2c1178896cThis implements a reasonable facsimile of going back on Android. The back button first goes back in a history of visited pages. When there's no history left, it closes the app. Fixes #3816.
81 lines
2 KiB
Lua
81 lines
2 KiB
Lua
local Device = require("device")
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local Event = require("ui/event")
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local EventListener = require("ui/widget/eventlistener")
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local logger = require("logger")
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local util = require("util")
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local ReaderBack = EventListener:new{
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location_stack = {},
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-- a limit not intended to be a practical limit but just a failsafe
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max_stack = 5000,
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}
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function ReaderBack:init()
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if Device:hasKeys() then
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self.ui.key_events.Back = { {"Back"}, doc = "Reader back" }
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end
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end
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function ReaderBack:_getCurrentLocation()
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local current_location
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if self.ui.document.info.has_pages then
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current_location = self.ui.paging:getBookLocation()
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else
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current_location = {
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xpointer = self.ui.rolling:getBookLocation(),
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}
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end
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return current_location
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end
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local ignore_location
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function ReaderBack:addCurrentLocationToStack()
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local location_stack = self.location_stack
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local new_location = self:_getCurrentLocation()
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if util.tableEquals(ignore_location, new_location) then return end
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table.insert(location_stack, new_location)
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if #location_stack > self.max_stack then
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table.remove(location_stack, 1)
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end
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end
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-- Scroll mode crengine
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function ReaderBack:onPosUpdate()
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self:addCurrentLocationToStack()
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end
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-- Paged media
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function ReaderBack:onPageUpdate()
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self:addCurrentLocationToStack()
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end
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-- Called when loading new document
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function ReaderBack:onReadSettings(config)
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self.location_stack = {}
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end
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function ReaderBack:onBack()
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local location_stack = self.location_stack
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if #location_stack > 1 then
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local saved_location = table.remove(location_stack)
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if saved_location then
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ignore_location = self:_getCurrentLocation()
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logger.dbg("[ReaderBack] restoring:", saved_location)
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self.ui:handleEvent(Event:new('RestoreBookLocation', saved_location))
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return true
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end
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else
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logger.dbg("[ReaderBack] no location history, closing")
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self.ui:handleEvent(Event:new("Close"))
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end
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end
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return ReaderBack
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