adjust font sizes in credocument according to screen dpi

and font sizes list is moved to defaults.lua

defaults.lua

@@ -60,6 +60,10 @@ DKOPTREADER_CONFIG_DOC_LANGS_TEXT = {"English", "Chinese"}
 DKOPTREADER_CONFIG_DOC_LANGS_CODE = {"eng", "chi_sim"}	-- language code, make sure you have corresponding training data
 DKOPTREADER_CONFIG_DOC_DEFAULT_LANG_CODE = "eng"  		-- that have filenames starting with the language codes
 
+-- crereader font sizes
+-- feel free to add more entries in this list
+DCREREADER_CONFIG_FONT_SIZES = {16, 20, 22, 24, 28, 32, 38, 44}  -- range from 16 to 44
+
 -- gesture detector defaults
 DGESDETECT_DISABLE_DOUBLE_TAP = true
 

frontend/document/credocument.lua

@@ -89,6 +89,10 @@ function CreDocument:init()
 	ok, self._document = pcall(cre.newDocView,
 		Screen:getWidth(), Screen:getHeight(), self.PAGE_VIEW_MODE
 	)
+	
+	-- adjust font sizes according to screen dpi
+	self._document:adjustFontSizes(Screen:getDPI())
+	
 	if not ok then
 		self.error_message = self.doc -- will contain error message
 		return

frontend/ui/data/creoptions.lua

@@ -1,6 +1,17 @@
 require "ui/screen"
 require "ui/data/strings"
 
+-- add multiply operator to Aa dict
+local Aa = setmetatable({"Aa"}, {
+	__mul = function(t, mul)
+	    local new = {}
+	    for i = 1, mul do
+	    	for _, v in ipairs(t) do table.insert(new, v) end
+	    end
+	    return new
+	end
+})
+
 CreOptions = {
 	prefix = 'copt',
 	{
@@ -52,13 +63,13 @@ CreOptions = {
 		options = {
 			{
 				name = "font_size",
-				item_text = {"Aa", "Aa", "Aa", "Aa", "Aa", "Aa", "Aa", "Aa"},
+				item_text = Aa * #DCREREADER_CONFIG_FONT_SIZES,
 				item_align_center = 1.0,
 				spacing = 15,
-				item_font_size = {18, 20, 22, 24, 29, 33, 39, 44},
+				item_font_size = DCREREADER_CONFIG_FONT_SIZES,
-				values = {18, 20, 22, 24, 29, 33, 39, 44},
+				values = DCREREADER_CONFIG_FONT_SIZES,
 				default_value = 22,
-				args = {18, 20, 22, 24, 29, 33, 39, 44},
+				args = DCREREADER_CONFIG_FONT_SIZES,
 				event = "SetFontSize",
 			},
 		}

frontend/ui/reader/readerfont.lua

@@ -141,14 +141,14 @@ end
 
 function ReaderFont:onSetFontSize(new_size)
 	if new_size > 44 then new_size = 44 end
-	if new_size < 18 then new_size = 18 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(new_size)
+	self.ui.document:setFontSize(scaleByDPI(new_size))
 	self.ui:handleEvent(Event:new("UpdatePos"))
 
 	return true