yui/slider.lua

114 lines
3.3 KiB
Lua

--- Implements a scrollable slider widget
--
-- @classmod yui.Slider
-- @copyright 2022, The DoubleFourteen Code Forge
-- @author Lorenzo Cogotti, Andrea Pasquini
--
--- Slider widget receives the following callbacks: @{yui.Widget.WidgetCallbacks|onEnter}(), @{yui.Widget.WidgetCallbacks|onChange}(), @{yui.Widget.WidgetCallbacks|onLeave}().
local BASE = (...):gsub('slider$', '')
local Widget = require(BASE..'widget')
local core = require(BASE..'core')
local Slider = setmetatable({}, Widget)
Slider.__index = Slider
--- Attributes accepted by the @{Slider} widget beyond the standard @{yui.Widget.WidgetAttributes|attributes}
-- and @{yui.Widget.WidgetCallbacks|callbacks}.
--
-- @field min (number) min value of the slider
-- @field max (number) max value of the slider
-- @field vertical (boolean) true for vertical slider, false or nil for horizontal slider
-- @field value (number) default value
-- @field step (number) number of slider's steps
-- @field cornerRadius (number) radius for rounded corners
-- @table SliderAttributes
--- Slider constructor
-- @param args (@{SliderAttributes}) widget attributes
function Slider.new(args)
local self = setmetatable(args, Slider)
self.color = self.color or core.theme.color
self.cornerRadius = self.cornerRadius or core.theme.cornerRadius
self.vertical = self.vertical or false
self.min = self.min or 0
self.max = self.max or 1
self.value = self.value or self.min
self.step = self.step or (self.max - self.min) / 10
return self
end
function Slider:onPointerInput(px,py, clicked, down)
self:grabFocus()
if not down then
return
end
local x,y,w,h = self.x,self.y,self.w,self.h
local fraction
if self.vertical then
fraction = math.min(1, math.max(0, (y+h - py) / h))
else
fraction = math.min(1, math.max(0, (px - x) / w))
end
local v = fraction*(self.max - self.min) + self.min
if v ~= self.value then
self.value = v
self:onChange(v)
end
end
function Slider:onActionInput(action)
local up = self.vertical and 'up' or 'right'
local down = self.vertical and 'down' or 'left'
local handled = false
if action[up] then
self.value = math.min(self.max, self.value + self.step)
handled = true
elseif action[down] then
self.value = math.max(self.min, self.value - self.step)
handled = true
end
if handled then
self:onChange(self.value)
end
return handled
end
function Slider:draw()
local x,y,w,h = self.x,self.y,self.w,self.h
local r = math.min(w,h) / 2.1
local c = self:colorForState()
local fraction = (self.value - self.min) / (self.max - self.min)
local xb, yb, wb, hb -- size of the progress bar
if self.vertical then
x, w = x + w*.25, w*.5
xb, yb, wb, hb = x, y+h*(1-fraction), w, h*fraction
else
y, h = y + h*.25, h*.5
xb, yb, wb, hb = x,y, w*fraction, h
end
core.drawBox(x,y,w,h, c, self.cornerRadius)
core.drawBox(xb,yb,wb,hb, {bg=c.fg}, self.cornerRadius)
if self:isFocused() then
love.graphics.setColor(c.fg)
if self.vertical then
love.graphics.circle('fill', x+wb/2, yb, r)
else
love.graphics.circle('fill', x+wb, yb+hb/2, r)
end
end
end
return Slider