I have QListView with a custom delegate
Custom delegate paint method:
QStyleOptionViewItemV4 opt = option;
initStyleOption(&opt,index);
opt.decorationSize = QSize(deco_size,deco_size);
opt.decorationAlignment |= Qt::AlignCenter;
opt.displayAlignment |= Qt::AlignCenter;
opt.decorationPosition = QStyleOptionViewItem::Top;
opt.font.setBold(true);
const QWidget *widget = opt.widget;
QStyle *style = widget ? widget->style() : QApplication::style();
style->drawControl(QStyle::CE_ItemViewItem,&opt,painter);
My problem is that If I set stylesheet for my QListView::item
e.g.:
#lv::item:selected:active { background: red; }
it won't work!
If I'm using internal, none custom delegate everything is fine.
2.
I only use custom delegate to put the decoration icon to the top of the text, is there a stylesheet option to force the icon to appear on top?
I missed the 4th parameter of QStyle::drawControl function "widget":
style->drawControl(QStyle::CE_ItemViewItem,&opt,painter,widget);
Here, QStyledItemDelegate source code, paint method:
https://qt.gitorious.org/qt/webkit/source/435bbd4be73768f617e4a4083a345d1d8d62daa3:src/gui/itemviews/qstyleditemdelegate.cpp#L444
Related
I am trying to implement a QComboBox, which holds QIcon and QString, like this:
QComboBox.addItem(icon, label);
I want the icons to be visible in the drop-down list, but not in the toolbar. Only the string should be visible after item selection.
Is there an easy way to do this?
To solve this problem, it is enough to override the paintEvent method, taking the default implementation from the sources. Before drawing control QStyle::CE_ComboBoxLabel, it is necessary to set an invalid value of the QStyleOptionComboBox.currentIcon
This works well if the combobox is not editable, otherwise there is an empty space on the left side intended for drawing the icon. Looking at the source, I found out that the combobox changes the geometry of the QLineEdit. If the current element has an icon then geometrically QLineEdit will shift to the right. In order to prevent this in the same paintEvent, it is necessary to force the geometry of QLineEdit without taking into account the icon.
The following code takes this into account and works well in both modes:
class ComboBox : public QComboBox {
public:
ComboBox(QWidget *parent = nullptr)
: QComboBox(parent) { }
protected:
void paintEvent(QPaintEvent *) override {
QStylePainter painter(this);
painter.setPen(palette().color(QPalette::Text));
// draw the combobox frame, focusrect and selected etc.
QStyleOptionComboBox opt;
initStyleOption(&opt);
painter.drawComplexControl(QStyle::CC_ComboBox, opt);
// draw the icon and text
opt.currentIcon = QIcon();
if (auto le = lineEdit()) {
le->setGeometry(style()->subControlRect(QStyle::CC_ComboBox, &opt, QStyle::SC_ComboBoxEditField, this));
} else {
painter.drawControl(QStyle::CE_ComboBoxLabel, opt);
}
}
};
The best way is to set a delegate and to draw the items yourself.
Then you can choose when or not to draw the icon ( decorationRole ), you can choose not to draw the icon for the index which is the current index.
I could find a quick example on how to use a delegate on combobox:
http://programmingexamples.net/wiki/Qt/Delegates/ComboBoxDelegate
But I am afraid it is not the most easist of the ways.
Good luck!
In QtCreater I added a table to my project. in my code I am generating some data to output into the table. I want to add a QCheckbox into each row to allow the row to be selected. All the content of the table is aligned left, how do I make only these checkboxes in the first column of every row align to the center?
I'm adding the QCheckbox using:
ui->data_table->setCellWidget(rowCount,0, new QCheckBox);
Two thumbs up for Barry Mavin! You don't even have to subclass.
one line...
pCheckBox->setStyleSheet("margin-left:50%; margin-right:50%;");
done!!
I usually use a layout and a container widget for this. It is an ugly solution, but it works:
QWidget * w = new QWidget();
QHBoxLayout *l = new QHBoxLayout();
l->setAlignment( Qt::AlignCenter );
l->addWidget( <add your checkbox here> );
w->setLayout( l );
ui->data_table->setCellWidget(rowCount,0, w);
So basically you will have:
Table Cell -> Widget -> Layout -> Checkbox
you'll have to consider it if you will need to access the checkbox through the table.
This is an old post but in fact there is a much easier and lighter way of achieving this, just subclass QCheckBox and set the stylesheet to
margin-left:50%;
margin-right:50%;
It works for me, but my checkbox is not completely displayed.
To have a complete view of the widget, remove margins in layout :
l->setContentsMargins(0,0,0,0);
As stated in similar question around Stack Overflow, it's currently an open BUG:
https://bugreports.qt-project.org/browse/QTBUG-5368
can be center like this too using layout if want to add more customization
// Create a widget that will contain a checkbox
QWidget *checkBoxWidget = new QWidget();
QCheckBox *checkBox = new QCheckBox(); // We declare and initialize the checkbox
QHBoxLayout *layoutCheckBox = new QHBoxLayout(checkBoxWidget); // create a layer with reference to the widget
layoutCheckBox->addWidget(checkBox); // Set the checkbox in the layer
layoutCheckBox->setAlignment(Qt::AlignCenter); // Center the checkbox
layoutCheckBox->setContentsMargins(0,0,0,0); // Set the zero padding
ui->my_table_view->setCellWidget(row_number,column_number, checkBoxWidget); // set cell widget
OR simply add left right margins
checkBox->setStyleSheet("margin-left:50%; margin-right:50%;");
#if QT_VERSION < 0x046000
#include <QCommonStyle>
class MyStyle : public QCommonStyle {
public:
QRect subElementRect(SubElement subElement, const QStyleOption *option, const QWidget *widget = 0) const {
switch(subElement) {
case QStyle::SE_CheckBoxIndicator: {
QRect r = QCommonStyle::subElementRect(subElement, option, widget);
r.setRect( (widget->width() - r.width())/2, r.top(), r.width(), r.height());
return QRect(r);
}
default: return QCommonStyle::subElementRect(subElement, option, widget);
}
}
};
#else
#include <QProxyStyle>
#include <QStyleFactory>
class MyStyle: public QProxyStyle {
public:
MyStyle():QProxyStyle(QStyleFactory::create("Fusion")) {}
QRect subElementRect(SubElement subElement, const QStyleOption *option, const QWidget *widget = 0) const {
switch(subElement) {
case QStyle::SE_CheckBoxIndicator: {
QRect r = QProxyStyle::subElementRect(subElement, option, widget);
r.setRect( (widget->width() - r.width())/2, r.top(), r.width(), r.height());
return QRect(r);
}
default: return QProxyStyle::subElementRect(subElement, option, widget);
}
}
};
#endif
QCheckBox *box = new QCheckBox();
box->setStyle(new MyStyle());
I'm having problems with my QTableView and QItemDelegate classes. For one column my delegate creates a simple combo box and everything works just fine. For my 2nd column I need a widget that has two combo boxes in a single widget.
I've written the following code in my QItemDelegate, just to be clear this only shows code for my 2nd column, the one that doesn't work. The other simple Combo-box isn't shown as it works fine:
QWidget *UserDefinedUnitsDelegate::createEditor(QWidget *parent,const QStyleOptionViewItem & option ,const QModelIndex & index ) const
{
//set up a simple widget with a layout
QWidget* pWidget = new QWidget(parent);
QHBoxLayout* hLayout = new QHBoxLayout(pWidget);
pWidget->setLayout(hLayout);
//add two combo boxes to the layout
QComboBox* comboEditor = new QComboBox(pWidget);
QComboBox* comboEditor2 = new QComboBox(pWidget);
//now add both editors to this
hLayout->addWidget(comboEditor);
hLayout->addWidget(comboEditor2);
return pWidget;
}
Now this displays just fine but when I edit it and click elsewhere it doesn't stop editing. Can anyone offer any pointers?
Edit: So i need to call CommitData() and closeEditor() at some point. Can anyone offer pointers on where to call these?
Thanks.
You can keep the editor widget as a member of class and emit commitData when the current index of one of the comboboxes has changed. So you can connect currentIndexChanged(int) to a slot and emit commitData from there:
QWidget *UserDefinedUnitsDelegate::createEditor(QWidget *parent,const QStyleOptionViewItem & option ,const QModelIndex & index ) const
{
//set up a simple widget with a layout
pWidget = new QWidget(parent);
QHBoxLayout* hLayout = new QHBoxLayout(pWidget);
pWidget->setLayout(hLayout);
//add two combo boxes to the layout
QComboBox* comboEditor = new QComboBox(pWidget);
QComboBox* comboEditor2 = new QComboBox(pWidget);
connect(comboEditor,SIGNAL(currentIndexChanged(int)),this,SLOT(setData(int)));
connect(comboEditor2,SIGNAL(currentIndexChanged(int)),this,SLOT(setData(int)));
//now add both editors to this
hLayout->addWidget(comboEditor);
hLayout->addWidget(comboEditor2);
return pWidget;
}
void UserDefinedUnitsDelegate::setData(int val)
{
emit commitData(pWidget);
}
In QtCreater I added a table to my project. in my code I am generating some data to output into the table. I want to add a QCheckbox into each row to allow the row to be selected. All the content of the table is aligned left, how do I make only these checkboxes in the first column of every row align to the center?
I'm adding the QCheckbox using:
ui->data_table->setCellWidget(rowCount,0, new QCheckBox);
Two thumbs up for Barry Mavin! You don't even have to subclass.
one line...
pCheckBox->setStyleSheet("margin-left:50%; margin-right:50%;");
done!!
I usually use a layout and a container widget for this. It is an ugly solution, but it works:
QWidget * w = new QWidget();
QHBoxLayout *l = new QHBoxLayout();
l->setAlignment( Qt::AlignCenter );
l->addWidget( <add your checkbox here> );
w->setLayout( l );
ui->data_table->setCellWidget(rowCount,0, w);
So basically you will have:
Table Cell -> Widget -> Layout -> Checkbox
you'll have to consider it if you will need to access the checkbox through the table.
This is an old post but in fact there is a much easier and lighter way of achieving this, just subclass QCheckBox and set the stylesheet to
margin-left:50%;
margin-right:50%;
It works for me, but my checkbox is not completely displayed.
To have a complete view of the widget, remove margins in layout :
l->setContentsMargins(0,0,0,0);
As stated in similar question around Stack Overflow, it's currently an open BUG:
https://bugreports.qt-project.org/browse/QTBUG-5368
can be center like this too using layout if want to add more customization
// Create a widget that will contain a checkbox
QWidget *checkBoxWidget = new QWidget();
QCheckBox *checkBox = new QCheckBox(); // We declare and initialize the checkbox
QHBoxLayout *layoutCheckBox = new QHBoxLayout(checkBoxWidget); // create a layer with reference to the widget
layoutCheckBox->addWidget(checkBox); // Set the checkbox in the layer
layoutCheckBox->setAlignment(Qt::AlignCenter); // Center the checkbox
layoutCheckBox->setContentsMargins(0,0,0,0); // Set the zero padding
ui->my_table_view->setCellWidget(row_number,column_number, checkBoxWidget); // set cell widget
OR simply add left right margins
checkBox->setStyleSheet("margin-left:50%; margin-right:50%;");
#if QT_VERSION < 0x046000
#include <QCommonStyle>
class MyStyle : public QCommonStyle {
public:
QRect subElementRect(SubElement subElement, const QStyleOption *option, const QWidget *widget = 0) const {
switch(subElement) {
case QStyle::SE_CheckBoxIndicator: {
QRect r = QCommonStyle::subElementRect(subElement, option, widget);
r.setRect( (widget->width() - r.width())/2, r.top(), r.width(), r.height());
return QRect(r);
}
default: return QCommonStyle::subElementRect(subElement, option, widget);
}
}
};
#else
#include <QProxyStyle>
#include <QStyleFactory>
class MyStyle: public QProxyStyle {
public:
MyStyle():QProxyStyle(QStyleFactory::create("Fusion")) {}
QRect subElementRect(SubElement subElement, const QStyleOption *option, const QWidget *widget = 0) const {
switch(subElement) {
case QStyle::SE_CheckBoxIndicator: {
QRect r = QProxyStyle::subElementRect(subElement, option, widget);
r.setRect( (widget->width() - r.width())/2, r.top(), r.width(), r.height());
return QRect(r);
}
default: return QProxyStyle::subElementRect(subElement, option, widget);
}
}
};
#endif
QCheckBox *box = new QCheckBox();
box->setStyle(new MyStyle());
I have a QPushButton and on that I have a text and and icon. I want to make the text on the button to be bold and red. Looked at other forums, googled and lost my hope. Seems there is no way to do that if the button has an icon (of course if you don't create a new icon which is text+former icon). Is that the only way? Anyone has a better idea?
You really don't need to subclass to change the formatting of your button, rather use stylesheets e.g.
QPushButton {
font-size: 18pt;
font-weight: bold;
color: #ff0000;
}
Applying this to the button that you want to change will make the buttons text 18pt, bold and red. You can apply via widget->setStyleSheet()
Applying this to a widget in the hierarchy above will style all the buttons underneath, the QT stylesheet mechanism is very flexible and fairly well documented.
You can set stylesheets in the designer too, this will style the widget that you are editing immediately
you make the subclass of "QPushbutton", then override the paint event,
there you modify the text to your wish.
here it is,
class button : public QPushButton
{
Q_OBJECT
public:
button(QWidget *parent = 0)
{
}
~button()
{
}
void paintEvent(QPaintEvent *p2)
{
QPushButton::paintEvent(p2);
QPainter paint(this);
paint.save();
QFont sub(QApplication::font());
sub.setPointSize(sub.pointSize() + 7);
paint.setFont(sub);
paint.drawText(QPoint(300,300),"Hi");
paint.restore();
}
};
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
button b1;
b1.showMaximized();
return a.exec();
}
Note:My answer is inspired by the idea from #Петър Петров and the comment from #mjwach.
You can subclass QPushButton and give it two private fields:
self.__lbl: A QLabel() instance to hold the rich text. Its background is made transparent and it doesn't catch mouse events.
self.__lyt: A QHBoxLayout() to hold the label. The layout margins are set to zero, such that the label's borders touch the button's borders. In other words: we ensure that the label has the exact same size as the button, and is positioned right on top of it.
Finally you have to override the setText() method, such that the text ends up in the label instead of the button.
class RichTextPushButton(QPushButton):
def __init__(self, parent=None, text=None):
if parent is not None:
super().__init__(parent)
else:
super().__init__()
self.__lbl = QLabel(self)
if text is not None:
self.__lbl.setText(text)
self.__lyt = QHBoxLayout()
self.__lyt.setContentsMargins(0, 0, 0, 0)
self.__lyt.setSpacing(0)
self.setLayout(self.__lyt)
self.__lbl.setAttribute(Qt.WA_TranslucentBackground)
self.__lbl.setAttribute(Qt.WA_TransparentForMouseEvents)
self.__lbl.setSizePolicy(
QSizePolicy.Expanding,
QSizePolicy.Expanding,
)
self.__lbl.setTextFormat(Qt.RichText)
self.__lyt.addWidget(self.__lbl)
return
def setText(self, text):
self.__lbl.setText(text)
self.updateGeometry()
return
def sizeHint(self):
s = QPushButton.sizeHint(self)
w = self.__lbl.sizeHint()
s.setWidth(w.width())
s.setHeight(w.height())
return s
You can subclass a QLabel and completely throw away all of its mouse events (so they reach the parent).
Then crate a QPushButton, set a layout on it and in this layout insert a QLabel with formatted text. You get a button that contains QLabel and is clickable. (Any Qt Widget can have layout set, including ones that you never ever expected they can.)