Creating QActions on the fly for history

nicky j

I don't have a file, how do I put the sender() into the slot?

SGaist

I meant "Recent File" menu like you have in e.g. Qt Creator

@
void MyClass::mySlot()
{
QObject *senderObject = sender();
// rest of your code
}
@

nicky j

Oh okay, sorry I misunderstood you.

So would I call senderObject in the connect() as well as the slot? Would it have to be in both slots?

SGaist

Have a look at the "Recent File" example in Qt's documentation it shows a variation of the technique nicely

nicky j

I checked out the 'Recent File' example, and it is really helpful! I have a small problem though that I don't know how to fix.
Here is my code thus far:
@void browseTab::addToHistory()
{
QString url = webView->url().toString();

QString historyEntry = url;

QString title = webView->title();

QIcon icon = webView->icon();

int numRecentHistory = 1;

for (int i = 0; i < numRecentHistory; ++i)
{
    QString text = tr("&%1").arg(title);

    historyAction = new QAction(this);
    historyAction->setText(text);
    historyAction->setData(historyEntry);
    historyAction->setIcon(webView->icon());
    historyAction->setIconVisibleInMenu(true);
    HistoryMenu->addAction(historyAction);
    connect(historyAction, SIGNAL(triggered()), SLOT(goToHistoryURL()));
}

}

void browseTab::goToHistoryURL()
{
QAction *action = qobject_cast<QAction *>(sender());
if (action)
loadHistory(action->data().toString());
}

void browseTab::loadHistory(const QString &name)
{
webView->setUrl(QUrl(QString(name)));
}
@

When my webView finishes loading a URL, it calls addToHistory() which adds a new QAction. When this QAction is triggered, it calls goToHistoryURL(). goToHistoryURL() in turn calls loadHistory() which sets the webView to the URL enclosed in the QActions data() property. When I run the program, it runs great until I click one of the historyActions to go to that page. My entire application freezes up and crashes. How can I make it just go to the URL without crashing?

Thanks for your help, I know these are n00bie problems, but I appreciate your help nonetheless!

SGaist

You are probably creating a loop

Why are you creating numRecentHistory actions each time you call addToHistory ?

nicky j

What would be a better way to do it?

SGaist

Like I said, follow the Recent File Example, it shows how to handle that

nicky j

I have tried to follow that example, and based on it thats what I have so far.
How is it creating a loop and how do I fix it?

SGaist

You're code doesn't reflect the example, you are creating each time numRecentHistory actions.

The best way to see where the problem lies is to run your application through the debugger

nicky j

As in 'debug' vs 'release' when i hit the run button?

nicky j

Would having numRecentHistory outside of the function so it isn't created every time be better?

SGaist

As in use the button with a little bug on it with a debug build of your application

nicky j

Okay now if I click on one one of the historyActions, nothing happens. It doesn't load the page, crash, or anything.

Code:

@void browseTab::addToHistory()
{
QString url = webView->url().toString();

QString historyEntry = url;

QString title = webView->title();

QIcon icon = webView->icon();

int numRecentHistory = 1;

for (int i = 0; i < numRecentHistory; ++i)
{
    QString text = tr("&%1").arg(title);

    historyAction = new QAction(this);
    historyAction->setText(text);
    historyAction->setData(historyEntry);
    historyAction->setIcon(webView->icon());
    historyAction->setIconVisibleInMenu(true);
    HistoryMenu->addAction(historyAction);
    connect(historyAction, SIGNAL(triggered()), SLOT(goToHistoryURL()));
}

}

//determines which historyAction has been clicked, calls loadHistory().
void browseTab::goToHistoryURL()
{
QAction *action = qobject_cast<QAction *>(sender());
if (action)
loadHistory(action->data().toString());
}

//sets the webView to the historyAction's url, called by goToHistoryURL().
void browseTab::loadHistory(const QString &name)
{
webView->setUrl(QUrl(QString(name)));
}
@

nicky j

Okay I restarted Qt and now it crashes again like it has been. I ran the debugger and it seemed to have an issue with the following code:
@loadHistory(action->data().toString());@

How can I fix this?
Thanks! I appreciate your help SGaist!

nicky j

Sorry to resurrect the thread,

I am still having trouble with my application crashing when I click one of the historyActions, I have read the examples provided, and I still don't understand why it crashes. Could someone please help me?

andre

If it crashes, the first thing to do is to get out your debugger to figure out where it crashes.