[RQt-devel] Layers and layout

[Deepayan Sarkar]

Hi,

In my efforts to resurrect mosaiq, I have managed to put two "panel"
layers on the root layer as follows:

-----------

library(qtpaint)

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

scatterplotLayer <-
    function(x = runif(10), y = runif(10),
             fill = "black", row, col)
{
    force(x)
    force(y)
    paintFun <- function(item, painter, exposed)
    {
        qdrawGlyph(painter, qglyphCircle(), x, y, fill = qcolor(fill))
    }
    qlayer(root, paintFun = paintFun, cache = TRUE,
           limits = qrect(c(0, 1), c(0, 1)),
           row = row, col = col)
}

panel1 <- scatterplotLayer(row = 0, col = 0, fill = "red")
panel2 <- scatterplotLayer(row = 1, col = 1, fill = "green")

(view <- qplotView(scene = scene, opengl = FALSE))

-----------

However, this requires that I specify the position in the layout at
the time of creating the layer. The old mosaiq created parent-less
layers first and then put them in the root layer's layout. I have
tried this in two ways, both have failed:

-----------

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

scatterplotLayer <- function(x = runif(10), y = runif(10), fill = "black")
{
    force(x)
    force(y)
    paintFun <- function(item, painter, exposed)
    {
        qdrawGlyph(painter, qglyphCircle(), x, y, fill = qcolor(fill))
    }
    qlayer(NULL, paintFun = paintFun, cache = TRUE,
           limits = qrect(c(0, 1), c(0, 1)))
}

panel1 <- scatterplotLayer()
panel2 <- scatterplotLayer()

## This gives an error: Wrong number or types of arguments passed to
## 'Qanviz::RLayer::addLayer'
root[0, 0] <- panel1
root[1, 1] <- panel2

## This crashes
layout <- root$gridLayout()
layout$addItem(panel1, 0, 0)
layout$addItem(panel2, 1, 1)

-----------

Is there a way to achieve this? How is addLayer supposed to work?

-Deepayan