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opus/sys/apis/ui/components/Viewport.lua
kepler155c@gmail.com 915085ac5f ui overhaul
2019-02-05 23:03:57 -05:00

97 lines
2.4 KiB
Lua

local class = require('class')
local UI = require('ui')
local colors = _G.colors
--[[-- Viewport --]]--
UI.Viewport = class(UI.Window)
UI.Viewport.defaults = {
UIElement = 'Viewport',
backgroundColor = colors.cyan,
accelerators = {
down = 'scroll_down',
up = 'scroll_up',
home = 'scroll_top',
[ 'end' ] = 'scroll_bottom',
pageUp = 'scroll_pageUp',
[ 'control-b' ] = 'scroll_pageUp',
pageDown = 'scroll_pageDown',
[ 'control-f' ] = 'scroll_pageDown',
},
}
function UI.Viewport:setParent()
UI.Window.setParent(self)
self.canvas = self:addLayer()
end
function UI.Viewport:enable()
UI.Window.enable(self)
self.canvas:setVisible(true)
end
function UI.Viewport:disable()
UI.Window.disable(self)
self.canvas:setVisible(false)
end
function UI.Viewport:setScrollPosition(offset)
local oldOffset = self.offy
self.offy = math.max(offset, 0)
self.offy = math.min(self.offy, math.max(#self.canvas.lines, self.height) - self.height)
if self.offy ~= oldOffset then
if self.scrollBar then
self.scrollBar:draw()
end
self.canvas.offy = offset
self.canvas:dirty()
end
end
function UI.Viewport:write(x, y, text, bg, tc)
if y > #self.canvas.lines then
for i = #self.canvas.lines, y do
self.canvas.lines[i + 1] = { }
self.canvas:clearLine(i + 1, self.backgroundColor, self.textColor)
end
end
return UI.Window.write(self, x, y, text, bg, tc)
end
function UI.Viewport:reset()
self.offy = 0
self.canvas.offy = 0
for i = self.height + 1, #self.canvas.lines do
self.canvas.lines[i] = nil
end
end
function UI.Viewport:getViewArea()
return {
y = (self.offy or 0) + 1,
height = self.height,
totalHeight = #self.canvas.lines,
offsetY = self.offy or 0,
}
end
function UI.Viewport:eventHandler(event)
if event.type == 'scroll_down' then
self:setScrollPosition(self.offy + 1)
elseif event.type == 'scroll_up' then
self:setScrollPosition(self.offy - 1)
elseif event.type == 'scroll_top' then
self:setScrollPosition(0)
elseif event.type == 'scroll_bottom' then
self:setScrollPosition(10000000)
elseif event.type == 'scroll_pageUp' then
self:setScrollPosition(self.offy - self.height)
elseif event.type == 'scroll_pageDown' then
self:setScrollPosition(self.offy + self.height)
elseif event.type == 'scroll_to' then
self:setScrollPosition(event.offset)
else
return false
end
return true
end