GSOC project updates

[Lubomir I. Ivanov]

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.

lubomir
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