != QLatin1String( "ogr" ) )return result;}QStringList sublayers = layer->dataProvider()->subLayers();QgsSublayersDialog::LayerDefinitionList list;QMap< QString, int > mapLayerNameToCount;bool uniqueNames = true;int lastLayerId = -1;const auto constSublayers = sublayers;for ( const QString &sublayer : constSublayers ){// OGR provider returns items in this format:// <layer_index>:<name>:<feature_count>:<geom_type>QStringList elements = splitSubLayerDef( sublayer );if ( elements.count() >= 4 ){QgsSublayersDialog::LayerDefinition def;def.layerId = elements[0].toInt();def.layerName = elements[1];def.count = elements[2].toInt();def.type = elements[3];// ignore geometry column name at elements[4]if ( elements.count() >= 6 )def.description = elements[5];if ( lastLayerId != def.layerId ){int count = ++mapLayerNameToCount[def.layerName];if ( count > 1 || def.layerName.isEmpty() )uniqueNames = false;lastLayerId = def.layerId;}list << def;}else{QgsDebugMsg( "Unexpected output from OGR provider's subLayers()! " + sublayer );}}// Check if the current layer uri contains the// We initialize a selection dialog and display it.QgsSublayersDialog chooseSublayersDialog( QgsSublayersDialog::Ogr, QStringLiteral( "ogr" ), this );chooseSublayersDialog.setShowAddToGroupCheckbox( true );chooseSublayersDialog.populateLayerTable( list );if ( !chooseSublayersDialog.exec() )return result;QString name = layer->name();auto uriParts = QgsProviderRegistry::instance()->decodeUri(layer->providerType(), layer->dataProvider()->dataSourceUri() );QString uri( uriParts.value( QStringLiteral( "path" ) ).toString() );// The uri must contain the actual uri of the vectorLayer from which we are// going to load the sublayers.QString fileName = QFileInfo( uri ).baseName();const auto constSelection = chooseSublayersDialog.selection();for ( const QgsSublayersDialog::LayerDefinition &def : constSelection ){QString layerGeometryType = def.type;QString composedURI = uri;if ( uniqueNames ){composedURI += "|layername=" + def.layerName;}else{// Only use layerId if there are ambiguities with namescomposedURI += "|layerid=" + QString::number( def.layerId );}if ( !layerGeometryType.isEmpty() ){composedURI += "|geometrytype=" + layerGeometryType;}QgsDebugMsg( "Creating new vector layer using " + composedURI );QString name = fileName + " " + def.layerName;QgsVectorLayer::LayerOptions options { QgsProject::instance()->transformContext() };options.loadDefaultStyle = false;QgsVectorLayer *layer = new QgsVectorLayer( composedURI, name, QStringLiteral( "ogr" ), options );if ( layer && layer->isValid() ){result << layer;}else{QString msg = tr( "%1 is not a valid or recognized data source" ).arg( composedURI );visibleMessageBar()->pushMessage( tr( "Invalid Data Source" ), msg, Qgis::Critical, messageTimeout() );delete layer;}}if ( !result.isEmpty() ){QgsSettings settings;bool addToGroup = settings.value( QStringLiteral( "/qgis/openSublayersInGroup" ), true ).toBool();bool newLayersVisible = settings.value( QStringLiteral( "/qgis/new_layers_visible" ), true ).toBool();QgsLayerTreeGroup *group = nullptr;if ( addToGroup )group = QgsProject::instance()->layerTreeRoot()->insertGroup( 0, name );QgsProject::instance()->addMapLayers( result, ! addToGroup );for ( QgsMapLayer *l : qgis::as_const( result ) ){bool ok;l->loadDefaultStyle( ok );l->loadDefaultMetadata( ok );if ( addToGroup )group->addLayer( l );}// Respect if user don't want the new group of layers visible.if ( addToGroup && ! newLayersVisible )group->setItemVisibilityCheckedRecursive( newLayersVisible );}return result;
}bool QgsSdkApp::askUserForDatumTransform(const QgsCoordinateReferenceSystem &sourceCrs, const QgsCoordinateReferenceSystem &destinationCrs, const QgsMapLayer *layer)
{Q_ASSERT( qApp->thread() == QThread::currentThread() );QString title;if ( layer ){// try to make a user-friendly (short!) identifier for the layerQString layerIdentifier;if ( !layer->name().isEmpty() ){layerIdentifier = layer->name();}else{const QVariantMap parts = QgsProviderRegistry::instance()->decodeUri( layer->providerType(), layer->source() );if ( parts.contains( QStringLiteral( "path" ) ) ){const QFileInfo fi( parts.value( QStringLiteral( "path" ) ).toString() );layerIdentifier = fi.fileName();}else if ( layer->dataProvider() ){const QgsDataSourceUri uri( layer->source() );layerIdentifier = uri.table();}}if ( !layerIdentifier.isEmpty() )title = tr( "Select Transformation for %1" ).arg( layerIdentifier );}return QgsDatumTransformDialog::run( sourceCrs, destinationCrs, this, mMapCanvas, title );
}static QStringList splitSubLayerDef( const QString &subLayerDef )
{return subLayerDef.split( QgsDataProvider::sublayerSeparator() );
}static void setupVectorLayer( const QString &vectorLayerPath,const QStringList &sublayers,QgsVectorLayer *&layer,const QString &providerKey,QgsVectorLayer::LayerOptions options )
{//set friendly name for datasources with only one layerQgsSettings settings;QStringList elements = splitSubLayerDef( sublayers.at( 0 ) );QString rawLayerName = elements.size() >= 2 ? elements.at( 1 ) : QString();QString subLayerNameFormatted = rawLayerName;if ( settings.value( QStringLiteral( "qgis/formatLayerName" ), false ).toBool() ){subLayerNameFormatted =  QgsMapLayer::formatLayerName( subLayerNameFormatted );}if ( elements.size() >= 4 && layer->name().compare( rawLayerName, Qt::CaseInsensitive ) != 0&& layer->name().compare( subLayerNameFormatted, Qt::CaseInsensitive ) != 0 ){layer->setName( QStringLiteral( "%1 %2" ).arg( layer->name(), rawLayerName ) );}// Systematically add a layername= option to OGR datasets in case// the current single layer dataset becomes layer a multi-layer one.// Except for a few select extensions, known to be always single layer dataset.QFileInfo fi( vectorLayerPath );QString ext = fi.suffix().toLower();if ( providerKey == QLatin1String( "ogr" ) &&ext != QLatin1String( "shp" ) &&ext != QLatin1String( "mif" ) &&ext != QLatin1String( "tab" ) &&ext != QLatin1String( "csv" ) &&ext != QLatin1String( "geojson" ) &&! vectorLayerPath.contains( QStringLiteral( "layerid=" ) ) &&! vectorLayerPath.contains( QStringLiteral( "layername=" ) ) ){auto uriParts = QgsProviderRegistry::instance()->decodeUri(layer->providerType(), layer->dataProvider()->dataSourceUri() );QString composedURI( uriParts.value( QStringLiteral( "path" ) ).toString() );composedURI += "|layername=" + rawLayerName;auto newLayer = qgis::make_unique<QgsVectorLayer>( composedURI, layer->name(), QStringLiteral( "ogr" ), options );if ( newLayer && newLayer->isValid() ){delete layer;layer = newLayer.release();}}
}

QgsSdkApp::QgsSdkApp(QWidget *parent): QMainWindow(parent), ui(new Ui::QgsSdkApp)
{ui->setupUi(this);mMapCanvas = ui->centralwidget;mMapCanvas->setObjectName(QStringLiteral("theMapCanvas"));/** [BEGIN] 添加的用于将 `QgsMapCanvas` 和 `QgsProject` 建立关联的代码 */mLayerTreeCanvasBridge = new QgsLayerTreeMapCanvasBridge(QgsProject::instance()->layerTreeRoot(), mMapCanvas, this);/** [END] */connect(ui->actionAdd_Shp_Layer, &QAction::triggered, this, &QgsSdkApp::on_actionShp_Layer_triggered);
}

void QgisApp::dataSourceManager( const QString &pageName )
{if ( ! mDataSourceManagerDialog ){mDataSourceManagerDialog = new QgsDataSourceManagerDialog( mBrowserModel, this, mapCanvas() );connect( this, &QgisApp::connectionsChanged, mDataSourceManagerDialog, &QgsDataSourceManagerDialog::refresh );connect( mDataSourceManagerDialog, &QgsDataSourceManagerDialog::connectionsChanged, this, &QgisApp::connectionsChanged );connect( mDataSourceManagerDialog, SIGNAL( addRasterLayer( QString const &, QString const &, QString const & ) ),this, SLOT( addRasterLayer( QString const &, QString const &, QString const & ) ) );connect( mDataSourceManagerDialog, SIGNAL( addVectorLayer( QString const &, QString const &, QString const & ) ),this, SLOT( addVectorLayer( QString const &, QString const &, QString const & ) ) );connect( mDataSourceManagerDialog, SIGNAL( addVectorLayers( QStringList const &, QString const &, QString const & ) ),this, SLOT( addVectorLayers( QStringList const &, QString const &, QString const & ) ) );connect( mDataSourceManagerDialog, &QgsDataSourceManagerDialog::addMeshLayer, this, &QgisApp::addMeshLayer );connect( mDataSourceManagerDialog, &QgsDataSourceManagerDialog::showStatusMessage, this, &QgisApp::showStatusMessage );connect( mDataSourceManagerDialog, &QgsDataSourceManagerDialog::addDatabaseLayers, this, &QgisApp::addDatabaseLayers );connect( mDataSourceManagerDialog, &QgsDataSourceManagerDialog::replaceSelectedVectorLayer, this, &QgisApp::replaceSelectedVectorLayer );connect( mDataSourceManagerDialog, static_cast<void ( QgsDataSourceManagerDialog::* )()>( &QgsDataSourceManagerDialog::addRasterLayer ), this, static_cast<void ( QgisApp::* )()>( &QgisApp::addRasterLayer ) );connect( mDataSourceManagerDialog, &QgsDataSourceManagerDialog::handleDropUriList, this, &QgisApp::handleDropUriList );connect( this, &QgisApp::newProject, mDataSourceManagerDialog, &QgsDataSourceManagerDialog::updateProjectHome );connect( mDataSourceManagerDialog, &QgsDataSourceManagerDialog::openFile, this, &QgisApp::openFile );}else{mDataSourceManagerDialog->reset();}// Try to open the dialog on a particular pageif ( ! pageName.isEmpty() ){mDataSourceManagerDialog->openPage( pageName );}if ( QgsSettings().value( QStringLiteral( "/qgis/dataSourceManagerNonModal" ), true ).toBool() ){mDataSourceManagerDialog->show();}else{mDataSourceManagerDialog->exec();}
}

QgsSdkApp::QgsSdkApp(QWidget *parent) : QMainWindow(parent), ui(new Ui::QgsSdkApp)
{ui->setupUi(this);mMapCanvas = ui->centralwidget;mMapCanvas->setObjectName(QStringLiteral("theMapCanvas"));mLayerTreeCanvasBridge = new QgsLayerTreeMapCanvasBridge(QgsProject::instance()->layerTreeRoot(), mMapCanvas, this);/** [BEGIN] 设置 QgsLayerTreeView 的 Model */QgsLayerTreeModel* model = new QgsLayerTreeModel(QgsProject::instance()->layerTreeRoot(), this);ui->layerTreeView->setModel(model);ui->layerTreeView->setObjectName(QStringLiteral( "theLayerTreeView" ));/** [END] */mInfoBar = new QgsMessageBar(this);ui->statusbar->addWidget(mInfoBar);connect(ui->actionAdd_Shp_Layer, &QAction::triggered, this, &QgsSdkApp::on_actionShp_Layer_triggered);
}

// qgisapp.cpp [4493行]
mLayerTreeView->setMenuProvider( new QgsAppLayerTreeViewMenuProvider( mLayerTreeView, mMapCanvas ) );