I need to achieve below requirements in WinUI 3 Desktop applications.
How to get screen bounds?
How to change windows cursor type in runtime?
I already did this in WinUI UWP applications.
For Screen bounds,
var visibleBounds = Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().VisibleBounds;
var scaleFactor = Windows.Graphics.Display.DisplayInformation.GetForCurrentView().RawPixelsPerViewPixel;
Size screenSize = new Size((visibleBounds.Width * scaleFactor), (visibleBounds.Height * scaleFactor));
For Cursor:
Window.Current.CoreWindow.PointerCursor = new CoreCursor(CoreCursorType.SizeNorthwestSoutheast, 0);
Anyone please suggest how to achieve same requirement in WinUI Desktop applications?
I've added the following to App.xaml.cs:
private static MainWindow m_window;
public static MainWindow MainWindow { get { return m_window; } }
protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs e)
{
m_window = new MainWindow();
m_window.Activate();
}
And when I need bounds anywhere, I can use MainWindow.Bounds.
Regarding cursor, you need ProtectedCursor
this.ProtectedCursor = InputSystemCursor.Create(InputSystemCursorShape.Arrow);
Only thing it is protected, so you need to use it from right class.
Related
I'm trying to get my QMainWindow to allow only tabbed QDockWidgets. If I understood the Qt Documentation right it should work with the setDockOptions-method.
The following code didn't work for me:
QMainWindow window;
window.setDockOptions(QMainWindow::ForceTabbedDocks);
What am I doing wrong? Or is it a bug in the current Qt version? I'm coding on a MacPro an I'm using Qt 5.7.
thanks
ForceTabbedDocks only applies to user interactions with the docks.
To programatically add new docks in tabs, you need to use QMainWindow::tabifyDockWidgets. For example,
void MainWindow::addTabbedDock(Qt::DockWidgetArea area, QDockWidget *widget)
{
QList<QDockWidget*> allDockWidgets = findChildren<QDockWidget*>();
QVector<QDockWidget*> areaDockWidgets;
for(QDockWidget *w : allDockWidgets) {
if(dockWidgetArea(w) == area) {
areaDockWidgets.append(w);
}
}
if(areaDockWidgets.empty()) {
// no other widgets
addDockWidget(area, widget);
} else {
tabifyDockWidget(areaDockWidgets.last(), widget);
}
}
This is the same answer as #Xian Nox, but adapted for python:
def addTabbedDock(self, area: QtCore.Qt.DockWidgetArea, dockwidget: QtWidgets.QDockWidget):
curAreaWidgets = [d for d in self.findChildren(QtWidgets.QDockWidget)
if self.dockWidgetArea(d) == area]
try:
self.tabifyDockWidget(curAreaWidgets[-1], dockwidget)
except IndexError:
# First dock in area
self.addDockWidget(area, dockwidget)
I have a delete button(QPushButton) in the last column of each row of my table view. I am creating these push buttons and directly setting them in view. Since I have allocated memory dynamically I wish to free this memory but I haven't stored pointers of these buttons anywhere so I am trying to obtain the widget at the time of clean up and deleting them.
SDelegate* myDelegate;
myDelegate = new SDelegate();
STableModel* model = new STableModel(1, 7, this);
myWindow->tableView->setModel(model);
myWindow->tableView->setItemDelegate(myDelegate);
for(int i = 0; i < no_of_rows; ++i) {
QPushButton* deleteButton = new QPushButton();
myWindow->tableView->setIndexWidget(model->index(i, 6), deleteButton);
}
exec();
// Cleanup
for(int i = 0; i < no_of_rows; ++i) {
// code works fine on removing this particular section
QWidget* widget = myWindow->tableView->indexWidget(model->index(i, 6));
if (widget)
delete widget;
}
delete model;
delete myDelegate;
I am getting a crash in qt5cored.dll (Unhandled exception) and application is crashing in qcoreapplication.h at the following code:
#ifndef QT_NO_QOBJECT
inline bool QCoreApplication::sendEvent(QObject *receiver, QEvent *event)
{ if (event) event->spont = false; return self ? self->notifyInternal(receiver, event) : false; }
While debugging there is no issue in deleting these widgets but code crashes afterwards at some other point. I am using QTableView and custom class for model which has inherited QAbstractTableModel.
There's a Qt bug that manifests as follow: if there are any index widgets, and you invoke setModel(nullptr) on the view, it'll crash in an assertion on visualRow != -1 in qtableview.cpp:1625 (in Qt 5.6.0). Presumably this bug could be triggered when the model is being removed in some other fashion too.
But I can't reproduce it by merely destroying the model instance. So I doubt that it's relevant here unless you get the same assertion failure.
Given the style of your code, it's more likely that you have a memory bug elsewhere. If you think that the code above is crashing, you should have a self-contained test case that demonstrates the crash. Is your model or delegate to blame? Would it crash using no delegate? Would it crash using a stock model?
Your code excerpt seems to be fine, if mostly unnecessary. You could allocate the delegate and the model locally. The buttons are owned by the view: as soon as the need for the buttons goes away, such as when the model changes the row count or goes away, they will get appropriately deleted. So you don't have to delete them yourself, it's safe but completely unnecessary.
Here's an example that demonstrates that in all cases, the buttons will get disposed when the model gets destroyed or the view gets destroyed, whichever comes first. Tracking object lifetime is super simple in Qt: keep a set of objects, and remove them from the set using a functor attached to the object's destroyed signal. In Qt 4 you'd use a helper class with a slot.
// https://github.com/KubaO/stackoverflown/tree/master/questions/model-indexwidget-del-38796375
#include <QtWidgets>
int main(int argc, char ** argv) {
QApplication app{argc, argv};
QSet<QObject*> live;
{
QDialog dialog;
QVBoxLayout layout{&dialog};
QTableView view;
QPushButton clear{"Clear"};
layout.addWidget(&view);
layout.addWidget(&clear);
QScopedPointer<QStringListModel> model{new QStringListModel{&dialog}};
model->setStringList(QStringList{"a", "b", "c"});
view.setModel(model.data());
for (int i = 0; i < model->rowCount(); ++i) {
auto deleteButton = new QPushButton;
view.setIndexWidget(model->index(i), deleteButton);
live.insert(deleteButton);
QObject::connect(deleteButton, &QObject::destroyed, [&](QObject* obj) {
live.remove(obj); });
}
QObject::connect(&clear, &QPushButton::clicked, [&]{ model.reset(); });
dialog.exec();
Q_ASSERT(model || live.isEmpty());
}
Q_ASSERT(live.isEmpty());
}
Check out QObject::deleteLater() , it usually helps with issues around deleting QObjects / QWidgets.
So the non-QMdiArea version of my code,
MyWidget::MyWidget(QWidget* parent)
{
...
layout()->setSizeConstraint( QLayout::SetFixedSize );
}
MainWindow::MainWindow(...)
{
...
MyWidget* wgt = new MyWidget(NULL);
wgt->show();
}
works just fine and produces a widget that the user can't resize. But when the MainWindow code is replaced with
MainWindow::MainWindow(...)
{
...
MyWidget* wgt = new MyWidget(ui->mdiArea); //Or MyWidget(NULL), same result
ui->mdiArea->addSubWindow(wgt);
}
the window, now within the QMdiArea, is resizeable. It doesn't seem to be an issue of Qt::WindowFlags, they don't handle resize policy. Surely there is a way to do this? NB I cant use something like setFixedSize(ht, wd) since the size of the widget can change programmatically (subwidgets are added and removed). But the user should not be able to resize it.
Even though MyWidget is not resizeable, when you call:
ui->mdiArea->addSubWindow(wgt);
The widget is put in a QMdiSubWindow which is resizeable. All you have to do is get the window that's created and fix its size:
QMdiSubWindow* subWindow = ui->mdiArea->addSubWindow(wgt);
subWindow->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
This should work, but I haven't tried this code myself.
EDIT: well... apparently that doesn't fix the size. :(
The following worked for me:
MyWidget* wgt = new MyWidget(ui->mdiArea);
QMdiSubWindow* subWindow = ui->mdiArea->addSubWindow(wgt);
subWindow->setFixedSize(wgt->size());
wgt->show();
I face a very serious situation. By writing this question I hope that really professionals will express their opinion regarding to the problem I am going to describe. I have reported a bug in https://bugreports.qt.io/ :
I have created QPropertyAnimation for maximumWidth property of QTextEdit and it does not work (it immediately changes state from starting state to the end state), though it works for minimumWidth property.
Please see the attached code.
And have attached .h and .cpp files. See those files here (files are named new.h and new.cpp).
And I got the follwing response:
MaximumWidth is not the property you want to animate. It holds the maximum width that the widget can have, it's related to layouting and so on. Changing the maximumWidth (as well as the minimumWidth) does not necessarily trigger a relayout and repaint. You should animate the size.
Please explain me whether it is a bug or no? Please tell me how the minimumWith property is being animated but when it concerns to the maximumWidth property, then I should not work and that is OK? I just don't get their point... Please explain.
P.S. I have written this code because I wanted to close by animation the right QTextEdit and be sure that when I resize the main window, where the button and two QTextEdit are, the closed QTextEdit does not being restored.
Did you check the actual value of maximumWidth? You don't seem to set a specific maximumWidth in your code.
The default value for maximumWidth is 16777215, and you set a duration of 1 msec. for the closing animation. Fading from 16777215 to 3 in 1 msec. would look like "instant", I guess.
I don't think it is a bug; I'd call it "undefined behavior". That means that if you try to animate minimumWidth, nobody can tell you for sure what is supposed to happen, and maybe the code has some optimizations or corner cases where sometimes it works, others it doesn't.
Anyway, minimumWidth and maximumWidth aren't supposed to be used to define what the size of a QWidget is, only what it must not exceed; i.e. they weren't designed to do what you are trying to do, so it can be called a bug. If you want to animate, you have to use a deterministic approach, which in this case is using the geometry property.
This is not a bug, the response you got from the bug report pretty well explains the problem with your code and a solution.
Dear Sofahamster I have changed my code to the code below and it works fine. Thanks for your hint!
Header file
class MyWidget : public QWidget
{
Q_OBJECT
QTextEdit *m_textEditor1;
QTextEdit *m_textEditor2;
QPushButton *m_pushButton;
QHBoxLayout *m_layout;
QVBoxLayout *m_buttonLayout;
int m_deltaX;
bool m_isClosed;
public:
MyWidget(QWidget * parent = 0);
~MyWidget(){}
void resizeEvent( QResizeEvent * event );
private slots:
void closeOrOpenTextEdit2(bool isClosing);
};
Source file
MyWidget::MyWidget(QWidget * parent):QWidget(parent),m_deltaX(0)
{
m_pushButton = new QPushButton(this);
m_pushButton->setText(">");
m_pushButton->setCheckable(true);
m_pushButton->setFixedSize(16,16);
connect(m_pushButton, SIGNAL(clicked(bool)), this, SLOT(closeOrOpenTextEdit2(bool)));
m_textEditor1 = new QTextEdit(this);
m_textEditor1->setText("AAAAA AAAAAAAAAAA AAAAAAAAAAA AAAAAAA AAAAAAAAAAA AAAAAAAAAAA AA");
m_textEditor2 = new QTextEdit(this);
m_buttonLayout = new QVBoxLayout();
m_buttonLayout->addWidget(m_pushButton);
m_buttonLayout->addItem( new QSpacerItem(1, 1, QSizePolicy::Minimum, QSizePolicy::Expanding) );
m_layout = new QHBoxLayout;
m_layout->addWidget(m_textEditor1, 10);
m_layout->addSpacing(15);
m_layout->addLayout(m_buttonLayout);
m_layout->setSpacing(0);
m_layout->addWidget(m_textEditor2, 4);
setLayout(m_layout);
resize(800,500);
}
void MyWidget::closeOrOpenTextEdit2(bool isClosing)
{
m_isClosed = isClosing;
QPropertyAnimation *animation1 = new QPropertyAnimation(m_textEditor2, "maximumWidth");
if(isClosing) //close the second textEdit
{
m_textEditor2->setMaximumWidth(m_textEditor2->width());
int textEdit2_start = m_textEditor2->maximumWidth();
m_deltaX = textEdit2_start;
int textEdit2_end = 3;
animation1->setDuration(500);
animation1->setStartValue(textEdit2_start);
animation1->setEndValue(textEdit2_end);
m_pushButton->setText("<");
}
else //open
{
int textEdit2_start = m_textEditor2->maximumWidth();
int textEdit2_end = m_deltaX;
animation1->setDuration(500);
animation1->setStartValue(textEdit2_start);
animation1->setEndValue(textEdit2_end);
m_pushButton->setText(">");
}
animation1->start();
}
void MyWidget::resizeEvent( QResizeEvent * event )
{
if(!m_isClosed)
m_textEditor2->setMaximumWidth( QWIDGETSIZE_MAX );
}
when I am programming with "gtkmm", there is a widget "Gtk::DrawingArea".
I can program that widget "by hand" (so write the code) or more elegant way is to use "glade" user interface designer, where I can do the same "graphically".
Now I am trying to connect OpenGL with gtkmm through "gtkglextmm" library. In that library, there is a widget "Gtk::GL::DrawingArea" - but this widget "IS NOT" available in glade.
So is there any way to program with "OpenGL + gtkglextmm" using "glade" (for the "graphical user interface" part)?
Thanks.
First of all libglade is an old library. If you are writing new project start with gtk builder.
As you can see here gtkmm provide easy way to create your own widgets and see them (almost) in glade tool. You simply insert plain DrawinArea widget to window and then tell gtk-builder to put in this place yours derived class.
Here is all together:
Setting up gtk-builder:
refBuilder = Gtk::Builder::create_from_file(ui_file);
GlDrawingArea*glArea = NULL;
refBuilder->get_widget_derived("drawing_gl",glArea);
Opengl DrawingArea class:
class GlDrawingArea : public Gtk::DrawingArea ,
public Gtk::GL::Widget<GlDrawingArea>
{
public:
GlDrawingArea(BaseObjectType* cobject, const Glib::RefPtr<Gtk::Builder>& builder);
virtual ~GlDrawingArea();
protected:
void on_realize();
bool on_expose_event(GdkEventExpose* event);
bool on_configure_event(GdkEventConfigure* event);
private:
Glib::RefPtr<Gtk::Builder> refBuilder;
};
Constructing opengl drawingarea:
// GlDrawingArea:
GlDrawingArea::GlDrawingArea(BaseObjectType*cobject, const Glib::RefPtr<Gtk::Builder>& builder)
: Gtk::DrawingArea(cobject),
refBuilder(builder),
screen_tex(0)
{
//
// Configure OpenGL-capable visual.
//
Glib::RefPtr<Gdk::GL::Config> glconfig;
// Try double-buffered visual
glconfig = Gdk::GL::Config::create(Gdk::GL::MODE_RGB |
Gdk::GL::MODE_DEPTH |
Gdk::GL::MODE_DOUBLE);
if (!glconfig) {
std::cerr << "*** Cannot find the double-buffered visual.\n"
<< "*** Trying single-buffered visual.\n";
// Try single-buffered visual
glconfig = Gdk::GL::Config::create(Gdk::GL::MODE_RGB |Gdk::GL::MODE_DEPTH);
if (!glconfig) {
std::cerr << "*** Cannot find any OpenGL-capable visual.\n";
std::exit(1);
}
}
// print frame buffer attributes.
GLConfigUtil::examine_gl_attrib(glconfig);
//
// Set OpenGL-capability to the widget.
//
set_gl_capability(glconfig);
}