QGIS API Documentation  3.14.0-Pi (9f7028fd23)
qgssteppedlinescalebarrenderer.cpp
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1 /***************************************************************************
2  qgssteppedlinescalebarrenderer.cpp
3  --------------------------------
4  begin : March 2020
5  copyright : (C) 2020 by Nyall Dawson
6  email : nyall dot dawson at gmail dot com
7  ***************************************************************************/
8 /***************************************************************************
9  * *
10  * This program is free software; you can redistribute it and/or modify *
11  * it under the terms of the GNU General Public License as published by *
12  * the Free Software Foundation; either version 2 of the License, or *
13  * (at your option) any later version. *
14  * *
15  ***************************************************************************/
16 
18 #include "qgsscalebarsettings.h"
19 #include "qgslayoututils.h"
20 #include "qgssymbol.h"
21 #include "qgstextrenderer.h"
22 #include <QList>
23 #include <QPainter>
24 
26 {
27  return QStringLiteral( "stepped" );
28 }
29 
31 {
32  return QObject::tr( "Stepped Line" );
33 }
34 
36 {
37  return 7;
38 }
39 
40 QgsScaleBarRenderer::Flags QgsSteppedLineScaleBarRenderer::flags() const
41 {
50 }
51 
53 {
54  return new QgsSteppedLineScaleBarRenderer( *this );
55 }
56 
57 void QgsSteppedLineScaleBarRenderer::draw( QgsRenderContext &context, const QgsScaleBarSettings &settings, const ScaleBarContext &scaleContext ) const
58 {
59  if ( !context.painter() )
60  {
61  return;
62  }
63  QPainter *painter = context.painter();
64 
65  std::unique_ptr< QgsLineSymbol > sym( settings.lineSymbol()->clone() );
66  sym->startRender( context ) ;
67 
68  double scaledLabelBarSpace = context.convertToPainterUnits( settings.labelBarSpace(), QgsUnitTypes::RenderMillimeters );
69  double scaledBoxContentSpace = context.convertToPainterUnits( settings.boxContentSpace(), QgsUnitTypes::RenderMillimeters );
70  QFontMetricsF fontMetrics = QgsTextRenderer::fontMetrics( context, settings.textFormat() );
71  double barTopPosition = scaledBoxContentSpace + ( settings.labelVerticalPlacement() == QgsScaleBarSettings::LabelAboveSegment ? fontMetrics.ascent() + scaledLabelBarSpace : 0 );
72  const double barBottomPosition = barTopPosition + context.convertToPainterUnits( settings.height(), QgsUnitTypes::RenderMillimeters );
73 
74  painter->save();
75  if ( context.flags() & QgsRenderContext::Antialiasing )
76  painter->setRenderHint( QPainter::Antialiasing, true );
77 
78  painter->setPen( Qt::NoPen );
79 
80  double xOffset = firstLabelXOffset( settings, context, scaleContext );
81 
82  QList<double> positions = segmentPositions( context, scaleContext, settings );
83  QList<double> widths = segmentWidths( scaleContext, settings );
84 
85  QPolygonF points;
86 
87  for ( int i = 0; i < positions.size() + 1; ++i )
88  {
89  // we render one extra place, corresponding to the final position + width (i.e. the "end" of the bar)
90  double x = i < positions.size() ? context.convertToPainterUnits( positions.at( i ), QgsUnitTypes::RenderMillimeters ) + xOffset
91  : context.convertToPainterUnits( positions.at( i - 1 ), QgsUnitTypes::RenderMillimeters ) + xOffset + context.convertToPainterUnits( widths.at( i - 1 ), QgsUnitTypes::RenderMillimeters );
92  if ( i % 2 == 0 )
93  {
94  points << QPointF( x, barBottomPosition ) << QPointF( x, barTopPosition );
95  }
96  else
97  {
98  points << QPointF( x, barTopPosition ) << QPointF( x, barBottomPosition ) ;
99  }
100  }
101 
102  sym->renderPolyline( points, nullptr, context );
103 
104  painter->restore();
105 
106  sym->stopRender( context );
107 
108  //draw labels using the default method
109  drawDefaultLabels( context, settings, scaleContext );
110 }
111 
112 
113 
QgsScaleBarSettings::height
double height() const
Returns the scalebar height (in millimeters).
Definition: qgsscalebarsettings.h:550
QgsScaleBarSettings::lineSymbol
QgsLineSymbol * lineSymbol() const
Returns the line symbol used to render the scalebar (only used for some scalebar types).
Definition: qgsscalebarsettings.cpp:191
QgsRenderContext::convertToPainterUnits
double convertToPainterUnits(double size, QgsUnitTypes::RenderUnit unit, const QgsMapUnitScale &scale=QgsMapUnitScale()) const
Converts a size from the specified units to painter units (pixels).
Definition: qgsrendercontext.cpp:287
QgsScaleBarRenderer::ScaleBarContext
Contains parameters regarding scalebar calculations.
Definition: qgsscalebarrenderer.h:70
QgsScaleBarRenderer::Flag::FlagUsesUnitLabel
@ FlagUsesUnitLabel
Renderer uses the QgsScaleBarSettings::unitLabel() setting.
qgstextrenderer.h
QgsScaleBarRenderer::segmentWidths
QList< double > segmentWidths(const QgsScaleBarRenderer::ScaleBarContext &scaleContext, const QgsScaleBarSettings &settings) const
Returns a list of widths of each segment of the scalebar.
Definition: qgsscalebarrenderer.cpp:394
QgsLineSymbol::clone
QgsLineSymbol * clone() const override
Returns a deep copy of this symbol.
Definition: qgssymbol.cpp:2139
QgsSteppedLineScaleBarRenderer::draw
void draw(QgsRenderContext &context, const QgsScaleBarSettings &settings, const QgsScaleBarRenderer::ScaleBarContext &scaleContext) const override
Draws the scalebar using the specified settings and scaleContext to a destination render context.
Definition: qgssteppedlinescalebarrenderer.cpp:57
qgssteppedlinescalebarrenderer.h
QgsRenderContext
Definition: qgsrendercontext.h:57
QgsUnitTypes::RenderMillimeters
@ RenderMillimeters
Millimeters.
Definition: qgsunittypes.h:168
QgsScaleBarRenderer::Flag::FlagUsesLabelHorizontalPlacement
@ FlagUsesLabelHorizontalPlacement
Renderer uses the QgsScaleBarSettings::labelHorizontalPlacement() setting.
QgsTextRenderer::fontMetrics
static QFontMetricsF fontMetrics(QgsRenderContext &context, const QgsTextFormat &format)
Returns the font metrics for the given text format, when rendered in the specified render context.
Definition: qgstextrenderer.cpp:231
qgsscalebarsettings.h
qgslayoututils.h
QgsScaleBarSettings::labelBarSpace
double labelBarSpace() const
Returns the spacing (in millimeters) between labels and the scalebar.
Definition: qgsscalebarsettings.h:562
QgsScaleBarRenderer::Flag::FlagUsesLabelVerticalPlacement
@ FlagUsesLabelVerticalPlacement
Renderer uses the QgsScaleBarSettings::labelVerticalPlacement() setting.
QgsScaleBarSettings::boxContentSpace
double boxContentSpace() const
Returns the spacing (margin) between the scalebar box and content in millimeters.
Definition: qgsscalebarsettings.h:602
QgsScaleBarSettings::labelVerticalPlacement
LabelVerticalPlacement labelVerticalPlacement() const
Returns the vertical placement of text labels.
Definition: qgsscalebarsettings.h:575
QgsScaleBarSettings::textFormat
QgsTextFormat & textFormat()
Returns the text format used for drawing text in the scalebar.
Definition: qgsscalebarsettings.h:268
QgsScaleBarRenderer::Flag::FlagUsesLineSymbol
@ FlagUsesLineSymbol
Renderer utilizes the scalebar line symbol (see QgsScaleBarSettings::lineSymbol() )
QgsScaleBarSettings
Definition: qgsscalebarsettings.h:40
QgsScaleBarRenderer::Flag::FlagRespectsMapUnitsPerScaleBarUnit
@ FlagRespectsMapUnitsPerScaleBarUnit
Renderer respects the QgsScaleBarSettings::mapUnitsPerScaleBarUnit() setting.
QgsScaleBarRenderer::firstLabelXOffset
Q_DECL_DEPRECATED double firstLabelXOffset(const QgsScaleBarSettings &settings) const
Returns the x-offset (in millimeters) used for the first label in the scalebar.
Definition: qgsscalebarrenderer.cpp:309
QgsSteppedLineScaleBarRenderer::QgsSteppedLineScaleBarRenderer
QgsSteppedLineScaleBarRenderer()=default
Constructor for QgsSteppedLineScaleBarRenderer.
QgsSteppedLineScaleBarRenderer::sortKey
int sortKey() const override
Returns a sorting key value, where renderers with a lower sort key will be shown earlier in lists.
Definition: qgssteppedlinescalebarrenderer.cpp:35
QgsScaleBarSettings::LabelAboveSegment
@ LabelAboveSegment
Labels are drawn above the scalebar.
Definition: qgsscalebarsettings.h:68
QgsScaleBarRenderer::drawDefaultLabels
void drawDefaultLabels(QgsRenderContext &context, const QgsScaleBarSettings &settings, const QgsScaleBarRenderer::ScaleBarContext &scaleContext) const
Draws default scalebar labels using the specified settings and scaleContext to a destination render c...
Definition: qgsscalebarrenderer.cpp:28
QgsScaleBarRenderer::Flag::FlagRespectsUnits
@ FlagRespectsUnits
Renderer respects the QgsScaleBarSettings::units() setting.
QgsSteppedLineScaleBarRenderer::flags
Flags flags() const override
Returns the scalebar rendering flags, which dictates the renderer's behavior.
Definition: qgssteppedlinescalebarrenderer.cpp:40
QgsRenderContext::Antialiasing
@ Antialiasing
Use antialiasing while drawing.
Definition: qgsrendercontext.h:78
QgsScaleBarRenderer::Flag::FlagUsesLabelBarSpace
@ FlagUsesLabelBarSpace
Renderer uses the QgsScaleBarSettings::labelBarSpace() setting.
QgsScaleBarRenderer::Flag::FlagUsesSegments
@ FlagUsesSegments
Renderer uses the scalebar segments.
QgsSteppedLineScaleBarRenderer::clone
QgsSteppedLineScaleBarRenderer * clone() const override
Returns a clone of the renderer.
Definition: qgssteppedlinescalebarrenderer.cpp:52
QgsRenderContext::painter
QPainter * painter()
Returns the destination QPainter for the render operation.
Definition: qgsrendercontext.h:174
QgsSteppedLineScaleBarRenderer::id
QString id() const override
Returns the unique ID for this renderer.
Definition: qgssteppedlinescalebarrenderer.cpp:25
qgssymbol.h
QgsSteppedLineScaleBarRenderer
Definition: qgssteppedlinescalebarrenderer.h:30
QgsSteppedLineScaleBarRenderer::visibleName
QString visibleName() const override
Returns the user friendly, translated name for the renderer.
Definition: qgssteppedlinescalebarrenderer.cpp:30
QgsRenderContext::flags
Flags flags() const
Returns combination of flags used for rendering.
Definition: qgsrendercontext.cpp:160
QgsScaleBarRenderer::segmentPositions
Q_DECL_DEPRECATED QList< double > segmentPositions(const QgsScaleBarRenderer::ScaleBarContext &scaleContext, const QgsScaleBarSettings &settings) const
Returns a list of positions for each segment within the scalebar.
Definition: qgsscalebarrenderer.cpp:339