save and restore gamma_index for crengine

frontend/document/credocument.lua

@@ -277,6 +277,10 @@ function CreDocument:toggleFontBolder()
 	self._document:toggleFontBolder()
 end
 
+function CreDocument:setGammaIndex(index)
+	cre.setGammaIndex(index)
+end
+
 DocumentRegistry:addProvider("txt", "application/txt", CreDocument)
 DocumentRegistry:addProvider("epub", "application/epub", CreDocument)
 DocumentRegistry:addProvider("html", "application/html", CreDocument)

frontend/ui/reader/readerfont.lua

@@ -5,7 +5,7 @@ ReaderFont = InputContainer:new{
 	font_menu_title = "Font Menu",
 	face_table = nil,
 	-- default gamma from crengine's lvfntman.cpp
-	gamma_index = 15,
+	gamma_index = nil,
 }
 
 function ReaderFont:init()
@@ -77,6 +77,12 @@ function ReaderFont:onReadSettings(config)
 		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.
@@ -187,11 +193,11 @@ function ReaderFont:onChangeFontGamma(direction)
 end
 
 function ReaderFont:onCloseDocument()
-	--@TODO save gamma index    (houqp)
 	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)