[RQt-devel] mosaiq

[Deepayan Sarkar]

On Mon, Sep 27, 2010 at 1:48 PM, Michael Lawrence
<lawrence.michael at gene.com> wrote:

> I've not had enough time to play around with the layout. There have been
> many examples from others where the layout behaves strangely, and I don't
> really have an explanation.
>
> The row/col stretch factors are the most obvious way to control the packing
> of the rows and columns. In theory, the grid layout is considering the size
> request of the widget, but in some simple attempts I did not have much luck
> playing with that.

OK, I will try to see if I can come up with anything.

[...]

> There is a cache mode, just pass cache=TRUE to qlayer(). Note that this will
> basically require clip=TRUE, since the cache surface will be maximally
> allocated to the size of the layer. Clipping can cause issues.

No, I already have cache=TRUE set in qlayer(). Here is a nice simple
example showing the problem:

-------

library(qtpaint)

scene <- qscene()
root <- qlayer(scene)

points1 <-
    qlayer(root,
           paintFun = function(item, painter, exposed) {
               qdrawGlyph(painter, qglyphCircle(10),
                          runif(10), runif(10), stroke = NA,
                          fill = sample(colors(), 1))
           },
           row = 1L, col = 0L,
           cache = TRUE,
           limits = qrect(c(0, 1), c(0, 1)))

v <- qplotView(scene, opengl = FALSE)

w <- Qt$QTabWidget()
w$addTab(v, "view")
w$addTab((ted <- Qt$QTextEdit()), "text")
w

-------

If I now switch between the two tabs (either using mouse or keyboard),
I see the paint function being called every time v becomes visible.

The following is even more interesting. Start this infinite loop:

while (TRUE) {
    w$currentIndex <- 1
    w$update()
    Sys.sleep(0.2)
    w$currentIndex <- 0
    w$update()
    Sys.sleep(0.2)
}

Then while the window with w

  - does not have focus, there is no repaint,

  - does have focus, there's a repaint on every run.

This is fairly convincing evidence that this is a focus issue, but I
haven't been able to find anything more specific.

-Deepayan