window.cpp Example File
embeddedqwindow/window.cpp
#include "window.h"
#include <private/qguiapplication_p.h>
#include <QBackingStore>
#include <QPainter>
#include <QtWidgets>
static int colorIndexId = 0;
QColor colorTable[] =
{
QColor("#f09f8f"),
QColor("#a2bff2"),
QColor("#c0ef8f")
};
Window::Window(QScreen *screen)
: QWindow(screen)
, m_backgroundColorIndex(colorIndexId++)
, m_backingStore(0)
{
initialize();
}
Window::Window(QWindow *parent)
: QWindow(parent)
, m_backgroundColorIndex(colorIndexId++)
, m_backingStore(0)
{
initialize();
}
void Window::initialize()
{
if (parent())
setGeometry(QRect(160, 120, 320, 240));
else {
setGeometry(QRect(10, 10, 640, 480));
setSizeIncrement(QSize(10, 10));
setBaseSize(QSize(640, 480));
setMinimumSize(QSize(240, 160));
setMaximumSize(QSize(800, 600));
}
setFlags(flags() | Qt::SubWindow);
create();
m_backingStore = new QBackingStore(this);
m_image = QImage(geometry().size(), QImage::Format_RGB32);
m_image.fill(colorTable[m_backgroundColorIndex % (sizeof(colorTable) / sizeof(colorTable[0]))].rgba());
m_lastPos = QPoint(-1, -1);
m_renderTimer = 0;
}
void Window::mousePressEvent(QMouseEvent *event)
{
m_lastPos = event->pos();
}
void Window::mouseMoveEvent(QMouseEvent *event)
{
if (m_lastPos != QPoint(-1, -1)) {
QPainter p(&m_image);
p.setRenderHint(QPainter::Antialiasing);
p.drawLine(m_lastPos, event->pos());
m_lastPos = event->pos();
}
scheduleRender();
}
void Window::mouseReleaseEvent(QMouseEvent *event)
{
if (m_lastPos != QPoint(-1, -1)) {
QPainter p(&m_image);
p.setRenderHint(QPainter::Antialiasing);
p.drawLine(m_lastPos, event->pos());
m_lastPos = QPoint(-1, -1);
}
scheduleRender();
}
void Window::exposeEvent(QExposeEvent *)
{
scheduleRender();
}
void Window::resizeEvent(QResizeEvent *)
{
QImage old = m_image;
int width = qMax(geometry().width(), old.width());
int height = qMax(geometry().height(), old.height());
if (width > old.width() || height > old.height()) {
m_image = QImage(width, height, QImage::Format_RGB32);
m_image.fill(colorTable[(m_backgroundColorIndex) % (sizeof(colorTable) / sizeof(colorTable[0]))].rgba());
QPainter p(&m_image);
p.drawImage(0, 0, old);
}
render();
}
void Window::keyPressEvent(QKeyEvent *event)
{
switch (event->key()) {
case Qt::Key_Backspace:
m_text.chop(1);
break;
case Qt::Key_Enter:
case Qt::Key_Return:
m_text.append('\n');
break;
default:
m_text.append(event->text());
break;
}
scheduleRender();
}
void Window::scheduleRender()
{
if (!m_renderTimer)
m_renderTimer = startTimer(1);
}
void Window::timerEvent(QTimerEvent *)
{
render();
killTimer(m_renderTimer);
m_renderTimer = 0;
}
void Window::render()
{
if (!m_backingStore)
return;
QRect rect(QPoint(), geometry().size());
m_backingStore->resize(rect.size());
m_backingStore->beginPaint(rect);
QPaintDevice *device = m_backingStore->paintDevice();
QPainter p(device);
p.drawImage(0, 0, m_image);
QFont font;
font.setPixelSize(32);
p.setFont(font);
p.drawText(rect, 0, m_text);
m_backingStore->endPaint();
m_backingStore->flush(rect);
}