[RQt-devel] layout issues

[Hadley Wickham]

Looks good.  Will you add that example to the vignette?

What do you think about moving the currently intro pdf to the wiki?

Hadley

On Tue, Oct 5, 2010 at 1:07 PM, Michael Lawrence
<lawrence.michael at gene.com> wrote:
> Looked a bit into the layout issues. I've found that the following script
> gives a fairly desirable result. Forget about the stretch factor stuff for
> now, because unless a maximum or fixed size is set for a row/column, there
> is no guarantee that the row/column will not expand.
>
> library(qtpaint)
>
> fill_painter <- function(color) {
>   function(item, painter) qdrawRect(painter, 0, 0, 1, 1, fill = color)
> }
>
> layout_layer <- function(Color, ...) {
>   qlayer(figLayer, fill_painter(Color), limits = qrect(0, 0, 1, 1), ...)
> }
>
> scene <- qscene()
> figLayer <- qlayer(scene)
> layout <- figLayer$gridLayout()
>
> titleLayer <- layout_layer("red", colSpan = 2)
> yaxisLayer <- layout_layer("blue", row = 1)
> plotLayer <- layout_layer("green", row = 1, col = 1)
> xaxisLayer <- layout_layer("yellow", row = 2, col = 1)
>
> ## Set the maximum widths/heights:
>
> layout$setRowMaximumHeight(0, 50)
> layout$setColumnMaximumWidth(0, 50)
> layout$setRowMaximumHeight(2, 50)
>
> ## Could use Preferred here, with stretch factor set to zero, but this
> ## breaks when a layer spans multiple cells. It is hard to say if this
> ## is a bug in Qt, since QGraphicsGridLayout is largely
> ## undocumented. QGridLayout says a stretch-zero row/column can grow
> ## when no other row/column can grow. Setting a fixed or minimum
> ## width/height probably sets undue restrictions on the layout. The
> ## user should be able to shrink the window down, even if it is not
> ## longer possible to draw the data effectively. Thus, it's probably
> ## best to set the maximum.
>
> ## It is probably cleaner to set the dimensions directly on the layer:
> ## titleLayer$setMaximumHeight(50)
> ## xaxisLayer$setMaximumHeight(50)
> ## yaxisLayer$setMaximumWidth(50)
> ## But this currently crashes due to a (reported) bug in Smoke.
>
> qplotView(scene)
>
>
>
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>
>



-- 
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/