GSOC project updates

[Tomaz Canabrava]

On Mon, Jul 28, 2014 at 2:20 PM, Lubomir I. Ivanov <neolit123 at gmail.com> wrote:
> On 28 July 2014 20:13, Tomaz Canabrava <tcanabrava at kde.org> wrote:
>> On Mon, Jul 28, 2014 at 2:01 PM, Lubomir I. Ivanov <neolit123 at gmail.com> wrote:
>>> On 28 July 2014 19:54, Tomaz Canabrava <tcanabrava at kde.org> wrote:
>>>> On Mon, Jul 28, 2014 at 1:39 PM, Lubomir I. Ivanov <neolit123 at gmail.com> wrote:
>>>>> On 28 July 2014 19:29, Tomaz Canabrava <tcanabrava at kde.org> wrote:
>>>>>> On Mon, Jul 28, 2014 at 1:27 PM, Lubomir I. Ivanov <neolit123 at gmail.com> wrote:
>>>>>>> On 28 July 2014 19:19, Tomaz Canabrava <tcanabrava at kde.org> wrote:
>>>>>>>> On Mon, Jul 28, 2014 at 1:16 PM, Lubomir I. Ivanov <neolit123 at gmail.com> wrote:
>>>>>>>>> On 28 July 2014 19:03, Anton Lundin <glance at acc.umu.se> wrote:
>>>>>>>>>> Just a note here from how we thought.
>>>>>>>>>>
>>>>>>>>>> The scope of this GSOC project is to produce a usable downloader app
>>>>>>>>>> for android and one pre-req for that is a usable touch friendly ui.
>>>>>>>>>>
>>>>>>>>>> The current Android port of subsurface is unusable as a ui, but it
>>>>>>>>>> works as a technical product. It needs a better ui for touch.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> i haven't followed previous discussions; can you elaborate on why it's unusable?
>>>>>>>>> is it more of a cosmetic issue or perhaps QWidget based things like
>>>>>>>>> QTreeView (divelist) do not work at all?
>>>>>>>>
>>>>>>>> The UI becomes too small to be used on a phone and it's not stetically
>>>>>>>> appealing to be used on Tablet.
>>>>>>>>
>>>>>>>
>>>>>>> hmm, how about allowing only one view at time: profile, divelist,
>>>>>>> diveinfo etc and increasing the font sizes?
>>>>>>> the "one view at a time" thing, is the mobile way of doing it because
>>>>>>> of resolution restrictions.
>>>>>>
>>>>>> QML can takes care of that, I'v already created a Subsurface QML
>>>>>> interface just for fun and it was almost easy to do. :)
>>>>>>
>>>>>
>>>>> and can be done in C++ based on our current UI - just show the "view"
>>>>> that is needed?
>>>>>
>>>>> for a recent Qt / POC project i completely ditched QML in favor of C++
>>>>> because i wanted a more direct QGraphicsScene interaction.
>>>>> QML only provided the "quick" part in terms of instantiating UI
>>>>> elements, but not the control and performance i wanted.
>>>>
>>>> True in Qt4, false in Qt5. in Qt5 QML uses OpenGL directly so it
>>>> should be faster / smoother than QGraphicsView.
>>>>
>>>
>>> well, QML to my knowledge is built based on QGraphicsView and
>>> QGraphicsView can use QGLWidget as a viewport, which i've tried and it
>>> works apart from minor font glitches for now.
>>
>> True for Qt4, False for Qt5.
>> for Qt5 QML is build not on QGraphicsView anymore, but SceneGraph.
>> There's a very nice blog post about it here:
>>
>> http://blog.qt.digia.com/blog/2013/09/02/new-scene-graph-renderer/
>>
>
> oh yes, forgot about the SceneGraph...
>
>>> the performance of QML's animation (this should be also based on Qt's
>>> animation framework) and of Context2D (for heavy SVG like drawing)
>>> were main decision factors to stick to C++.
>>
>> yes - true for Qt4 :)
>>
>
> dunno, my tests were based on Qt5.2 for Win32.
> RotationAnimation on a declarative image, 15% CPU on a dual core with OpenGL.
> rotating with QGraphicsScene / C++ ~0% CPU with or without OpenGL.

Then I hope they fix this bug, as they are selling QML as the big thing in Qt.
We can do a touch ui based on QGraphicsView, but it will be so much
easier in QML ( mostly because now there's a widget's QML package )


> lubomir
> --