Is there a way to detect whether execution is currently in the middle of QDialog.exec()?
I'm the author of DreamPie, a Python shell, and it lets you run Python code while Qt GUI is being displayed. It does that by running the Qt event loop for 1/10 of a second, and then checking if any Python commands need to be executed. The event loop is stopped by a QTimer which calls QApplication.quit() after the timeout.
If a QDialog.exec() is active, however, I don't want to call QApplication.quit(), because it will break the code. The current solution is to check whether there's a modal dialog active, by checking if QApplication.activeModalWidget() is None. However, I currently have a modal dialog which is not run with QDialog.exec(), and it's blocking Python commands for no reason.
Is there a way to exit the event loop only if it's not called recursively by QDialog.exec()?
Thanks!
You can check whether your dialog is visible with QDialog.isVisible. Normally, a modal dialog is visible only while it is being executed.
Related
My Qt 4 application can only update the log box area (actually the whole GUI) until a function finishes execution. Is there any way to update the GUI/log box during the execution? Like adding something like QWidget::repaint() or QWidget::update() in the for loop, so the user can see that the GUI is processing, rather than wait until the function finishes and print out the log at once.
You need to occasionally call QCoreApplication::processEvents() during the execution of your function. This will keep the GUI alive and responsive by letting the event loop run.
An alternative is to execute your function in a separate thread. More information on threads in Qt can be found here: http://qt-project.org/doc/qt-4.8/threads.html.
I've written a short script (in another language, happens to be Python) which passes arguments to the command line as follows -
ildrt <path/filename.sav> -args p1 p2 --o1 --o2
where p, o are positional and optional arguments respectively (obvious). To get to the point, this script calls an IDL routine any number of times. Each time, the IDL virtual machine is loaded, the IDL routine runs until completion, rinse and repeat.
Unfortunately if an error occurs in the IDL routine execution a dialog box will popup and halt program execution until manually clicked. Since the idea is to run this as a batch process I want to ignore the dialog boxes, (accepting the error), and continue to the next run. Any thoughts on preferences or optional commands I can run IDL with to prevent the popups? Thanks in advance.
I guess I'm not following. Can't you just pass a flag to your program and then check that flag before popping up a dialog in your code? If you don't have access to the .pro code, then I don't think you can prevent the popups.
when using FlexPrintJob, after calling start(), a OS system print interface will appear, and at the same time Flex code execution will be paused, and it will remain paused until user finished interaction with the OS print dialog. the problem is I do have data from server, and the connection will time out within certain period, so is there any walk around to not pause the Flex code execution while OS print dialog is popped up. Thanks.
From the doc for FlexPrintJob:
You use the FlexPrintJob class to print a dynamically rendered document that you format specifically for printing.
This makes me wonder if you couldn't (essentially) fork off a second page from the browser that contains your print job and do the printing from there. This would leave your original page still running. In my flex apps I do this via PHP (create additional pages for printing and such). Example here.
Otherwise: you should finish all the server data d/l before starting the print job to avoid this issue.
Flex is only just recently starting to add multi-threading. It's adding worker threads of a sort but this won't help what you're asking for.
I'm currently writing a macro that performs a series of control sends and control clicks.
They must be done in the exact order.
At first I didn't have any sleep statements, so the script would just go through each command regardless whether the previous has finished or not (ie: click SUBMIT before finish sending the input string)
So I thought maybe I'll just put some sleep statements, but then I have to figure out how best to optimize it, AND I have to consider whether others' computers' speeds because a slow computer would need to have longer delays between commands. That would be impossible to optimize for everyone.
I was hoping there was a way to force each line to be run only after the previous has finished?
EDIT: To be more specific, I want the controlsend command to finish executing before I click the buttons.
Instead of ControlSend, use ControlSetText. This is immediate (like GuiEdit).
My solution: use functions from the user-defined library "GuiEdit" to directly set the value of the textbox. It appears to be immediate, thus allowing me to avoid having to wait for the keystrokes to be sent.
I have an application which makes use of 20 different classes. The program execution starts in mainwindow. I start a progress dialog. I will make use of different classes for different purposes. After each function call which the execution goes to the particular class and does the required and come back to the mainwindow class, I will update the progress dialog. Now, the issue is the progress dialog freezes when the execution goes away from the mainwindow class. The cancel button is unable to accessed and so, the execution could not be stopped at the required time.
mainclass::mainclass()
{
ProgressDialog->exec();
x->add();
updateProgressDialog();
y->do();
updateProgressDialog();
zz->bring();
updateProgressDialog();
}
// x, y, z are three different classes.
This is how the execution goes. As soon as I enter the function in the main class, I will start the progress dialog. and call functions from different classes. The functions take considerable amount of time. I have invoked a thread to do the execution part, but I am unable to cancel the progress diaolog. I want the program execution to be stopped as and when the cancel button is pressed on the proggress dialog.
Please let me know how to get away with this issue. Hope I am clear here.
Without knowing exactly what calculations are being preformed in your threads its hard to isolate the problem. Maybe this can help: Keeping the GUI Responsive
Excerpt from: Performing Long Operations (by: Witold Wysota)
During long calculations (regardless of any usage of signals and slots) all event processing gets halted. As a result, the GUI is not refreshed, user input is not processed, network activity stops and timers don't fire—the application looks like it's frozen and, in fact, the part of it not related to the time-intensive task is frozen.
The functions you are calling are not processing the Qt events loop. You are using a modal progress bar, since you are calling exec(). This means that Qt only gets control at the times where you update the dialog.
The only way that I know of to work around this is to code the dialog as modeless, but you will also have to provide an opportunity for the events loop to process.
This is explained in a fair amount of detail in the Qt docs: QProgressDialog