I'm starting to look into the Qt WaylandCompositor and I am wondering if it is possible to get access to the composed frame of a WaylandOutput, preferably rendered off-screen. So that I can implement something similar than the Weston remoting plugin for streaming the composed scene to other devices.
Looking into the topic, I found the QWaylandView that offers access to a QWaylandBufferRef, but I guess this can be only used for a surface that is input to the composer... Is there something similar for the QWaylandOutput?
About the off-screen rendering, I found QOffscreenSurface, but I found no way so far on how to tell the output to use the OffscreenSurface instead of the window binding.
Does anyone have ideas on how to approach this?
Any help is deeply appreciated.
Related
I hope someone could give me a quick example how to configure the BTLE-Device correctly without the huge BLE-Manager library. Simply a litte GAP Authetication and one GATT-Service would be enough to start. I've managed to create my own GATT-Service and characteristics without the need for BLE-Manager but thanks to several defines, typedefs etc. I can't figure out how to do this for GAP and how to register my callbacks for it. Maybe someone has used these modules before and can give me a quick example how it's done?
Since you mentioned One GATT-Service with Authentication Atmel-BAS [Battery Service] example is easy one. To better understand you can download the getting started guide see the architecture. In-order to register the callbacks you need to check the order of callbacks in function ble_event_manager in ble_manager.c file.
I am learning Qt5 using PyQt.
My goal is to create a UI with several goals (I will base my need on the screenshot below).
So here are my goals:
My need
Add directories to a list of directories to be scanned (I know how to use QFileDialog.getExistingDirectory for that). For this I'd like to have a "+" button.
When pressed the QFileDialog would open and a new row would be added.
Then I would scan the directory to look for files. It won't be my first implementation but I'd like to have a circular progress bar being displayed during the scan (at the place of the classic progress bar).
When the scan is done, the UI would display the number of files found during the scan. And the progress bar would be replaced by a tick mark icon (not shown on the screenshot...).
At the beginning of each row, I'd like to have a "-" button to delete the row.
My goal is to learn
This is important, I know I am not the first one to have the idea of such a UI.
So I not looking for a third party lib on top of Qt.
My goal is to learn Qt5 (with PyQt) with this example.
But if its unrealistic, please tell me!
My knowledge
Mode View: I implemented some basic model view widgets to display strings, and I understand how to extend the idea to tables or trees.
In this case the number of rows in the table would be handled automatically.
But is it possible to created a table that would display not only strings but also widgets?
Widget Mapper: I read that another methodology is the QDataWidgetMapper. In this case, I would have to deal with creation of news rows by myself, and then I would map data onto them.
But it seems to be a hard and long job.
So, is it a good idea?
So finally could someone tell what is the best direction for that?
I am not looking for code, but since it takes a lots of time to learn new concepts, I'd like to learn and use the correct one before starting coding.
Thank you for your help :)!
After so more searches, I found that I need to use the delegate methodology.
In Qt5 it's QStyledItemDelegate and in Qt4 it's QItemDelegate.
I could find a nice tutorial at the moment, but I started coded it.
The scenario:
I'm editing some CGImages and strangely enough until now I was first creating NSImages from those CGImages before drawing them. So I tried to change the code so that I would draw the CGImages directly in into NSGraphicsContext.currentContext().graphicsPort. As you see I'm using Swing here but the same problem goes for Objective-C I presume.
Having a look into the documentation I saw that graphicsPort will be deprecated in 10.10, but I couldn't find another way to the current CGContext from NSGraphicsContext nor is there a way to create the CGContext from an NSGraphicsContext.
The Question:
Does anybody know what the proper way to retrieve the context would be? If not - Is there a way to cast the graphicsPort's COpaquePointer, which apparently is an initialized NSPipeObject, to a CGContextRef? Although using code that has already been marked deprecated would be quite unsatisfactory I would consider it until there is a better solution.
After spending a half hour digging around for information on this, I realized I should just check out the header file for NSGraphicsContext. Turns out there's a new property on NSGraphicsContext that's apparently not documented yet: CGContext. The header also notes that this should be used instead of graphicsPort.
Good day!
There are instances of classes QListView and QTreeView.
Both of the instances loads data from model (QStandardItemModel).
QTreeView displays positions (For example: Chief, Manager, Developer, etc).
Clicking on the title of position a list of employees revealed.
QListView displays only positions of staff.
Question:
How can I display a full list of names of employees in QListView not showing their positions?
Which methods I need to override?
What can you advise in this situation?
P.S. Thanks!
I don't think you are going to be able to do that with a single model.
This thread suggests using a proxy model to flatten the original one without having to maintain two instances of that data. But the implementation pointed to (KDE's KReparentingProxyModel) isn't exactly trivial.
There is some documentation on proxy models, and the QSortFilterProxyModel might be usable in your context, although I think you'll need something more specific.
You might also find the classes attached to the third response on this thread: ModelView - how to use proxies to filter this data? interesting as a starting point.
(Sorry this isn't very specific. Searching for "qt flatten tree model" will give you other ideas.)
Try to use QListWidget, is easier than QListView.
So basically what I'm trying to do is make something like this:
http://store.kapit.biz/demo/treemap/prod/index.html#
I've searched long and hard to find a site that would show me some pseudocode (at least) or an algorithm as to how to implement this type of application. But everything I find are only applications that take in data and do all the work for me to create the graph. I need to actually create it for myself, just a simple one for now. Does anyone know where I can find this? What I want it to do is take data from a database and use it to create the treemap, then express it in a GUI like in the link above. If any specifics are needed I can provide it. I'm trying to do this in Flash Builder using Flex and using ColdFusion as the backend. Thanks!
Check this out
Axiis is a open source library based on Degrafa that enables you to make complex data visualizations.
Cheers