Using kqmlgraphplugin in Plasma Next

Mark Gaiser markg85 at
Fri Jan 31 13:56:24 GMT 2014

On Fri, Jan 31, 2014 at 5:34 AM, Bhushan Shah <bhush94 at> wrote:
> To people from kde-core-devel: please keep me and plasma-devel in CC,
> I am not subscribed to list
> Hello,
> Currently I am working on a QML Canvas based SignalPlotter, to replace
> the old Plasma1SignalPlotter which is KSignalPlotter and
> QGraphicWidget based. My SignalPlotter is in bshah/plotter-qml branch
> of plasma-framework
> (src/declarativeimports/plasmaextracomponents/SignalPlotter.qml)
> Meanwhile I was notified by apol that something like this already
> exist, which is QML, So basically my plan is to port kqmlgraphplugin
> to KDE Frameworks 5 and use it to plot data in Plasma Next.
> I am interested in porting it to KDE Frameworks 5. Is someone already
> working on that? If yes can I help with that? Otherwise I will start
> to port it. :)
> Thanks!

Now this is tricky!

You basically have two separate projects:
1. (yours) which is QML2 + Canvas based and probably needs quite a bit
more to be a replacement for the "graph-plugin" from sebas [1].
2. The Qt4 based graph-plugin from sebas with quite a bit of features.

Lets get tech details right first:
- Both are written with classes/components that use software
rendering. (QPainter and Canvas are both software rendering)
- Both are not usable for a real animation because of the software
rendering. So you'd have to update the frame just once per - say -
second to avoid high CPU load.

Porting the graph-plugin to Qt5 is likely going to take you a few days
depending on how much you work on it. However, you probably also drag
in a QWidget dependency while doing so (not 100% sure, please correct

Then again, extending your plugin to support all the graph-plugin
functionality is also going to take you a few days and quite some
coordination with probably Sebas.

My preference would be QML only as long as it doesn't involve much javascript.


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