yui/layout.lua

252 lines
5.8 KiB
Lua

local BASE = (...):gsub('layout', '')
local Widget = require(BASE..'widget')
local core = require(BASE..'core')
local gear = require 'lib.gear'
local isinstance = gear.meta.isinstance
local rectunion = gear.rect.union
local pointinrect = gear.rect.pointinside
local Layout = setmetatable({}, Widget)
Layout.__index = Layout
-- Calculate initial widget size.
local function calcsize(sizes, widget)
local w, h = widget.w, widget.h
if w == nil then
assert(#sizes > 0, "Default width is undefined!")
w = sizes[#sizes].w
end
if h == nil then
assert(#sizes > 0, "Default height is undefined!")
h = sizes[#sizes].h
end
if w == 'max' then
w = 0
for _,v in ipairs(sizes) do
if v.w > w then
w = v.w
end
end
elseif w == 'median' then
w = 0
for _,v in ipairs(sizes) do
w = w + v.w
end
w = math.ceil(w / #sizes)
elseif w == 'min' then
w = math.huge
for _,v in ipairs(sizes) do
if v.w < w then
w = v.w
end
end
else
assert(type(w) == 'number')
end
if h == 'max' then
h = 0
for _,v in ipairs(sizes) do
if v.h > h then
h = v.h
end
end
elseif h == 'median' then
h = 0
for _,v in ipairs(sizes) do
h = h + v.h
end
h = math.ceil(h / #sizes)
elseif h == 'min' then
h = math.huge
for _,v in ipairs(sizes) do
if v.h < h then
h = v.h
end
end
else
assert(type(h) == 'number')
end
sizes[#sizes+1] = { w = w, h = h }
widget.w, widget.h = w, h
return w, h
end
-- Lay down container widgets according to Layout type.
function Layout:layoutWidgets()
local nx,ny = self.x,self.y
local sizes = {}
local stack = self.stack
local pad = self.padding
-- Container bounds, empty
local rx,ry,rw,rh = nx,ny,-1,-1
-- Layout container children
for _,widget in ipairs(self) do
widget.x, widget.y = nx, ny
widget.ui = self.ui
widget.parent = self
if isinstance(widget, Layout) then
widget:layoutWidgets()
end
local w,h = calcsize(sizes, widget)
rx,ry,rw,rh = rectunion(rx,ry,rw,rh, nx,ny,w,h)
nx,ny = self.advance(nx,ny, w,h, pad)
stack[#stack+1] = widget
end
self.x = rx
self.y = ry
self.w = math.max(rw, 0)
self.h = math.max(rh, 0)
end
function Layout:onPointerInput(px,py, clicked, down)
local stack = self.stack
-- Propagate pointer event from topmost widget to bottom
for i = #stack,1,-1 do
local widget = stack[i]
local x,y,w,h = widget.x,widget.y,widget.w,widget.h
if pointinrect(px,py, x,y,w,h) then
widget:handlePointer(px,py, clicked, down)
break
end
end
end
-- Find layout's child containing the provided widget.
local function childof(layout, widget)
local parent = widget.parent
while parent ~= layout do
widget = parent
parent = widget.parent
end
return widget
end
local function findfirst(widget)
while isinstance(widget, Layout) do
-- Find first element accepting focus
for i = 1,#widget do
if not widget[i].nofocus then
widget = widget[i]
break
end
end
end
return widget
end
local function findnext(layout, widget)
local child = childof(layout, widget)
for i,w in ipairs(layout) do
if w == child then
-- Search to the right, wraparound to the left
for j = i+1,#layout do
if not layout[j].nofocus then
return findfirst(layout[j])
end
end
for j = 1,i-1 do
if not layout[j].nofocus then
return findfirst(layout[j])
end
end
end
end
return widget
end
local function findprev(layout, widget)
local child = childof(layout, widget)
for i,w in ipairs(layout) do
if w == child then
-- Search to the left, wraparound to the right
for j = i-1,1,-1 do
if not layout[j].nofocus then
return findfirst(layout[j])
end
end
for j = #layout,i+1,-1 do
if not layout[j].nofocus then
return findfirst(layout[j])
end
end
end
end
return widget
end
function Layout:firstFocusableWidget()
return findfirst(self)
end
function Layout:nextFocusableWidget()
return findnext(self, self.ui.focused)
end
function Layout:previousFocusableWidget()
return findprev(self, self.ui.focused)
end
function Layout:onActionInput(action)
local handled = false
if action[self.next] then
local n = self:nextFocusableWidget()
n:grabFocus()
handled = true
end
if action[self.prev] then
local p = self:previousFocusableWidget()
p:grabFocus()
handled = true
end
return handled
end
function Layout:update(dt)
for _,widget in ipairs(self.stack) do
widget:update(dt)
end
end
function Layout:draw()
-- Draw all children according to their order (topmost last)
for _,widget in ipairs(self.stack) do
widget:draw()
end
end
function Layout.new(args)
local self = setmetatable(args, Layout)
self.padding = self.padding or 0
self.stack = {}
-- A Layout ignores focus if empty or containing only nofocus widgets
self.nofocus = true
for _,w in ipairs(self) do
if not w.nofocus then
self.nofocus = false
break
end
end
return self
end
return Layout