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mirror of https://github.com/koreader/koreader synced 2024-11-10 01:10:34 +00:00
koreader/frontend/ui/widget/overlapgroup.lua
NiLuJe fadee1f5dc
Clarify our OOP semantics across the codebase (#9586)
Basically:

* Use `extend` for class definitions
* Use `new` for object instantiations

That includes some minor code cleanups along the way:

* Updated `Widget`'s docs to make the semantics clearer.
* Removed `should_restrict_JIT` (it's been dead code since https://github.com/koreader/android-luajit-launcher/pull/283)
* Minor refactoring of LuaSettings/LuaData/LuaDefaults/DocSettings to behave (mostly, they are instantiated via `open` instead of `new`) like everything else and handle inheritance properly (i.e., DocSettings is now a proper LuaSettings subclass).
* Default to `WidgetContainer` instead of `InputContainer` for stuff that doesn't actually setup key/gesture events.
* Ditto for explicit `*Listener` only classes, make sure they're based on `EventListener` instead of something uselessly fancier.
* Unless absolutely necessary, do not store references in class objects, ever; only values. Instead, always store references in instances, to avoid both sneaky inheritance issues, and sneaky GC pinning of stale references.
  * ReaderUI: Fix one such issue with its `active_widgets` array, with critical implications, as it essentially pinned *all* of ReaderUI's modules, including their reference to the `Document` instance (i.e., that was a big-ass leak).
* Terminal: Make sure the shell is killed on plugin teardown.
* InputText: Fix Home/End/Del physical keys to behave sensibly.
* InputContainer/WidgetContainer: If necessary, compute self.dimen at paintTo time (previously, only InputContainers did, which might have had something to do with random widgets unconcerned about input using it as a baseclass instead of WidgetContainer...).
* OverlapGroup: Compute self.dimen at *init* time, because for some reason it needs to do that, but do it directly in OverlapGroup instead of going through a weird WidgetContainer method that it was the sole user of.
* ReaderCropping: Under no circumstances should a Document instance member (here, self.bbox) risk being `nil`ed!
* Kobo: Minor code cleanups.
2022-10-06 02:14:48 +02:00

91 lines
3.1 KiB
Lua

--[[--
A layout widget that puts objects above each other.
--]]
local BD = require("ui/bidi")
local Geom = require("ui/geometry")
local WidgetContainer = require("ui/widget/container/widgetcontainer")
local OverlapGroup = WidgetContainer:extend{
-- Note: we default to allow_mirroring = true.
-- When using LeftContainer, RightContainer or HorizontalGroup
-- in an OverlapGroup, mostly when they take the whole width,
-- either OverlapGroup, or all the others, need to have
-- allow_mirroring=false (otherwise, some upper mirroring would
-- cancel a lower one...).
-- It's usually safer to set it to false on the OverlapGroup,
-- but some thinking is needed when many of them are nested.
allow_mirroring = true,
_size = nil,
}
function OverlapGroup:getSize()
if not self._size then
self._size = {w = 0, h = 0}
self._offsets = { x = math.huge, y = math.huge }
for i, widget in ipairs(self) do
local w_size = widget:getSize()
if self._size.h < w_size.h then
self._size.h = w_size.h
end
if self._size.w < w_size.w then
self._size.w = w_size.w
end
end
end
return self._size
end
-- NOTE: OverlapGroup is one of those special snowflakes that will compute self.dimen at init,
-- instead of at paintTo...
function OverlapGroup:init()
self:getSize() -- populate self._size
-- sync self._size with self.dimen, self.dimen has higher priority
if self.dimen then
-- Jump through some extra hoops because this may not be a Geom...
if self.dimen.w then
self._size.w = self.dimen.w
end
if self.dimen.h then
self._size.h = self.dimen.h
end
end
-- Regardless of what was passed to the constructor, make sure dimen is actually a Geom
self.dimen = Geom:new{x = 0, y = 0, w = self._size.w, h = self._size.h}
end
function OverlapGroup:paintTo(bb, x, y)
local size = self:getSize()
for i, wget in ipairs(self) do
local wget_size = wget:getSize()
local overlap_align = wget.overlap_align
if BD.mirroredUILayout() and self.allow_mirroring then
-- Checks in the same order as how they are checked below
if overlap_align == "right" then
overlap_align = "left"
elseif overlap_align == "center" then
overlap_align = "center"
elseif wget.overlap_offset then
wget.overlap_offset[1] = size.w - wget_size.w - wget.overlap_offset[1]
else
overlap_align = "right"
end
-- see if something to do with wget.overlap_offset
end
if overlap_align == "right" then
wget:paintTo(bb, x+size.w-wget_size.w, y)
elseif overlap_align == "center" then
wget:paintTo(bb, x+math.floor((size.w-wget_size.w)/2), y)
elseif wget.overlap_offset then
wget:paintTo(bb, x+wget.overlap_offset[1], y+wget.overlap_offset[2])
else
-- default to left
wget:paintTo(bb, x, y)
end
end
end
return OverlapGroup