Forward Mouse input to Makie

[Rasmus Henningsson]

It would be useful to forward mouse (and keyboard) input to Makie. E.g. to be able to spin 3d plots using the mouse.

The proper way to do this would probably to adapt the code at https://github.com/jwahlstrand/GtkMakie.jl/blob/main/src/events.jl

At the moment, I have a workaround, by putting a MouseArea over the Makie viewport.
Here's an example of how it can be done, it might be useful to someone in the meantime. 🙂

MouseArea {
	anchors.fill: parent
	acceptedButtons: Qt.AllButtons

	onPressed: mouse=>Julia.mouse_press_callback(mouse.x,height-mouse.y-1,mouse.button)
	onReleased: mouse=>Julia.mouse_release_callback(mouse.x,height-mouse.y-1,mouse.button)
	onPositionChanged: mouse=>Julia.mouse_position_callback(mouse.x,height-mouse.y-1)
	onWheel: wheel=>Julia.mouse_wheel_callback(wheel.x, wheel.y, wheel.angleDelta.x, wheel.angleDelta.y)
}

and in the callbacks we update the Observables in scene.events:

function mouse_button_qt2makie(button)
	button == 1 && return Makie.Mouse.left
	button == 2 && return Makie.Mouse.right
	button == 4 && return Makie.Mouse.middle
	Makie.Mouse.none
end

function mouse_press_callback(mouseX, mouseY, button)
	scene.events.mouseposition[] = (mouseX,mouseY)
	b = mouse_button_qt2makie(button)
	if b != Makie.Mouse.none
		scene.events.mousebutton[] = Makie.MouseButtonEvent(b, Makie.Mouse.press)
	end
end
function mouse_release_callback(mouseX, mouseY, button)
	scene.events.mouseposition[] = (mouseX,mouseY)
	b = mouse_button_qt2makie(button)
	if b != Makie.Mouse.none
		scene.events.mousebutton[] = Makie.MouseButtonEvent(b, Makie.Mouse.release)
	end
end
function mouse_position_callback(mouseX, mouseY)
	scene.events.mouseposition[] = (mouseX,mouseY)
end
function mouse_wheel_callback(mouseX, mouseY, angleDeltaX, angleDeltaY)
	scene.events.mouseposition[] = (mouseX,mouseY)
	scene.events.scroll[] = (angleDeltaX/120,angleDeltaY/120)
end