1/****************************************************************************
2**
3** Copyright (C) 2016 The Qt Company Ltd.
4** Contact: https://www.qt.io/licensing/
5**
6** This file is part of the examples of the Qt Toolkit.
7**
8** $QT_BEGIN_LICENSE:BSD$
9** Commercial License Usage
10** Licensees holding valid commercial Qt licenses may use this file in
11** accordance with the commercial license agreement provided with the
12** Software or, alternatively, in accordance with the terms contained in
13** a written agreement between you and The Qt Company. For licensing terms
14** and conditions see https://www.qt.io/terms-conditions. For further
15** information use the contact form at https://www.qt.io/contact-us.
16**
17** BSD License Usage
18** Alternatively, you may use this file under the terms of the BSD license
19** as follows:
20**
21** "Redistribution and use in source and binary forms, with or without
22** modification, are permitted provided that the following conditions are
23** met:
24** * Redistributions of source code must retain the above copyright
25** notice, this list of conditions and the following disclaimer.
26** * Redistributions in binary form must reproduce the above copyright
27** notice, this list of conditions and the following disclaimer in
28** the documentation and/or other materials provided with the
29** distribution.
30** * Neither the name of The Qt Company Ltd nor the names of its
31** contributors may be used to endorse or promote products derived
32** from this software without specific prior written permission.
33**
34**
35** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
36** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
37** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
38** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
39** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
41** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
42** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
43** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
44** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
45** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
46**
47** $QT_END_LICENSE$
48**
49****************************************************************************/
50
51#include <QtWidgets>
52#if defined(QT_PRINTSUPPORT_LIB)
53#include <QtPrintSupport/qtprintsupportglobal.h>
54#if QT_CONFIG(printdialog)
55#include <QPrinter>
56#include <QPrintDialog>
57#endif
58#endif
59
60#include "scribblearea.h"
61
62static const qreal MinimumDiameter = 3.0;
63static const qreal MaximumDiameter = 50.0;
64
65//! [0]
66ScribbleArea::ScribbleArea(QWidget *parent)
67 : QWidget(parent)
68{
69 setAttribute(Qt::WA_AcceptTouchEvents);
70 setAttribute(Qt::WA_StaticContents);
71 modified = false;
72
73 myPenColors
74 << QColor("green")
75 << QColor("purple")
76 << QColor("red")
77 << QColor("blue")
78 << QColor("yellow")
79
80 << QColor("pink")
81 << QColor("orange")
82 << QColor("brown")
83 << QColor("grey")
84 << QColor("black");
85}
86//! [0]
87
88//! [1]
89bool ScribbleArea::openImage(const QString &fileName)
90//! [1] //! [2]
91{
92 QImage loadedImage;
93 if (!loadedImage.load(fileName))
94 return false;
95
96 QSize newSize = loadedImage.size().expandedTo(size());
97 resizeImage(&loadedImage, newSize);
98 image = loadedImage;
99 modified = false;
100 update();
101 return true;
102}
103//! [2]
104
105//! [3]
106bool ScribbleArea::saveImage(const QString &fileName, const char *fileFormat)
107//! [3] //! [4]
108{
109 QImage visibleImage = image;
110 resizeImage(&visibleImage, size());
111
112 if (visibleImage.save(fileName, fileFormat)) {
113 modified = false;
114 return true;
115 } else {
116 return false;
117 }
118}
119//! [4]
120
121//! [9]
122void ScribbleArea::clearImage()
123//! [9] //! [10]
124{
125 image.fill(qRgb(255, 255, 255));
126 modified = true;
127 update();
128}
129//! [10]
130
131//! [12] //! [13]
132void ScribbleArea::paintEvent(QPaintEvent *event)
133//! [13] //! [14]
134{
135 QPainter painter(this);
136 const QRect rect = event->rect();
137 painter.drawImage(rect.topLeft(), image, rect);
138}
139//! [14]
140
141//! [15]
142void ScribbleArea::resizeEvent(QResizeEvent *event)
143//! [15] //! [16]
144{
145 if (width() > image.width() || height() > image.height()) {
146 int newWidth = qMax(width() + 128, image.width());
147 int newHeight = qMax(height() + 128, image.height());
148 resizeImage(&image, QSize(newWidth, newHeight));
149 update();
150 }
151 QWidget::resizeEvent(event);
152}
153//! [16]
154
155//! [19]
156void ScribbleArea::resizeImage(QImage *image, const QSize &newSize)
157//! [19] //! [20]
158{
159 if (image->size() == newSize)
160 return;
161
162 QImage newImage(newSize, QImage::Format_RGB32);
163 newImage.fill(qRgb(255, 255, 255));
164 QPainter painter(&newImage);
165 painter.drawImage(QPoint(0, 0), *image);
166 *image = newImage;
167}
168//! [20]
169
170//! [21]
171void ScribbleArea::print()
172{
173#if defined(QT_PRINTSUPPORT_LIB) && QT_CONFIG(printdialog)
174 QPrinter printer(QPrinter::HighResolution);
175
176 QPrintDialog printDialog(&printer, this);
177//! [21] //! [22]
178 if (printDialog.exec() == QDialog::Accepted) {
179 QPainter painter(&printer);
180 QRect rect = painter.viewport();
181 QSize size = image.size();
182 size.scale(rect.size(), Qt::KeepAspectRatio);
183 painter.setViewport(rect.x(), rect.y(), size.width(), size.height());
184 painter.setWindow(image.rect());
185 painter.drawImage(0, 0, image);
186 }
187#endif // QT_CONFIG(printdialog)
188}
189//! [22]
190
191bool ScribbleArea::event(QEvent *event)
192{
193 switch (event->type()) {
194 case QEvent::TouchBegin:
195 case QEvent::TouchUpdate:
196 case QEvent::TouchEnd:
197 {
198 const QTouchEvent *touch = static_cast<QTouchEvent *>(event);
199 const QList<QTouchEvent::TouchPoint> touchPoints = static_cast<QTouchEvent *>(event)->touchPoints();
200 for (const QTouchEvent::TouchPoint &touchPoint : touchPoints) {
201 switch (touchPoint.state()) {
202 case Qt::TouchPointStationary:
203 case Qt::TouchPointReleased:
204 // don't do anything if this touch point hasn't moved or has been released
205 continue;
206 default:
207 {
208 QSizeF diams = touchPoint.ellipseDiameters();
209 if (diams.isEmpty()) {
210 qreal diameter = MaximumDiameter;
211 if (touch->pointingDevice()->capabilities().testFlag(QPointingDevice::Capability::Pressure))
212 diameter = MinimumDiameter + (MaximumDiameter - MinimumDiameter) * touchPoint.pressure();
213 diams = QSizeF(diameter, diameter);
214 }
215
216 QPainter painter(&image);
217 painter.setPen(Qt::NoPen);
218 painter.setBrush(myPenColors.at(touchPoint.id() % myPenColors.count()));
219 painter.drawEllipse(touchPoint.position(), diams.width() / 2, diams.height() / 2);
220 painter.end();
221
222 modified = true;
223 const int rad = 2;
224 QRectF rect(QPointF(), diams);
225 rect.moveCenter(touchPoint.position());
226 update(rect.toRect().adjusted(-rad,-rad, +rad, +rad));
227 }
228 break;
229 }
230 }
231 break;
232 }
233 default:
234 return QWidget::event(event);
235 }
236 return true;
237}
238