void ImageViewer::paintEvent(QPaintEvent *e)
{
QPainter painter(this);
if(bgColor.isValid())
painter.fillRect(e->rect(), bgColor);
if(noPicture() && !errStr.isEmpty()){
painter.drawText(rect(), Qt::AlignCenter, errStr);
return;
}
switch(antialiasMode){
case Config::AntialiasWhenZoomIn:
if(scale <= 1) break;
case Config::AlwaysAntialias:
painter.setRenderHint(QPainter::SmoothPixmapTransform);
break;
case Config::NoAntialias:
default:
break;
}
painter.save();
painter.translate(topLeft + shift);
painter.scale(scale, scale);
// painter.setClipRect(e->rect());
painter.drawImage(Config::OriginPoint, image);
painter.restore(); ///
// draw scroll bar
if(velocityTracker->isScrolling()){
const QColor LINE_COLOR(0, 0, 0, 80);
painter.setBrush(LINE_COLOR);
painter.setPen(Qt::NoPen);
const int LINE_WIDTH = 10;
const int MARGE = 3;
const qreal RADIUS = 6.0;
int rectW = rect().width(), rectH = rect().height();
qreal scaleW = image.width() * scale; //! qreal
qreal scaleH = image.height() * scale;
if(scaleW > rectW){ // draw horizontal scroll bar
QRectF rectangle(-(topLeft + shift).x() / scaleW * rectW,
rectH - LINE_WIDTH - MARGE,
rectW / scaleW * rectW,
LINE_WIDTH);
painter.drawRoundedRect(rectangle, RADIUS, RADIUS);
}
if(scaleH > rectH){ // draw vertical scroll bar
QRectF rectangle(rectW - LINE_WIDTH - MARGE,
-(topLeft + shift).y() / scaleH * rectH,
LINE_WIDTH,
rectH / scaleH * rectH);
painter.drawRoundedRect(rectangle, RADIUS, RADIUS);
}
}
}
void ImageViewer::updateCursor()
{
if(noPicture() || !scaleLargeThanWidget()) {
changeCursor(Qt::ArrowCursor);
} else if(leftMousePressed) {
changeCursor(Qt::ClosedHandCursor);
} else {
changeCursor(Qt::OpenHandCursor);
}
}
void ImageViewer::rotatePixmap(int degree)
{
if(noPicture()) return;
rotate += degree;
rotate %= 360;
QMatrix matrix = QMatrix().rotate(degree);
image = image.transformed(matrix, Qt::SmoothTransformation);
layoutImage();
update();
}
void ImageViewer::rotatePixmap(bool isLeft)
{
if(noPicture()) return;
rotate += (isLeft ? -90 : 90);
rotate %= 360;
QMatrix m = QMatrix().rotate(isLeft ? -90 : 90);
image = image.transformed(m, Qt::SmoothTransformation);
initToFitWidget();
update();
}
void ImageViewer::resizeEvent(QResizeEvent *e)
{
if(noPicture()) return;
if(hasUserZoom){
updateTopLeft();
updateShift();
}else{
initToFitWidget();
}
QWidget::resizeEvent(e);
}
void ImageViewer::resizeEvent(QResizeEvent *e)
{
if(noPicture()) return;
if(hasUserZoom){
calcTopLeft();
updateShift();
updateCursor();
}else{
layoutImage(); //! FIXME: if user drag and move image content (when AlignCenter is hasUserZoom and shift != (0,0)) , this will reset the shift if align mode isn't AlignCenterCenter.
}
QWidget::resizeEvent(e);
}
void ImageViewer::zoomIn(double factor, const QPoint &pivot)
{
if(noPicture() || !rect().contains(pivot)) // pivot must inner widget
return;
qreal scale_old = scale;
zoomIn(factor);
QPointF distance(rect().center() - pivot);
QPointF change(distance / scale_old * scale - distance);
shift += change; // to keep the pivot position, must after scale.
updateShift();
}
void ImageViewer::mirrored(bool horizontal, bool vertical)
{
if(noPicture()) return;
if(horizontal)
mirrorH = !mirrorH;
if(vertical)
mirrorV = !mirrorV;
image = image.mirrored(horizontal, vertical);
initToFitWidget();
update();
}
void ImageViewer::mirrored(MirrorMode mode)
{
if(noPicture()) return;
switch (mode) {
case MirrorHorizontal:
mirrorH = !mirrorH;
break;
case MirrorVertical:
mirrorV = !mirrorV;
break;
default:
return;
}
image = image.mirrored(mode == MirrorHorizontal, mode == MirrorVertical);
layoutImage();
update();
}
void ImageViewer::initToFitWidget()//no change the value of rotate
{
//restore the cursor even if the image cannot load.
setCursor(QCursor(Qt::ArrowCursor));
if(noPicture()) return;
QSize pixSize(image.size());
//if image large than widget, will scale image to fit widget.
if(!(rect().size() - pixSize).isValid())//! SIZE_ADJUST !!!
pixSize.scale(rect().size() + Config::SizeAdjusted, Qt::KeepAspectRatio);
if(image.width() == 0)
scale = 1.0;
else
scale = qreal(pixSize.width()) / image.width();
scaleMin = qMin(Config::ScaleMin, scale);
updateTopLeft();
shift = Config::OriginPoint;
}
void ImageViewer::zoomIn(double factor)
{
if(noPicture()) return;
qreal scale_old = scale;
scale += factor;
scale = qMax(scaleMin, qMin(Config::ScaleMax, scale));
if(scale == scale_old)//scale no changed
return;
/*! topLeft must determined before shift,
* otherwise will impact updateShift()
*/
updateTopLeft();
shift /= scale_old;
shift *= scale;
updateShift();
hasUserZoom = true;
ToolTip::showText(mapToGlobal(rect().center()),
QString("<font size='7'><b>%1%</b></font>").arg(scale * 100, 0, 'g', 4),
true, 0.7, 800);
}
void ImageViewer::wheelEvent(QWheelEvent *e)
{
if(noPicture() || !rect().contains(e->pos())) //cursor is not in widget
return;
qreal scale_old = scale;
switch(e->modifiers()){
case Qt::ShiftModifier:
zoomIn(e->delta() / qreal(2400)); //e->delta() is +120 or -120
break;
case Qt::ControlModifier:
zoomIn(e->delta() / qreal(600));
break;
default:
zoomIn(e->delta() / qreal(1200));
break;
}
QPointF distance(rect().center() - e->pos());
QPointF change(distance / scale_old * scale - distance);
shift += change; //to keep the cursor position, must after scale.
updateShift();
}
