Tablet widget
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#ifndef TABLETCANVAS_H
#define TABLETCANVAS_H
#include <QWidget>
#include <QImage>
#include <QPoint>
#include <QTabletEvent>
#include <QColor>
#include <QBrush>
#include <QPen>
#include <QPoint>
QT_BEGIN_NAMESPACE
class QPaintEvent;
class QString;
QT_END_NAMESPACE
class TabletCanvas : public QWidget
{
Q_OBJECT
public:
enum AlphaChannelType { AlphaPressure, AlphaTilt, NoAlpha };
enum ColorSaturationType { SaturationVTilt, SaturationHTilt,
SaturationPressure, NoSaturation };
enum LineWidthType { LineWidthPressure, LineWidthTilt, NoLineWidth };
TabletCanvas();
bool saveImage(const QString &file);
bool loadImage(const QString &file);
void setAlphaChannelType(AlphaChannelType type)
{ alphaChannelType = type; }
void setColorSaturationType(ColorSaturationType type)
{ colorSaturationType = type; }
void setLineWidthType(LineWidthType type)
{ lineWidthType = type; }
void setColor(const QColor &color)
{ myColor = color; }
QColor color() const
{ return myColor; }
void setTabletDevice(QTabletEvent::TabletDevice device)
{ myTabletDevice = device; }
int maximum(int a, int b)
{ return a > b ? a : b; }
protected:
void tabletEvent(QTabletEvent *event);
void paintEvent(QPaintEvent *event);
void resizeEvent(QResizeEvent *event);
private:
void initImage();
void paintImage(QPainter &painter, QTabletEvent *event);
Qt::BrushStyle brushPattern(qreal value);
void updateBrush(QTabletEvent *event);
AlphaChannelType alphaChannelType;
ColorSaturationType colorSaturationType;
LineWidthType lineWidthType;
QTabletEvent::PointerType pointerType;
QTabletEvent::TabletDevice myTabletDevice;
QColor myColor;
QImage image;
QBrush myBrush;
QPen myPen;
bool deviceDown;
QPoint polyLine[3];
};
#endif
#include <QtGui>
#include <math.h>
#include "tabletcanvas.h"
TabletCanvas::TabletCanvas()
{
resize(500, 500);
myBrush = QBrush();
myPen = QPen();
initImage();
setAutoFillBackground(true);
deviceDown = false;
myColor = Qt::red;
myTabletDevice = QTabletEvent::Stylus;
alphaChannelType = NoAlpha;
colorSaturationType = NoSaturation;
lineWidthType = LineWidthPressure;
}
void TabletCanvas::initImage()
{
QImage newImage = QImage(width(), height(), QImage::Format_ARGB32);
QPainter painter(&newImage);
painter.fillRect(0, 0, newImage.width(), newImage.height(), Qt::white);
if (!image.isNull())
painter.drawImage(0, 0, image);
painter.end();
image = newImage;
}
bool TabletCanvas::saveImage(const QString &file)
{
return image.save(file);
}
bool TabletCanvas::loadImage(const QString &file)
{
bool success = image.load(file);
if (success) {
update();
return true;
}
return false;
}
void TabletCanvas::tabletEvent(QTabletEvent *event)
{
switch (event->type()) {
case QEvent::TabletPress:
if (!deviceDown)
deviceDown = true;
break;
case QEvent::TabletRelease:
if (deviceDown)
deviceDown = false;
break;
case QEvent::TabletMove:
polyLine[2] = polyLine[1];
polyLine[1] = polyLine[0];
polyLine[0] = event->pos();
if (deviceDown) {
updateBrush(event);
QPainter painter(&image);
paintImage(painter, event);
}
break;
default:
break;
}
update();
}
void TabletCanvas::paintEvent(QPaintEvent *)
{
QPainter painter(this);
painter.drawImage(QPoint(0, 0), image);
}
void TabletCanvas::paintImage(QPainter &painter, QTabletEvent *event)
{
QPoint brushAdjust(10, 10);
switch (myTabletDevice) {
case QTabletEvent::Stylus:
painter.setBrush(myBrush);
painter.setPen(myPen);
painter.drawLine(polyLine[1], event->pos());
break;
case QTabletEvent::Airbrush:
myBrush.setColor(myColor);
myBrush.setStyle(brushPattern(event->pressure()));
painter.setPen(Qt::NoPen);
painter.setBrush(myBrush);
for (int i = 0; i < 3; ++i) {
painter.drawEllipse(QRect(polyLine[i] - brushAdjust,
polyLine[i] + brushAdjust));
}
break;
case QTabletEvent::Puck:
case QTabletEvent::FourDMouse:
case QTabletEvent::RotationStylus:
qWarning("This input device is not supported by the example.");
break;
default:
qWarning("Unknown tablet device.");
}
}
Qt::BrushStyle TabletCanvas::brushPattern(qreal value)
{
int pattern = int((value) * 100.0) % 7;
switch (pattern) {
case 0:
return Qt::SolidPattern;
case 1:
return Qt::Dense1Pattern;
case 2:
return Qt::Dense2Pattern;
case 3:
return Qt::Dense3Pattern;
case 4:
return Qt::Dense4Pattern;
case 5:
return Qt::Dense5Pattern;
case 6:
return Qt::Dense6Pattern;
default:
return Qt::Dense7Pattern;
}
}
void TabletCanvas::updateBrush(QTabletEvent *event)
{
int hue, saturation, value, alpha;
myColor.getHsv(&hue, &saturation, &value, &alpha);
int vValue = int(((event->yTilt() + 60.0) / 120.0) * 255);
int hValue = int(((event->xTilt() + 60.0) / 120.0) * 255);
switch (alphaChannelType) {
case AlphaPressure:
myColor.setAlpha(int(event->pressure() * 255.0));
break;
case AlphaTilt:
myColor.setAlpha(maximum(abs(vValue - 127), abs(hValue - 127)));
break;
default:
myColor.setAlpha(255);
}
switch (colorSaturationType) {
case SaturationVTilt:
myColor.setHsv(hue, vValue, value, alpha);
break;
case SaturationHTilt:
myColor.setHsv(hue, hValue, value, alpha);
break;
case SaturationPressure:
myColor.setHsv(hue, int(event->pressure() * 255.0), value, alpha);
break;
default:
;
}
switch (lineWidthType) {
case LineWidthPressure:
myPen.setWidthF(event->pressure() * 10 + 1);
break;
case LineWidthTilt:
myPen.setWidthF(maximum(abs(vValue - 127), abs(hValue - 127)) / 12);
break;
default:
myPen.setWidthF(1);
}
if (event->pointerType() == QTabletEvent::Eraser) {
myBrush.setColor(Qt::white);
myPen.setColor(Qt::white);
myPen.setWidthF(event->pressure() * 10 + 1);
} else {
myBrush.setColor(myColor);
myPen.setColor(myColor);
}
}
void TabletCanvas::resizeEvent(QResizeEvent *event)
{
initImage();
polyLine[0] = polyLine[1] = polyLine[2] = QPoint();
}
#ifndef TABLETAPPLICATION_H
#define TABLETAPPLICATION_H
#include <QApplication>
#include "tabletcanvas.h"
class TabletApplication : public QApplication
{
Q_OBJECT
public:
TabletApplication(int &argv, char **args)
: QApplication(argv, args) {}
bool event(QEvent *event);
void setCanvas(TabletCanvas *canvas)
{ myCanvas = canvas; }
private:
TabletCanvas *myCanvas;
};
#endif
#include <QtGui>
#include "tabletapplication.h"
bool TabletApplication::event(QEvent *event)
{
if (event->type() == QEvent::TabletEnterProximity ||
event->type() == QEvent::TabletLeaveProximity) {
myCanvas->setTabletDevice(
static_cast<QTabletEvent *>(event)->device());
return true;
}
return QApplication::event(event);
}
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
QT_BEGIN_NAMESPACE
class QAction;
class QActionGroup;
class QMenu;
class QStatusBar;
QT_END_NAMESPACE
class TabletCanvas;
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(TabletCanvas *canvas);
private slots:
void brushColorAct();
void alphaActionTriggered(QAction *action);
void lineWidthActionTriggered(QAction *action);
void saturationActionTriggered(QAction *action);
void saveAct();
void loadAct();
void aboutAct();
private:
void createActions();
void createMenus();
TabletCanvas *myCanvas;
QAction *brushColorAction;
QActionGroup *brushActionGroup;
QActionGroup *alphaChannelGroup;
QAction *alphaChannelPressureAction;
QAction *alphaChannelTiltAction;
QAction *noAlphaChannelAction;
QActionGroup *colorSaturationGroup;
QAction *colorSaturationVTiltAction;
QAction *colorSaturationHTiltAction;
QAction *colorSaturationPressureAction;
QAction *noColorSaturationAction;
QActionGroup *lineWidthGroup;
QAction *lineWidthPressureAction;
QAction *lineWidthTiltAction;
QAction *lineWidthFixedAction;
QAction *exitAction;
QAction *saveAction;
QAction *loadAction;
QAction *aboutAction;
QAction *aboutQtAction;
QMenu *fileMenu;
QMenu *brushMenu;
QMenu *tabletMenu;
QMenu *helpMenu;
QMenu *colorSaturationMenu;
QMenu *lineWidthMenu;
QMenu *alphaChannelMenu;
};
#endif
#include <QtGui>
#include "mainwindow.h"
#include "tabletcanvas.h"
MainWindow::MainWindow(TabletCanvas *canvas)
{
myCanvas = canvas;
createActions();
createMenus();
myCanvas->setColor(Qt::red);
myCanvas->setLineWidthType(TabletCanvas::LineWidthPressure);
myCanvas->setAlphaChannelType(TabletCanvas::NoAlpha);
myCanvas->setColorSaturationType(TabletCanvas::NoSaturation);
setWindowTitle(tr("Tablet Example"));
setCentralWidget(myCanvas);
}
void MainWindow::brushColorAct()
{
QColor color = QColorDialog::getColor(myCanvas->color());
if (color.isValid())
myCanvas->setColor(color);
}
void MainWindow::alphaActionTriggered(QAction *action)
{
if (action == alphaChannelPressureAction) {
myCanvas->setAlphaChannelType(TabletCanvas::AlphaPressure);
} else if (action == alphaChannelTiltAction) {
myCanvas->setAlphaChannelType(TabletCanvas::AlphaTilt);
} else {
myCanvas->setAlphaChannelType(TabletCanvas::NoAlpha);
}
}
void MainWindow::lineWidthActionTriggered(QAction *action)
{
if (action == lineWidthPressureAction) {
myCanvas->setLineWidthType(TabletCanvas::LineWidthPressure);
} else if (action == lineWidthTiltAction) {
myCanvas->setLineWidthType(TabletCanvas::LineWidthTilt);
} else {
myCanvas->setLineWidthType(TabletCanvas::NoLineWidth);
}
}
void MainWindow::saturationActionTriggered(QAction *action)
{
if (action == colorSaturationVTiltAction) {
myCanvas->setColorSaturationType(TabletCanvas::SaturationVTilt);
} else if (action == colorSaturationHTiltAction) {
myCanvas->setColorSaturationType(TabletCanvas::SaturationHTilt);
} else if (action == colorSaturationPressureAction) {
myCanvas->setColorSaturationType(TabletCanvas::SaturationPressure);
} else {
myCanvas->setColorSaturationType(TabletCanvas::NoSaturation);
}
}
void MainWindow::saveAct()
{
QString path = QDir::currentPath() + "/untitled.png";
QString fileName = QFileDialog::getSaveFileName(this, tr("Save Picture"),
path);
if (!myCanvas->saveImage(fileName))
QMessageBox::information(this, "Error Saving Picture",
"Could not save the image");
}
void MainWindow::loadAct()
{
QString fileName = QFileDialog::getOpenFileName(this, tr("Open Picture"),
QDir::currentPath());
if (!myCanvas->loadImage(fileName))
QMessageBox::information(this, "Error Opening Picture",
"Could not open picture");
}
void MainWindow::aboutAct()
{
QMessageBox::about(this, tr("About Tablet Example"),
tr("This example shows use of a Wacom tablet in Qt"));
}
void MainWindow::createActions()
{
brushColorAction = new QAction(tr("&Brush Color..."), this);
brushColorAction->setShortcut(tr("Ctrl+C"));
connect(brushColorAction, SIGNAL(triggered()),
this, SLOT(brushColorAct()));
alphaChannelPressureAction = new QAction(tr("&Pressure"), this);
alphaChannelPressureAction->setCheckable(true);
alphaChannelTiltAction = new QAction(tr("&Tilt"), this);
alphaChannelTiltAction->setCheckable(true);
noAlphaChannelAction = new QAction(tr("No Alpha Channel"), this);
noAlphaChannelAction->setCheckable(true);
noAlphaChannelAction->setChecked(true);
alphaChannelGroup = new QActionGroup(this);
alphaChannelGroup->addAction(alphaChannelPressureAction);
alphaChannelGroup->addAction(alphaChannelTiltAction);
alphaChannelGroup->addAction(noAlphaChannelAction);
connect(alphaChannelGroup, SIGNAL(triggered(QAction *)),
this, SLOT(alphaActionTriggered(QAction *)));
colorSaturationVTiltAction = new QAction(tr("&Vertical Tilt"), this);
colorSaturationVTiltAction->setCheckable(true);
colorSaturationHTiltAction = new QAction(tr("&Horizontal Tilt"), this);
colorSaturationHTiltAction->setCheckable(true);
colorSaturationPressureAction = new QAction(tr("&Pressure"), this);
colorSaturationPressureAction->setCheckable(true);
noColorSaturationAction = new QAction(tr("&No Color Saturation"), this);
noColorSaturationAction->setCheckable(true);
noColorSaturationAction->setChecked(true);
colorSaturationGroup = new QActionGroup(this);
colorSaturationGroup->addAction(colorSaturationVTiltAction);
colorSaturationGroup->addAction(colorSaturationHTiltAction);
colorSaturationGroup->addAction(colorSaturationPressureAction);
colorSaturationGroup->addAction(noColorSaturationAction);
connect(colorSaturationGroup, SIGNAL(triggered(QAction *)),
this, SLOT(saturationActionTriggered(QAction *)));
lineWidthPressureAction = new QAction(tr("&Pressure"), this);
lineWidthPressureAction->setCheckable(true);
lineWidthPressureAction->setChecked(true);
lineWidthTiltAction = new QAction(tr("&Tilt"), this);
lineWidthTiltAction->setCheckable(true);
lineWidthFixedAction = new QAction(tr("&Fixed"), this);
lineWidthFixedAction->setCheckable(true);
lineWidthGroup = new QActionGroup(this);
lineWidthGroup->addAction(lineWidthPressureAction);
lineWidthGroup->addAction(lineWidthTiltAction);
lineWidthGroup->addAction(lineWidthFixedAction);
connect(lineWidthGroup, SIGNAL(triggered(QAction *)),
this, SLOT(lineWidthActionTriggered(QAction *)));
exitAction = new QAction(tr("E&xit"), this);
exitAction->setShortcut(tr("Ctrl+X"));
connect(exitAction, SIGNAL(triggered()),
this, SLOT(close()));
loadAction = new QAction(tr("&Open..."), this);
loadAction->setShortcut(tr("Ctrl+O"));
connect(loadAction, SIGNAL(triggered()),
this, SLOT(loadAct()));
saveAction = new QAction(tr("&Save As..."), this);
saveAction->setShortcut(tr("Ctrl+S"));
connect(saveAction, SIGNAL(triggered()),
this, SLOT(saveAct()));
aboutAction = new QAction(tr("A&bout"), this);
aboutAction->setShortcut(tr("Ctrl+B"));
connect(aboutAction, SIGNAL(triggered()),
this, SLOT(aboutAct()));
aboutQtAction = new QAction(tr("About &Qt"), this);
aboutQtAction->setShortcut(tr("Ctrl+Q"));
connect(aboutQtAction, SIGNAL(triggered()),
qApp, SLOT(aboutQt()));
}
void MainWindow::createMenus()
{
fileMenu = menuBar()->addMenu(tr("&File"));
fileMenu->addAction(loadAction);
fileMenu->addAction(saveAction);
fileMenu->addSeparator();
fileMenu->addAction(exitAction);
brushMenu = menuBar()->addMenu(tr("&Brush"));
brushMenu->addAction(brushColorAction);
tabletMenu = menuBar()->addMenu(tr("&Tablet"));
lineWidthMenu = tabletMenu->addMenu(tr("&Line Width"));
lineWidthMenu->addAction(lineWidthPressureAction);
lineWidthMenu->addAction(lineWidthTiltAction);
lineWidthMenu->addAction(lineWidthFixedAction);
alphaChannelMenu = tabletMenu->addMenu(tr("&Alpha Channel"));
alphaChannelMenu->addAction(alphaChannelPressureAction);
alphaChannelMenu->addAction(alphaChannelTiltAction);
alphaChannelMenu->addAction(noAlphaChannelAction);
colorSaturationMenu = tabletMenu->addMenu(tr("&Color Saturation"));
colorSaturationMenu->addAction(colorSaturationVTiltAction);
colorSaturationMenu->addAction(colorSaturationHTiltAction);
colorSaturationMenu->addAction(noColorSaturationAction);
helpMenu = menuBar()->addMenu("&Help");
helpMenu->addAction(aboutAction);
helpMenu->addAction(aboutQtAction);
}
#include <QtGui>
#include "mainwindow.h"
#include "tabletapplication.h"
#include "tabletcanvas.h"
int main(int argv, char *args[])
{
TabletApplication app(argv, args);
TabletCanvas *canvas = new TabletCanvas;
app.setCanvas(canvas);
MainWindow mainWindow(canvas);
mainWindow.resize(500, 500);
mainWindow.show();
return app.exec();
}
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