mirror of
https://github.com/koreader/koreader
synced 2024-11-16 06:12:56 +00:00
7166efd777
ImageWidget: removed 'autostretch' setting (replaced by scale_factor=0) and renamed 'autoscale' setting to 'scale_for_dpi'.
355 lines
13 KiB
Lua
355 lines
13 KiB
Lua
--[[--
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ImageWidget shows an image from a file or memory
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Show image from file example:
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UIManager:show(ImageWidget:new{
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file = "resources/info-i.png",
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-- Make sure alpha is set to true if png has transparent background
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-- alpha = true,
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})
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Show image from memory example:
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UIManager:show(ImageWidget:new{
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-- bitmap_buffer should be a block of memory that holds the raw
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-- uncompressed bitmap.
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image = bitmap_buffer,
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})
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]]
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local Widget = require("ui/widget/widget")
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local Screen = require("device").screen
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local UIManager = require("ui/uimanager")
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local CacheItem = require("cacheitem")
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local Mupdf = require("ffi/mupdf")
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local Geom = require("ui/geometry")
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local Cache = require("cache")
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local logger = require("logger")
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local ImageCache = Cache:new{
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max_memsize = 2*1024*1024, -- 2M of image cache
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current_memsize = 0,
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cache = {},
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-- this will hold the LRU order of the cache
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cache_order = {}
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}
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local ImageCacheItem = CacheItem:new{}
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function ImageCacheItem:onFree()
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if self.bb.free then
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logger.dbg("free image blitbuffer", self.bb)
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self.bb:free()
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end
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end
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local ImageWidget = Widget:new{
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-- Can be provided with a path to a file
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file = nil,
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-- or an already made BlitBuffer (ie: made by Mupdf.renderImage())
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image = nil,
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-- Whether BlitBuffer rendered from file should be cached
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file_do_cache = true,
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-- Whether provided BlitBuffer can be modified by us and SHOULD be free() by us,
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-- normally true unless our caller wants to reuse it's provided image
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image_disposable = true,
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-- Width and height of container, to limit rendering to this area
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-- (if provided, and scale_factor is nil, image will be resized to
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-- these width and height without regards to original aspect ratio)
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width = nil,
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height = nil,
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hide = nil, -- to not be painted
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-- Settings that apply at paintTo() time
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invert = nil,
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dim = nil,
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alpha = false, -- honors alpha values from the image
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-- When rotation_angle is not 0, native image is rotated by this angle
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-- before scaling.
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rotation_angle = 0,
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-- If scale_for_dpi is true image will be rescaled according to screen dpi
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-- (x2 if DPI > 332) - (formerly known as 'autoscale')
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scale_for_dpi = false,
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-- When scale_factor is not nil, native image is scaled by this factor
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-- (if scale_factor == 1, native image size is kept)
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-- Special case : scale_factor == 0 : image will be scaled to best fit provided
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-- width and height, keeping aspect ratio (scale_factor will be updated
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-- from 0 to the factor used at _render() time)
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-- (former 'autostrech' setting removed, use "scale_factor=0" instead)
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scale_factor = nil,
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-- For initial positionning, if (possibly scaled) image overflows width/height
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center_x_ratio = 0.5, -- default is centered on image's center
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center_y_ratio = 0.5,
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-- For pan & zoom management:
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-- offsets to use in blitFrom()
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_offset_x = 0,
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_offset_y = 0,
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-- limits to center_x_ratio variation around 0.5 (0.5 +/- these values)
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-- to keep image centered (0 means center_x_ratio will be forced to 0.5)
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_max_off_center_x_ratio = 0,
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_max_off_center_y_ratio = 0,
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-- So we can reset self.scale_factor to its initial value in free(), in
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-- case this same object is free'd but re-used and and re-render'ed
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_initial_scale_factor = nil,
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_bb = nil,
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_bb_disposable = true, -- whether we should free() our _bb
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_bb_w = nil,
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_bb_h = nil,
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}
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function ImageWidget:_loadimage()
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self._bb = self.image
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-- don't touch or free if caller doesn't want that
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self._bb_disposable = self.image_disposable
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end
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function ImageWidget:_loadfile()
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local itype = string.lower(string.match(self.file, ".+%.([^.]+)") or "")
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if itype == "png" or itype == "jpg" or itype == "jpeg"
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or itype == "tiff" then
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local hash = "image|"..self.file.."|"..(self.width or "").."|"..(self.height or "")
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local cache = ImageCache:check(hash)
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if cache then
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-- hit cache
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self._bb = cache.bb
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self._bb_disposable = false -- don't touch or free a cached _bb
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else
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if not self.file_do_cache then
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self._bb = Mupdf.renderImageFile(self.file, self.width, self.height)
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self._bb_disposable = true -- we made it, we can modify and free it
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else
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-- cache this image
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logger.dbg("cache", hash)
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cache = ImageCacheItem:new{
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bb = Mupdf.renderImageFile(self.file, self.width, self.height),
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}
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cache.size = cache.bb.pitch * cache.bb.h * cache.bb:getBpp() / 8
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ImageCache:insert(hash, cache)
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self._bb = cache.bb
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self._bb_disposable = false -- don't touch or free a cached _bb
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end
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end
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else
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error("Image file type not supported.")
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end
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end
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function ImageWidget:_render()
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if self._bb then -- already rendered
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return
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end
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logger.dbg("ImageWidget: _render'ing")
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if self.image then
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self:_loadimage()
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elseif self.file then
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self:_loadfile()
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else
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error("cannot render image")
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end
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-- Store initial scale factor
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self._initial_scale_factor = self.scale_factor
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-- First, rotation
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if self.rotation_angle ~= 0 then
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if not self._bb_disposable then
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-- we can't modify _bb, make a copy
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self._bb = self._bb:copy()
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self._bb_disposable = true -- new object will have to be freed
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end
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self._bb:rotate(self.rotation_angle) -- rotate in-place
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end
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local bb_w, bb_h = self._bb:getWidth(), self._bb:getHeight()
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-- scale_for_dpi setting: update scale_factor (even if not set) with it
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if self.scale_for_dpi then
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local dpi_scale = Screen:getDPI() / 167
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-- rounding off to power of 2 to avoid alias with pow(2, floor(log(x)/log(2))
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dpi_scale = math.pow(2, math.max(0, math.floor(math.log(dpi_scale)/0.69)))
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if self.scale_factor == nil then
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self.scale_factor = 1
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end
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self.scale_factor = self.scale_factor * dpi_scale
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end
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-- scale to best fit container : compute scale_factor for that
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if self.scale_factor == 0 then
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if self.width and self.height then
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self.scale_factor = math.min(self.width / bb_w, self.height / bb_h)
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logger.dbg("ImageWidget: scale to fit, setting scale_factor to", self.scale_factor)
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else
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-- no width and height provided (inconsistencies from caller),
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self.scale_factor = 1 -- native image size
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end
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end
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-- replace blitbuffer with a resizd one if needed
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local new_bb = nil
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if self.scale_factor == nil then
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-- no scaling, but strech to width and height, only if provided
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if self.width and self.height then
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logger.dbg("ImageWidget: stretching")
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new_bb = self._bb:scale(self.width, self.height)
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end
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elseif self.scale_factor ~= 1 then
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-- scale by scale_factor (not needed if scale_factor == 1)
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logger.dbg("ImageWidget: scaling by", self.scale_factor)
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new_bb = self._bb:scale(bb_w * self.scale_factor, bb_h * self.scale_factor)
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end
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if new_bb then
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-- We made a new blitbuffer, we need to explicitely free
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-- the old one to not leak memory
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if self._bb_disposable then
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self._bb:free()
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end
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self._bb = new_bb
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self._bb_disposable = true -- new object will have to be freed
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bb_w, bb_h = self._bb:getWidth(), self._bb:getHeight()
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end
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-- deal with positionning
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if self.width and self.height then
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-- if image is bigger than paint area, allow center_ratio variation
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-- around 0.5 so we can pan till image border
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if bb_w > self.width then
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self._max_off_center_x_ratio = 0.5 - self.width/2 / bb_w
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end
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if bb_h > self.height then
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self._max_off_center_y_ratio = 0.5 - self.height/2 / bb_h
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end
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-- correct provided center ratio if out limits
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if self.center_x_ratio < 0.5 - self._max_off_center_x_ratio then
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self.center_x_ratio = 0.5 - self._max_off_center_x_ratio
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elseif self.center_x_ratio > 0.5 + self._max_off_center_x_ratio then
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self.center_x_ratio = 0.5 + self._max_off_center_x_ratio
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end
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if self.center_y_ratio < 0.5 - self._max_off_center_y_ratio then
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self.center_y_ratio = 0.5 - self._max_off_center_y_ratio
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elseif self.center_y_ratio > 0.5 + self._max_off_center_y_ratio then
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self.center_y_ratio = 0.5 + self._max_off_center_y_ratio
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end
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-- set offsets to reflect center ratio, whether oversized or not
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self._offset_x = self.center_x_ratio * bb_w - self.width/2
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self._offset_y = self.center_y_ratio * bb_h - self.height/2
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logger.dbg("ImageWidget: initial offsets", self._offset_x, self._offset_y)
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end
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-- store final bb's width and height
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self._bb_w = bb_w
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self._bb_h = bb_h
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end
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function ImageWidget:getSize()
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self:_render()
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-- getSize will be used by the widget stack for centering/padding
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if not self.width or not self.height then
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-- no width/height provided, return bb size to let widget stack do the centering
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return Geom:new{ w = self._bb:getWidth(), h = self._bb:getHeight() }
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end
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-- if width or height provided, return them as is, even if image is smaller
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-- and would be centered: we'll do the centering ourselves with offsets
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return Geom:new{ w = self.width, h = self.height }
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end
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function ImageWidget:getScaleFactor()
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-- return computed scale_factor, useful if 0 (scale to fit) was used
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return self.scale_factor
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end
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function ImageWidget:getPanByCenterRatio(x, y)
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-- returns center ratio (without limits check) we would get with this panBy
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local center_x_ratio = (x + self._offset_x + self.width/2) / self._bb_w
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local center_y_ratio = (y + self._offset_y + self.height/2) / self._bb_h
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return center_x_ratio, center_y_ratio
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end
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function ImageWidget:panBy(x, y)
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-- update center ratio from new offset
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self.center_x_ratio = (x + self._offset_x + self.width/2) / self._bb_w
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self.center_y_ratio = (y + self._offset_y + self.height/2) / self._bb_h
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-- correct new center ratio if out limits
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if self.center_x_ratio < 0.5 - self._max_off_center_x_ratio then
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self.center_x_ratio = 0.5 - self._max_off_center_x_ratio
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elseif self.center_x_ratio > 0.5 + self._max_off_center_x_ratio then
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self.center_x_ratio = 0.5 + self._max_off_center_x_ratio
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end
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if self.center_y_ratio < 0.5 - self._max_off_center_y_ratio then
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self.center_y_ratio = 0.5 - self._max_off_center_y_ratio
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elseif self.center_y_ratio > 0.5 + self._max_off_center_y_ratio then
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self.center_y_ratio = 0.5 + self._max_off_center_y_ratio
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end
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-- new offsets that reflect this new center ratio
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local new_offset_x = self.center_x_ratio * self._bb_w - self.width/2
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local new_offset_y = self.center_y_ratio * self._bb_h - self.height/2
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-- only trigger screen refresh it we actually pan
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if new_offset_x ~= self._offset_x or new_offset_y ~= self._offset_y then
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self._offset_x = new_offset_x
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self._offset_y = new_offset_y
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UIManager:setDirty("all", function()
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return "partial", self.dimen
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end)
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end
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-- return new center ratio, so caller can use them later to create a new
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-- ImageWidget with a different scale_factor, while keeping center point
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return self.center_x_ratio, self.center_y_ratio
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end
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function ImageWidget:paintTo(bb, x, y)
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if self.hide then return end
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-- self:_render is called in getSize method
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local size = self:getSize()
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self.dimen = Geom:new{
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x = x, y = y,
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w = size.w,
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h = size.h
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}
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logger.dbg("blitFrom", x, y, self._offset_x, self._offset_y, size.w, size.h)
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if self.alpha == true then
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bb:alphablitFrom(self._bb, x, y, self._offset_x, self._offset_y, size.w, size.h)
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else
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bb:blitFrom(self._bb, x, y, self._offset_x, self._offset_y, size.w, size.h)
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end
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if self.invert then
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bb:invertRect(x, y, size.w, size.h)
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end
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if self.dim then
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bb:dimRect(x, y, size.w, size.h)
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end
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end
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-- This will normally be called by our WidgetContainer:free()
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-- But it SHOULD explicitely be called if we are getting replaced
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-- (ie: in some other widget's update()), to not leak memory with
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-- BlitBuffer zombies
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function ImageWidget:free()
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if self._bb and self._bb_disposable and self._bb.free then
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self._bb:free()
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self._bb = nil
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end
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-- reset self.scale_factor to its initial value, in case
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-- self._render() is called again (happens with iconbutton,
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-- avoids x2 x2 x2 if high dpi and icon scaled x8 after 3 calls)
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self.scale_factor = self._initial_scale_factor
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end
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function ImageWidget:onCloseWidget()
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-- free when UIManager:close() was called
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self:free()
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end
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return ImageWidget
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