Hi,
I’m being faced with a performance problem.
The app i’m building displays rows of tracks. Each track can contains a list a
cells. This combination of columns and rows and easily go beyond 50x50;
The problem is that every track has a lot of buttons and sliders. Each cell by
it’s turn has inside some elements to provide additional cosmetics.
I was testing my prototype with only a few tracks and cells on each track
(4x8). I started realising my problems when I added 50 tracks and 50 cells on
each one and started scrolling. On a PC this is easy and doesn’t give any
problems, but when doing it on a iPad 2… things are quite different.
The way I was doing this was:
ListView {
id: tracks
model: controller.tracks
delegate: TrackView {
cells: model.cells
...
}
}
}
TrackView {
property alias cells: cells.model
ListView {
id: cells
}
...
}
I need to have a really good performance so I started analysing other options.
My next idea was to replace the list on each track by a grid view which
received the model as a list of cells. The cells should then be arranged in a
single array. The problem here is that grid view will start laying out the
cells at the end of its bounds. I cannot specify when it should start switching
rows. For example. I have 10 tracks but I can only 5. I have 1 cell on each
track. I want to see cells in the following way:
(Pipes define my viewport)
| 0, 1 , 2, 3, 4|, 5, 6, 7, 8, 9
| 10, 11, 12, 13, 14|, 15, 16, 17, 18, 19
The way GridView is done doesn’t allow me this.
Obviously, I start to think that my only option here is to go to scene graph
implementation of a custom element.
Question:
Is there anyway to easily customise the way GridView chooses the cells to
render?
I would love to have an advise from more experienced developers before starting
to code like a mad.
Thanks,
With my best regards,
Nuno Santos
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