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
Related
I have a QStackedWidget with QWidgets. My QWidgets differ a bit, one has an additional button, other lacks a combo box and so on but all of them can be arranged in the same QGridLayout.
And that is exactly what I would like to achieve. I would like to have a QGridLayout in my QStackedWidget that is shared by all my QWidgets. Additionally my main window (QDockWidget) can be resized and I would like to set different column and row stretch for the grid layout.
Is there a clean solution for this?
I came up with two ideas.
One is to have a QGridLayout in each QWidget and connect them all together so that when one is resized, others do the same. However, the more QWidgets I had, the more complicated it would have been.
My second idea is to have one QGridLayout with QStackedWidget in each cell. The bigger the QGridLayout was, the harder it would be to maintain it.
None of my ideas seem to be good.
I am using PyQt4 but examples in C++ are welcome as well.
This doesn't seem to warrant anything more than maybe a shared addWidgetsToGridLayout function that can be used for each widget in the stack, which is a different object because it shows different things. Sharing widgets is bad in this setup, so make sure each widget in the stack has its own distinct widgets.
I don't understand why you would want to resize invisible widgets on resize. When you switch to another widget on the stack, Qt will make sure the proper events are called to properly resize the layout.
A layout cannot be shared. The layout system was not designed for it.
You could have a setup function that creates widgets in a layout, and returns the layout. The layout carries the widgets. You can then apply that layout to a widget, establishing the contents that way. The setup function can take parameters that customize its behavior. For example:
enum WidgetType {
Normal, WithButton, WithCombo
};
QGridLayout* setup(WidgetType type) {
auto l = new QGridLayout;
l.addWidget(0, 0, new QLabel("Hello"));
l.addWidget(0, 1, new QLabel("World"));
switch (type) {
case WithButton:
l.addWidget(1, 0, new QPushButton("Click Me!"));
break;
case WithCombo:
if (auto combo = new QComboBox) {
...
l.addWidget(1, 1, combo);
}
break;
case Normal:
break;
}
return l;
};
void test() {
QWidget w1, w2;
w1.setLayout(setup(Normal));
w2.setLayout(setup(WithButton));
}
Of course, presumably you'll want to easily refer to the widgets. Thus it's best that you create a custom widget that can take multple forms, and holds the widget by value or by pointer as needed:
class Widget : public QWidget {
QGridLayout m_layout{this};
QLabel m_label1("Hello");
QLabel m_label2("World");
QPointer<QPushButton> m_button;
QPointer<QComboBox> m_combo;
public:
Widget(WidgetType type, QWidget *parent = nullptr) : QWidget(parent) {
m_layout.addWidget(0, 0, &m_label1);
m_layout.addWidget(0, 1, &m_label2);
switch (type) {
case WithButton:
m_button = new QPushButton("Click Me!");
m_layout.addWidget(1, 0, m_button.data());
break;
case WithCombo:
m_combo = new QComboBox;
...
m_layout.addWidget(1, 1, m_combo.data());
break;
case Normal:
break;
}
}
};
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 am working on QT v5.2
I need to hide the blinking cursor (caret) of QLineEdit permanently.
But at the same time, I want the QLineEdit to be editable (so readOnly and/or setting editable false is not an option for me).
I am already changing the Background color of the QLineEdit when it is in focus, so I will know which QLineEdit widget is getting edited.
For my requirement, cursor (the blinking text cursor) display should not be there.
I have tried styleSheets, but I can't get the cursor hidden ( {color:transparent; text-shadow:0px 0px 0px black;} )
Can someone please let me know how can I achieve this?
There is no standard way to do that, but you can use setReadOnly method which hides the cursor. When you call this method it disables processing of keys so you'll need to force it.
Inherit from QLineEdit and reimplement keyPressEvent.
LineEdit::LineEdit(QWidget* parent)
: QLineEdit(parent)
{
setReadOnly(true);
}
void LineEdit::keyPressEvent(QKeyEvent* e)
{
setReadOnly(false);
__super::keyPressEvent(e);
setReadOnly(true);
}
As a workaround you can create a single line QTextEdit and set the width of the cursor to zero by setCursorWidth.
For a single line QTextEdit you should subclass QTextEdit and do the following:
Disable word wrap.
Disable the scroll bars (AlwaysOff).
setTabChangesFocus(true).
Set the sizePolicy to (QSizePolicy::Expanding, QSizePolicy::Fixed)
Reimplement keyPressEvent() to ignore the event when Enter/Return is hit
Reimplement sizeHint to return size depending on the font.
The implementation is :
#include <QTextEdit>
#include <QKeyEvent>
#include <QStyleOption>
#include <QApplication>
class TextEdit : public QTextEdit
{
public:
TextEdit()
{
setTabChangesFocus(true);
setWordWrapMode(QTextOption::NoWrap);
setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
setFixedHeight(sizeHint().height());
}
void keyPressEvent(QKeyEvent *event)
{
if (event->key() == Qt::Key_Return || event->key() == Qt::Key_Enter)
event->ignore();
else
QTextEdit::keyPressEvent(event);
}
QSize sizeHint() const
{
QFontMetrics fm(font());
int h = qMax(fm.height(), 14) + 4;
int w = fm.width(QLatin1Char('x')) * 17 + 4;
QStyleOptionFrameV2 opt;
opt.initFrom(this);
return (style()->sizeFromContents(QStyle::CT_LineEdit, &opt, QSize(w, h).
expandedTo(QApplication::globalStrut()), this));
}
};
Now you can create an instance of TextEdit and set the cursor width to zero :
textEdit->setCursorWidth(0);
Most straight forward thing I found was stolen from this github repo:
https://github.com/igogo/qt5noblink/blob/master/qt5noblink.cpp
Basically you just want to disable the internal "blink timer" Qt thinks is somehow good UX (hint blinking cursors never were good UX and never will be - maybe try color or highlighting there eh design peeps).
So the code is pretty simple:
from PyQt5 import QtGui
app = QtGui.QApplication.instance()
app.setCursorFlashTime(0)
voilà.
Solution in python:
# somelibraries
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
self.layout = QVBoxLayout()
self.setFocus() # this is what you need!!!
container = QWidget()
container.setLayout(self.layout)
# Set the central widget of the Window.
self.setCentralWidget(container)
app = QApplication(sys.argv)
window = MainWindow()
window.show()
app.exec()
I ran into the same problem but setReadOnly is not a viable option because it alters the UI behavior in other places too.
Somewhere in a Qt-forum I found the following solution that actually solves the problem exactly where it occurs without having impact on other parts.
In the first step you need to derive from QProxyStyle and overwrite the pixelMetric member function:
class CustomLineEditProxyStyle : public QProxyStyle
{
public:
virtual int pixelMetric(PixelMetric metric, const QStyleOption* option = 0, const QWidget* widget = 0) const
{
if (metric == QStyle::PM_TextCursorWidth)
return 0;
return QProxyStyle::pixelMetric(metric, option, widget);
}
};
The custom function simply handles QStyle::PM_TextCursorWidth and forwards otherwise.
In your custom LineEdit class constructor you can then use the new Style like this:
m_pCustomLineEditStyle = new CustomLineEditProxyStyle();
setStyle(m_pCustomLineEditStyle);
And don't forget to delete it in the destructor since the ownership of the style is not transferred (see documentation). You can, of course, hand the style form outside to your LineEdit instance if you wish.
Don't get complicated:
In QtDesigner ,
1.Go the the lineEdit 's property tab
2.Change focusPolicy to ClickFocus
That's it...
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 want to set an image on QPushButton, and the size of QPushButton should depend on the size of the image. I am able to do this when using QLabel, but not with QPushButton.
So, if anyone has a solution, then please help me out.
What you can do is use a pixmap as an icon and then put this icon onto the button.
To make sure the size of the button will be correct, you have to reisze the icon according to the pixmap size.
Something like this should work :
QPixmap pixmap("image_path");
QIcon ButtonIcon(pixmap);
button->setIcon(ButtonIcon);
button->setIconSize(pixmap.rect().size());
QPushButton *button = new QPushButton;
button->setIcon(QIcon(":/icons/..."));
button->setIconSize(QSize(65, 65));
You can also use:
button.setStyleSheet("qproperty-icon: url(:/path/to/images.png);");
Note: This is a little hacky. You should use this only as last resort. Icons should be set from C++ code or Qt Designer.
You may also want to set the button size.
QPixmap pixmap("image_path");
QIcon ButtonIcon(pixmap);
button->setIcon(ButtonIcon);
button->setIconSize(pixmap.rect().size());
button->setFixedSize(pixmap.rect().size());
I don't think you can set arbitrarily sized images on any of the existing button classes.
If you want a simple image behaving like a button, you can write your own QAbstractButton-subclass, something like:
class ImageButton : public QAbstractButton {
Q_OBJECT
public:
...
void setPixmap( const QPixmap& pm ) { m_pixmap = pm; update(); }
QSize sizeHint() const { return m_pixmap.size(); }
protected:
void paintEvent( QPaintEvent* e ) {
QPainter p( this );
p.drawPixmap( 0, 0, m_pixmap );
}
};
You can do this in QtDesigner. Just click on your button then go to icon property and then choose your image file.
This is old but it is still useful,
Fully tested with QT5.3.
Be carreful, example concerning the ressources path :
In my case I created a ressources directory named "Ressources" in the source directory project.
The folder "ressources" contain pictures and icons.Then I added a prefix "Images" in Qt So the pixmap path become:
QPixmap pixmap(":/images/Ressources/icone_pdf.png");
JF
Just use this code
QPixmap pixmap("path_to_icon");
QIcon iconBack(pixmap);
Note that:"path_to_icon" is the path of image icon in file .qrc of your project You can find how to add .qrc file here
In case anybody needs a PyQt version of the first answer:
class PictureButton(QAbstractButton):
def __init__(self, picture, parent):
super().__init__(parent)
self.setPicture(QPixmap(picture))
def setPicture(self, picture):
self.picture = picture
self.update()
def sizeHint(self):
return self.picture.size()
def paintEvent(self, e):
painter = QPainter(self)
painter.drawPixmap(0, 0, self.picture)