ENV["QSG_RENDER_LOOP"] = "basic"

using CxxWrap # for safe_cfunction

using QML

using Observables

using Plots

import GR

ENV["GKSwstype"] = "use_default"

gr(show=true)

const qmlfile = joinpath(dirname(Base.source_path()), "qml_ex.qml")

nbins = Observable(30)

w, h = (600, 450)

function paint(p::CxxPtr{QPainter}, item::CxxPtr{JuliaPaintedItem})

global w, h

ENV["GKS_WSTYPE"] = 381

ENV["GKS_CONID"] = split(repr(p.cpp_object), "@")[2]

dev = device(p[])[]

r = effectiveDevicePixelRatio(window(item[])[])

w, h = width(dev) / r, height(dev) / r

num_bins = Int64(round(nbins[]))

histogram(randn(10000), nbins=num_bins, size=(w, h))

return

function mousePosition(eventx, eventy, deltay)

if w > h

xn = eventx / w

yn = (h - eventy) / w

else

xn = eventx / h

yn = (h - eventy) / h

end

x, y = GR.ndctowc(xn, yn)

"($(round(x,digits=4)), $(round(y,digits=4)))"

loadqml(qmlfile,

paint_cfunction = @safe_cfunction(paint, Cvoid, (CxxPtr{QPainter}, CxxPtr{JuliaPaintedItem})),

parameters = JuliaPropertyMap("nbins" => nbins))

@qmlfunction mousePosition

exec()