QGIS API Documentation 3.41.0-Master (45a0abf3bec)
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qgshollowscalebarrenderer.cpp
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1/***************************************************************************
2 qgshollowscalebarrenderer.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 "qgssymbol.h"
20#include "qgsfillsymbollayer.h"
21#include "qgstextrenderer.h"
22#include "qgslinesymbol.h"
23#include "qgsfillsymbol.h"
24#include <QList>
25#include <QPainter>
26
28{
29 return QStringLiteral( "hollow" );
30}
31
33{
34 return QObject::tr( "Hollow" );
35}
36
50
52{
53 return 8;
54}
55
60
61void QgsHollowScaleBarRenderer::draw( QgsRenderContext &context, const QgsScaleBarSettings &settings, const ScaleBarContext &scaleContext ) const
62{
63 if ( !context.painter() )
64 {
65 return;
66 }
67 QPainter *painter = context.painter();
68
69 const double scaledLabelBarSpace = context.convertToPainterUnits( settings.labelBarSpace(), Qgis::RenderUnit::Millimeters );
70 const double scaledBoxContentSpace = context.convertToPainterUnits( settings.boxContentSpace(), Qgis::RenderUnit::Millimeters );
71 const QFontMetricsF fontMetrics = QgsTextRenderer::fontMetrics( context, settings.textFormat() );
72 const double barTopPosition = scaledBoxContentSpace + ( settings.labelVerticalPlacement() == Qgis::ScaleBarDistanceLabelVerticalPlacement::AboveSegment ? fontMetrics.ascent() + scaledLabelBarSpace : 0 );
73 const double barHeight = context.convertToPainterUnits( settings.height(), Qgis::RenderUnit::Millimeters );
74
75 painter->save();
76 context.setPainterFlagsUsingContext( painter );
77
78 std::unique_ptr< QgsLineSymbol > lineSymbol( settings.lineSymbol()->clone() );
79 lineSymbol->startRender( context );
80
81 std::unique_ptr< QgsFillSymbol > fillSymbol1( settings.fillSymbol()->clone() );
82 fillSymbol1->startRender( context );
83
84 std::unique_ptr< QgsFillSymbol > fillSymbol2( settings.alternateFillSymbol()->clone() );
85 fillSymbol2->startRender( context );
86
87 painter->setPen( Qt::NoPen );
88 painter->setBrush( Qt::NoBrush );
89
90 bool useColor = true; //alternate brush color/white
91 const double xOffset = firstLabelXOffset( settings, context, scaleContext );
92
93 const QList<double> positions = segmentPositions( context, scaleContext, settings );
94 const QList<double> widths = segmentWidths( scaleContext, settings );
95
96 // draw the fill
97 double minX = 0;
98 double maxX = 0;
99 QgsFillSymbol *currentSymbol = nullptr;
100 for ( int i = 0; i < positions.size(); ++i )
101 {
102 if ( useColor ) //alternating colors
103 {
104 currentSymbol = fillSymbol1.get();
105 }
106 else //secondary fill
107 {
108 currentSymbol = fillSymbol2.get();
109 }
110
111 const double thisX = context.convertToPainterUnits( positions.at( i ), Qgis::RenderUnit::Millimeters ) + xOffset;
112 const double thisWidth = context.convertToPainterUnits( widths.at( i ), Qgis::RenderUnit::Millimeters );
113
114 if ( i == 0 )
115 minX = thisX;
116 if ( i == positions.size() - 1 )
117 maxX = thisX + thisWidth;
118
119 const QRectF segmentRect( thisX, barTopPosition, thisWidth, barHeight );
120 currentSymbol->renderPolygon( QPolygonF()
121 << segmentRect.topLeft()
122 << segmentRect.topRight()
123 << segmentRect.bottomRight()
124 << segmentRect.bottomLeft()
125 << segmentRect.topLeft(), nullptr, nullptr, context );
126 useColor = !useColor;
127 }
128
129 // and then the lines
130 // note that we do this layer-by-layer, to avoid ugliness where the lines touch the outer rect
131 for ( int layer = 0; layer < lineSymbol->symbolLayerCount(); ++layer )
132 {
133 // horizontal lines
134 bool drawLine = false;
135 for ( int i = 0; i < positions.size(); ++i )
136 {
137 drawLine = !drawLine;
138 if ( !drawLine )
139 continue;
140
141 const double lineX = context.convertToPainterUnits( positions.at( i ), Qgis::RenderUnit::Millimeters ) + xOffset;
142 const double lineLength = context.convertToPainterUnits( widths.at( i ), Qgis::RenderUnit::Millimeters );
143 lineSymbol->renderPolyline( QPolygonF()
144 << QPointF( lineX, barTopPosition + barHeight / 2.0 )
145 << QPointF( lineX + lineLength, barTopPosition + barHeight / 2.0 ),
146 nullptr, context, layer );
147 }
148
149 // vertical lines
150 for ( int i = 1; i < positions.size(); ++i )
151 {
152 const double lineX = context.convertToPainterUnits( positions.at( i ), Qgis::RenderUnit::Millimeters ) + xOffset;
153 lineSymbol->renderPolyline( QPolygonF()
154 << QPointF( lineX, barTopPosition )
155 << QPointF( lineX, barTopPosition + barHeight ),
156 nullptr, context, layer );
157 }
158
159 // outside line
160 lineSymbol->renderPolyline( QPolygonF()
161 << QPointF( minX, barTopPosition )
162 << QPointF( maxX, barTopPosition )
163 << QPointF( maxX, barTopPosition + barHeight )
164 << QPointF( minX, barTopPosition + barHeight )
165 << QPointF( minX, barTopPosition ),
166 nullptr, context, layer );
167 }
168
169 lineSymbol->stopRender( context );
170 fillSymbol1->stopRender( context );
171 fillSymbol2->stopRender( context );
172 painter->restore();
173
174 //draw labels using the default method
175 drawDefaultLabels( context, settings, scaleContext );
176}
177
179{
180 // null the fill symbols by default
181 std::unique_ptr< QgsFillSymbol > fillSymbol = std::make_unique< QgsFillSymbol >();
182 std::unique_ptr< QgsSimpleFillSymbolLayer > fillSymbolLayer = std::make_unique< QgsSimpleFillSymbolLayer >();
183 fillSymbolLayer->setColor( QColor( 0, 0, 0 ) );
184 fillSymbolLayer->setBrushStyle( Qt::NoBrush );
185 fillSymbolLayer->setStrokeStyle( Qt::NoPen );
186 fillSymbol->changeSymbolLayer( 0, fillSymbolLayer->clone() );
187 settings.setFillSymbol( fillSymbol.release() );
188
189 fillSymbol = std::make_unique< QgsFillSymbol >();
190 fillSymbolLayer->setColor( QColor( 255, 255, 255 ) );
191 fillSymbol->changeSymbolLayer( 0, fillSymbolLayer.release() );
192 settings.setAlternateFillSymbol( fillSymbol.release() );
193
194 return true;
195}
196
197
198
@ AboveSegment
Labels are drawn above the scalebar.
@ Millimeters
Millimeters.
A fill symbol type, for rendering Polygon and MultiPolygon geometries.
void renderPolygon(const QPolygonF &points, const QVector< QPolygonF > *rings, const QgsFeature *f, QgsRenderContext &context, int layer=-1, bool selected=false)
Renders the symbol using the given render context.
QgsFillSymbol * clone() const override
Returns a deep copy of this symbol.
Scalebar style that draws a single box with alternating color for the segments, with horizontal lines...
int sortKey() const override
Returns a sorting key value, where renderers with a lower sort key will be shown earlier in lists.
bool applyDefaultSettings(QgsScaleBarSettings &settings) const override
Applies any default settings relating to the scalebar to the passed settings object.
QgsHollowScaleBarRenderer * clone() const override
Returns a clone of the renderer.
QString visibleName() const override
Returns the user friendly, translated name for the renderer.
QgsHollowScaleBarRenderer()=default
Flags flags() const override
Returns the scalebar rendering flags, which dictates the renderer's behavior.
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.
QString id() const override
Returns the unique ID for this renderer.
QgsLineSymbol * clone() const override
Returns a deep copy of this symbol.
Contains information about the context of a rendering operation.
double convertToPainterUnits(double size, Qgis::RenderUnit unit, const QgsMapUnitScale &scale=QgsMapUnitScale(), Qgis::RenderSubcomponentProperty property=Qgis::RenderSubcomponentProperty::Generic) const
Converts a size from the specified units to painter units (pixels).
QPainter * painter()
Returns the destination QPainter for the render operation.
void setPainterFlagsUsingContext(QPainter *painter=nullptr) const
Sets relevant flags on a destination painter, using the flags and settings currently defined for the ...
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...
QList< double > segmentWidths(const QgsScaleBarRenderer::ScaleBarContext &scaleContext, const QgsScaleBarSettings &settings) const
Returns a list of widths of each segment of the scalebar.
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.
Q_DECL_DEPRECATED double firstLabelXOffset(const QgsScaleBarSettings &settings) const
Returns the x-offset (in millimeters) used for the first label in the scalebar.
@ FlagUsesLabelVerticalPlacement
Renderer uses the QgsScaleBarSettings::labelVerticalPlacement() setting.
@ FlagUsesLabelHorizontalPlacement
Renderer uses the QgsScaleBarSettings::labelHorizontalPlacement() setting.
@ FlagUsesLineSymbol
Renderer utilizes the scalebar line symbol (see QgsScaleBarSettings::lineSymbol() )
@ FlagUsesUnitLabel
Renderer uses the QgsScaleBarSettings::unitLabel() setting.
@ FlagUsesSegments
Renderer uses the scalebar segments.
@ FlagUsesLabelBarSpace
Renderer uses the QgsScaleBarSettings::labelBarSpace() setting.
@ FlagUsesFillSymbol
Renderer utilizes the scalebar fill symbol (see QgsScaleBarSettings::fillSymbol() )
@ FlagRespectsMapUnitsPerScaleBarUnit
Renderer respects the QgsScaleBarSettings::mapUnitsPerScaleBarUnit() setting.
@ FlagRespectsUnits
Renderer respects the QgsScaleBarSettings::units() setting.
@ FlagUsesAlternateFillSymbol
Renderer utilizes the alternate scalebar fill symbol (see QgsScaleBarSettings::alternateFillSymbol() ...
The QgsScaleBarSettings class stores the appearance and layout settings for scalebar drawing with Qgs...
QgsLineSymbol * lineSymbol() const
Returns the line symbol used to render the scalebar (only used for some scalebar types).
void setAlternateFillSymbol(QgsFillSymbol *symbol)
Sets the secondary fill symbol used to render the scalebar (only used for some scalebar types).
Qgis::ScaleBarDistanceLabelVerticalPlacement labelVerticalPlacement() const
Returns the vertical placement of text labels.
void setFillSymbol(QgsFillSymbol *symbol)
Sets the primary fill symbol used to render the scalebar (only used for some scalebar types).
QgsTextFormat & textFormat()
Returns the text format used for drawing text in the scalebar.
double boxContentSpace() const
Returns the spacing (margin) between the scalebar box and content in millimeters.
QgsFillSymbol * alternateFillSymbol() const
Returns the secondary fill symbol used to render the scalebar (only used for some scalebar types).
QgsFillSymbol * fillSymbol() const
Returns the primary fill symbol used to render the scalebar (only used for some scalebar types).
double labelBarSpace() const
Returns the spacing (in millimeters) between labels and the scalebar.
double height() const
Returns the scalebar height (in millimeters).
static QFontMetricsF fontMetrics(QgsRenderContext &context, const QgsTextFormat &format, double scaleFactor=1.0)
Returns the font metrics for the given text format, when rendered in the specified render context.
Contains parameters regarding scalebar calculations.