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50#include "svgview.h"
51
52#include <QSvgRenderer>
53
54#include <QWheelEvent>
55#include <QMouseEvent>
56#include <QGraphicsRectItem>
57#include <QGraphicsSvgItem>
58#include <QPaintEvent>
59#include <qmath.h>
60
61#ifndef QT_NO_OPENGL
62#include <QGLWidget>
63#endif
64
65SvgView::SvgView(QWidget *parent)
66 : QGraphicsView(parent)
67 , m_renderer(Native)
68 , m_svgItem(nullptr)
69 , m_backgroundItem(nullptr)
70 , m_outlineItem(nullptr)
71{
72 setScene(new QGraphicsScene(this));
73 setTransformationAnchor(AnchorUnderMouse);
74 setDragMode(ScrollHandDrag);
75 setViewportUpdateMode(FullViewportUpdate);
76
77 // Prepare background check-board pattern
78 QPixmap tilePixmap(64, 64);
79 tilePixmap.fill(fillColor: Qt::white);
80 QPainter tilePainter(&tilePixmap);
81 QColor color(220, 220, 220);
82 tilePainter.fillRect(x: 0, y: 0, w: 32, h: 32, b: color);
83 tilePainter.fillRect(x: 32, y: 32, w: 32, h: 32, b: color);
84 tilePainter.end();
85
86 setBackgroundBrush(tilePixmap);
87}
88
89void SvgView::drawBackground(QPainter *p, const QRectF &)
90{
91 p->save();
92 p->resetTransform();
93 p->drawTiledPixmap(rect: viewport()->rect(), pm: backgroundBrush().texture());
94 p->restore();
95}
96
97QSize SvgView::svgSize() const
98{
99 return m_svgItem ? m_svgItem->boundingRect().size().toSize() : QSize();
100}
101
102bool SvgView::openFile(const QString &fileName)
103{
104 QGraphicsScene *s = scene();
105
106 const bool drawBackground = (m_backgroundItem ? m_backgroundItem->isVisible() : false);
107 const bool drawOutline = (m_outlineItem ? m_outlineItem->isVisible() : true);
108
109 QScopedPointer<QGraphicsSvgItem> svgItem(new QGraphicsSvgItem(fileName));
110 if (!svgItem->renderer()->isValid())
111 return false;
112
113 s->clear();
114 resetTransform();
115
116 m_svgItem = svgItem.take();
117 m_svgItem->setFlags(QGraphicsItem::ItemClipsToShape);
118 m_svgItem->setCacheMode(mode: QGraphicsItem::NoCache);
119 m_svgItem->setZValue(0);
120
121 m_backgroundItem = new QGraphicsRectItem(m_svgItem->boundingRect());
122 m_backgroundItem->setBrush(Qt::white);
123 m_backgroundItem->setPen(Qt::NoPen);
124 m_backgroundItem->setVisible(drawBackground);
125 m_backgroundItem->setZValue(-1);
126
127 m_outlineItem = new QGraphicsRectItem(m_svgItem->boundingRect());
128 QPen outline(Qt::black, 2, Qt::DashLine);
129 outline.setCosmetic(true);
130 m_outlineItem->setPen(outline);
131 m_outlineItem->setBrush(Qt::NoBrush);
132 m_outlineItem->setVisible(drawOutline);
133 m_outlineItem->setZValue(1);
134
135 s->addItem(item: m_backgroundItem);
136 s->addItem(item: m_svgItem);
137 s->addItem(item: m_outlineItem);
138
139 s->setSceneRect(m_outlineItem->boundingRect().adjusted(xp1: -10, yp1: -10, xp2: 10, yp2: 10));
140 return true;
141}
142
143void SvgView::setRenderer(RendererType type)
144{
145 m_renderer = type;
146
147 if (m_renderer == OpenGL) {
148#ifndef QT_NO_OPENGL
149 setViewport(new QGLWidget(QGLFormat(QGL::SampleBuffers)));
150#endif
151 } else {
152 setViewport(new QWidget);
153 }
154}
155
156void SvgView::setAntialiasing(bool antialiasing)
157{
158 setRenderHint(hint: QPainter::Antialiasing, enabled: antialiasing);
159}
160
161void SvgView::setViewBackground(bool enable)
162{
163 if (!m_backgroundItem)
164 return;
165
166 m_backgroundItem->setVisible(enable);
167}
168
169void SvgView::setViewOutline(bool enable)
170{
171 if (!m_outlineItem)
172 return;
173
174 m_outlineItem->setVisible(enable);
175}
176
177qreal SvgView::zoomFactor() const
178{
179 return transform().m11();
180}
181
182void SvgView::zoomIn()
183{
184 zoomBy(factor: 2);
185}
186
187void SvgView::zoomOut()
188{
189 zoomBy(factor: 0.5);
190}
191
192void SvgView::resetZoom()
193{
194 if (!qFuzzyCompare(p1: zoomFactor(), p2: qreal(1))) {
195 resetTransform();
196 emit zoomChanged();
197 }
198}
199
200void SvgView::paintEvent(QPaintEvent *event)
201{
202 if (m_renderer == Image) {
203 if (m_image.size() != viewport()->size()) {
204 m_image = QImage(viewport()->size(), QImage::Format_ARGB32_Premultiplied);
205 }
206
207 QPainter imagePainter(&m_image);
208 QGraphicsView::render(painter: &imagePainter);
209 imagePainter.end();
210
211 QPainter p(viewport());
212 p.drawImage(x: 0, y: 0, image: m_image);
213
214 } else {
215 QGraphicsView::paintEvent(event);
216 }
217}
218
219void SvgView::wheelEvent(QWheelEvent *event)
220{
221 zoomBy(factor: qPow(x: 1.2, y: event->angleDelta().y() / 240.0));
222}
223
224void SvgView::zoomBy(qreal factor)
225{
226 const qreal currentZoom = zoomFactor();
227 if ((factor < 1 && currentZoom < 0.1) || (factor > 1 && currentZoom > 10))
228 return;
229 scale(sx: factor, sy: factor);
230 emit zoomChanged();
231}
232
233QSvgRenderer *SvgView::renderer() const
234{
235 if (m_svgItem)
236 return m_svgItem->renderer();
237 return nullptr;
238}
239

source code of qtsvg/examples/svg/svgviewer/svgview.cpp