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koreader/frontend/ui/widget/listview.lua
NiLuJe 2011cf1ad1 Various blitting related cleanups (#4789)
* Fix the "Enable debug logging" checkbox so that it properly disables "Enable verbose debug logging" when it gets disabled
* Avoid asking ImageWidget for alpha-blending when it's not useful
* Make ImageWidget's alpha-blending code-path double-check that alpha-blending actually is needed, and avoid it if possible
* In the same vein, only do alpha-blending in textboxwidget when absolutely necessary
* Prefer color constants over the gray() method, ensuring that they're part of the eInk palette

Depends on https://github.com/koreader/koreader-base/pull/853

Fix #4774
2019-03-14 20:58:45 +01:00

126 lines
3.7 KiB
Lua

--[[--
Widget component that handles pagination for a list of items.
Example:
local list_view = ListView:new{
height = Screen:scaleBySize(400),
width = Screen:scaleBySize(200),
page_update_cb = function(curr_page_num, total_pages)
-- This callback function will be called whenever a page
-- turn event is triggered. You can use it to update
-- information on the parent widget.
end,
items = {
FrameContainer:new{
bordersize = 0,
background = Blitbuffer.COLOR_WHITE,
TextWidget:new{
text = "foo",
fact = Font:getFace("cfont"),
}
},
FrameContainer:new{
bordersize = 0,
background = Blitbuffer.COLOR_LIGHT_GRAY,
TextWidget:new{
text = "bar",
fact = Font:getFace("cfont"),
}
},
-- You can add as many widgets as you want here...
}
}
Note that ListView is created mainly to be used as a building block for other
widgets like @{ui.widget.networksetting|NetworkSetting}, so they can share the same pagination code.
]]
local Blitbuffer = require("ffi/blitbuffer")
local Device = require("device")
local FrameContainer = require("ui/widget/container/framecontainer")
local Geom = require("ui/geometry")
local GestureRange = require("ui/gesturerange")
local InputContainer = require("ui/widget/container/inputcontainer")
local Size = require("ui/size")
local VerticalGroup = require("ui/widget/verticalgroup")
local ListView = InputContainer:new{
width = nil,
height = nil,
padding = nil,
item_height = nil,
itmes = nil,
}
function ListView:init()
if #self.items <= 0 then return end
self.show_page = 1
self.dimen = Geom:new{w = self.width, h = self.height}
if Device:isTouchDevice() then
self.ges_events.Swipe = {
GestureRange:new{
ges = "swipe",
range = self.dimen,
}
}
end
local padding = self.padding or Size.padding.large
self.item_height = self.item_height or self.items[1]:getSize().h
self.item_width = self.dimen.w - 2 * padding
self.items_per_page = math.floor(self.height / self.item_height)
self.main_content = VerticalGroup:new{}
self:_populateItems()
self[1] = FrameContainer:new{
height = self.dimen.h,
padding = padding,
bordersize = 0,
background = Blitbuffer.COLOR_WHITE,
self.main_content,
}
end
-- make sure self.item_height are set before calling this
function ListView:_populateItems()
self.pages = math.ceil(#self.items / self.items_per_page)
self.main_content:clear()
local idx_offset = (self.show_page - 1) * self.items_per_page
for idx = 1, self.items_per_page do
local item = self.items[idx_offset + idx]
if item == nil then break end
table.insert(self.main_content, item)
end
self.page_update_cb(self.show_page, self.pages)
end
function ListView:nextPage()
local new_page = math.min(self.show_page+1, self.pages)
if new_page > self.show_page then
self.show_page = new_page
self:_populateItems()
end
end
function ListView:prevPage()
local new_page = math.max(self.show_page-1, 1)
if new_page < self.show_page then
self.show_page = new_page
self:_populateItems()
end
end
function ListView:onSwipe(arg, ges_ev)
if ges_ev.direction == "west" then
self:nextPage()
return true
elseif ges_ev.direction == "east" then
self:prevPage()
return true
end
end
return ListView