koreader/frontend/ui/reader/readerfont.lua

local InputContainer = require("ui/widget/container/inputcontainer")
local Device = require("ui/device")
local Screen = require("ui/screen")
local UIManager = require("ui/uimanager")
local _ = require("gettext")

local ReaderFont = InputContainer:new{
	font_face = nil,
	font_size = nil,
	line_space_percent = nil,
	font_menu_title = _("Change font"),
	face_table = nil,
	-- default gamma from crengine's lvfntman.cpp
	gamma_index = nil,
}

function ReaderFont:init()
	if Device:hasKeyboard() then
		-- add shortcut for keyboard
		self.key_events = {
			ShowFontMenu = { {"F"}, doc = _("show font menu") },
			IncreaseSize = {
				{ "Shift", Input.group.PgFwd },
				doc = _("increase font size"),
				event = "ChangeSize", args = "increase" },
			DecreaseSize = {
				{ "Shift", Input.group.PgBack },
				doc = _("decrease font size"),
				event = "ChangeSize", args = "decrease" },
			IncreaseLineSpace = {
				{ "Alt", Input.group.PgFwd },
				doc = _("increase line space"),
				event = "ChangeLineSpace", args = "increase" },
			DecreaseLineSpace = {
				{ "Alt", Input.group.PgBack },
				doc = _("decrease line space"),
				event = "ChangeLineSpace", args = "decrease" },
		}
	end
	-- build face_table for menu
	self.face_table = {}
	local face_list = cre.getFontFaces()
	for k,v in ipairs(face_list) do
		table.insert(self.face_table, {
			text = v,
			callback = function()
				self:setFont(v)
			end
		})
		face_list[k] = {text = v}
	end
	self.ui.menu:registerToMainMenu(self)
end

function ReaderFont:onSetDimensions(dimen)
	self.dimen = dimen
end

function ReaderFont:onReadSettings(config)
	self.font_face = config:readSetting("font_face")
	if not self.font_face then
		self.font_face = self.ui.document.default_font
	end
	self.ui.document:setFontFace(self.font_face)

	self.header_font_face = config:readSetting("header_font_face")
	if not self.header_font_face then
		self.header_font_face = self.ui.document.header_font
	end
	self.ui.document:setHeaderFont(self.header_font_face)

	self.font_size = config:readSetting("font_size")
	if not self.font_size then
		--@TODO change this!  12.01 2013 (houqp)
		self.font_size = 29
	end
	self.ui.document:setFontSize(self.font_size)

	self.line_space_percent = config:readSetting("line_space_percent")
	if not self.line_space_percent then
		self.line_space_percent = 100
	else
		self.ui.document:setInterlineSpacePercent(self.line_space_percent)
	end

	self.gamma_index = config:readSetting("gamma_index")
	if not self.gamma_index then
		self.gamma_index = 15
	end
	self.ui.document:setGammaIndex(self.gamma_index)

	-- Dirty hack: we have to add folloing call in order to set
	-- m_is_rendered(member of LVDocView) to true. Otherwise position inside
	-- document will be reset to 0 on first view render.
	-- So far, I don't know why this call will alter the value of m_is_rendered.
	table.insert(self.ui.postInitCallback, function()
		self.ui:handleEvent(Event:new("UpdatePos"))
	end)
end

function ReaderFont:onShowFontMenu()
	-- build menu widget
	local main_menu = Menu:new{
		title = self.font_menu_title,
		item_table = self.face_table,
		width = Screen:getWidth() - 100,
	}
	-- build container
	local menu_container = CenterContainer:new{
		main_menu,
		dimen = Screen:getSize(),
	}
	main_menu.close_callback = function ()
		UIManager:close(menu_container)
	end
	-- show menu
	UIManager:show(menu_container)
	return true
end

--[[
	UpdatePos event is used to tell ReaderRolling to update pos.
--]]
function ReaderFont:onChangeSize(direction)
	local delta = 1
	local msg = ""

	if direction == "decrease" then
	   delta = -1
	   msg = _("Decrease font size to ")
	else
	   msg = _("Increase font size to ")
	end

	self.font_size = self.font_size + delta

	UIManager:show(Notification:new{
		text = msg..self.font_size,
		timeout = 1,
	})
	self.ui.document:zoomFont(delta)
	self.ui:handleEvent(Event:new("UpdatePos"))
	UIManager:close(msg)

	return true
end

function ReaderFont:onSetFontSize(new_size)
	if new_size > 44 then new_size = 44 end
	if new_size < 16 then new_size = 16 end

	self.font_size = new_size
	UIManager:show(Notification:new{
		text = _("Set font size to ")..self.font_size,
		timeout = 1,
	})
	self.ui.document:setFontSize(scaleByDPI(new_size))
	self.ui:handleEvent(Event:new("UpdatePos"))

	return true
end

function ReaderFont:onChangeLineSpace(direction)
	local msg = ""
	if direction == "decrease" then
		self.line_space_percent = self.line_space_percent - 10
		-- NuPogodi, 15.05.12: reduce lowest space_percent to 80
		self.line_space_percent = math.max(self.line_space_percent, 80)
		msg = _("Decrease line space to ")
	else
		self.line_space_percent = self.line_space_percent + 10
		self.line_space_percent = math.min(self.line_space_percent, 200)
		msg = _("Increase line space to ")
	end
	UIManager:show(Notification:new{
		text = msg..self.line_space_percent.."%",
		timeout = 1,
	})
	self.ui.document:setInterlineSpacePercent(self.line_space_percent)
	self.ui:handleEvent(Event:new("UpdatePos"))

	return true
end

function ReaderFont:onToggleFontBolder()
	self.ui.document:toggleFontBolder()
	self.ui:handleEvent(Event:new("UpdatePos"))
	return true
end

function ReaderFont:onChangeFontGamma(direction)
	local msg = ""
	if direction == "increase" then
		cre.setGammaIndex(self.gamma_index+2)
		msg = _("Increase gamma to ")
	elseif direction == "decrease" then
		cre.setGammaIndex(self.gamma_index-2)
		msg = _("Decrease gamma to ")
	end
	self.gamma_index = cre.getGammaIndex()
	UIManager:show(Notification:new{
		text = msg..self.gamma_index,
		timeout = 1
	})
	self.ui:handleEvent(Event:new("RedrawCurrentView"))
	return true
end

function ReaderFont:onCloseDocument()
	self.ui.doc_settings:saveSetting("font_face", self.font_face)
	self.ui.doc_settings:saveSetting("header_font_face", self.header_font_face)
	self.ui.doc_settings:saveSetting("font_size", self.font_size)
	self.ui.doc_settings:saveSetting("line_space_percent", self.line_space_percent)
	self.ui.doc_settings:saveSetting("gamma_index", self.gamma_index)
end

function ReaderFont:setFont(face)
	if face and self.font_face ~= face then
		self.font_face = face
		UIManager:show(Notification:new{
			text = _("Redrawing with font ")..face,
			timeout = 1,
		})

		self.ui.document:setFontFace(face)
		-- signal readerrolling to update pos in new height
		self.ui:handleEvent(Event:new("UpdatePos"))

		UIManager:close(msg)
	end
end

function ReaderFont:addToMainMenu(tab_item_table)
	-- insert table to main reader menu
	table.insert(tab_item_table.typeset, {
		text = self.font_menu_title,
		sub_item_table = self.face_table,
	})
end

return ReaderFont