buldthensnip/pkg/base/icegui/widgets.lua

413 lines
12 KiB
Lua

-- Icegui widget layout library
local P = {}
local widget_mt = {}
function widget_mt.__add(a, b) a.add_child(b) return a end
function widget_mt.__sub(a, b) a.remove_child(b) return a end
function widget_mt.__tostring(a)
return a.x.."x "..a.y.."y "..a.relx.."rx "..a.rely.."ry"
end
function widget_mt.__index(self, key)
local getters = rawget(self, "getter_keys")
if getters[key] ~= nil then
return getters[key]()
else
return rawget(self, key)
end
end
function widget_mt.__newindex(self, key, value)
local setters = rawget(self, "setter_keys")
if setters[key] ~= nil then
setters[key](value)
else
rawset(self, key, value)
end
end
function P.widget(options)
options = options or {}
local getter_keys = {}
local setter_keys = {}
local this = { x = options.x or 0, y = options.y or 0,
parent = options.parent or nil,
children = options.children or {},
align_x = options.align_x or 0.5,
align_y = options.align_y or 0.5,
width = options.width or 0,
height = options.height or 0,
margin_left = options.margin_left or 0,
margin_right = options.margin_right or 0,
margin_top = options.margin_top or 0,
margin_bottom = options.margin_bottom or 0,
getter_keys = getter_keys, setter_keys = setter_keys }
-- align 0 = top-left
-- align 1 = bottom-right
-- align 0.5 = center
function this.propogate_dirty()
this.dirty = true
for k, v in pairs(this.children) do
v.propogate_dirty()
end
end
function setter_keys.x(v) rawset(this, 'x', v) this.propogate_dirty() end
function setter_keys.y(v) rawset(this, 'y', v) this.propogate_dirty() end
function setter_keys.width(v) rawset(this, 'width', v) this.propogate_dirty() end
function setter_keys.height(v) rawset(this, 'height', v) this.propogate_dirty() end
function setter_keys.margin_left(v) rawset(this, 'margin_left', v) this.propogate_dirty() end
function setter_keys.margin_top(v) rawset(this, 'margin_top', v) this.propogate_dirty() end
function setter_keys.margin_right(v) rawset(this, 'margin_right', v) this.propogate_dirty() end
function setter_keys.margin_bottom(v) rawset(this, 'margin_bottom', v) this.propogate_dirty() end
function getter_keys.min_width() return this.width end
function setter_keys.min_width(v) error("cannot set widget.min_width externally") end
function getter_keys.min_height() return this.height end
function setter_keys.min_height(v) error("cannot set widget.min_height externally") end
function getter_keys.relx()
local pos = this.x - (this.width * this.align_x)
if this.parent == nil then return pos
else return this.parent.relx + this.parent.width * this.parent.align_x + pos end
end
function setter_keys.relx(v)
local pos = v + (this.width * this.align_x)
if this.parent == nil then this.x = pos
else this.x = pos - (this.parent.relx + this.parent.width * this.parent.align_x) end
end
function getter_keys.rely()
local pos = this.y - (this.height * this.align_y)
if this.parent == nil then return pos
else return this.parent.rely + this.parent.height * this.parent.align_y + pos end
end
function setter_keys.rely(v)
local pos = v + (this.width * this.align_y)
if this.parent == nil then this.y = pos
else this.y = pos - (this.parent.rely + this.parent.height * this.parent.align_y) end
end
function getter_keys.l() return this.relx end
function setter_keys.l(v) this.relx = v end
function getter_keys.t() return this.rely end
function setter_keys.t(v) this.rely = v end
function getter_keys.r() return this.relx + this.width end
function setter_keys.r(v) this.relx = v - this.width end
function getter_keys.b() return this.rely + this.height end
function setter_keys.b(v) this.rely = v - this.height end
function getter_keys.cx() return this.relx + this.width * 0.5 end
function setter_keys.cx(v) this.relx = v - this.width * 0.5 end
function getter_keys.cy() return this.rely + this.height * 0.5 end
function setter_keys.cy(v) this.rely = v - this.height * 0.5 end
function this.inner()
local l = this.l() + this.margin_left()
local t = this.t() + this.margin_top()
local r = this.r() - this.margin_right()
local b = this.b() - this.margin_bottom()
return {x=l, y=t, left=l, top=t, right=r, bottom=b,
width=r-l, height=b-t, cx=l+(r-l)*0.5, cy=t+(b-t)*0.5}
end
function this.aabb(x, y, w, h)
return not (this.l>x or this.r<x+w or this.t>y or this.b<y+h)
end
function this.child_boundaries()
local child_boundaries = {}
local ct = 1
for c_k, child in pairs(this.children) do
for b_k, boundary in pairs(child.child_boundaries) do
child_boundaries[ct] = boundary
ct = ct + 1
end
end
child_boundaries[ct] = {l=this.l, t=this.t, r=this.r, b=this.b}
return child_boundaries
end
function getter_keys.full_dimensions()
local boundaries = this.child_boundaries()
local left = boundaries[1].l
local top = boundaries[1].t
local right = boundaries[1].r
local bottom = boundaries[1].b
for k, v in pairs(boundaries) do
left = math.min(v.l, left)
top = math.min(v.t, top)
right = math.max(v.r, right)
bottom = math.max(v.b, bottom)
end
return {l=left, t=top, r=right, b=bottom}
end
-- very simple aabb collision for mousing. returns the "first and deepest child".
function this.collide(x, y, w, h)
w = w or 1
h = h or 1
local hit = this.aabb(x, y, w, h)
local result = this
for k, v in pairs(this.children) do
result = v.collide(x, y, w, h) or this
end
return result
end
setmetatable(this, widget_mt)
-- stub method for graphics resource management
function this.free() end
-- remove the parent-child connection but do not deallocate the object
function this.detach()
if this.parent then
local pos = this.parent.get_child_position(this)
table.remove(this.parent.children, pos)
this.parent = nil
return pos
end
return nil
end
-- remove the parent-child connection but do not deallocate the object
function
this.remove_child(child) child.detach()
end
-- remove the parent-child connection but do not deallocate the objects
function this.remove_all_children() for k,child in pairs(this.children) do this.remove_child(child) end end
-- create a relationship between the parent and child's size and coordinates (with optional sort position)
function this.add_child(child, position)
if child.parent ~= this then
position = position or #this.children+1
child.detach(); child.parent = this;
table.insert(this.children, position, child)
end
end
-- create a relationship between the parent and child's size and coordinates
function this.set_parent(parent) parent.add_child(this) end
-- remove the object and its children and deallocate all memory
function this.despawn()
this.detach(); while #this.children>0 do this.children[1].despawn() end this.free()
end
-- get the index of the child, or nil if it's not in this node
function this.get_child_position(child)
local i
for i=1, #this.children do if this.children[i] == child then return i end end
return nil
end
-- swap the children at the indicated index values
function this.swap_indices(a, b)
local tmp = this.children[a]
this.children[a] = this.children[b]
this.children[b] = tmp
end
-- swap the child objects (assuming they exist and are searchable in the children table)
function this.swap_children(a, b)
this.swap_children(this.get_child_position(a), this.get_child_position(b))
end
-- make the child the top-most element without disturbing other ordering
function this.child_to_top(child) child.detach() this.add_child(child) end
-- make the child the bottom-most element without disturbing other ordering
function this.child_to_bottom(child) child.detach() this.add_child(child, 1) end
-- when using spacers, this walks through the tree and reflows them
function this.reflow() for k, v in pairs(this.children) do v.reflow() end end
--[[Return a concatenated list of children so that they can be batch processed
even if tree position changes midflight.]]
function this.flatten()
local flat = {this}
for k,v in pairs(this.children) do
local sublist = v.flatten()
for i=1, #sublist do
table.insert(flat, sublist[i])
end
end
return flat
end
return this
end
-- Abstract spacer implementation
local function spacer(options)
local this = P.widget(options)
this.fixed_width = options.fixed_width or false
this.fixed_height = options.fixed_height or false
this.spread = options.spread or 0
local width_auto = function()
local b = this.child_boundaries()
return b.r - b.l
end
local height_auto = function()
local b = this.child_boundaries()
return b.b - b.t
end
this.getter_keys.width = function()
if this.fixed_width then return rawget(this, 'width') else return width_auto() end
end
this.getter_keys.height = function()
if this.fixed_height then return rawget(this, 'height') else return height_auto() end
end
this.getter_keys.min_width = function()
local w = 0
for k, v in pairs(this.children) do
w = w + v.min_width
end
return w
end
this.getter_keys.min_height = function()
local h = 0
for k, v in pairs(this.children) do
h = h + v.min_height
end
return h
end
return this
end
--[[ FIXME: We can use min_width and min_height some more to force percentage allocation
to achieve the minimally overlapped result. (This would mean refactoring the table gen a bit.) ]]
-- percentage allocation table
local function percentage_table(p, children, width)
if p == nil then
-- default: all elements get same %
local c = #children
local i
p = {}
for i=1,c do table.insert(p, i, 1./c) end
elseif not (#children == #p) then
error("mismatched # of children in percentage table: expected "..#children.." got "..#p)
end
local result = {}
-- create a result positioning table that is each element centered inside their allocated %
local i
local pct = 0
for i=1, #children do
pct = pct + p[i]
table.insert(result, i, pct - p[i]/2)
end
return result
end
-- Horizontal spacer
function P.hspacer(options)
local this = spacer(options)
function this.reflow()
local children = this.children
for k, v in pairs(children) do v.reflow() end
local tw = 0
if this.fixed_width then
-- allocate space to the children inside the given width
local w = this.width
tw = w
local p = percentage_table(this.percentage, this.children)
local i = 1
for i=1, #children do
children[i].x = p[i]
end
else
-- allocate in order, left-positioned, based on the 'spread' value
local i = 1
local pos = 0
for i=1, #children do
children[i].l = pos + this.relx
pos = pos + this.spread + children[i].min_width
end
tw = pos - this.spread
end
-- final pass: fix up alignment
tw = tw * -this.align_x
for i=1, #children do
children[i].x = children[i].x + tw
end
this.propogate_dirty()
end
return this
end
-- Vertical spacer
function P.vspacer(options)
local this = spacer(options)
function this.reflow()
local children = this.children
for k, v in pairs(children) do v.reflow() end
local th = 0
if this.fixed_height then
-- allocate space to the children inside the given width
local h = this.height
th = h
local p = percentage_table(this.percentage, this.children)
local i = 1
for i=1, #children do
children[i].y = p[i]
end
else
-- allocate in order, top-positioned, based on the 'spread' value
local i = 1
local pos = 0
for i=1, #children do
children[i].t = pos + this.rely
pos = pos + this.spread + children[i].min_height
end
th = pos - this.spread
end
-- final pass: fix up alignment
th = th * -this.align_y
for i=1, #children do
children[i].y = children[i].y + th
end
this.propogate_dirty()
end
return this
end
if _REQUIREDNAME == nil then
widgets = P
else
_G[_REQUIREDNAME] = P
end
return P