In order to create a QComboBox that can filter its values list when typing in it, I attached a slot to the QComboBox's editTextChanged-event, to open its list view popup when the user starts typing. This is done like so:
void SearchableComboBox::slotEditing(QString in_text)
{
this->showPopup();
}
Unfortunately, this immediatly steals the focus from the QLineEdit and I can't type anymore.
Calling lineEdit()->setFocus() makes no difference, and I don't want to grabKeyboard() since this creates a whole other world of pain.
Any recommendations?
This isn't really a combobox then, more of a completion listview for a lineedit. I implemented exactly that in ruqola (KDE client for rocket chat), you can see the source code at https://lxr.kde.org/source/network/ruqola/src/widgets/common/completionlistview.cpp. Notice the little dance with the focus proxy thing:
setFocusPolicy(Qt::NoFocus);
textWidget->setFocusPolicy(origPolicy);
setFocusProxy(textWidget);
and the long method slotCompletionAvailable() for positioning the completion popup at the right place...
Use the Focus Proxy method for this purpose. See https://doc.qt.io/qt-5/qwidget.html#setFocusProxy
With this the pop-up would relay its inputs to the lineedit.
In your case you could try something like
this->setFocusProxy( this->lineEdit() );
But maybe you should read how to use a QCompleter. This would provide Autocompletion while typing and is maybe also useful for you.
Related
I have a dialog that initially has several buttons, let's call them Write, View, OK, and Cancel.
The way it should to is to have the dialog upon creation only have those three buttons and nothing more.
When the Write button is cancelled, it's supposed to create a QLineEdit object in the window above the buttons where the user can enter a new string,which when OK is then clicked will be added to an external QStringList.
When View is clicked, LineEdit should go away (if it's up) and a QListView to come up instead to view everything in that list.
The problem is, I know how to use hide() to get objects that are already in the dialog to NOT appear.
but I am having trouble figuring out how to get an object not currently on the table to appear. I'm new to using Qt so it may be something easy I'm just accidentally overlooking (in fact I hope it is).
Could anyone please offer advice? Thanks!
Just create the items normally and then set:
ui->control->setVisible(false);
after you have created the UI (after ui->setupUi(this);) possibly in the constructor (in case you use code generated by Qt Creator).
And when you need them:
ui->control->setVisible(true);
Doc for this:
http://qt-project.org/doc/qt-4.8/qwidget.html#visible-prop
when using a QListView you should also have a QListModel that provides the data to it, if you only have QStrings then a QStringListModel is premade for you to use
to add a row you can do:
int rows = model->rowCount();
model->addRow(rows,1);
QModelIndex index = model->index(rows,0);
model->setData(index, string);
I am writing a simple GUI, in which I have a ComboBoxText. I write a log message when ever the user clicks on the ComboBoxText.
I have tried almost all the button release and popup signals but no results. The only thing which works is signal_changed() but I don't not need that. Please help me, below is my sample code :
myCombo->signal_button_release_event().connect(sigc::mem_fun(this,&ComboBoxText::ComboInput),false);
and here is the call back function:
bool ComboBoxText::ComboInput(GdkEventButton *pEvt) {
// Here do the desired stuffs !!
return false; }
Use GTK+ property popup-shown. Not sure about Gtkmm syntax, probably property_popup_shown().get_value().
If you need a signal to listen to, connect to popdown or notify::popup-shown (the latter is invoked when property value changes; again, I'm not sure about Gtkmm syntax).
The idea here was to fire an event when the ComboBoxText is clicked. After some readings I figured it out that the ComboBoxText does not fire any on_click event as such.
One could mask a key press event (which by the way gets fired) and call the signal handler. This might not be handy for people who specifically looking for a on_click event but for those who are working with a keyboard or touch screen device. Here is a small chunk of code :`
mCombo.add_events(Gdk::KEY_PRESS_MASK);
mCombo.signal_event().connect(sigc::mem_fun(this,&ClassName::Handler),false);
cheers :)
I was originally thinking this would be extremely easy to do. Google searches returned results for everything but this.
I am trying to have a normal button that I can click, and it stays down, click again, and it rises back up.
I found one function that did what I wanted, but only worked if the button retained focus, click anywhere else and it rises again.
Button_SetState(GetDlgItem(hwnd, IDC_BTN_SLEEPCLICK), TRUE);
Is there any real way to do this? Or am I gonna need to do this kind of thing by hand?
Thanks.
Create a check box, then set the "push like" property for that check box to true.
You want a checkbox with BS_PUSHLIKE style. To toggle it programmatically, use Button_SetCheck
The "staying down" and "rising back up" are a matter of how you draw the button.
You could create your own button class by using the Paint and Redraw methods.
Problem
Windows has a system setting that will cause the mouse pointer to jump (move) to a new focus element automatically, e.g. the default button of a dialog that pops up. While the advantage is an increase in speed and a reduction of mouse movements, it has a disadvantage:
If this happens just when before the user clicks on another element, the user is unable to abort his/her action in time and will immediately accept the dialogs default button because the focus is moved by the system. Usually this may entail cumbersome work to retrace the steps up to this point (think a file chooser dialog that forgot the very long path you input previously) but it could also mean triggering an irreversible process (e.g. file deletion).
Aim
Essentially I would like to disable the dialog's inputs for a small amount of time, just enough to prevent an inadvertant mouse click or keyboard button press.
Question
It comes down to a C++ question, namely how to access the base classes' objects (GUI widgets) from the inheriting class, i.e.
disable the button widgets of a QMessageBox
start a single shot QTimer and connect it to a slot that
enables the previously disabled widgets
(As alternative, I probably could reimplement input event handlers that suppress all input for a specific amount of time, but although I intend to keep that time very short (e.g. 100 ms), the user is not informed of the disabled input using that method.)
A simple class derived from QDialogBox can be found at http://www.qtforum.org/article/24342/messagebox-auto-close-mouse-event-close.html.
Do you need to use one of the "native"-ish message boxes provided by the QMessageBox static functions?
Otherwise, that's pretty simple to achieve, by building a QMessageBox and adding standard buttons to it:
QMessageBox *messageBox = new QMessageBox;
QPushButton *okButton = messageBox->addButton(QMessageBox::Ok);
okButton->setEnabled(false);
// use a QTimer to add logic to reenable the button
// use QCursor to move the mouse cursor on the button
// add a nice countdown in the button's label, like Firefox does
// add other nice UX touches as wanted
Last points are left as an exercise to the reader :)
To en/disable the buttons in QMessagebox one would need access to them.
qmessagebox.cpp uses buttonBox = new QDialogButtonBox; and the addButton() method
d->buttonBox->addButton(button, (QDialogButtonBox::ButtonRole)role);
d->customButtonList.append(button);
But I don't understand Qt internals and am unable to find these in qmessagebox.h and thus fail to find out if there is a chance to access the buttons..
I have a QLineEdit which I would like to hide from the user but still take in input form somewhere. I am creating a typing tutor and I want to take input in a hidden manner in order to provide a more dynamic form of feedback.
Any other suggestions as to best accomplish would be greatly appreciated
You can not do it. When QLineEdit is hidden, there is no focus on it, and you can not grab events.
If you persist on using QLineEdit there's an option to turn off displaying text.QLineEdit::NoEcho.
lineEdit->setEchoMode(QLineEdit::NoEcho);
This will show the edit box, but it doesn't show any text.
Otherwise, you should write a slot to grab window keyPressed signals, and handle everything yourself.
For other people who try to do such a thing, a workaround is simply to implement a QLineEdit visible, but with a MinimumSize = MaximumSize = 0x0 :)