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[labeling] When label map tools are used to select a label and the
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user clicks on overlapping labels, prioritise either the labels in
the current layer OR fallback to picking the smallest candidate
label (since it will be the most difficult to select)
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@nyalldawson
nyalldawson committed Jul 16, 2019
1 parent 8420780 commit bf05575
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Showing 4 changed files with 272 additions and 7 deletions.
45 changes: 38 additions & 7 deletions src/app/qgsmaptoollabel.cpp
View file
Expand Up @@ -48,18 +48,49 @@ bool QgsMapToolLabel::labelAtPosition( QMouseEvent *e, QgsLabelPosition &p )
{
QgsPointXY pt = toMapCoordinates( e->pos() );
const QgsLabelingResults *labelingResults = mCanvas->labelingResults();
if ( labelingResults )
if ( !labelingResults )
return false;

QList<QgsLabelPosition> labelPosList = labelingResults->labelsAtPosition( pt );
if ( labelPosList.empty() )
return false;

// prioritise labels in the current selected layer, in case of overlaps
QList<QgsLabelPosition> activeLayerLabels;
if ( const QgsVectorLayer *currentLayer = qobject_cast< QgsVectorLayer * >( mCanvas->currentLayer() ) )
{
QList<QgsLabelPosition> labelPosList = labelingResults->labelsAtPosition( pt );
QList<QgsLabelPosition>::const_iterator posIt = labelPosList.constBegin();
if ( posIt != labelPosList.constEnd() )
for ( const QgsLabelPosition &pos : qgis::as_const( labelPosList ) )
{
p = *posIt;
return true;
if ( pos.layerID == currentLayer->id() )
{
activeLayerLabels.append( pos );
}
}
}
if ( !activeLayerLabels.empty() )
labelPosList = activeLayerLabels;

return false;
if ( labelPosList.count() > 1 )
{
// multiple candidates found, so choose the smallest (i.e. most difficult to select otherwise)
double minSize = std::numeric_limits< double >::max();
for ( const QgsLabelPosition &pos : qgis::as_const( labelPosList ) )
{
const double labelSize = pos.width * pos.height;
if ( labelSize < minSize )
{
minSize = labelSize;
p = pos;
}
}
}
else
{
// only one candidate
p = labelPosList.at( 0 );
}

return true;
}

void QgsMapToolLabel::createRubberBands()
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2 changes: 2 additions & 0 deletions src/app/qgsmaptoollabel.h
View file
Expand Up @@ -188,6 +188,8 @@ class APP_EXPORT QgsMapToolLabel: public QgsMapTool

QList<QgsPalLayerSettings::Property> mPalProperties;
QList<QgsDiagramLayerSettings::Property> mDiagramProperties;

friend class TestQgsMapToolLabel;
};

#endif // QGSMAPTOOLLABEL_H
2 changes: 2 additions & 0 deletions tests/src/app/CMakeLists.txt
View file
Expand Up @@ -11,6 +11,7 @@ INCLUDE_DIRECTORIES(
${CMAKE_SOURCE_DIR}/src/core/locator
${CMAKE_SOURCE_DIR}/src/core/metadata
${CMAKE_SOURCE_DIR}/src/core/mesh
${CMAKE_SOURCE_DIR}/src/core/pal
${CMAKE_SOURCE_DIR}/src/core/raster
${CMAKE_SOURCE_DIR}/src/core/symbology
${CMAKE_SOURCE_DIR}/src/core/validity
Expand Down Expand Up @@ -108,6 +109,7 @@ ADD_QGIS_TEST(fieldcalculatortest testqgsfieldcalculator.cpp)
ADD_QGIS_TEST(maptooladdfeatureline testqgsmaptooladdfeatureline.cpp)
ADD_QGIS_TEST(maptooladdfeaturepoint testqgsmaptooladdfeaturepoint.cpp)
ADD_QGIS_TEST(maptoolidentifyaction testqgsmaptoolidentifyaction.cpp)
ADD_QGIS_TEST(maptoollabel testqgsmaptoollabel.cpp)
ADD_QGIS_TEST(maptoolselect testqgsmaptoolselect.cpp)
ADD_QGIS_TEST(maptoolreshape testqgsmaptoolreshape.cpp)
ADD_QGIS_TEST(maptoolcircularstringtest testqgsmaptoolcircularstring.cpp)
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230 changes: 230 additions & 0 deletions tests/src/app/testqgsmaptoollabel.cpp
View file
@@ -0,0 +1,230 @@
/***************************************************************************
testqgsmaptoollabel.cpp
-----------------------
Date : July 2019
Copyright : (C) 2019 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 "qgstest.h"
#include <QObject>
#include <QString>
#include <QMouseEvent>

#include "qgsapplication.h"
#include "qgsvectorlayer.h"
#include "qgsvectordataprovider.h"
#include "qgsgeometry.h"
#include "qgsmapcanvas.h"
#include "qgsmaptoollabel.h"
#include "qgsfontutils.h"
#include "qgsvectorlayerlabelprovider.h"
#include "qgsvectorlayerlabeling.h"

class TestQgsMapToolLabel : public QObject
{
Q_OBJECT

public:
TestQgsMapToolLabel() = default;

private:

private slots:

void initTestCase()
{
QgsApplication::init();
QgsApplication::initQgis();

}

void cleanupTestCase()
{
QgsApplication::exitQgis();
}

void testSelectLabel()
{
std::unique_ptr< QgsVectorLayer > vl1 = qgis::make_unique< QgsVectorLayer >( QStringLiteral( "Point?crs=epsg:3946&field=text:string" ), QStringLiteral( "vl1" ), QStringLiteral( "memory" ) );
QVERIFY( vl1->isValid() );
QgsFeature f1;
f1.setAttributes( QgsAttributes() << QStringLiteral( "label" ) );
f1.setGeometry( QgsGeometry::fromPointXY( QgsPointXY( 1, 1 ) ) );
QVERIFY( vl1->dataProvider()->addFeature( f1 ) );
f1.setGeometry( QgsGeometry::fromPointXY( QgsPointXY( 3, 3 ) ) );
f1.setAttributes( QgsAttributes() << QStringLiteral( "l" ) );
QVERIFY( vl1->dataProvider()->addFeature( f1 ) );

std::unique_ptr< QgsVectorLayer > vl2 = qgis::make_unique< QgsVectorLayer >( QStringLiteral( "Point?crs=epsg:3946&field=text:string" ), QStringLiteral( "vl1" ), QStringLiteral( "memory" ) );
QVERIFY( vl2->isValid() );
f1.setGeometry( QgsGeometry::fromPointXY( QgsPointXY( 1, 1 ) ) );
f1.setAttributes( QgsAttributes() << QStringLiteral( "label" ) );
QVERIFY( vl2->dataProvider()->addFeature( f1 ) );
f1.setGeometry( QgsGeometry::fromPointXY( QgsPointXY( 3, 3 ) ) );
f1.setAttributes( QgsAttributes() << QStringLiteral( "label2" ) );
QVERIFY( vl2->dataProvider()->addFeature( f1 ) );
f1.setGeometry( QgsGeometry::fromPointXY( QgsPointXY( 3, 1 ) ) );
f1.setAttributes( QgsAttributes() << QStringLiteral( "label3" ) );
QVERIFY( vl2->dataProvider()->addFeature( f1 ) );

std::unique_ptr< QgsMapCanvas > canvas = qgis::make_unique< QgsMapCanvas >();
canvas->setDestinationCrs( QgsCoordinateReferenceSystem( QStringLiteral( "EPSG:3946" ) ) );
canvas->setLayers( QList<QgsMapLayer *>() << vl1.get() << vl2.get() );

QgsMapSettings mapSettings;
mapSettings.setOutputSize( QSize( 500, 500 ) );
mapSettings.setExtent( QgsRectangle( -1, -1, 4, 4 ) );
QVERIFY( mapSettings.hasValidSettings() );

mapSettings.setLayers( QList<QgsMapLayer *>() << vl1.get() << vl2.get() );

canvas->setFrameStyle( QFrame::NoFrame );
canvas->resize( 500, 500 );
canvas->setExtent( QgsRectangle( -1, -1, 4, 4 ) );
canvas->show(); // to make the canvas resize
canvas->hide();
QCOMPARE( canvas->mapSettings().outputSize(), QSize( 500, 500 ) );
QCOMPARE( canvas->mapSettings().visibleExtent(), QgsRectangle( -1, -1, 4, 4 ) );

std::unique_ptr< QgsMapToolLabel > tool( new QgsMapToolLabel( canvas.get() ) );

// no labels yet
QgsPointXY pt;
pt = tool->canvas()->mapSettings().mapToPixel().transform( 1, 1 );
std::unique_ptr< QMouseEvent > event( new QMouseEvent(
QEvent::MouseButtonPress,
QPoint( std::round( pt.x() ), std::round( pt.y() ) ), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier
) );
QgsLabelPosition pos;
QVERIFY( !tool->labelAtPosition( event.get(), pos ) );

// add some labels
QgsPalLayerSettings pls1;
pls1.fieldName = QStringLiteral( "text" );
pls1.placement = QgsPalLayerSettings::OverPoint;
pls1.quadOffset = QgsPalLayerSettings::QuadrantOver;
pls1.displayAll = true;
QgsTextFormat format = pls1.format();
format.setFont( QgsFontUtils::getStandardTestFont( QStringLiteral( "Bold" ) ) );
format.setSize( 12 );
pls1.setFormat( format );

vl1->setLabeling( new QgsVectorLayerSimpleLabeling( pls1 ) );
vl1->setLabelsEnabled( true );

QEventLoop loop;
connect( canvas.get(), &QgsMapCanvas::mapCanvasRefreshed, &loop, &QEventLoop::quit );
canvas->refreshAllLayers();
canvas->show();
loop.exec();

QVERIFY( canvas->labelingResults() );
QVERIFY( tool->labelAtPosition( event.get(), pos ) );
QCOMPARE( pos.layerID, vl1->id() );
QCOMPARE( pos.labelText, QStringLiteral( "label" ) );

pt = tool->canvas()->mapSettings().mapToPixel().transform( 3, 3 );
event = qgis::make_unique< QMouseEvent >(
QEvent::MouseButtonPress,
QPoint( std::round( pt.x() ), std::round( pt.y() ) ), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier
);
QVERIFY( tool->labelAtPosition( event.get(), pos ) );
QCOMPARE( pos.layerID, vl1->id() );
QCOMPARE( pos.labelText, QStringLiteral( "l" ) );

pt = tool->canvas()->mapSettings().mapToPixel().transform( 3, 1 );
event = qgis::make_unique< QMouseEvent >(
QEvent::MouseButtonPress,
QPoint( std::round( pt.x() ), std::round( pt.y() ) ), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier
);
QVERIFY( !tool->labelAtPosition( event.get(), pos ) );

// label second layer
vl2->setLabeling( new QgsVectorLayerSimpleLabeling( pls1 ) );
vl2->setLabelsEnabled( true );

canvas->refreshAllLayers();
canvas->show();
loop.exec();

// should prioritise current layer
canvas->setCurrentLayer( vl1.get() );
pt = tool->canvas()->mapSettings().mapToPixel().transform( 1, 1 );
event = qgis::make_unique< QMouseEvent >(
QEvent::MouseButtonPress,
QPoint( std::round( pt.x() ), std::round( pt.y() ) ), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier
);
QVERIFY( tool->labelAtPosition( event.get(), pos ) );
QCOMPARE( pos.layerID, vl1->id() );
QCOMPARE( pos.labelText, QStringLiteral( "label" ) );

pt = tool->canvas()->mapSettings().mapToPixel().transform( 3, 3 );
event = qgis::make_unique< QMouseEvent >(
QEvent::MouseButtonPress,
QPoint( std::round( pt.x() ), std::round( pt.y() ) ), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier
);
QVERIFY( tool->labelAtPosition( event.get(), pos ) );
QCOMPARE( pos.layerID, vl1->id() );
QCOMPARE( pos.labelText, QStringLiteral( "l" ) );

//... but fallback to any labels if nothing in current layer
pt = tool->canvas()->mapSettings().mapToPixel().transform( 3, 1 );
event = qgis::make_unique< QMouseEvent >(
QEvent::MouseButtonPress,
QPoint( std::round( pt.x() ), std::round( pt.y() ) ), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier
);
QVERIFY( tool->labelAtPosition( event.get(), pos ) );
QCOMPARE( pos.layerID, vl2->id() );
QCOMPARE( pos.labelText, QStringLiteral( "label3" ) );

canvas->setCurrentLayer( vl2.get() );
pt = tool->canvas()->mapSettings().mapToPixel().transform( 1, 1 );
event = qgis::make_unique< QMouseEvent >(
QEvent::MouseButtonPress,
QPoint( std::round( pt.x() ), std::round( pt.y() ) ), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier
);
QVERIFY( tool->labelAtPosition( event.get(), pos ) );
QCOMPARE( pos.layerID, vl2->id() );
QCOMPARE( pos.labelText, QStringLiteral( "label" ) );

pt = tool->canvas()->mapSettings().mapToPixel().transform( 3, 3 );
event = qgis::make_unique< QMouseEvent >(
QEvent::MouseButtonPress,
QPoint( std::round( pt.x() ), std::round( pt.y() ) ), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier
);
QVERIFY( tool->labelAtPosition( event.get(), pos ) );
QCOMPARE( pos.layerID, vl2->id() );
QCOMPARE( pos.labelText, QStringLiteral( "label2" ) );
pt = tool->canvas()->mapSettings().mapToPixel().transform( 3, 1 );
event = qgis::make_unique< QMouseEvent >(
QEvent::MouseButtonPress,
QPoint( std::round( pt.x() ), std::round( pt.y() ) ), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier
);
QVERIFY( tool->labelAtPosition( event.get(), pos ) );
QCOMPARE( pos.layerID, vl2->id() );
QCOMPARE( pos.labelText, QStringLiteral( "label3" ) );

canvas->setCurrentLayer( nullptr );

// when multiple candidates exist, pick the smallest
pt = tool->canvas()->mapSettings().mapToPixel().transform( 3, 3 );
event = qgis::make_unique< QMouseEvent >(
QEvent::MouseButtonPress,
QPoint( std::round( pt.x() ), std::round( pt.y() ) ), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier
);
QVERIFY( tool->labelAtPosition( event.get(), pos ) );
QCOMPARE( pos.layerID, vl1->id() );
QCOMPARE( pos.labelText, QStringLiteral( "l" ) );
}
};

QGSTEST_MAIN( TestQgsMapToolLabel )
#include "testqgsmaptoollabel.moc"

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