So I'm using QTCreator to create a GUI for a project. I'm reading items from a file, and then those items are imported into a ListWidget with checkboxes next to each item. I was wondering if it's possible to have the checkbox along with a spin box or some other sort of numeric attribute tied to each item, and if so could you explain how?
Edit: If anyone know hows to add any of the editable text boxes instead that'd actually work even better.
This is what I'm currently doing to open/read the file:
QFile ingFile("/root/Desktop/file.txt");
ingFile.open(QIODevice::ReadOnly);
QTextStream in(&ingFile);
QStringList inglist;
QString line = in.readLine();
while(!line.isNull()){
inglist.append(line);
line = in.readLine();
}
QStringListIterator it(inglist);
while(it.hasNext()){
QListWidgetItem *listitem = new QListWidgetItem(it.next());
listitem->setCheckState(Qt::Unchecked);
ui->ingList->addItem(listitem);
}
Thanks!
Related
QPushButton can have icon, but I need to set animated icon to it. How to do this?
I created new class implemented from QPushButton but how to replace icon from QIcon to QMovie?
This can be accomplished without subclassing QPushButton by simply using the signal / slot mechanism of Qt. Connect the frameChanged signal of QMovie to a custom slot in the class that contains this QPushButton. This function will apply the current frame of the QMovie as the icon of the QPushButton. It should look something like this:
// member function that catches the frameChanged signal of the QMovie
void MyWidget::setButtonIcon(int frame)
{
myPushButton->setIcon(QIcon(myMovie->currentPixmap()));
}
And when allocating your QMovie and QPushButton members ...
myPushButton = new QPushButton();
myMovie = new QMovie("someAnimation.gif");
connect(myMovie,SIGNAL(frameChanged(int)),this,SLOT(setButtonIcon(int)));
// if movie doesn't loop forever, force it to.
if (myMovie->loopCount() != -1)
connect(myMovie,SIGNAL(finished()),myMovie,SLOT(start()));
myMovie->start();
Since I had to solve this problem for a project of mine today, I just wanted to drop the solution I found for future people, because this question has lots of views and I considered the solution quite elegant. The solution was posted here. It sets the icon of the pushButton every time, the frame of the QMovie changes:
auto movie = new QMovie(this);
movie->setFileName(":/sample.gif");
connect(movie, &QMovie::frameChanged, [=]{
pushButton->setIcon(movie->currentPixmap());
});
movie->start();
This also has the advantage, that the icon will not appear, until the QMovie was started. Here is also the python solution, I derived for my project:
#'hide' the icon on the pushButton
pushButton.setIcon(QIcon())
animated_spinner = QtGui.QMovie(":/icons/images/loader.gif")
animated_spinner.frameChanged.connect(updateSpinnerAniamation)
def updateSpinnerAniamation(self):
#'hide' the text of the button
pushButton.setText("")
pushButton.setIcon(QtGui.QIcon(animated_spinner.currentPixmap()))
Once you want to show the spinner, just start the QMovie:
animated_spinner.start()
If the spinner should disappear again, then stop the animation and 'hide' the spinner again. Once the animation is stopped, the frameChanged slot won't update the button anymore.
animated_spinner.stop()
pushButton.setIcon(QtGui.QIcon())
I wanted to know whether is there any way of fixing child layouts within a parent layout. For example...
QVBoxLayout *vbox = new QVBoxLayout;
// adding pushbuttons/layouts...
vbox->addWidget(one);
vbox->addWidget(two);
vbox->addWidget(three);
vbox->addWidget(four);
Now this ends up as four buttons/layouts in a vertical layout in the sequence that they are added. But if I remove buttons/layouts "one", "two" and "three"...
vbox->removeWidget(one);
vbox->removeWidget(two);
vbox->removeWidget(three);
After doing this, the pushbutton "four" will move up the layout as you remove widgets on top of "four". I don't want this to happen.
Is there any way that even if I remove the widget/layout on top, I need that last widget/layout to stay where it is currently.
How do I achieve this ?
UPDATE: Well I was experimenting and I was kind of able to achieve what I wanted using QGridLayout. Here is the code, but I am using QGridLayout instead of QVBoxLayout.
connect(one,SIGNAL(clicked()),this,SLOT(remove_btns()));
g = new QGridLayout(this);
g->addWidget(one,0,0,1,2);
g->addWidget(two,1,0,1,2);
g->addWidget(three,2,0,1,2);
g->addWidget(four,3,0,1,2,Qt::AlignBottom);
setLayout(g);
If I delete the above three buttons, the fourth one stays where it is, because of QT::AlignBottom , it does not work without that thing.
Here is the SLOT remove_btns()
void test::remove_btns()
{
g->removeWidget(one);
g->removeWidget(two);
g->removeWidget(three);
delete one;
delete two;
delete three;
}
When I click "one", top three buttons vanish, and the fourth one stays where it is. But it does not work if I don't give the QT::AlignBottom . Also, these alignment things are a mystery to me, I am unable to find how exactly they work.
This is definitely NOT an answer..., because I don't understand how it worked :P
If you are immediately replacing the widgets you removed, you can always insert your new widgets by index.
void insertWidget ( int index, QWidget * widget, int stretch = 0, Qt::Alignment alignment = 0 )
Yes, just hide the widgets instead of removing them:
one->hide();
two->hide();
three->hide();
If you really have to remove the widgets, perhaps you can replace them with some lightweight widget like a QLabel with no text.
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)
I want to draw a QComboBox inside a delegate, which works fine except that I can't figure out how to draw the inital text that's visible inside the combo box.
The documentation says that QStyleOptionComboBox.currentText holds: "the text for the current item of the combo box." but setting the variable does not have any effect.
This is my code:
void MyDelegate::paint(QPainter *painter,
const QStyleOptionViewItem& option,
const QModelIndex& index) const
{
QStyleOptionComboBox comboBoxOption;
comboBoxOption.rect = option.rect;
comboBoxOption.state = option.state;
comboBoxOption.state |= QStyle::State_Enabled;
comboBoxOption.editable = false;
comboBoxOption.currentText = "CCC"; // This doesn't show up.
QApplication::style()->drawComplexControl(QStyle::CC_ComboBox, &comboBoxOption, painter);
}
Looking at qwindowsxpstyle.cpp I don't see where the text of a "real" combo box is drawn since currentText is not used inside the drawComplexControl method. The only place where it seems to be used for Windows XP style is in qcommonstyle.cpp (Line 2107, Qt 4.7.2), but I can't figure out how those two classes play together.
It seems you also need to force Qt to draw the combo box label, in addition to the complex control. Try this:
QApplication::style()->drawControl(QStyle::CE_ComboBoxLabel, &comboBoxOption, painter)
If I read the documentation, and source, correctly that might force QStyle to draw a combo box label. It seems odd that you'd have to specify both...but I don't know a whole lot about how Qt styles draw themselves, to be honest.
i'm new to pyqt , and i'm still facing some newbie problems :D
i have a QTableWidget that is item delegated on a QChoice control ( hope i said it right )
i need to have the cell background color changes whenever a user change the choice control selection
briefly: how to change a cell background color in a table widget ??
i use pyqt4 and python 2.6
thanx in advance
I used something like this:
brush = QtGui.QBrush(QtGui.QColor(255, 0, 0))
brush.setStyle(QtCore.Qt.SolidPattern)
item.setBackground(brush)
Where item is QTableWidgetItem object
Use
QTableWidgetItem QTableWidget.item(row, column)
and
QTableWidgetItem setData(role, data)
with
Qt.BackgroundRole
as follows:
table.item(0, 0).setData(Qt.BackgroundRole, color).
And read about the Roles mechanism used in Qt Model/View.
if you use QTableView use this:
model.setData(model.index(0, 0), QVariant(QBrush(Qt::red)), Qt::BackgroundRole);
Here are some useful lines of code. Sorry for redundancy, I'm trying to gain some reputation.
QStandardItemModel* model = new QStandardItemModel(numRows, numColumns);
QStringList headers;
headers.append("Date");
model->setHorizontalHeaderLabels(headers);
QStandardItem* item = new QStandardItem(text);
item->setData(Qt::AlignCenter, Qt::TextAlignmentRole);
item->setData(QVariant(QBrush(Qt::green)), Qt::BackgroundRole);
model->setItem(row, column, item);
or simply:
item->setBackground(Qt::green);
Hey, you set the delegate method for the table widget. in the paint event of the delegate you handle the color changing technique..
have a look at this example,here they have done custom selection color. same way you handle the item cell painting
For supplement in C++ way, if you want to paint custom color unlike Qt::red and so on, you can do something like :
ui->tableWidget->item(i, j)->setBackground(QColor(152,234,112));