A = function()
	B()
	-- TODO: ugly that we're manipulating editor objects twice
	compute_layout(Page, Page.x,Page.y, Surface)
	compute_layout(Page2, Page2.x,Page2.y, Surface)
	-- continue the pipeline
	love.graphics.setFont(love.graphics.newFont(scale(20)))  -- editor objects implicitly depend on current font

compute_layout = function(node, x,y, nodes_to_render)
			subx,suby = compute_layout(child, subx,y, nodes_to_render)
			w = w + child.w
			if h < child.h then
				h = child.h
			end
		end
		node.w = w
		node.h = h
		if node_to_render then
			node_to_render.w = w
			node_to_render.h = h
		end
	end
			subx,suby = compute_layout(child, x,suby, nodes_to_render)
			if w < child.w then
				w = child.w
			end
			h = h+child.h
		end
		node.w = w
		node.h = h
		if node_to_render then
			node_to_render.w = w
			node_to_render.h = h
		end
	elseif node.type == 'cols' then
		node.x = x
		node.y = y
		-- lay out children left to right
		local node_to_render
		if node.bg then
			node_to_render = {type='rectangle', r=node.bg.r, g=node.bg.g, b=node.bg.b, x=node.x, y=node.y}
			table.insert(nodes_to_render, node_to_render)
		end
		local subx,suby = x,y
		local w,h = 0,0
		for _,child in ipairs(node.data) do
			if child.margin then
				subx = subx+child.margin
				w = w+child.margin
			end
			update_editor_box(node)
		end
	-- append to nodes_to_render flattened instructions to render a hierarchy of nodes
	-- return x,y rendered until (surface coordinates)
	if node.type == 'text' then
		-- leaf node containing raw text
		node.x = x
		node.y = y
		-- render background if necessary

A = function(skip_updating_screen_top_for)

A = function()

	B(skip_updating_screen_top_for)

	B()

		love.graphics.line(25, i*100, 75, i*100)

	elseif chord == 'C-up' then
		if Cursor_node.in_reply_to_id then
			Cursor_node = Nodes[Cursor_node.in_reply_to_id]
			ensure_cursor_node_within_viewport()
		end
	elseif chord == 'C-down' then
		if Cursor_node.children and #Cursor_node.children > 0 then
			Cursor_node = Nodes[Cursor_node.children[1]]
			ensure_cursor_node_within_viewport()
		end
	elseif chord == 'C-left' then
		if Cursor_node.in_reply_to_id then
			local parent = Nodes[Cursor_node.in_reply_to_id]
			assert(parent.children)
			if #parent.children > 1 then
				local idx = array.find(parent.children, Cursor_node.id)
				if idx > 1 then
					Cursor_node = Nodes[parent.children[idx-1]]
					ensure_cursor_node_within_viewport()
				end
			end
	elseif chord == 'C-right' then
		if Cursor_node.in_reply_to_id then
			local parent = Nodes[Cursor_node.in_reply_to_id]
			assert(parent.children)
			if #parent.children > 1 then
				local idx = array.find(parent.children, Cursor_node.id)
				if idx < #parent.children then
					Cursor_node = Nodes[parent.children[idx+1]]
					ensure_cursor_node_within_viewport()
				end
			end

		end

		pan_viewport_to_contain_cursor(Cursor_node)

compute_layout = function(node, x,y, nodes_to_render, skip_updating_screen_top_for)

compute_layout = function(node, x,y, nodes_to_render)

			update_editor_box(node, skip_updating_screen_top_for)

			update_editor_box(node)

			subx,suby = compute_layout(child, x,suby, nodes_to_render, skip_updating_screen_top_for)

			subx,suby = compute_layout(child, x,suby, nodes_to_render)

			subx,suby = compute_layout(child, subx,y, nodes_to_render, skip_updating_screen_top_for)

			subx,suby = compute_layout(child, subx,y, nodes_to_render)