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koreader/frontend/ui/widget/focusmanager.lua
HW 2154e7e852 Further refactoring
This should finish the work to make all globals to local variables.
That allows LuaJIT to properly compile things by interning the
references to the relevant parts (rather than looking up globals
all the time which stops a trace).
2013-10-22 17:11:31 +02:00

102 lines
3.0 KiB
Lua

local InputContainer = require("ui/widget/container/inputcontainer")
local Event = require("ui/event")
local UIManager = require("ui/uimanager")
--[[
Wrapper Widget that manages focus for a whole dialog
supports a 2D model of active elements
e.g.:
layout = {
{ textinput, textinput },
{ okbutton, cancelbutton }
}
this is a dialog with 2 rows. in the top row, there is the
single (!) widget <textinput>. when the focus is in this
group, left/right movement seems (!) to be doing nothing.
in the second row, there are two widgets and you can move
left/right. also, you can go up from both to reach <textinput>,
and from that go down and (depending on internat coordinates)
reach either <okbutton> or <cancelbutton>.
but notice that this does _not_ do the layout for you,
it rather defines an abstract layout.
]]
local FocusManager = InputContainer:new{
selected = nil, -- defaults to x=1, y=1
layout = nil, -- mandatory
movement_allowed = { x = true, y = true }
}
function FocusManager:init()
self.selected = { x = 1, y = 1 }
self.key_events = {
-- these will all generate the same event, just with different arguments
FocusUp = { {"Up"}, doc = "move focus up", event = "FocusMove", args = {0, -1} },
FocusDown = { {"Down"}, doc = "move focus down", event = "FocusMove", args = {0, 1} },
FocusLeft = { {"Left"}, doc = "move focus left", event = "FocusMove", args = {-1, 0} },
FocusRight = { {"Right"}, doc = "move focus right", event = "FocusMove", args = {1, 0} },
}
end
function FocusManager:onFocusMove(args)
local dx, dy = unpack(args)
if (dx ~= 0 and not self.movement_allowed.x)
or (dy ~= 0 and not self.movement_allowed.y) then
return true
end
if not self.layout or not self.layout[self.selected.y] or not self.layout[self.selected.y][self.selected.x] then
return true
end
local current_item = self.layout[self.selected.y][self.selected.x]
while true do
if self.selected.x + dx > #self.layout[self.selected.y]
or self.selected.x + dx < 1 then
break -- abort when we run into horizontal borders
end
-- move cyclic in vertical direction
if self.selected.y + dy > #self.layout then
if not self:onWrapLast() then
break
end
elseif self.selected.y + dy < 1 then
if not self:onWrapFirst() then
break
end
else
self.selected.y = self.selected.y + dy
end
self.selected.x = self.selected.x + dx
if self.layout[self.selected.y][self.selected.x] ~= current_item
or not self.layout[self.selected.y][self.selected.x].is_inactive then
-- we found a different object to focus
current_item:handleEvent(Event:new("Unfocus"))
self.layout[self.selected.y][self.selected.x]:handleEvent(Event:new("Focus"))
-- trigger a repaint (we need to be the registered widget!)
UIManager:setDirty(self, "partial")
break
end
end
return true
end
function FocusManager:onWrapFirst()
self.selected.y = #self.layout
return true
end
function FocusManager:onWrapLast()
self.selected.y = 1
return true
end
return FocusManager