I am writing small c++ application using QT creator and i have a problem, I want to get selecting text from any application, I am using to this QClipboard library (SIGNAL(selectionChanged())), but it doesn't work properly admittedly i am getting selected text, but only after I release a mouse button. I would like to get selected text in "real time" without mouse button up. Is there any simple way to do it?
first you need to add this header file: QClipboard
then...
connect(qApp->clipboard, SIGNAL(selectionChanged), this, SLOT(your_slot()));
void your_slot() {
QClipboard *clipboard = QApplication::clipboard();
clipboard->setText(qApp->clipboard->text());
}
http://doc.qt.io/qt-5/qclipboard.html#selectionChanged
It looks like that is only supported well on X11, like Linux.
If you are interested in tracking mouse selections in your program in realtime, you can look directly at the mouse events or keyboard events, or the Rich Text Processing framework (QTextCursor).
You could also send a copy call while the mouse is down on a timer, and then look at the dataChanged signal.
Hope that helps.
Related
How to create a button or something with title looking like a link, on Windows applications's windows, dialog boxes, etc? It should receive keyboard focus, and when mouse pointer is over it, its text should be underlined.
I am using C++ Builder. This can be done using TLabel or TStaticText. But the problem is that, it does not receive keyboard focus. I would like it to receive keyboard focus and be tab-stopped.
Thanks.
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 want to create a onscreen keyboard for a desktop application. The application will be built in Qt 5. I have couple of questions, please clarify them.
What is the replacement of QInputContext in Qt5? (Because I read somewhere about onscreen keybord by implementing QInputContext but this is not supported by Qt 5.)
Where can I find QPlatformInputContext and QInputPanel (on an internet search I found these two as alternatives of QInputContext but not sure about that and also I was unable to find them)?
My requirements:
Keyboard will not use QML or any external library (already build other keyboards).
Keyboard will use Qt Gui (traditional).
I understand there are two challenges you would have:
Getting notified as to when to show/hide the on-screen keyboard, based on the focus being on text widgets
How to post key-press event to the text widgets
ANSWER
As for the former, you could use QObject::InstallEventFilter() on widgets that you want to provide the keyboard service to. You can then look for the mouseReleaseEvent along the lines of the Qt code in the link.
This can be achieved by using QCoreApplication::postEvent()
As for QPlatformInputContext, get the example of a Qt Virtual Keyboard here.
I took me quite a while to find out how to do this in QT5 without qml and too much work. So thought I'd share:
#include <QCoreApplication>
#include <QGuiApplication>
#include <QKeyEvent>
void MainWindow::on_pushButton_clicked()
{
Qt::Key key = Qt::Key_1;;
QKeyEvent pressEvent = QKeyEvent(QEvent::KeyPress, key, Qt::NoModifier, QKeySequence(key).toString());
QKeyEvent releaseEvent = QKeyEvent(QEvent::KeyRelease, key, Qt::NoModifier);
QCoreApplication::sendEvent(QGuiApplication::focusObject(), &pressEvent);
QCoreApplication::sendEvent(QGuiApplication::focusObject(), &releaseEvent);
}
The clue here is that by clicking buttons (if you would manually make your keyboard), launches a sendevent to the current object thas has focus (for example a textbox). You could of course hardcode a textbox, but that only works if you have only a single input to use your keyboard for.
The last thing you have to make sure, is to set the focusPolicy of your keyboard buttons to NoFocus, to prevent focus from shifting when the keyboard is pressed.
Credits go to https://www.wisol.ch/w/articles/2015-07-26-virtual-keyboard-qt/
Hope this helps someone.
A good example is given in here http://tolszak-dev.blogspot.com.tr/2013/04/qplatforminputcontext-and-virtual.html
uses Qt Quick for on screen keyboard.
You can check it.
I just got this working in my awesome Qt app. Here is how I did it.
For Android and iOS:
QObject::connect(lineEdit, SIGNAL(returnPressed()), qApp->inputMethod(), SLOT(hide()));
For iOS:
Subclass QLineEdit and add the following:
void focusOutEvent(QFocusEvent * fe)
{
QLineEdit::focusOutEvent(fe);
#ifdef Q_OS_IOS
if(fe->reason() == Qt::OtherFocusReason)
{
// Done was pressed!
emit returnPressed();
}
#endif
}
Btw, the QInputMethod docs don't say much about how to access it from c++. You have to get an instance from QGuiApplication, like I did above.
Hope that helps.
Qt now provides a virtual keyboard framework in Qt 5.5.
http://doc.qt.io/QtVirtualKeyboard/
I have not tried it, so I can't say how easy it is to use. It looks like it's QML-based.
(It says it's for Linux and boot2qt, but it can also be built for Windows according to the building page (http://doc.qt.io/QtVirtualKeyboard/build.html))
I need to create an application which do the following:
At the beginning we have notepad window open with a lot of text in it.
Our application must scroll through this file and take notepad window screenshot after each scroll action.
I've tried to achieve this using SBM_GETRANGE, SBM_GETRANGE, SBM_SETPOS but it does not work for me.
Please note that emulating keyboard events (e.g. PageDown, PageUp) is not an option for me because this application should also work with other applications which may not support keyboard shortcuts for manipulating scrolls.
Thanks.
Don't try to manipulate the scrollbar directly - instead SetFocus() to the text window, then send Page Down messages. If there are applications where you must manipulate the scrollbar, you should get its window handle and send the messages there.
In Linux after text selecting it copies to buffer, so than we could paste it by clicking middle button of the mouse. I think that there is a special buffer for this thing. I want to use it. How could i get data of selected text?
OS: Linux
Programming language: c++
Own libraries: Qt
Thanks.
Just a more accurate answer than Paul Dixon's that answers your needs:
QClipboard* clipboard = QApplication::clipboard();
QString selectedText = clipboard->text(QClipboard::Selection);
You need to distinguish between selection and clipboard. The QClipboard documentation has this in the Notes for X11 Users section:
The X11 Window System has the concept
of a separate selection and clipboard.
When text is selected, it is
immediately available as the global
mouse selection. The global mouse
selection may later be copied to the
clipboard. By convention, the middle
mouse button is used to paste the
global mouse selection.
With QClipboard::Mode you can select which type (clipboard or selection) you want to access. The important part is that you need to be aware about the difference between selection and clipboard.
If you're using Qt, have you read the fine manual page on QClipboard?
QClipboard *clipboard = QApplication::clipboard();
QString clipboardText = clipboard->text();
the system that actually handles the selection and pasting system is X11 Windows. When you e.g paint some text in your favorite editor, the application sends and X11 request which tells to the X11 server that you have an active selection. If you then click the middle mouse button somewhere, the X11 server queries the application which told the server about the selection for the actual contents. Then the contents are forwarded to the receiving application.
Libraries like Qt provide wrappers for this mechanism, but the underlying mechanism is X11.