I'm writing an application were i use my own shortcut. It looks like this:
myShortcut= new QShortcut(Qt::SHIFT + Qt::Key_B,this);
connect(myShortcut, SIGNAL(activated()), this, SLOT(setCameraBack()));
I defined it in the constructor of main widget and it works fine until i click one of the spinbox buttons which are also located on the main widget. After that my shortcut stop working and it doesn't work until i click push button or check box. When i do that everything is fine again. I'd like to add that after i click spinbox it seems to be "active" (because the cursor is still "blinking" on it) until i click one of the other buttons. Do you have any idea what is wrong? Is it some kind process or event problem? Thanks for all answers
~Marwroc
A shortcut is "listened for" by Qt's
event loop when the shortcut's parent
widget is receiving events.
When the QSpinBox has keyboard focus, then the QShortcut object's parent is no longer receiving events. Therefore, the shortcut does not work until keyboard focus is removed form the QSpinBox. You can change this behavior by passing Qt::WidgetWithChildrenShortcut or Qt::ApplicationShortcut to the QShortcut::setContext method of your QShortcut.
Before a shortcut is activated, the focus widget is given a ShortcutOverride event. If the event is accepted, the key event is passed along to the widget and the shortcut is not activated.
Source: https://wiki.qt.io/ShortcutOverride
Looking at Qt source
QAbstractSpinBox::event(QEvent *event)
{
Q_D(QAbstractSpinBox);
switch (event->type()) {
...
case QEvent::ShortcutOverride:
if (d->edit->event(event))
return true;
break;
...
}
return QWidget::event(event);
}
QAbstractSpinBox is allowing the internal edit to accept the event. QLineEdit defers to QLineControl. From qt/src/gui/widgets/qlinecontrol.cpp
case QEvent::ShortcutOverride:{
if (isReadOnly())
return false;
QKeyEvent* ke = static_cast<QKeyEvent*>(ev);
if (ke == QKeySequence::Copy
|| ke == QKeySequence::Paste
|| ke == QKeySequence::Cut
|| ke == QKeySequence::Redo
|| ke == QKeySequence::Undo
|| ke == QKeySequence::MoveToNextWord
|| ke == QKeySequence::MoveToPreviousWord
|| ke == QKeySequence::MoveToStartOfDocument
|| ke == QKeySequence::MoveToEndOfDocument
|| ke == QKeySequence::SelectNextWord
|| ke == QKeySequence::SelectPreviousWord
|| ke == QKeySequence::SelectStartOfLine
|| ke == QKeySequence::SelectEndOfLine
|| ke == QKeySequence::SelectStartOfBlock
|| ke == QKeySequence::SelectEndOfBlock
|| ke == QKeySequence::SelectStartOfDocument
|| ke == QKeySequence::SelectAll
|| ke == QKeySequence::SelectEndOfDocument) {
ke->accept();
} else if (ke->modifiers() == Qt::NoModifier || ke->modifiers() == Qt::ShiftModifier
|| ke->modifiers() == Qt::KeypadModifier) {
if (ke->key() < Qt::Key_Escape) {
ke->accept();
} else {
switch (ke->key()) {
case Qt::Key_Delete:
case Qt::Key_Home:
case Qt::Key_End:
case Qt::Key_Backspace:
case Qt::Key_Left:
case Qt::Key_Right:
ke->accept();
default:
break;
}
}
}
}
This code accepts most keys if the control key is not also pressed.
So the easiest solution is to change the shortcut to include the control modifier.
Alternatively, you can subclass the spin box and override the event function
bool MySpinBox::event(QEvent *event)
{
if( event->type() == QEvent::ShortcutOverride && !isReadOnly() )
{
QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
// Ignore 'B' shortcuts
if( keyEvent->key() == Qt::Key_B )
{
Q_ASSERT( !event->isAccepted() );
return true;
}
return QSpinBox::event(event);
}
Have you tried MySpinBox -> setFocusPolicy (Qt::NoFocus) ?
Related
I started working with QT and want to program a little game named Pong ( 2 player and a ball). The left player should be moved with the keys 'W' and 'S', the right player with the arrow keys up and down. I have a class Game to handle my animation. There I have an eventfilter to handle the keyPress
bool Game::eventFilter(QObject *target, QEvent *e)
{
Q_UNUSED(target);
bool handled = false;
if(e->type() == QEvent::KeyPress)
{
QKeyEvent *keyEvent = (QKeyEvent *)e;
if(keyEvent->key() == Qt::Key_W)
{
leftPlayerDir = ((leftPlayerDir == 0) ? 5 : leftPlayerDir);
handled = true;
}
else if(keyEvent->key() == Qt::Key_S)
{
leftPlayerDir = ((leftPlayerDir == 0) ? -5 : leftPlayerDir);
handled = true;
}
else if(keyEvent->key() == Qt::Key_Up)
{
rightPlayerDir = ((rightPlayerDir == 0) ? 5 : rightPlayerDir);
handled = true;
}
else if(keyEvent->key() == Qt::Key_Down)
{
rightPlayerDir = ((rightPlayerDir == 0) ? -5 : rightPlayerDir);
handled = true;
}
}
return handled;
}
and in my class Pong, where I set up the Mainwindow and handle the buttons, I have a line to install the eventfilter
ui->animation->installEventFilter(game);
If I start my program the animation is working, but the players are not moving on keyPress and I don't know why. Some ideas?
I have a button on VendOpenTrans and implemented its clicked method.
I thought this would work but i get an exception and AX closes..
void clicked()
{
LedgerJournalTrans ledgerJournalTrans;
VendTransOpen vto;
super();
switch (originator.TableId)
{
case tableNum(LedgerJournalTrans):
ledgerJournalTrans = element.args().record();
}
for ( vto = vendTransOpen_ds.getFirst(0); vto; vto = vendTransOpen_ds.getNext() )
{
//vendTransOpen_ds.markRecord(vto, 1);
if (vto.RecId)
{
if (manager.getTransMarked(vto) == NoYes::No)
{
select Invoice from vendTrans
where vto.AccountNum == vendTrans.AccountNum &&
vto.RefRecId == vendTrans.RecId;
if (ledgerJournalTrans.Invoice == vendTrans.Invoice)
{
// Mark transaction for settlement
showError = NoYes::No;
manager.updateTransMarked(vto, NoYes::Yes);
showError = NoYes::Yes;
}
}
}
// Update dynamic controls & refresh form as auto-redraw is not triggered
element.updateDesignDynamic();
element.redraw();
}
vendTransOpen_ds.refreshEx(-2);
}
If i comment out the following lines it will work, basically marking all the lines in the grid.
//select Invoice from vendTrans
//where vto.AccountNum == vendTrans.AccountNum &&
//vto.RefRecId == vendTrans.RecId;
//if (ledgerJournalTrans.Invoice == vendTrans.Invoice)
//{
// Mark transaction for settlement
showError = NoYes::No;
manager.updateTransMarked(vto, NoYes::Yes);
showError = NoYes::Yes;
//}
So, to be more clear, what stays is: manager.updateTransMarked(vto, NoYes::Yes);
and this way, it works. As far as i see something happens when i add that select.
Using debug i was able to check it and i think the exception is thrown by the for loop ..
Is there any chance to get a hint about this ?
Try changing your for loop definition to this:
for (vto = vendTransOpen_ds.getFirst(0) ? vendTransOpen_ds.getFirst(0) : vendTransOpen_ds.cursor(); vto; vto = vendTransOpen_ds.getNext())
And change this:
select Invoice from vendTrans
where vto.AccountNum == vendTrans.AccountNum &&
vto.RefRecId == vendTrans.RecId;
if (ledgerJournalTrans.Invoice == vendTrans.Invoice)
{
To this:
if (ledgerJournalTrans.Invoice == vto.vendTrans().Invoice)
When i enter the keypressevent while pressing on a combobox, keypressevent is not triggered. Is there a way to still get events, when another widget is active?
def keyPressEvent(self, event):
if event.key() == 49: #49 = number 1 on keyboard
self.takeScreenshot()
Eventfilter:
def eventFilter(self, obj, event):
if event.type() == QtCore.QEvent.KeyPress:
if event.key() == Qt.Key_Delete:
print datetime.datetime.now().time()
return QtGui.QWidget.eventFilter(self, obj, event)
even using eventFilter, when i am clicking on a combobox, the event is not propagated to this function.
It's a C++ example but I think you will find the same for Python:
Sometimes an object needs to look at, and possibly intercept, the events that are delivered to another object. For example, dialogs commonly want to filter key presses for some widgets; for example, to modify Return-key handling.
bool FilterObject::eventFilter( QObject* object, QEvent* event )
{
if ( ( object == target ) && ( event->type() == QEvent::KeyPress ) )
{
QKeyEvent* keyEvent = static_cast< QKeyEvent* >( event );
if (keyEvent->key() == 49) // Better to use Qt::Key_*
{
return true;
}
else
{
return false;
}
}
return false;
}
So I suggest you to use the eventFilter( ... ).
I'm developing a virtual musical keyboard that allows you to press keys on your keyboard and have it play notes. So in my MainWindow class I have reimplemented keyPressEvent. I would like to ignore events generated by modifiers (Control, Alt, Shift, etc.), as well as events generated by other non-character keys such as Tab, Backspace, and Enter. Something like this would be ideal:
void MainWindow::keyPressEvent(QKeyEvent *event)
{
if (!event->key().isCharacter()))
{
event->ignore();
return;
}
// handle the event
}
Is there a way to do something like that (short of testing every possible non-character key individually)? If not, is there at least a way to easily ignore the event if it is a modifier?
Looks like you want QKeyEvent::text().
The accepted answer is unfortunately incomplete. If you press Ctrl+C, then QKeyEvent::text() will return "\x03" (^C "End of Text").
That is not an empty string.
I decided to look inside the Qt source code, since they need to handle this problem for QLineEdit as well:
In QLineEdit::keyPressEvent:
d->control->processKeyEvent(event);
src/widgets/widgets/qlineedit.cpp:1742
In QWidgetLineControl::processKeyEvent:
if (unknown
&& !isReadOnly()
&& isAcceptableInput(event)) {
insert(event->text());
src/widgets/widgets/qwidgetlinecontrol.cpp:1912
In QInputControl::isAcceptableInput:
bool QInputControl::isAcceptableInput(const QKeyEvent *event) const
{
const QString text = event->text();
if (text.isEmpty())
return false;
const QChar c = text.at(0);
// Formatting characters such as ZWNJ, ZWJ, RLM, etc. This needs to go before the
// next test, since CTRL+SHIFT is sometimes used to input it on Windows.
if (c.category() == QChar::Other_Format)
return true;
// QTBUG-35734: ignore Ctrl/Ctrl+Shift; accept only AltGr (Alt+Ctrl) on German keyboards
if (event->modifiers() == Qt::ControlModifier
|| event->modifiers() == (Qt::ShiftModifier | Qt::ControlModifier)) {
return false;
}
if (c.isPrint())
return true;
if (c.category() == QChar::Other_PrivateUse)
return true;
if (c.isHighSurrogate() && text.size() > 1 && text.at(1).isLowSurrogate())
return true;
if (m_type == TextEdit && c == u'\t')
return true;
return false;
}
src/gui/text/qinputcontrol.cpp:21
This is exactly what you need but you may want to change the check for \t and ignore that as well.
The .Net generated code for a form with the "DefaultButton" attribute set contains poor javascript that allows the functionality to work in IE but not in other browsers (Firefox specifcially).
Hitting enter key does submit the form with all browsers but Firefox cannot disregard the key press when it happens inside of a <textarea> control. The result is a multiline text area control that cannot be multiline in Firefox as the enter key submits the form instead of creating a new line.
For more information on the bug, read it here.
This could be fixed in Asp.Net 3.0+ but a workaround still has to be created for 2.0.
Any ideas for the lightest workaround (a hack that doesn't look like a hack =D)? The solution in the above link scares me a little as it could easily have unintended side-effects.
I use this function adapted from codesta. [Edit: the very same one, I see, that scares you! Oops. Can't help you then.]
http://blog.codesta.com/codesta_weblog/2007/12/net-gotchas---p.html.
You use it by surrounding your code with a div like so. You could subclass the Form to include this automatically. I don't use it that much, so I didn't.
<div onkeypress="return FireDefaultButton(event, '<%= aspButtonID.ClientID %>')">
(your form goes here)
</div>
Here's the function.
function FireDefaultButton(event, target)
{
// srcElement is for IE
var element = event.target || event.srcElement;
if (13 == event.keyCode && !(element && "textarea" == element.tagName.toLowerCase()))
{
var defaultButton;
defaultButton = document.getElementById(target);
if (defaultButton && "undefined" != typeof defaultButton.click)
{
defaultButton.click();
event.cancelBubble = true;
if (event.stopPropagation)
event.stopPropagation();
return false;
}
}
return true;
}
It seems that the fix codesta.com that harpo link to is no longer necessary, since the fix event.srcElement is not integrade in ASP.NET 3.5. The implementation of DefaultButton does however still have some problems, because it is catching the Enter key press in too many cases. For example: If you have activated a button in the form using tab, pressing Enter should click on the button and not submit the form.
Include the following JavaScript code at the bottom of your ASP.NET web page to make Enter behave the way it should.
// Fixes ASP.NET's behavior of default button by testing for more controls
// than just textarea where the event should not be caugt by the DefaultButton
// action. This method has to override ASP.NET's WebForm_FireDefaultButton, so
// it has to included at the bottom of the page.
function WebForm_FireDefaultButton(event, target) {
if (event.keyCode == 13) {
var src = event.srcElement || event.target;
if (!(
src
&&
(
src.tagName.toLowerCase() == "textarea"
|| src.tagName.toLowerCase() == "a"
||
(
src.tagName.toLowerCase() == "input"
&&
(
src.getAttribute("type").toLowerCase() == "submit"
|| src.getAttribute("type").toLowerCase() == "button"
|| src.getAttribute("type").toLowerCase() == "reset"
)
)
|| src.tagName.toLowerCase() == "option"
|| src.tagName.toLowerCase() == "select"
)
)) {
var defaultButton;
if (__nonMSDOMBrowser) {
defaultButton = document.getElementById(target);
}
else {
defaultButton = document.all[target];
}
if (defaultButton && typeof (defaultButton.click) != "undefined") {
defaultButton.click();
event.cancelBubble = true;
if (event.stopPropagation) event.stopPropagation();
return false;
}
}
}
return true;
}
For this particular issue, the reason is because javascript generated by
ASP.NET 2.0 has some IE only notation: event.srcElement is not availabe in
FireFox (use event.target instead):
function WebForm_FireDefaultButton(event, target) {
if (!__defaultFired && event.keyCode == 13 && !(event.srcElement &&
(event.srcElement.tagName.toLowerCase() == "textarea"))) {
var defaultButton;
if (__nonMSDOMBrowser) {
defaultButton = document.getElementById(target);
}
else {
defaultButton = document.all[target];
}
if (defaultButton && typeof(defaultButton.click) !=
"undefined") {
__defaultFired = true;
defaultButton.click();
event.cancelBubble = true;
if (event.stopPropagation) event.stopPropagation();
return false;
}
}
return true;
}
If we change the first 2 lines into:
function WebForm_FireDefaultButton(event, target) {
var element = event.target || event.srcElement;
if (!__defaultFired && event.keyCode == 13 && !(element &&
(element.tagName.toLowerCase() == "textarea"))) {
Put the changed code in a file and then do
protected void Page_Load(object sender, EventArgs e)
{
ClientScript.RegisterClientScriptInclude("js1", "JScript.js");
}
Then it will work for both IE and FireFox.
Source:
http://www.velocityreviews.com/forums/t367383-formdefaultbutton-behaves-incorrectly.html