Re: [Interest] how do I load massive table views instantly?
On 6/5/20 5:00 AM, interest-requ...@qt-project.org wrote: alternately, if "loading only what you see" is just "how it's done", then can i just set the scroll bar height to be the total height? so CAN still grab the scroll thumb, and drag it to the end, and see the data at the end, without waiting for all the unseen data to load? i know other apps do this... how is it done? I believe what you are trying to do is covered in "The Minimum You Need to Know About Qt and Databases." https://www.theminimumyouneedtoknow.com/qt_book.html You can see if WorldCat shows a university with a copy you get check out. https://www.worldcat.org/ They've done something to their search engine recently though because it doesn't show you all of the libraries anymore and it doesn't find all of the titles easily. There is a short (57 page) preview of the book on ScribD. https://www.scribd.com/document/156381069/The-Minimum-You-Need-to-Know-About-Qt-and-Databases This was written with an early version of Qt 4.x and there were bugs in QSqlDatabase it had to work around. On the page for the book is a download link to the source code for the book if you just want to muddle through. You should find what you are looking for there though. I distinctly remember doing it. I've had to do it at many sites. -- Roland Hughes, President Logikal Solutions (630)-205-1593 http://www.theminimumyouneedtoknow.com http://www.infiniteexposure.net http://www.johnsmith-book.com http://www.logikalblog.com http://www.interestingauthors.com/blog ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
Re: [Interest] how do I load massive table views instantly?
Il 04/06/20 23:31, David M. Cotter ha scritto: What table view are you talking about, specifically? QTableView with QSortFilterProxyModel What is the model _behind_ QSFPM? Does that model support async loading? Note that QSFPM may still need to load the entire source model (didn't check its source code) if you ask it to filter or sort. For 200k elements, I'd expect the source model itself to support filtering and sorting, without the need of a proxy in front of it. My 2 c, -- Giuseppe D'Angelo | giuseppe.dang...@kdab.com | Senior Software Engineer KDAB (France) S.A.S., a KDAB Group company Tel. France +33 (0)4 90 84 08 53, http://www.kdab.com KDAB - The Qt, C++ and OpenGL Experts smime.p7s Description: Firma crittografica S/MIME ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
Re: [Interest] how do I load massive table views instantly?
>>> What table view are you talking about, specifically? >> QTableView with QSortFilterProxyModel > > What is the model _behind_ QSFPM? i'm trying to understand your question. i'm not sure what you mean, cuz i'm not the SQLite dev what i know is that each song has a couple dozen bits of data (name, artist, album, several file paths, rating, duration etc etc) besides that, what are you asking? > Does that model support async loading? okay, how would i answer this question? i guess ask the developer of the DB > Note that QSFPM may still need to load the entire source model (didn't check > its source code) if you ask it to filter or sort. For 200k elements, I'd > expect the source model itself to support filtering and sorting, without the > need of a proxy in front of it. would this allow me to have multiple playlists, each with it's own view into the model, with different columns showing in different orders, different sets of songs, possibly with a filter? and switch between them instantly? ie: not have to take time to switch, to show the first page of data? and allow the scroll thumb to instantly be correctly sized, such that the user can take the thumb and drag it to the bottom, and instantly see the last page? no waiting? thanks, i'm a newbie here in terms of SQLite and how it all works, and i'm speaking on behalf of the dev, so i only know JUST enough to ask maybe dumb questions but not enough to answer perhaps some smart ones... sigh -dave ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
[Interest] Crash due to missing symbol
Hi all, when running my Qt app (compiled on Catalona with SDK10.15) on older OSX < 10.14 down to 10.10 I get the following crash when initializing the audio interface: Termination Reason: DYLD, [0x4] Symbol missing Dyld Error Message: Symbol not found: chkstk_darwin Referenced from: /Applications/soundjack.app/Contents/MacOS/soundjack Expected in: /usr/lib/libSystem.B.dylib Does anyone know how to debug this ? Thanks in advance, best Alex -- http://www.carot.de Email : alexan...@carot.de Tel.: +49 (0)177 5719797 ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
Re: [Interest] Crash due to missing symbol
Hi Alex. Do you have the “deployment target” set to 10.10, not 10.14, in your project? In Xcode this is in the project settings; in Qt Creator it’s a setting in the .pro file. You can’t set it to be any earlier than the Qt version you are running against, however, or precisely this sort of thing will happen. If you need to run on older OS X versions, you need to make sure the Qt version you’re using is compatible with those older versions. (I forget where this information is, but Google always finds it for me. :->) Cheers, -B. Benjamin C. Haller Messer Lab Cornell University > On Jun 5, 2020, at 3:55 PM, Alexander Carôt wrote: > > Hi all, > > when running my Qt app (compiled on Catalona with SDK10.15) on older OSX < > 10.14 down to 10.10 I get the following crash when initializing the audio > interface: > > Termination Reason: DYLD, [0x4] Symbol missing > > Dyld Error Message: > Symbol not found: chkstk_darwin > Referenced from: /Applications/soundjack.app/Contents/MacOS/soundjack > Expected in: /usr/lib/libSystem.B.dylib > > Does anyone know how to debug this ? > > Thanks in advance, > best > > Alex > > -- > http://www.carot.de > Email : alexan...@carot.de > Tel.: +49 (0)177 5719797 > > ___ > Interest mailing list > Interest@qt-project.org > https://lists.qt-project.org/listinfo/interest ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
Re: [Interest] Crash due to missing symbol
Hi Ben and all, thanks for the quick reply. In fact I am using two Qt versions - one for recent and one for older OSX. For the older ones I am using Qt5.9.2 and so far this had been working until now. Furthermore, I am compiling my app via qmake / make on the terminal and don't use XCode. In case you have further ideas please let me know. Best Alex -- http://www.carot.de Email : alexan...@carot.de Tel.: +49 (0)177 5719797 > Gesendet: Freitag, 05. Juni 2020 um 22:03 Uhr > Von: "Ben Haller" > An: "Alexander Carôt" > Cc: "qt qt" > Betreff: Re: [Interest] Crash due to missing symbol > > Hi Alex. Do you have the “deployment target” set to 10.10, not 10.14, in > your project? In Xcode this is in the project settings; in Qt Creator it’s a > setting in the .pro file. You can’t set it to be any earlier than the Qt > version you are running against, however, or precisely this sort of thing > will happen. If you need to run on older OS X versions, you need to make > sure the Qt version you’re using is compatible with those older versions. (I > forget where this information is, but Google always finds it for me. :->) > > Cheers, > -B. > > Benjamin C. Haller > Messer Lab > Cornell University > > > > On Jun 5, 2020, at 3:55 PM, Alexander Carôt wrote: > > > > Hi all, > > > > when running my Qt app (compiled on Catalona with SDK10.15) on older OSX < > > 10.14 down to 10.10 I get the following crash when initializing the audio > > interface: > > > > Termination Reason: DYLD, [0x4] Symbol missing > > > > Dyld Error Message: > > Symbol not found: chkstk_darwin > > Referenced from: /Applications/soundjack.app/Contents/MacOS/soundjack > > Expected in: /usr/lib/libSystem.B.dylib > > > > Does anyone know how to debug this ? > > > > Thanks in advance, > > best > > > > Alex > > > > -- > > http://www.carot.de > > Email : alexan...@carot.de > > Tel.: +49 (0)177 5719797 > > > > ___ > > Interest mailing list > > Interest@qt-project.org > > https://lists.qt-project.org/listinfo/interest > > ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
