@JonB said in "Progress MessageBox": OK. Forget about modeless for a moment, if you don't want to deal with threads. Take a look at http://doc.qt.io/qt-5/qdialog.html#open, and start from there instead of the normal QDialog::exec(). I'm thinking that may be all you are looking for. I still don't know what it is you think you are going to "show the progress against", but that's another issue..... Thanks for the recommendation. I will look into open(), etc. I will probably end up threading the heavy tasks, but I'm trying to avoid all the tedious synchronization for now. As for 'progress against': I realized why that may not have made sense. Individual time-consuming tasks will not be able to report on their progress mid-stream (no way to gauge how long to complete), but there is a series of them. Basically a chain of image processes--filters, denoising, etc. and each can take from 5 seconds to almost a minute. Awkward to just sit there looking at the barberpole progress bar, so I thought of setting up a timer in the progress dialog in order to monitor a 'status variable' back at the ranch. As each filter stage completes, the status variable would be updated. When the variable changes from "filter 1" to "filter 2", appropriate text could be displayed in the progress dialog. Or so I hope. :-)

@mjaga Just in case somebody wants to test this, here is a minimal example demonstrating the problem: #include <QApplication> #include <QProgressBar> int main(int argc, char *argv[]) { QApplication a(argc, argv); a.setStyle("plastique"); /* working... */ // a.setStyle("cleanlooks"); /* working... */ // a.setStyle("Windows"); /* working... */ // a.setStyle("Fusion"); /* working... */ // a.setStyle("gtk2"); /* NOT working! */ QProgressBar pb; pb.setMaximum(0); pb.setMinimum(0); pb.setValue(0); pb.show(); return a.exec(); }

This is weird, but I had applied a vertical layout to this dialog so it would resize a listbox properly. I removed the layout and the progress bar works properly. So solved, I guess...

@DougyDrumz said in Can't Cancel Progress Dialog.: OK. I found it. I was being dumb! I have two flavors of Progress Dialogs. One is inside an App, and the other is standalone, meant to be called form a script. I was looking at the one in the App when I should have been looking at the other one. The standalone one doesn't have have a cancel slot. Good !

The link provided by @Joel-Bodenmann is a good start.

Well, when buffersplit call setValue(buffersplit) on your progress bar. I'd recommend using a more descriptive variable name

@hamov well digging around, I also found m_list->viewport()->repaint(); which works for WidgetList. Did not test with model/view yet. I think it is by design as it does redraw when data changes but we are not alone finding it strange working if one google it