I'm trying to implement a show/hide widget animation. The widget is a QDockWidget and therefore is inside the QMainWindowLayout.
Using QPropertyAnimation doens't seem to work, I got something looking like that :
m_listViewDock->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
QPropertyAnimation* animation = new QPropertyAnimation(m_listViewDock, "geometry", m_listViewDock);
animation->setDuration(1000);
QRect g = m_listViewDock->geometry();
animation->setStartState(g);
g.setHeight(80);
animation->setEndState(g);
animation->start(QAbstractAnimation::DeleteWhenStopped);
Unfortunately it doesn't do anything. I tried with other properties (minimumHeight, fixedHeight), but same issue.
I thought I didn't setup my widget layout correctly using the designer but even if I play with minimum sizes I still don't have any result. What kind of size policy should I use if I want to play with the size?
I'm stuck, it would be so great if someone could clarify my issue. I'm not sure I'm doing anything wrong...
Thanks in advance for your help,
Boris -
By the way, here is how Qt programmers used it in the QWidgetAnimator, mainly used for animations of dock widgets, I'm doing exactly the same... :
const QRect final_geometry = _final_geometry.isValid() || widget->isWindow() ? _final_geometry :
QRect(QPoint(-500 - widget->width(), -500 - widget->height()), widget->size());
#ifndef QT_NO_ANIMATION
AnimationMap::const_iterator it = m_animation_map.constFind(widget);
if (it != m_animation_map.constEnd() && (*it)->endValue().toRect() == final_geometry)
return;
QPropertyAnimation *anim = new QPropertyAnimation(widget, "geometry", widget);
anim->setDuration(animate ? 200 : 0);
anim->setEasingCurve(QEasingCurve::InOutQuad);
anim->setEndValue(final_geometry);
m_animation_map[widget] = anim;
connect(anim, SIGNAL(finished()), SLOT(animationFinished()));
anim->start(QPropertyAnimation::DeleteWhenStopped);
Related
I am developing my own MessageBox because I need the functionality of:
Do not display this message next time
Which isn't supported by standard message boxes. However I would like to make it look as much as possible as original message box. Therefore I would like to reuse the same icon set you can find when message boxes are displayed.
Is there any way to retrieve this pixmap so that I can use it? Something like:
this->ui->icon->setPixmap(QMessageBox::questionPixmap);
Although this is an old question, I found an easy solution for those seeking an answer to this.
Create a qLabel in your custom class, and then in the constructor of that class create a QIcon with the style you want, convert it into a pixmap and use the QLabel::setPixmap() function to apply it to the one you created:
QIcon icon = style()->standardIcon(QStyle::SP_MessageBoxWarning); //or
//whatever icon you choose
QPixmap pixmap = icon.pixmap(QSize(60, 60));
ui->iconLabel->setPixmap(pixmap);
ui->iconLabel->setScaledContents(true); //you can set this to fill the
//dimensions of your qLabel if you wish.
Try QStyle::standardIcon with QStyle::SP_MessageBoxQuestion.
You can get style from current QWidget or QApplication.
This seems to work:
This is the original source code (internal Qt implementation) that gets the pixmap for message box:
QPixmap QMessageBoxPrivate::standardIcon(QMessageBox::Icon icon, QMessageBox *mb)
{
QStyle *style = mb ? mb->style() : QApplication::style();
int iconSize = style->pixelMetric(QStyle::PM_MessageBoxIconSize, 0, mb);
QIcon tmpIcon;
switch (icon) {
case QMessageBox::Information:
tmpIcon = style->standardIcon(QStyle::SP_MessageBoxInformation, 0, mb);
break;
case QMessageBox::Warning:
tmpIcon = style->standardIcon(QStyle::SP_MessageBoxWarning, 0, mb);
break;
case QMessageBox::Critical:
tmpIcon = style->standardIcon(QStyle::SP_MessageBoxCritical, 0, mb);
break;
case QMessageBox::Question:
tmpIcon = style->standardIcon(QStyle::SP_MessageBoxQuestion, 0, mb);
default:
break;
}
if (!tmpIcon.isNull())
return tmpIcon.pixmap(iconSize, iconSize);
return QPixmap();
}
Creating a similar function provides a way to obtain the pixmap for all these message box styles.
Source: http://www.qtcentre.org/threads/37395-Getting-the-Icon-of-a-MessageBox
Is it possible to use clipping in an widgets painEvent, if the widget is using stylesheets?
The background and reason for my question is that I want to make the widget animating when it appears and disappears. (Something like a resizing circle or square, that gets bigger starting as a small area from the center).
My first (and only) thought on how to solve this, was to use the clipping of a QPainter, so that only the required area is drawn.
If I make the Background of the widget transparent and use the primitive drawing functions from QPainter it works fine. But how can I solve this, if the widget has a stylesheet applied? Is it even possible?
The used Qt version is Qt 4.8.6
My questions are:
Is it possible to achieve what I want with the mentioned strategy?
Is it possible in any way to clip all the children, too?
Is my strategy appropriate or is it a bad Idea to solve it that way?
Are there any other ideas, best practices, Qt Classes, ... that can give me what I want?
Additional Information
I haven't much code to show, because I stuck with this clipping things. But here is something to get an idea of what I have tried:
This works.
/* Shows a small red circle inside the widget as expected */
void MyAnimatingWidget::paintEvent(QPaintEvent *ev) {
QPainter painter(this);
QRect rect = this->geometry()
QStyleOption opt;
painter.setClipRegion(QRegion(rect.width()/2,
rect.height()/2,
150, 150,
QRegion::Ellipse));
painter.setPen(QColor(255, 0, 0));
painter.setBrush(QColor(255, 0, 0));
painter.setOpacity(1);
painter.drawRect(rect);
}
But the following doesn't change anything:
/* This shows the widget as usual */
void MyAnimatingWidget::paintEvent(QPaintEvent *ev) {
QPainter painter(this);
QRect rect = this->geometry();
QStyleOption opt;
painter.setClipRegion(QRegion(rect.width()/2,
rect.height()/2,
150, 150,
QRegion::Ellipse));
painter.setRenderHint(QPainter::Antialiasing);
painter.setOpacity(1);
opt.init(this);
style()->drawPrimitive(QStyle::PE_Widget, &opt, &painter, this);
}
Moreover I have noticed, that the stylesheet is also drawn, even if I remove the style()->drawPrimitive(QStyle::PE_Widget, &opt, &painter, this); line at all.
The stylesheet you apply to your widget overrides the OS-specific style(s) widgets are equipped with by default. This can even cause problems, if you want to have a, say, Windows look, but still want to use a stylesheet. Anyway, you can check what each style does in the Qt source directory: src/gui/styles. For style()->drawPrimitive(QStyle::PE_Widget, &opt, &painter, this);, the code reads:
case PE_Widget:
if (w && !rule.hasDrawable()) {
QWidget *container = containerWidget(w);
if (styleSheetCaches->autoFillDisabledWidgets.contains(container)
&& (container == w || !renderRule(container, opt).hasBackground())) {
//we do not have a background, but we disabled the autofillbackground anyway. so fill the background now.
// (this may happen if we have rules like :focus)
p->fillRect(opt->rect, opt->palette.brush(w->backgroundRole()));
}
break;
}
As you can see clipping is not meddled with in any way, so your idea of setting a clip region should work. Now for the painting mystery. The painting of the background happens in void QWidgetPrivate::paintBackground(QPainter *painter, const QRegion &rgn, int flags) const, which is called from void QWidgetPrivate::drawWidget(QPaintDevice *pdev, const QRegion &rgn, const QPoint &offset, int flags, QPainter *sharedPainter, QWidgetBackingStore *backingStore). You can find the code in: /src/gui/kernel/qwidget.cpp. The relevant code reads:
if (q->testAttribute(Qt::WA_StyledBackground)) {
painter->setClipRegion(rgn);
QStyleOption opt;
opt.initFrom(q);
q->style()->drawPrimitive(QStyle::PE_Widget, &opt, painter, q);
}
Maybe turning the attribute off would help? The basic lesson you should draw from my answer is to get accustomed to source diving. The idea behind Qt is nice (instantiating controls, without bothering about implementation details), but it rarely works in practice, i.e. you often need to source dive.
To clip widget's children to arbitrary clip regions, you can capture them into a pixmap, example:
QPixmap pixmap(widget->size());
widget->render(&pixmap);
And then draw the pixmap manually. You might also be able to prevent them repainting automatically (via setUpdatesEnabled() or by hiding them) and then calling their render in you paintEvent handler manually.
I re-implemented QGraphicsView to have the scene zoomed with a mouse wheel event. The scene contains several QGraphicsPixmapItem. The wheel event calls QGraphicsView::scale(qreal sx, qreal sy)
Everything works perfectly but the rendering. As I zoom out (the scene gets smaller), aliasing appears. I tried setting the render hints as following in the re-implemented QGraphicsView constructor:
ImageViewer::ImageViewer(QWidget * parent) :
QGraphicsView(parent)
{
setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform | QPainter::HighQualityAntialiasing);
}
I still see these artifacts. How can I get rid of this ?
Please see my comments for this question.
Basically you have to call setTransformationMode(Qt::SmoothTransformation) on the QGraphicsPixmapItems you want anti-aliasing to apply to.
Calling setRenderHints on the view did not work for me, either.
The render hints are only applied if it is set bevor the painter is used. Here a snipped:
QGraphicsPixmapItem *
drawGraphicsPixmapItem(const QRectF &rect)
{
auto pixmap = new QPixmap(rect.size().toSize());
pixmap->fill("lightGrey");
auto painter = new QPainter(pixmap);
// set render hints bevor drawing with painter
painter->setRenderHints(QPainter::Antialiasing);
QPen pen;
pen.setColor("black");
pen.setWidth(3);
painter->setPen(pen);
QRectF rectT = rect;
rectT.adjust(pen.widthF()/2,pen.widthF()/2,-pen.widthF()/2,-pen.widthF()/2);
QPainterPath circlePath;
circlePath.addEllipse(rectT);
circlePath.closeSubpath();
painter->fillPath(circlePath,QBrush("green"));
painter->drawPath(circlePath);
auto pixmapItem = new QGraphicsPixmapItem(*pixmap);
pixmapItem->setCacheMode(
QGraphicsItem::CacheMode::DeviceCoordinateCache,
pixmap->size() );
return pixmapItem;
}
I implemented QLabel much like Qt's ImageViewer example, except I use QGridLayout for positioning my widgets. I also implemented similar lines for scaling my QLabel using QScrollBar, but QLabel just doesn't scale like it should inside the QScrollArea. I am not sure if it is related to some kind of GridLayout management issue or something else. I have been reading everywhere and trying different things for 3 days now. Below I list the relevant portion of my code.
In my Viewer class constructor:
{
imageLabel1 = new QLabel;
imageLabel1->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum);
imageLabel1->setScaledContents(true);
scrollArea1 = new QScrollArea;
scrollArea1->setWidget(imageLabel1);
scrollArea1->setWidgetResizable(true);
....
QGridLayout *centralLayout = new QGridLayout;
centralLayout->addWidget(scrollArea1, 0, 0);
...}
and my scaleImage method:
void Viewer::scaleImage1(int factor)
{
Q_ASSERT(imageLabel1->pixmap());
scaleFactor *= (1 + factor);
//imageLabel1->resize(scaleFactor* imageLabel1->pixmap()->size());
imageLabel1->pixmap()->toImage().scaled(scaleFactor* imageLabel1->pixmap()->size(), Qt::KeepAspectRatio, Qt::FastTransformation);
imageLabel1->adjustSize();
adjustScrollBar(scrollArea1->horizontalScrollBar(), factor);
adjustScrollBar(scrollArea1->verticalScrollBar(), factor);
imageLabel1->update();
}
My scaleImage1 function is a public slot, and it receives signal from a scrollbar that goes between 0 and 2 so that, into the scaleFactor, the imageLabel1 is designed to be capable of being zoomed in up to 3 times its original size. But when I run the code, I don’t observe the imageLabel becoming enlarged inside the QScrollArea, which I saw in the imageViewer demo. The imageLabel1 simply retains the original size as it is loaded and does not respond to the valueChange() of scrollbar.
I'd appreciate your advice/tips very much.
I think is because you set QSizePolicy::Minimum to the imageLabel, try with MinimumExpanding or other that better fit your needs.
I'm trying to put a QVBoxLayout inside a QScrollArea in order for it to be scrollable vertically. However items don't seem to be added to it.
I saw a suggestion that I ought to create an inner widget that the ScrollArea uses and to place the layout inside that, although it doesn't seem to have worked. My structure is supposed to look like this:
+-------------------------------
| QScrollArea(realmScroll)
| +----------------------------
| | QWidget(realmScrollInner)
| | +-------------------------
| | | QVBoxLayout(realmLayout)
And the code to do this:
# Irrelevant, added for context (this works)
centralWidget = QWidget(self)
self.container = QVBoxLayout(centralWidget)
centralWidget.setLayout(self.container)
self.setCentralWidget(centralWidget)
# Where trouble starts
self.realmScroll = QScrollArea(self.container.widget())
self.realmScroll.setVerticalScrollBarPolicy(Qt.ScrollBarAsNeeded)
self.realmLayout = QVBoxLayout(self.container.widget())
self.realmScrollInner = QWidget(self.realmScroll)
self.realmScrollInner.setLayout(self.realmLayout)
self.realmScroll.setWidget(self.realmScrollInner)
self.container.addWidget(self.realmScroll)
# Doesn't add to realmLayout
self.realmLayout.addWidget(QLabel("test"))
I'm still learning Qt (2 days in), so in-depth answers to where I'm going wrong would be appreciated.
Update:
It seems that the addWidget(QLabel()) works right up until the realmScrollInner has been set as realmScroll's widget. Since I'd like to add elements after the UI has been displayed I have to do this, which I'm not sure is really correct:
self.realmLayout.addWidget(QLabel("test"))
# realmScrollInner bound to realmScroll
realmScroll.setWidget(realmScrollInner)
self.container.addWidget(realmScroll)
# Access realmScroll's widget and then layout to add
realmScroll.widget().layout().addWidget(QLabel("test"))
But if you remove that first call to addWidget before the widget has been bound (so the layout has no widgets), then bind to the ScrollArea widgets added afterwards are not displayed. Perhaps the ScrollArea needs repainting (although I don't see a method for that)?
Update 2: Calling repaint() on realmScroll or its contained widget does nothing, as does calling activate/update() on the layout.
It turned out that I was lead down a wrong path by putting the layout as the layout of a widget. The actual way to do this is as simple as:
scrollarea = QScrollArea(parent.widget())
layout = QVBoxLayout(scrollarea)
realmScroll.setWidget(layout.widget())
layout.addWidget(QLabel("Test"))
Which I'm pretty sure I tried originally, but hey it's working.
However this adds an issue that the layout's items are shrunk vertically instead of causing the scrollarea to add a scrollbar.
OK, I just got done fighting with this. Here's a widget that can go into a scroll area (scrollarea->setWidget) and work correctly. It contains a QVBoxLayout and a list of label/listwidget pairs, each in their own little horizontal layout, and it does pretty much what you'd want.
The important thing was reading the QScrollArea docs section on Size Hints and Layouts, and finding the bit where having the sizeContraint QLayout::SetMinAndMaxSize on the layout would be necessary.
class MappingDisplayWidget : public QWidget
{
Q_OBJECT
public:
explicit MappingDisplayWidget(QWidget *parent = 0);
void addFile(QString name);
private:
QVBoxLayout *m_layout;
QMap<QString, QListWidget *> m_mappings;
};
MappingDisplayWidget::MappingDisplayWidget(QWidget *parent) :
QWidget(parent)
{
m_layout = new QVBoxLayout;
m_layout->setSizeConstraint(QLayout::SetMinAndMaxSize);
setLayout(m_layout);
}
void MappingDisplayWidget::addFile(QString name) {
if (m_mappings.find(name) == m_mappings.end()) {
QWidget *widg = new QWidget;
QHBoxLayout *lay = new QHBoxLayout;
widg->setLayout(lay);
QLabel *nlab = new QLabel(name);
lay->addWidget(nlab);
QListWidget *list = new QListWidget;
lay->addWidget(list);
m_layout->addWidget(widg);
m_mappings[name] = list;
}
}
I keep pointers to the list widgets so that I can add stuff to them later, and that works fine.
Try calling
self.realmScroll.setWidgetResizable(True)