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function tostr(t)
local str = ""
for k, v in next, t do
if #str > 0 then
str = str .. ", "
end
if type(k) == "number" then
str = str .. "[" .. k .. "] = "
else
str = str .. tostring(k) .. " = "
end
if type(v) == "table" then
str = str .. "{ " .. tostr(v) .. " }"
elseif type(v) == "string" then
str = str .. '"' .. v .. '"'
else
str = str .. tostring(v)
end
end
return str
end
function trim_ws(s)
return s:match("^%s*(.*)")
end
function count_hypens(s)
local leftover = s:match("^-*(.*)")
return string.len(s) - string.len(leftover)
end
function parse_file(file)
local slides = {}
local block = {}
for line in file:lines() do
local s = trim_ws(line)
if #s == 0 then -- done with a block
if #block > 0 then
slides[#slides + 1] = block
block = {}
end
else
local n = count_hypens(s)
block[#block + 1] = {
indent = n,
text = trim_ws(s:sub(n + 1, -1))
}
end
end
return slides
end
function pretty_print_slide(slide)
io.write("{\n")
for i = 1, #slide do
local node = slide[i]
for j = 0, node.indent do
io.write(" ")
end
io.write("{ ")
io.write(tostr(node))
io.write(" },\n")
end
io.write("},\n")
end
function pretty_print_slides(slides)
io.write("gSlides = {\n")
for i = 1, #slides do
pretty_print_slide(slides[i])
end
io.write("}\n")
end
gSlides = parse_file(io.open("/skia/trunk/resources/slides_content.lua", "r"))
function make_rect(l, t, r, b)
return { left = l, top = t, right = r, bottom = b }
end
function make_paint(typefacename, stylebits, size, color)
local paint = Sk.newPaint();
paint:setAntiAlias(true)
paint:setSubpixelText(true)
paint:setTypeface(Sk.newTypeface(typefacename, stylebits))
paint:setTextSize(size)
paint:setColor(color)
return paint
end
function drawSlide(canvas, slide, template)
template = template.slide -- need to sniff the slide to know if we're title or slide
local x = template.margin_x
local y = template.margin_y
local scale = 1.15
for i = 1, #slide do
local node = slide[i]
local paint = template[node.indent + 1]
local fm = paint:getFontMetrics()
local x_offset = -fm.ascent * node.indent
y = y - fm.ascent * scale
canvas:drawText(node.text, x + x_offset, y, paint)
y = y + fm.descent * scale
end
end
function slide_transition(prev, next, is_forward)
local rec = {
proc = function(self, canvas, drawSlideProc)
if self:isDone() then
drawSlideProc(canvas)
return nil
end
self.prevDrawable:draw(canvas, self.curr_x, 0)
self.nextDrawable:draw(canvas, self.curr_x + 640, 0)
self.curr_x = self.curr_x + self.step_x
return self
end
}
if is_forward then
rec.prevDrawable = prev
rec.nextDrawable = next
rec.curr_x = 0
rec.step_x = -15
rec.isDone = function (self) return self.curr_x <= -640 end
else
rec.prevDrawable = next
rec.nextDrawable = prev
rec.curr_x = -640
rec.step_x = 15
rec.isDone = function (self) return self.curr_x >= 0 end
end
return rec
end
function fade_slide_transition(prev, next, is_forward)
local rec = {
prevDrawable = prev,
nextDrawable = next,
proc = function(self, canvas, drawSlideProc)
if self:isDone() then
drawSlideProc(canvas)
return nil
end
self.prevDrawable:draw(canvas, self.prev_x, 0, self.prev_a)
self.nextDrawable:draw(canvas, self.next_x, 0, self.next_a)
self:step()
return self
end
}
if is_forward then
rec.prev_x = 0
rec.prev_a = 1
rec.next_x = 640
rec.next_a = 0
rec.isDone = function (self) return self.next_x <= 0 end
rec.step = function (self)
self.next_x = self.next_x - 20
self.next_a = (640 - self.next_x) / 640
self.prev_a = 1 - self.next_a
end
else
rec.prev_x = 0
rec.prev_a = 1
rec.next_x = 0
rec.next_a = 0
rec.isDone = function (self) return self.prev_x >= 640 end
rec.step = function (self)
self.prev_x = self.prev_x + 20
self.prev_a = (640 - self.prev_x) / 640
self.next_a = 1 - self.prev_a
end
end
return rec
end
--------------------------------------------------------------------------------------
function SkiaPoint_make_template()
local title = {
margin_x = 30,
margin_y = 100,
}
title[1] = make_paint("Arial", 1, 50, { a=1, r=0, g=0, b=0 })
title[1]:setTextAlign("center")
title[2] = make_paint("Arial", 1, 25, { a=1, r=.3, g=.3, b=.3 })
title[2]:setTextAlign("center")
local slide = {
margin_x = 20,
margin_y = 30,
}
slide[1] = make_paint("Arial", 1, 36, { a=1, r=0, g=0, b=0 })
slide[2] = make_paint("Arial", 0, 30, { a=1, r=0, g=0, b=0 })
slide[3] = make_paint("Arial", 0, 24, { a=1, r=.2, g=.2, b=.2 })
return {
title = title,
slide = slide,
}
end
gTemplate = SkiaPoint_make_template()
gRedPaint = Sk.newPaint()
gRedPaint:setAntiAlias(true)
gRedPaint:setColor{a=1, r=1, g=0, b=0 }
-- animation.proc is passed the canvas before drawing.
-- The animation.proc returns itself or another animation (which means keep animating)
-- or it returns nil, which stops the animation.
--
local gCurrAnimation
gSlideIndex = 1
function next_slide()
local prev = gSlides[gSlideIndex]
gSlideIndex = gSlideIndex + 1
if gSlideIndex > #gSlides then
gSlideIndex = 1
end
spawn_transition(prev, gSlides[gSlideIndex], true)
end
function prev_slide()
local prev = gSlides[gSlideIndex]
gSlideIndex = gSlideIndex - 1
if gSlideIndex < 1 then
gSlideIndex = #gSlides
end
spawn_transition(prev, gSlides[gSlideIndex], false)
end
function new_drawable_picture(pic)
return {
picture = pic,
width = pic:width(),
height = pic:height(),
draw = function (self, canvas, x, y, paint)
canvas:drawPicture(self.picture, x, y, paint)
end
}
end
function new_drawable_image(img)
return {
image = img,
width = img:width(),
height = img:height(),
draw = function (self, canvas, x, y, paint)
canvas:drawImage(self.image, x, y, paint)
end
}
end
function spawn_transition(prevSlide, nextSlide, is_forward)
local transition
if is_forward then
transition = prevSlide.transition
else
transition = nextSlide.transition
end
if not transition then
transition = fade_slide_transition
end
local rec = Sk.newPictureRecorder()
drawSlide(rec:beginRecording(640, 480), prevSlide, gTemplate)
local prevDrawable = new_drawable_picture(rec:endRecording())
drawSlide(rec:beginRecording(640, 480), nextSlide, gTemplate)
local nextDrawable = new_drawable_picture(rec:endRecording())
gCurrAnimation = transition(prevDrawable, nextDrawable, is_forward)
end
--------------------------------------------------------------------------------------
function spawn_rotate_animation()
gCurrAnimation = {
angle = 0,
angle_delta = 5,
pivot_x = 320,
pivot_y = 240,
proc = function (self, canvas, drawSlideProc)
if self.angle >= 360 then
drawSlideProc(canvas)
return nil
end
canvas:translate(self.pivot_x, self.pivot_y)
canvas:rotate(self.angle)
canvas:translate(-self.pivot_x, -self.pivot_y)
drawSlideProc(canvas)
self.angle = self.angle + self.angle_delta
return self
end
}
end
function spawn_scale_animation()
gCurrAnimation = {
scale = 1,
scale_delta = .95,
scale_limit = 0.2,
pivot_x = 320,
pivot_y = 240,
proc = function (self, canvas, drawSlideProc)
if self.scale < self.scale_limit then
self.scale = self.scale_limit
self.scale_delta = 1 / self.scale_delta
end
if self.scale > 1 then
drawSlideProc(canvas)
return nil
end
canvas:translate(self.pivot_x, self.pivot_y)
canvas:scale(self.scale, self.scale)
canvas:translate(-self.pivot_x, -self.pivot_y)
drawSlideProc(canvas)
self.scale = self.scale * self.scale_delta
return self
end
}
end
function onDrawContent(canvas, width, height)
local matrix = Sk.newMatrix()
matrix:setRectToRect(make_rect(0, 0, 640, 480), make_rect(0, 0, width, height), "center")
canvas:concat(matrix)
local drawSlideProc = function(canvas)
drawSlide(canvas, gSlides[gSlideIndex], gTemplate)
end
if gCurrAnimation then
gCurrAnimation = gCurrAnimation:proc(canvas, drawSlideProc)
return true
else
drawSlideProc(canvas)
return false
end
end
function onClickHandler(x, y)
return false
end
local keyProcs = {
n = next_slide,
p = prev_slide,
r = spawn_rotate_animation,
s = spawn_scale_animation,
}
function onCharHandler(uni)
local proc = keyProcs[uni]
if proc then
proc()
return true
end
return false
end
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