I have MainWindow form which has Widget inside. And I have another Widget class (promoted to MainWindow) which has only DockWidget inside. In MainWindow I am opening new one and placing into Widget. However when I close DockWidget from close(cross"X") button. Inside my MainWindow it is not cleaning..
Sorry for my bad english better to paste my code here:
qDebug() << ui->widget->layout()->count();
QueryWidget *lQueryWidget = new QueryWidget(this);
ui->widget->layout()->addWidget(lQueryWidget);
So in everytime although I close DockWindow(lQueryWidget), layout()->count() never decrease. I tried to delete everything inside layout like ;
QList<QObject*> child = ui->widget->layout()->children();
foreach (QObject *var, child)
{
delete var;
}
But it never enters foreach loop.. If you check image below you will see that there is something above DockWidget, but it is not visible.. Could you please help me how can I solve this issue ?
To make dockable widget you should use
QDockWidget::setWidget(QWidget * widget)
The widget will be deleted when the dock widget is deleted.
You should not manipulate the dock widget layout.
Related
I searched everywhere and found nothing that solved this. I make a QVBoxLayout and then make a web call for data. When the data comes back I add 4 custom widgets to this QVBoxLayout
verticalLayout->addWidget(nsd);
For the first four this works great. Everything appears as needed. However, I want to delete any one of the four widgets then add a widget at the bottom. Deleting works fine
verticalLayout->removeWidget(nsd);
delete nsd;
I know it works fine because then that widget not longer draws to my screen. The problem is that adding the widget is not working entirely. I call the same code
verticalLayout->addWidget(nsd);
and checking verticalLayout->count() tells me there are 4 items. The widget is created with the same parent widget as the ones added before. The paint event of the new widget never gets called. Furthermore the 3 that show on the screen show spaced for 3 items. It's not like there's a hole anywhere. I also tried adding then deleting but it's the same problem. The new item never gets drawn and its size never factored in.
If you want to get rid of a widget completely, you only need to destruct it. You don't have to worry if it was in a layout. If the widget is dynamically allocated, then delete nsd is all you need, the layout->removeWidget call is not needed. You also don't have to give widgets any explicit parents - insertion into the layout will set proper parent.
The following works and is safe no matter what is the type of the widget being added/removed. If the deletion had target widget on the call stack, you should use deleteLater instead of plain delete. But this can never be the case when you delete it in response to a signal from an unrelated widget, unless the target widget re-enters the event loop (aargh! it shouldn't).
// https://github.com/KubaO/stackoverflown/tree/master/questions/layout-addremove-37814292
#include <QtWidgets>
int main(int argc, char ** argv) {
QApplication app(argc, argv);
QWidget widget;
QVBoxLayout layout(&widget);
QPushButton button;
QLabel label("Hello");
layout.addWidget(&button);
layout.addWidget(&label);
auto onClick = [&]{
if (layout.count() == 3) {
delete layout.itemAt(2)->widget();
button.setText("Add");
} else {
layout.addWidget(new QLabel("Hello too!"));
button.setText("Remove");
}
};
QObject::connect(&button, &QPushButton::clicked, onClick);
onClick();
widget.show();
return app.exec();
}
Well, the thing is I have a tabwidget created in qtcreator, with many tabs and in the tabs there are many lineedit and other objects.
The closeable property of the tabWidget is set to true.
I execute the program and close the tabs, but when I want to reopen the tab, it's empty, I'm using this code:
tabs->addTab(new QWidget(),"TAB 1");
I want to use the same tab create on the design of qtcreator.
Your problem is that you are adding empty widget in your code:
tabs->addTab(new QWidget(),"TAB 1");
Instead you need to keep you widgets and add them like that:
QWidget* widget; // it is stored
int index = ui->tabWidget->addTab(widget, "TAB 1");
Where to take these widgets?
It is not enough to set closable to true, you also to use signal/slot:
connect(ui->tabWidget, SIGNAL(tabCloseRequested(int)), this, SLOT(closeTab(int)));
And finally:
void YourWindow::closeTab(int index)
{
// do something else
QWidget* widget = ui->tabWidget->widget(index);
ui->tabWidget->removeTab(index);
// here you can remember it and use later when adding tab
}
I want to have a line edit field in a popup menu I've got. I'm basically letting the user pick from one of several common sizes for something, but I want them to be able to enter a custom size as the last entry in the menu.
So I've got something like this (snipped from larger code, new_menu is the menu of interest):
QWidget *widget = new QWidget(new_menu);
QHBoxLayout *layout = new QHBoxLayout;
QLineEdit* le = new QLineEdit;
le->setPlaceholderText("Custom");
le->setFixedWidth(100);
ayout->addWidget(le);
widget->setLayout(layout);
QWidgetAction* wa = new QWidgetAction(new_menu);
wa->setActionGroup(group);
wa->setDefaultWidget(widget);
new_menu->addAction(wa);
connect(le, SIGNAL(returnPressed()), this, SLOT(leslot()));
Which works great, the LineEdit shows up nice and centered in the menu, it's got the placeholder text, I can click it and edit, everything. However, when I hit enter on the textBox, it emits the returnPressed signal and the menu emits a triggered signal with one of the other actions on the list, so at best I'm changing my configuration twice and at worst things break.
Additionally, when I click off the edge of the LineEdit (still in the menu though, but not in the editable area), the menu emits a triggered signal with the QWidgetAction associated with it, which isn't what I want.
So two questions:
1) Can I get the return to work the way I want. It's fine if the menu closes when it's hit, but it can't emit another action too.
2) Can I get it to not emit an action at all when the lineEdit is clicked?
Here's what I ended up doing for anyone that follows. I subclassed QLineEdit thusly:
class EnterLineEdit : public QLineEdit {
Q_OBJECT
public:
void keyPressEvent(QKeyEvent *evt) {
if (evt->key() == Qt::Key_Enter || evt->key() == Qt::Key_Return) {
emit returnPressed();
} else {
QLineEdit::keyPressEvent(evt);
}
}
};
This lets me manually emit the returnPressed signal when enter/return is hit and not pass it up the widget hierarchy, so the menu never sees it when enter is hit over the lineedit. I connected the returnPressed signal to the hide() slot of the menu so that the menu will still close, but without triggering an action.
I want to change a QWidget in a QMainWindow dynamically. Therefore, the old widget (if it exists) will be deleted, a new one will be constructed and added to the main window.
The widget (_visualization) is a QMainWindow itself that contains a menu bar and a widget that shows an OSG scene graph.
If I don´t call show() on the new widget, I will only see the menu bar, but not the scene graph.
My goal is to call show(), when the user clicks on a button. The button is connected with the outer QMainWindow (MyQMainWindow).
Unfortunately, when I call show() on _visualization in the connected method, the scene graph will not be shown. In contrast to that, the scene graph will be shown, if I call it in the constructor method (loadVisualization(...)).
MyQMainWindow::MyQMainWindow(QWidget *parent ) :
QMainWindow(parent) {
...
loadVisualization(...);
connect(_ui->nextButton, SIGNAL(clicked()), this, SLOT(showNext()));
...
}
void MyQMainWindow::loadVisualization(QString filePath) {
if (_visualization) {
_heightWidgetLayout->removeWidget(_visualization);
delete _visualization;
}
_visualization= new HeightVisualization(0, filePath);
_visualization->setParent(_mainWindowWidget);
_heightWidgetLayout->addWidget(_visualization);
//_visualization->show(); // will work here
}
void MyQMainWindow::showNext() {
_visualization->show(); // does not work here!
}
I know that QT will call setVisible(...) on the widget. This method first tests some states in QT (testAttribute(Qt::WA_WState_ExplicitShowHide) && !testAttribute(Qt::WA_WState_Hidden)). If I call show() in showNext(), these tests lead to a return without any change.
Is it a problem with connectors and slots? Is there a possibility to show the widget, when the user clicked on a button?
What I have learned is that it is easy to use stackedWidget.
You can then programmatically change it with this
currentPageIndex = (currentPageIndex + 1) % 3;
ui->stackedWidget->setCurrentIndex(0);
The 3 can be the total pages you have in your stack widget. You can either use currentPageIndex, or you can just create some constants with the page ids like I have done with the 0.
I'm trying to get every widget to scale with change in window size. I have a main window which has a QTabWidget with a QWidget holder for each tab. I then have a custom widget with a seperate .ui file that I set to fill the QWidget space of the tab. The problem is, I can't get the contents of the QWidget to expand, only the tab and QWidget of the main window. Also, I noticed if i change the ui->setupUi( ) argument for the custom widget from "this" to "parent" the problem is fixed, and the custom widget will scale correctly. The only problem with this is none of the buttons work when I do that. The application output reads out "No Slot" found errors for the buttons. What is the correct way to make this connection?
Edit: Example code
MainWindow:: ...
{
//assign customWidget to widget placeholder on tabWidget.
//holder is just a blank widget set in gridLayout on tab widget.
CustomWidget * customWidget = new CustomWidget(ui->customWidgetHolder);
setCentralWidget(ui->tabWidget);
//This gets the sizing I want with the tabs, but
//doesn't pass it past the customWidgetHolder.
}
From what I undertand, you need to use a layout, for your custom widget inside your tab
QTabWidget* tabWidget = new QTabWidget();
QWidget* tab = new QWidget();
QVBoxLayout* verticalLayout = new QVBoxLayout(tab);
YourWidget* widget = new YourWidget(tab);
verticalLayout->addWidget(widget);
tabWidget->addTab(tab, QString());
But you'll need to be more specific (code sample ?) about the SIGNAL/SLOT connection you've made if you want answer about it.