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koreader/frontend/ui/widget/container/alphacontainer.lua

88 lines
2.5 KiB
Lua

--[[--
AlphaContainer will paint its content (1 widget) onto lower levels using
a transparency (0..1)
Example:
local alpha
alpha = AlphaContainer:new{
alpha = 0.7,
FrameContainer:new{
background = Blitbuffer.COLOR_WHITE,
bordersize = Size.border.default,
margin = 0,
padding = Size.padding.default
}
}
--]]
local Blitbuffer = require("ffi/blitbuffer")
local WidgetContainer = require("ui/widget/container/widgetcontainer")
local AlphaContainer = WidgetContainer:new{
alpha = 1,
-- we cache a blitbuffer object for re-use here:
private_bb = nil,
-- we save the underlying area here:
background_bb = nil,
background_bb_x = nil,
background_bb_y = nil
}
function AlphaContainer:paintTo(bb, x, y)
local contentSize = self[1]:getSize()
local private_bb = self.private_bb
if self.background_bb then
-- we have a saved copy of what was below our paint area
-- we restore this first
bb:blitFrom(self.background_bb, self.background_bb_x, self.background_bb_y)
end
if not private_bb
or private_bb:getWidth() ~= contentSize.w
or private_bb:getHeight() ~= contentSize.h
then
if private_bb then
private_bb:free() -- free the one we're going to replace
end
-- create private blitbuffer for our child widget to paint to
private_bb = Blitbuffer.new(contentSize.w, contentSize.h, bb:getType())
self.private_bb = private_bb
-- save what is below our painting area
if not self.background_bb
or self.background_bb:getWidth() ~= contentSize.w
or self.background_bb:getHeight() ~= contentSize.h
then
if self.background_bb then
self.background_bb:free() -- free the one we're going to replace
end
self.background_bb = Blitbuffer.new(contentSize.w, contentSize.h, bb:getType())
end
self.background_bb:blitFrom(bb, 0, 0, x, y)
end
-- now have our childs paint to the private blitbuffer
private_bb:fill(Blitbuffer.COLOR_WHITE)
self[1]:paintTo(private_bb, 0, 0)
-- blit the private blitbuffer to our parent blitbuffer
bb:addblitFrom(private_bb, x, y, nil, nil, nil, nil, self.alpha)
end
function AlphaContainer:onCloseWidget()
if self.private_bb then
self.private_bb:free()
self.private_bb = nil
end
if self.background_bb then
self.background_bb:free()
self.background_bb = nil
end
end
return AlphaContainer