diff --git a/commands.lua b/commands.lua
new file mode 100644
index 000000000..43dfca87d
--- /dev/null
+++ b/commands.lua
@@ -0,0 +1,112 @@
+require "keys"
+
+Keydef = {
+	keycode = nil,
+	modifier = nil,
+	descr = nil
+}
+function Keydef:_new(obj)
+	-- obj definition
+	obj = obj or {}
+	setmetatable(obj, self)
+	self.__index = self
+	self.__tostring=Keydef.tostring
+	return obj
+end
+function Keydef:new(keycode,modifier,descr)
+	obj = Keydef:_new()
+	obj.keycode = keycode
+	obj.modifier = modifier
+	obj.descr = descr
+	return obj
+end
+function Keydef:display()
+	return ((self.modifier and self.modifier.."+") or "")..(self.descr or "")
+end
+function Keydef:tostring()
+	return ((self.modifier and self.modifier.."+") or "").."["..(self.keycode or "").."]"..(self.descr or "")
+end
+
+Command = {
+	keydef = nil,
+	keygroup = nil,
+	func = nil,
+	help = nil,
+	order = nil
+}
+function Command:_new(obj)
+	-- obj definition
+	obj = obj or {}
+	setmetatable(obj, self)
+	self.__index = self
+	self.__tostring=Command.tostring
+	return obj
+end
+function Command:new(keydef, func, help, keygroup, order)
+	obj = Command:_new()
+	obj.keydef = keydef
+	obj.func = func
+	obj.help = help
+	obj.keygroup = keygroup
+	obj.order = order
+	--print("creating command: ["..tostring(keydef).."] keygroup:["..(keygroup or "").."] help:"..help)
+	return obj
+end
+function Command:tostring()
+	return tostring(self.keydef)..": "..(self.help or "<no help defined>")
+end
+
+
+Commands = {
+	map = {},
+	size = 0
+}
+function Commands:add(keycode,modifier,keydescr,help,func)
+	local keydef = Keydef:new(keycode,modifier,keydescr)
+	self:_addImpl(keydef,help,func)
+end
+function Commands:addGroup(keygroup,keys,help,func)
+	for _k,keydef in pairs(keys) do
+		self:_addImpl(keydef,help,func,keygroup)
+	end
+end
+function Commands:_addImpl(keydef,help,func,keygroup)
+	if keydef.modifier==MOD_ANY then
+		self:addGroup(keygroup or keydef.descr,{Keydef:new(keydef.keycode,nil), Keydef:new(keydef.keycode,MOD_SHIFT), Keydef:new(keydef.keycode,MOD_ALT)},help,func)
+	elseif keydef.modifier==MOD_SHIFT_OR_ALT then
+		self:addGroup(keygroup or (MOD_SHIFT.."|"..MOD_ALT.."+"..(keydef.descr or "")),{Keydef:new(keydef.keycode,MOD_SHIFT), Keydef:new(keydef.keycode,MOD_ALT)},help,func)
+	else
+		local command = self.map[keydef]
+		if command == nil then
+			self.size = self.size + 1
+			command = Command:new(keydef,func,help,keygroup,self.size)
+			self.map[keydef] = command
+		else
+			command.func = func
+			command.help = help
+			command.keygroup = keygroup
+		end
+	end
+end
+function Commands:get(keycode,modifier)
+	return self.map[Keydef:new(keycode, modifier)]
+end
+function Commands:getByKeydef(keydef)
+	return self.map[keydef]
+end
+function Commands:new(obj)
+	-- payload
+	local mt = {}
+	setmetatable(self.map,mt)
+	mt.__index=function (table, key)
+		return rawget(table,(key.modifier or "").."@#@"..(key.keycode or ""))
+	end
+	mt.__newindex=function (table, key, value)
+		return rawset(table,(key.modifier or "").."@#@"..(key.keycode or ""),value)
+	end
+	-- obj definition
+	obj = obj or {}
+	setmetatable(obj, self)
+	self.__index = self
+	return obj
+end
diff --git a/filechooser.lua b/filechooser.lua
index 9e909198d..c4e2f1378 100644
--- a/filechooser.lua
+++ b/filechooser.lua
@@ -8,7 +8,7 @@ require "selectmenu"
 
 FileChooser = {
 	-- Class vars:
-	
+
 	-- spacing between lines
 	spacing = 40,
 
@@ -45,7 +45,7 @@ function getAbsolutePath(aPath)
 	return abs_path
 end
 
-function FileChooser:readdir()
+function FileChooser:readDir()
 	self.dirs = {}
 	self.files = {}
 	for f in lfs.dir(self.path) do
@@ -67,9 +67,9 @@ end
 function FileChooser:setPath(newPath)
 	local curr_path = self.path
 	self.path = getAbsolutePath(newPath)
-	local readdir_ok, exc = pcall(self.readdir,self)
+	local readdir_ok, exc = pcall(self.readDir,self)
 	if(not readdir_ok) then
-		print("readdir error: "..tostring(exc))
+		print("readDir error: "..tostring(exc))
 		self.exception_message = exc
 		return self:setPath(curr_path)
 	else
@@ -135,10 +135,10 @@ function FileChooser:choose(ypos, height)
 				end
 			end
 			renderUtf8Text(fb.bb, 5, ypos + self.spacing * perpage + 42, fface, ffhash,
-				"Page "..self.page.." of "..(math.floor(self.items / perpage)+1), true)		
+				"Page "..self.page.." of "..(math.floor(self.items / perpage)+1), true)
 			local msg = self.exception_message and self.exception_message:match("[^%:]+:%d+: (.*)") or "Path: "..self.path
 			self.exception_message = nil
-			renderUtf8Text(fb.bb, 5, ypos + self.spacing * (perpage+1) + 27, fface, ffhash, msg, true)			
+			renderUtf8Text(fb.bb, 5, ypos + self.spacing * (perpage+1) + 27, fface, ffhash, msg, true)
 			markerdirty = true
 		end
 		if markerdirty then
@@ -181,14 +181,14 @@ function FileChooser:choose(ypos, height)
 				pagedirty = true
 			elseif ev.code == KEY_S then -- invoke search input
 				keywords = InputBox:input(height-100, 100, "Search:")
-				if keywords then 
+				if keywords then
 					-- call FileSearcher
 					--[[
 					This might looks a little bit dirty for using callback.
 					But I cannot come up with a better solution for renewing
 					the height arguemtn according to screen rotation mode.
 
-					The callback might also be useful for calling system 
+					The callback might also be useful for calling system
 					settings menu in the future.
 					--]]
 					return nil, function()
diff --git a/filesearcher.lua b/filesearcher.lua
index 0d8153cd4..f2792c268 100644
--- a/filesearcher.lua
+++ b/filesearcher.lua
@@ -21,7 +21,7 @@ FileSearcher = {
 	oldcurrent = 1,
 }
 
-function FileSearcher:readdir()
+function FileSearcher:readDir()
 	self.dirs = {self.path}
 	self.files = {}
 	while #self.dirs ~= 0 do
@@ -46,7 +46,7 @@ end
 
 function FileSearcher:setPath(newPath)
 	self.path = newPath
-	self:readdir()
+	self:readDir()
 	self.items = #self.files
 	--@TODO check none found  19.02 2012
 	if self.items == 0 then
@@ -116,9 +116,9 @@ function FileSearcher:choose(ypos, height, keywords)
 		end
 	end
 
-	-- if given keywords, set new result according to keywords. 
+	-- if given keywords, set new result according to keywords.
 	-- Otherwise, display the previous search result.
-	if keywords then 
+	if keywords then
 		self:setSearchResult(keywords)
 	end
 
@@ -139,17 +139,17 @@ function FileSearcher:choose(ypos, height, keywords)
 			local c
 			if self.items == 0 then -- nothing found
 				y = ypos + self.title_H + self.spacing * 2
-				renderUtf8Text(fb.bb, 20, y, cface, cfhash, 
-					"Sorry, no match found.", true) 
-				renderUtf8Text(fb.bb, 20, y + self.spacing, cface, cfhash, 
+				renderUtf8Text(fb.bb, 20, y, cface, cfhash,
+					"Sorry, no match found.", true)
+				renderUtf8Text(fb.bb, 20, y + self.spacing, cface, cfhash,
 					"Please try a different keyword.", true)
 				markerdirty = false
 			else -- found something, draw it
 				for c = 1, perpage do
-					local i = (self.page - 1) * perpage + c 
+					local i = (self.page - 1) * perpage + c
 					if i <= self.items then
 						y = ypos + self.title_H + (self.spacing * c)
-						renderUtf8Text(fb.bb, 50, y, cface, cfhash, 
+						renderUtf8Text(fb.bb, 50, y, cface, cfhash,
 							self.result[i].name, true)
 					end
 				end
@@ -236,7 +236,7 @@ function FileSearcher:choose(ypos, height, keywords)
 				file_entry = self.result[perpage*(self.page-1)+self.current]
 				file_full_path = file_entry.dir .. "/" .. file_entry.name
 
-				-- rotation mode might be changed while reading, so 
+				-- rotation mode might be changed while reading, so
 				-- record height_percent here
 				local height_percent = height/fb.bb:getHeight()
 				openFile(file_full_path)
diff --git a/font.lua b/font.lua
index 9aadbb3b7..ef31d6277 100644
--- a/font.lua
+++ b/font.lua
@@ -8,7 +8,7 @@ Font = {
 	ffont = "sans",
 
 	-- built in fonts
-	fonts = {"sans", "cjk", "mono", 
+	fonts = {"sans", "cjk", "mono",
 		"Courier", "Courier-Bold", "Courier-Oblique", "Courier-BoldOblique",
 		"Helvetica", "Helvetica-Oblique", "Helvetica-BoldOblique",
 		"Times-Roman", "Times-Bold", "Times-Italic", "Times-BoldItalic",},
@@ -42,6 +42,5 @@ end
 
 function Font:update()
 	self.faces = {}
-	clearglyphcache()
+	clearGlyphCache()
 end
-
diff --git a/helppage.lua b/helppage.lua
new file mode 100644
index 000000000..33ba5e9a9
--- /dev/null
+++ b/helppage.lua
@@ -0,0 +1,96 @@
+require "rendertext"
+require "keys"
+require "graphics"
+require "font"
+require "inputbox"
+require "selectmenu"
+require "commands"
+
+HelpPage = {
+	-- Other Class vars:
+
+	-- spacing between lines
+	spacing = 25,
+
+	-- state buffer
+	commands = nil,
+	items = 0,
+	page = 1
+}
+
+-- Other Class vars:
+
+-- font for displaying keys
+HelpPage.fsize = 20
+HelpPage.face, HelpPage.fhash = Font:getFaceAndHash(HelpPage.fsize, "mono")
+-- font for displaying help messages
+HelpPage.hfsize = 20
+HelpPage.hface, HelpPage.hfhash = Font:getFaceAndHash(HelpPage.hfsize, "sans")
+-- font for paging display
+HelpPage.ffsize = 15
+HelpPage.fface, HelpPage.ffhash = Font:getFaceAndHash(HelpPage.ffsize, "sans")
+
+function HelpPage:show(ypos, height,commands)
+	self.commands = {}
+	self.items = 0
+	local keys = {}
+	for k,v in pairs(commands.map) do
+		local key = v.keygroup or v.keydef:display()
+		--print("order: "..v.order.." command: "..tostring(v.keydef).." - keygroup:"..(v.keygroup or "nil").." -keys[key]:"..(keys[key] or "nil"))
+		if keys[key] == nil then
+			keys[key] = 1
+			table.insert(self.commands,{shortcut=key,help=v.help,order=v.order})
+			self.items = self.items + 1
+		end
+	end
+	table.sort(self.commands,function(w1,w2) return w1.order<w2.order end)
+	local perpage = math.floor( (height - 1 * (self.ffsize + 5)) / self.spacing )
+	local pagedirty = true
+
+	while true do
+		if pagedirty then
+			fb.bb:paintRect(0, ypos, fb.bb:getWidth(), height, 0)
+			local c
+			local max_x = 0
+			for c = 1, perpage do
+				local i = (self.page - 1) * perpage + c
+				if i <= self.items then
+					local pen_x = renderUtf8Text(fb.bb, 5, ypos + self.spacing*c, self.face, self.fhash, self.commands[i].shortcut, true)
+					max_x = math.max(max_x, pen_x)
+				end
+			end
+			for c = 1, perpage do
+				local i = (self.page - 1) * perpage + c
+				if i <= self.items then
+					renderUtf8Text(fb.bb, max_x + 20, ypos + self.spacing*c, self.hface, self.hfhash, self.commands[i].help, true)
+				end
+			end
+			renderUtf8Text(fb.bb, 5, height - math.floor(self.ffsize * 0.4), self.fface, self.ffhash,
+				"Page "..self.page.." of "..math.ceil(self.items / perpage).."  - click Back to close this page", true)
+			markerdirty = true
+		end
+		if pagedirty then
+			fb:refresh(0, 0, ypos, fb.bb:getWidth(), height)
+			pagedirty = false
+		end
+
+		local ev = input.waitForEvent()
+		--print("key code:"..ev.code)
+		ev.code = adjustKeyEvents(ev)
+		if ev.type == EV_KEY and ev.value == EVENT_VALUE_KEY_PRESS then
+			if ev.code == KEY_PGFWD then
+				if self.page < (self.items / perpage) then
+					self.page = self.page + 1
+					pagedirty = true
+				end
+			elseif ev.code == KEY_PGBCK then
+				if self.page > 1 then
+					self.page = self.page - 1
+					pagedirty = true
+				end
+			elseif ev.code == KEY_BACK or ev.code == KEY_HOME then
+				return nil
+			end
+		end
+	end
+end
diff --git a/keys.lua b/keys.lua
index cc630f09e..43e683120 100644
--- a/keys.lua
+++ b/keys.lua
@@ -94,8 +94,18 @@ EV_KEY = 1
 EVENT_VALUE_KEY_PRESS = 1
 EVENT_VALUE_KEY_REPEAT = 2
 EVENT_VALUE_KEY_RELEASE = 0
- 
-function set_k3_keycodes()
+
+-- modifiers
+MOD_SHIFT = "Shift"
+MOD_ALT = "Alt"
+MOD_SHIFT_OR_ALT = "ShiftAlt"
+MOD_ANY = "Any"
+
+function getKeyModifier()
+	return Keys.altmode and MOD_ALT or Keys.shiftmode and MOD_SHIFT
+end
+
+function setK3Keycodes()
 	KEY_AA = 190
 	KEY_SYM = 126
 	KEY_HOME = 102
@@ -110,7 +120,7 @@ function set_k3_keycodes()
 	KEY_FW_PRESS = 194
 end
 
-function set_emu_keycodes()
+function setEmuKeycodes()
 	KEY_PGFWD = 117
 	KEY_PGBCK = 112
 	KEY_HOME = 110 -- home
diff --git a/reader.lua b/reader.lua
index 7afefa90f..0ad9da911 100755
--- a/reader.lua
+++ b/reader.lua
@@ -23,6 +23,8 @@ require "djvureader"
 require "filechooser"
 require "settings"
 require "screen"
+require "keys"
+require "commands"
 
 -- option parsing:
 longopts = {
@@ -45,10 +47,10 @@ function openFile(filename)
 		local ok, err = reader:open(filename)
 		if ok then
 			reader:loadSettings(filename)
-			page_num = reader.settings:readsetting("last_page") or 1
+			page_num = reader.settings:readSetting("last_page") or 1
 			reader:goto(tonumber(page_num))
 			reader_settings:savesetting("lastfile", filename)
-			return reader:inputloop()
+			return reader:inputLoop()
 		else
 			-- TODO: error handling
 		end
@@ -90,11 +92,11 @@ if optarg["d"] == "k3" then
 	input.open("/dev/input/event0")
 	input.open("/dev/input/event1")
 	input.open("/dev/input/event2")
-	set_k3_keycodes()
+	setK3Keycodes()
 elseif optarg["d"] == "emu" then
 	input.open("")
 	-- SDL key codes
-	set_emu_keycodes()
+	setEmuKeycodes()
 else
 	input.open("/dev/input/event0")
 	input.open("/dev/input/event1")
@@ -105,7 +107,7 @@ else
 	if f then
 		print("Auto-detected Kindle 3")
 		input.open("/dev/input/event2")
-		set_k3_keycodes()
+		setK3Keycodes()
 	end
 end
 
@@ -121,7 +123,7 @@ origin_rotation_mode = Screen.cur_rotation_mode
 
 -- set up reader's setting: font
 reader_settings = DocSettings:open(".reader")
-r_cfont = reader_settings:readsetting("cfont")
+r_cfont = reader_settings:readSetting("cfont")
 if r_cfont ~=nil then
 	Font.cfont = r_cfont
 end
@@ -133,7 +135,7 @@ PDFReader:init()
 DJVUReader:init()
 
 -- display directory or open file
-local patharg = reader_settings:readsetting("lastfile")
+local patharg = reader_settings:readSetting("lastfile")
 if ARGV[optind] and lfs.attributes(ARGV[optind], "mode") == "directory" then
 	local running = true
 	FileChooser:setPath(ARGV[optind])
diff --git a/rendertext.lua b/rendertext.lua
index 56822f98f..1d95598e3 100644
--- a/rendertext.lua
+++ b/rendertext.lua
@@ -2,7 +2,7 @@ glyphcache_max_memsize = 256*1024 -- 256kB glyphcache
 glyphcache_current_memsize = 0
 glyphcache = {}
 glyphcache_max_age = 4096
-function glyphcacheclaim(size)
+function glyphCacheClaim(size)
 	if(size > glyphcache_max_memsize) then
 		error("too much memory claimed")
 		return false
@@ -20,12 +20,12 @@ function glyphcacheclaim(size)
 	glyphcache_current_memsize = glyphcache_current_memsize + size
 	return true
 end
-function getglyph(face, facehash, charcode)
-	local hash = glyphcachehash(facehash, charcode)
+function getGlyph(face, facehash, charcode)
+	local hash = glyphCacheHash(facehash, charcode)
 	if glyphcache[hash] == nil then
 		local glyph = face:renderGlyph(charcode)
 		local size = glyph.bb:getWidth() * glyph.bb:getHeight() / 2 + 32
-		glyphcacheclaim(size);
+		glyphCacheClaim(size);
 		glyphcache[hash] = {
 			age = glyphcache_max_age,
 			size = size,
@@ -36,10 +36,10 @@ function getglyph(face, facehash, charcode)
 	end
 	return glyphcache[hash].g
 end
-function glyphcachehash(face, charcode)
+function glyphCacheHash(face, charcode)
 	return face..'_'..charcode;
 end
-function clearglyphcache()
+function clearGlyphCache()
 	glyphcache = {}
 end
 
@@ -55,7 +55,7 @@ function renderUtf8Text(buffer, x, y, face, facehash, text, kerning)
 	for uchar in string.gfind(text, "([%z\1-\127\194-\244][\128-\191]*)") do
 		if pen_x < buffer:getWidth() then
 			local charcode = util.utf8charcode(uchar)
-			local glyph = getglyph(face, facehash, charcode)
+			local glyph = getGlyph(face, facehash, charcode)
 			if kerning and prevcharcode then
 				local kern = face:getKerning(prevcharcode, charcode)
 				pen_x = pen_x + kern
@@ -67,5 +67,5 @@ function renderUtf8Text(buffer, x, y, face, facehash, text, kerning)
 			prevcharcode = charcode
 		end
 	end
+	return pen_x
 end
-
diff --git a/settings.lua b/settings.lua
index 04b277606..fb379743f 100644
--- a/settings.lua
+++ b/settings.lua
@@ -9,7 +9,7 @@ function DocSettings:open(docfile)
 	return setmetatable(new, { __index = DocSettings})
 end
 
-function DocSettings:readsetting(key)
+function DocSettings:readSetting(key)
 	return self.data[key]
 end
 
diff --git a/unireader.lua b/unireader.lua
index b738197a2..bf956be15 100644
--- a/unireader.lua
+++ b/unireader.lua
@@ -1,6 +1,8 @@
 require "keys"
 require "settings"
 require "selectmenu"
+require "commands"
+require "helppage"
 
 UniReader = {
 	-- "constants":
@@ -54,9 +56,11 @@ UniReader = {
 	doc = nil,
 	-- the document's setting store:
 	settings = nil,
+	-- list of available commands:
+	commands = nil,
 
 	-- we will use this one often, so keep it "static":
-	nulldc = DrawContext.new(), 
+	nulldc = DrawContext.new(),
 
 	-- tile cache configuration:
 	cache_max_memsize = 1024*1024*5, -- 5MB tile cache
@@ -81,7 +85,7 @@ function UniReader:new(o)
 	return o
 end
 
---[[ 
+--[[
 	For a new specific reader,
 	you must always overwrite following two methods:
 
@@ -106,20 +110,20 @@ function UniReader:loadSettings(filename)
 	if self.doc ~= nil then
 		self.settings = DocSettings:open(filename)
 
-		local gamma = self.settings:readsetting("gamma")
+		local gamma = self.settings:readSetting("gamma")
 		if gamma then
 			self.globalgamma = gamma
 		end
 
-		local jumpstack = self.settings:readsetting("jumpstack")
+		local jumpstack = self.settings:readSetting("jumpstack")
 		self.jump_stack = jumpstack or {}
 
-		local bbox = self.settings:readsetting("bbox")
+		local bbox = self.settings:readSetting("bbox")
 		print("# bbox loaded "..dump(bbox))
 		self.bbox = bbox
 
-		self.globalzoom = self.settings:readsetting("globalzoom") or 1.0
-		self.globalzoommode = self.settings:readsetting("globalzoommode") or -1
+		self.globalzoom = self.settings:readSetting("globalzoom") or 1.0
+		self.globalzoommode = self.settings:readSetting("globalzoommode") or -1
 
 		return true
 	end
@@ -127,24 +131,26 @@ function UniReader:loadSettings(filename)
 end
 
 function UniReader:initGlobalSettings(settings)
-	local pan_overlap_vertical = settings:readsetting("pan_overlap_vertical")
+	local pan_overlap_vertical = settings:readSetting("pan_overlap_vertical")
 	if pan_overlap_vertical then
 		self.pan_overlap_vertical = pan_overlap_vertical
 	end
+	-- initialize commands
+	self:addAllCommands()
 
-	local cache_max_memsize = settings:readsetting("cache_max_memsize")
+	local cache_max_memsize = settings:readSetting("cache_max_memsize")
 	if cache_max_memsize then
 		self.cache_max_memsize = cache_max_memsize
 	end
 
-	local cache_max_ttl = settings:readsetting("cache_max_ttl")
+	local cache_max_ttl = settings:readSetting("cache_max_ttl")
 	if cache_max_ttl then
 		self.cache_max_ttl = cache_max_ttl
 	end
 end
 
 -- guarantee that we have enough memory in cache
-function UniReader:cacheclaim(size)
+function UniReader:cacheClaim(size)
 	if(size > self.cache_max_memsize) then
 		-- we're not allowed to claim this much at all
 		error("too much memory claimed")
@@ -167,7 +173,7 @@ function UniReader:cacheclaim(size)
 	return true
 end
 
-function UniReader:draworcache(no, preCache)
+function UniReader:drawOrCache(no, preCache)
 	-- our general caching strategy is as follows:
 	-- #1 goal: we must render the needed area.
 	-- #2 goal: we render as much of the requested page as we can
@@ -180,11 +186,11 @@ function UniReader:draworcache(no, preCache)
 		-- TODO: error handling
 		return nil
 	end
-	local dc = self:setzoom(page)
+	local dc = self:setZoom(page)
 
 	-- offset_x_in_page & offset_y_in_page is the offset within zoomed page
-	-- they are always positive. 
-	-- you can see self.offset_x_& self.offset_y as the offset within 
+	-- they are always positive.
+	-- you can see self.offset_x_& self.offset_y as the offset within
 	-- draw space, which includes the page. So it can be negative and positive.
 	local offset_x_in_page = -self.offset_x
 	local offset_y_in_page = -self.offset_y
@@ -218,7 +224,7 @@ function UniReader:draworcache(no, preCache)
 	-- okay, we do not have it in cache yet.
 	-- so render now.
 	-- start off with the requested area
-	local tile = { x = offset_x_in_page, y = offset_y_in_page, 
+	local tile = { x = offset_x_in_page, y = offset_y_in_page,
 					w = width, h = height }
 	-- can we cache the full page?
 	local max_cache = self.cache_max_memsize
@@ -256,7 +262,7 @@ function UniReader:draworcache(no, preCache)
 		end
 		return nil
 	end
-	self:cacheclaim(tile.w * tile.h / 2);
+	self:cacheClaim(tile.w * tile.h / 2);
 	self.cache[pagehash] = {
 		x = tile.x,
 		y = tile.y,
@@ -279,13 +285,13 @@ function UniReader:draworcache(no, preCache)
 end
 
 -- blank the cache
-function UniReader:clearcache()
+function UniReader:clearCache()
 	self.cache = {}
 	self.cache_current_memsize = 0
 end
 
 -- set viewer state according to zoom state
-function UniReader:setzoom(page)
+function UniReader:setZoom(page)
 	local dc = DrawContext.new()
 	local pwidth, pheight = page:getSize(self.nulldc)
 	print("# page::getSize "..pwidth.."*"..pheight);
@@ -306,14 +312,14 @@ function UniReader:setzoom(page)
 		print("# ORIGINAL page::getUsedBBox "..x0.."*"..y0.." "..x1.."*"..y1);
 		local bbox = self.bbox[self.pageno] -- exact
 
-		local odd_even = self:odd_even(self.pageno)
+		local oddEven = self:oddEven(self.pageno)
 		if bbox ~= nil then
 			print("## bbox from "..self.pageno)
 		else
-			bbox = self.bbox[odd_even] -- odd/even
+			bbox = self.bbox[oddEven] -- odd/even
 		end
 		if bbox ~= nil then -- last used up to this page
-			print("## bbox from "..odd_even)
+			print("## bbox from "..oddEven)
 		else
 			for i = 0,self.pageno do
 				bbox = self.bbox[ self.pageno - i ]
@@ -424,7 +430,7 @@ function UniReader:setzoom(page)
 		self.min_offset_y = 0
 	end
 
-	print("# Reader:setzoom globalzoom:"..self.globalzoom.." globalrotate:"..self.globalrotate.." offset:"..self.offset_x.."*"..self.offset_y.." pagesize:"..self.fullwidth.."*"..self.fullheight.." min_offset:"..self.min_offset_x.."*"..self.min_offset_y)
+	print("# Reader:setZoom globalzoom:"..self.globalzoom.." globalrotate:"..self.globalrotate.." offset:"..self.offset_x.."*"..self.offset_y.." pagesize:"..self.fullwidth.."*"..self.fullheight.." min_offset:"..self.min_offset_x.."*"..self.min_offset_y)
 
 	-- set gamma here, we don't have any other good place for this right now:
 	if self.globalgamma ~= self.GAMMA_NO_GAMMA then
@@ -436,7 +442,7 @@ end
 
 -- render and blit a page
 function UniReader:show(no)
-	local pagehash, offset_x, offset_y = self:draworcache(no)
+	local pagehash, offset_x, offset_y = self:drawOrCache(no)
 	if not pagehash then
 		return
 	end
@@ -448,15 +454,15 @@ function UniReader:show(no)
 		-- we can't fill the whole output width, center the content
 		dest_x = (width - (bb:getWidth() - offset_x)) / 2
 	end
-	if bb:getHeight() - offset_y < height and 
+	if bb:getHeight() - offset_y < height and
 	self.globalzoommode ~= self.ZOOM_FIT_TO_CONTENT_WIDTH_PAN then
-		-- we can't fill the whole output height and not in 
+		-- we can't fill the whole output height and not in
 		-- ZOOM_FIT_TO_CONTENT_WIDTH_PAN mode, center the content
 		dest_y = (height - (bb:getHeight() - offset_y)) / 2
 	elseif self.globalzoommode == self.ZOOM_FIT_TO_CONTENT_WIDTH_PAN and
 	self.offset_y > 0 then
 		-- if we are in ZOOM_FIT_TO_CONTENT_WIDTH_PAN mode and turning to
-		-- the top of the page, we might leave an empty space between the 
+		-- the top of the page, we might leave an empty space between the
 		-- page top and screen top.
 		dest_y = self.offset_y
 	end
@@ -482,9 +488,9 @@ end
 --[[
 	@ pageno is the page you want to add to jump_stack
 --]]
-function UniReader:add_jump(pageno, notes)
+function UniReader:addJump(pageno, notes)
 	local jump_item = nil
-	local notes_to_add = notes 
+	local notes_to_add = notes
 	if not notes_to_add then
 		-- no notes given, auto generate from TOC entry
 		notes_to_add = self:getTOCTitleByPage(self.pageno)
@@ -525,7 +531,7 @@ function UniReader:add_jump(pageno, notes)
 	end
 end
 
-function UniReader:del_jump(pageno)
+function UniReader:delJump(pageno)
 	for _t,_v in ipairs(self.jump_stack) do
 		if _v.page == pageno then
 			table.remove(self.jump_stack, _t)
@@ -541,7 +547,7 @@ function UniReader:goto(no)
 
 	-- for jump_stack, distinguish jump from normal page turn
 	if self.pageno and math.abs(self.pageno - no) > 1 then
-		self:add_jump(self.pageno)
+		self:addJump(self.pageno)
 	end
 
 	self.pageno = no
@@ -552,7 +558,7 @@ function UniReader:goto(no)
 	if no < self.doc:getPages() then
 		if #self.bbox == 0 or not self.bbox.enabled then
 			-- pre-cache next page, but if we will modify bbox don't!
-			self:draworcache(no+1, true)
+			self:drawOrCache(no+1, true)
 		end
 	end
 end
@@ -588,7 +594,7 @@ function UniReader:prevView()
 	if self.globalzoommode == self.ZOOM_FIT_TO_CONTENT_WIDTH_PAN then
 		if self.offset_y >= self.content_top then
 			-- hit content top, turn to previous page
-			-- set self.content_top with magic num to signal self:setzoom 
+			-- set self.content_top with magic num to signal self:setZoom
 			self.content_top = -2012
 			pageno = pageno - 1
 		else
@@ -609,14 +615,14 @@ function UniReader:prevView()
 end
 
 -- adjust global gamma setting
-function UniReader:modify_gamma(factor)
-	print("modify_gamma, gamma="..self.globalgamma.." factor="..factor)
+function UniReader:modifyGamma(factor)
+	print("modifyGamma, gamma="..self.globalgamma.." factor="..factor)
 	self.globalgamma = self.globalgamma * factor;
 	self:goto(self.pageno)
 end
 
 -- adjust zoom state and trigger re-rendering
-function UniReader:setglobalzoommode(newzoommode)
+function UniReader:setGlobalZoomMode(newzoommode)
 	if self.globalzoommode ~= newzoommode then
 		self.globalzoommode = newzoommode
 		self:goto(self.pageno)
@@ -624,7 +630,7 @@ function UniReader:setglobalzoommode(newzoommode)
 end
 
 -- adjust zoom state and trigger re-rendering
-function UniReader:setglobalzoom(zoom)
+function UniReader:setGlobalZoom(zoom)
 	if self.globalzoom ~= zoom then
 		self.globalzoommode = self.ZOOM_BY_VALUE
 		self.globalzoom = zoom
@@ -632,7 +638,7 @@ function UniReader:setglobalzoom(zoom)
 	end
 end
 
-function UniReader:setrotate(rotate)
+function UniReader:setRotate(rotate)
 	self.globalrotate = rotate
 	self:goto(self.pageno)
 end
@@ -641,7 +647,7 @@ end
 function UniReader:screenRotate(orien)
 	Screen:screenRotate(orien)
 	width, height = fb:getSize()
-	self:clearcache()
+	self:clearCache()
 	self:goto(self.pageno)
 end
 
@@ -663,7 +669,7 @@ function UniReader:getTOCTitleByPage(pageno)
 	if #self.toc == 0 then
 		return ""
 	end
-	
+
 	local pre_entry = self.toc[1]
 	for _k,_v in ipairs(self.toc) do
 		if _v.page > pageno then
@@ -703,11 +709,11 @@ end
 function UniReader:showJumpStack()
 	local menu_items = {}
 	for _k,_v in ipairs(self.jump_stack) do
-		table.insert(menu_items, 
+		table.insert(menu_items,
 			_v.datetime.." -> Page ".._v.page.." ".._v.notes)
 	end
 	jump_menu = SelectMenu:new{
-		menu_title = "Jump Keeper      (current page: "..self.pageno..")", 
+		menu_title = "Jump Keeper      (current page: "..self.pageno..")",
 		item_array = menu_items,
 		no_item_msg = "No jump history.",
 	}
@@ -737,7 +743,7 @@ function UniReader:showMenu()
 		"    "..cur_section, true)
 
 	ypos = ypos + 15
-	blitbuffer.progressBar(fb.bb, 10, ypos, width-20, 15, 
+	blitbuffer.progressBar(fb.bb, 10, ypos, width-20, 15,
 							5, 4, load_percent, 8)
 	fb:refresh(1)
 	while 1 do
@@ -751,8 +757,8 @@ function UniReader:showMenu()
 	end
 end
 
-function UniReader:odd_even(number)
-	print("## odd_even "..number)
+function UniReader:oddEven(number)
+	print("## oddEven "..number)
 	if number % 2 == 1 then
 		return "odd"
 	else
@@ -761,228 +767,24 @@ function UniReader:odd_even(number)
 end
 
 -- wait for input and handle it
-function UniReader:inputloop()
+function UniReader:inputLoop()
 	local keep_running = true
 	while 1 do
 		local ev = input.waitForEvent()
 		ev.code = adjustKeyEvents(ev)
 		if ev.type == EV_KEY and ev.value == EVENT_VALUE_KEY_PRESS then
 			local secs, usecs = util.gettime()
-			if ev.code == KEY_PGFWD or ev.code == KEY_LPGFWD then
-				if Keys.shiftmode then
-					self:setglobalzoom(self.globalzoom+self.globalzoom_orig*0.2)
-				elseif Keys.altmode then
-					self:setglobalzoom(self.globalzoom+self.globalzoom_orig*0.1)
-				else
-					-- turn page forward
-					local pageno = self:nextView()
-					self:goto(pageno)
-				end
-			elseif ev.code == KEY_PGBCK or ev.code == KEY_LPGBCK then
-				if Keys.shiftmode then
-					self:setglobalzoom(self.globalzoom-self.globalzoom_orig*0.2)
-				elseif Keys.altmode then
-					self:setglobalzoom(self.globalzoom-self.globalzoom_orig*0.1)
-				else
-					-- turn page back
-					local pageno = self:prevView()
-					self:goto(pageno)
-				end
-			elseif ev.code == KEY_BACK then
-				if Keys.altmode then
-					-- altmode, exit reader
-					break
-				else
-					-- not altmode, back to last jump
-					if #self.jump_stack ~= 0 then
-						self:goto(self.jump_stack[1].page)
-					end
-				end
-			elseif ev.code == KEY_VPLUS then
-				self:modify_gamma( 1.25 )
-			elseif ev.code == KEY_VMINUS then
-				self:modify_gamma( 0.8 )
-			elseif ev.code == KEY_1 then
-				self:goto(1)
-			elseif ev.code >= KEY_2 and ev.code <= KEY_9 then
-				self:goto(math.floor(self.doc:getPages()/90*(ev.code-KEY_1)*10))
-			elseif ev.code == KEY_0 then
-				self:goto(self.doc:getPages())						
-			elseif ev.code == KEY_A then
-				if Keys.shiftmode then
-					self:setglobalzoommode(self.ZOOM_FIT_TO_CONTENT)
-				else
-					self:setglobalzoommode(self.ZOOM_FIT_TO_PAGE)
-				end
-			elseif ev.code == KEY_S then
-				if Keys.shiftmode then
-					self:setglobalzoommode(self.ZOOM_FIT_TO_CONTENT_WIDTH)
-				else
-					self:setglobalzoommode(self.ZOOM_FIT_TO_PAGE_WIDTH)
-				end
-			elseif ev.code == KEY_D then
-				if Keys.shiftmode then
-					self:setglobalzoommode(self.ZOOM_FIT_TO_CONTENT_HEIGHT)
-				else
-					self:setglobalzoommode(self.ZOOM_FIT_TO_PAGE_HEIGHT)
-				end
-			elseif ev.code == KEY_F then
-				if Keys.shiftmode then
-					self:setglobalzoommode(self.ZOOM_FIT_TO_CONTENT_HALF_WIDTH)
-				else
-					self:setglobalzoommode(self.ZOOM_FIT_TO_CONTENT_HALF_WIDTH_MARGIN)
-				end
-			elseif ev.code == KEY_G then
-				local page = InputBox:input(height-100, 100, "Page:")
-				-- convert string to number
-				if not pcall(function () page = page + 0 end) then
-					page = self.pageno
-				else
-					if page < 1 or page > self.doc:getPages() then
-						page = self.pageno
-					end
-				end
-				self:goto(page)
-			elseif ev.code == KEY_T then
-				self:showTOC()
-			elseif ev.code == KEY_B then
-				if Keys.shiftmode then
-					self:add_jump(self.pageno)
-				else
-					self:showJumpStack()
-				end
-			elseif ev.code == KEY_J then
-				if Keys.shiftmode then
-					self:screenRotate("clockwise")
-				else
-					self:setrotate( self.globalrotate + 10 )
-				end
-			elseif ev.code == KEY_K then
-				if Keys.shiftmode then
-					self:screenRotate("anticlockwise")
-				else
-					self:setrotate( self.globalrotate - 10 )
-				end
-			elseif ev.code == KEY_HOME then
-				if Keys.shiftmode or Keys.altmode then
-					-- signal quit
-					keep_running = false
-				end
-				break
-			elseif ev.code == KEY_Z and not (Keys.shiftmode or Keys.altmode) then
-				local bbox = {}
-				bbox["x0"] = - self.offset_x / self.globalzoom
-				bbox["y0"] = - self.offset_y / self.globalzoom
-				bbox["x1"] = bbox["x0"] + width / self.globalzoom
-				bbox["y1"] = bbox["y0"] + height / self.globalzoom
-				bbox.pan_x = self.pan_x
-				bbox.pan_y = self.pan_y
-				self.bbox[self.pageno] = bbox
-				self.bbox[self:odd_even(self.pageno)] = bbox
-				self.bbox.enabled = true
-				print("# bbox " .. self.pageno .. dump(self.bbox)) 
-				self.globalzoommode = self.ZOOM_FIT_TO_CONTENT -- use bbox
-			elseif ev.code == KEY_Z and Keys.shiftmode then
-				self.bbox[self.pageno] = nil;
-				print("# bbox remove "..self.pageno .. dump(self.bbox));
-			elseif ev.code == KEY_Z and Keys.altmode then
-				self.bbox.enabled = not self.bbox.enabled;
-				print("# bbox override: ", self.bbox.enabled);
-			elseif ev.code == KEY_MENU then
-				self:showMenu()
-				self:goto(self.pageno)
-			end
-
-			-- switch to ZOOM_BY_VALUE to enable panning on fiveway move
-			if ev.code == KEY_FW_LEFT
-			or ev.code == KEY_FW_RIGHT
-			or ev.code == KEY_FW_UP
-			or ev.code == KEY_FW_DOWN
-			then
-				self.globalzoommode = self.ZOOM_BY_VALUE
-			end
-
-			if self.globalzoommode == self.ZOOM_BY_VALUE then
-				local x
-				local y
-
-				if Keys.shiftmode then -- shift always moves in small steps
-					x = self.shift_x / 2
-					y = self.shift_y / 2
-				elseif Keys.altmode then
-					x = self.shift_x / 5
-					y = self.shift_y / 5
-				elseif self.pan_by_page then
-					x = width;
-					y = height - self.pan_overlap_vertical; -- overlap for lines which didn't fit
-				else
-					x = self.shift_x
-					y = self.shift_y
-				end
-
-				print("offset "..self.offset_x.."*"..self.offset_x.." shift "..x.."*"..y.." globalzoom="..self.globalzoom)
-				local old_offset_x = self.offset_x
-				local old_offset_y = self.offset_y
-
-				if ev.code == KEY_FW_LEFT then
-					print("# KEY_FW_LEFT "..self.offset_x.." + "..x.." > 0");
-					self.offset_x = self.offset_x + x
-					if self.pan_by_page then
-						if self.offset_x > 0 and self.pageno > 1 then
-							self.offset_x = self.pan_x
-							self.offset_y = self.min_offset_y -- bottom
-							self:goto(self.pageno - 1)
-						else
-							self.offset_y = self.min_offset_y
-						end
-					elseif self.offset_x > 0 then
-						self.offset_x = 0
-					end
-				elseif ev.code == KEY_FW_RIGHT then
-					print("# KEY_FW_RIGHT "..self.offset_x.." - "..x.." < "..self.min_offset_x.." - "..self.pan_margin);
-					self.offset_x = self.offset_x - x
-					if self.pan_by_page then
-						if self.offset_x < self.min_offset_x - self.pan_margin and self.pageno < self.doc:getPages() then
-							self.offset_x = self.pan_x
-							self.offset_y = self.pan_y
-							self:goto(self.pageno + 1)
-						else
-							self.offset_y = self.pan_y
-						end
-					elseif self.offset_x < self.min_offset_x then
-						self.offset_x = self.min_offset_x
-					end
-				elseif ev.code == KEY_FW_UP then
-					self.offset_y = self.offset_y + y
-					if self.offset_y > 0 then
-						self.offset_y = 0
-					end
-				elseif ev.code == KEY_FW_DOWN then
-					self.offset_y = self.offset_y - y
-					if self.offset_y < self.min_offset_y then
-						self.offset_y = self.min_offset_y
-					end
-				elseif ev.code == KEY_FW_PRESS then
-					if Keys.shiftmode then
-						if self.pan_by_page then
-							self.offset_x = self.pan_x
-							self.offset_y = self.pan_y
-						else
-							self.offset_x = 0
-							self.offset_y = 0
-						end
-					else
-						self.pan_by_page = not self.pan_by_page
-						if self.pan_by_page then
-							self.pan_x = self.offset_x
-							self.pan_y = self.offset_y
-						end
-					end
-				end
-				if old_offset_x ~= self.offset_x
-				or old_offset_y ~= self.offset_y then
-						self:goto(self.pageno)
+			keydef = Keydef:new(ev.code, getKeyModifier())
+			print("key pressed: "..tostring(keydef))
+			command = self.commands:getByKeydef(keydef)
+			if command ~= nil then
+				print("command to execute: "..tostring(command))
+				ret_code = command.func(self,keydef)
+				if ret_code == "break" then
+					break;
 				end
+			else
+				print("command not found: "..tostring(command))
 			end
 
 			local nsecs, nusecs = util.gettime()
@@ -992,7 +794,7 @@ function UniReader:inputloop()
 	end
 
 	-- do clean up stuff
-	self:clearcache()
+	self:clearCache()
 	self.toc = nil
 	if self.doc ~= nil then
 		self.doc:close()
@@ -1009,3 +811,298 @@ function UniReader:inputloop()
 
 	return keep_running
 end
+
+-- command definitions
+function UniReader:addAllCommands()
+	self.commands = Commands:new()
+	self.commands:add(KEY_PGFWD,nil,">",
+		"next page",
+		function(unireader)
+			unireader:goto(unireader:nextView())
+		end)
+	self.commands:add(KEY_PGBCK,nil,"<",
+		"previous page",
+		function(unireader)
+			unireader:goto(unireader:prevView())
+		end)
+	self.commands:add(KEY_PGFWD,MOD_ALT,">",
+		"zoom in 10%",
+		function(unireader)
+			unireader:setGlobalZoom(unireader.globalzoom+unireader.globalzoom_orig*0.1)
+		end)
+	self.commands:add(KEY_PGBCK,MOD_ALT,"<",
+		"zoom out 10%",
+		function(unireader)
+			unireader:setGlobalZoom(unireader.globalzoom-unireader.globalzoom_orig*0.1)
+		end)
+	self.commands:add(KEY_PGFWD,MOD_SHIFT,">",
+		"zoom in 20%",
+		function(unireader)
+			unireader:setGlobalZoom(unireader.globalzoom+unireader.globalzoom_orig*0.2)
+		end)
+	self.commands:add(KEY_PGBCK,MOD_SHIFT,"<",
+		"zoom out 20%",
+		function(unireader)
+			unireader:setGlobalZoom(unireader.globalzoom-unireader.globalzoom_orig*0.2)
+		end)
+	self.commands:add(KEY_BACK,nil,"back",
+		"back to last jump",
+		function(unireader)
+			if #unireader.jump_stack ~= 0 then
+				unireader:goto(unireader.jump_stack[1].page)
+			end
+		end)
+	self.commands:add(KEY_BACK,MOD_ALT,"back",
+		"close document",
+		function(unireader)
+			return "break"
+		end)
+	self.commands:add(KEY_VPLUS,nil,"vol+",
+		"increase gamma 25%",
+		function(unireader)
+			unireader:modifyGamma( 1.25 )
+		end)
+	self.commands:add(KEY_VMINUS,nil,"vol-",
+		"decrease gamma 25%",
+		function(unireader)
+			unireader:modifyGamma( 0.80 )
+		end)
+	--numeric key group
+	local numeric_keydefs = {}
+	for i=1,10 do numeric_keydefs[i]=Keydef:new(KEY_1+i-1,nil,tostring(i%10)) end
+	self.commands:addGroup("[1..0]",numeric_keydefs,
+		"jump to <key>*10% of document",
+		function(unireader,keydef)
+			print('jump to page: '..math.max(math.floor(unireader.doc:getPages()*(keydef.keycode-KEY_1)/9),1)..'/'..unireader.doc:getPages())
+			unireader:goto(math.max(math.floor(unireader.doc:getPages()*(keydef.keycode-KEY_1)/9),1))
+		end)
+	-- end numeric keys
+	self.commands:add(KEY_A,nil,"A",
+		"zoom to fit page",
+		function(unireader)
+			unireader:setGlobalZoomMode(unireader.ZOOM_FIT_TO_PAGE)
+		end)
+	self.commands:add(KEY_A,MOD_SHIFT,"A",
+		"zoom to fit content",
+		function(unireader)
+			unireader:setGlobalZoomMode(unireader.ZOOM_FIT_TO_CONTENT)
+		end)
+	self.commands:add(KEY_S,nil,"S",
+		"zoom to fit page width",
+		function(unireader)
+			unireader:setGlobalZoomMode(unireader.ZOOM_FIT_TO_PAGE_WIDTH)
+		end)
+	self.commands:add(KEY_S,MOD_SHIFT,"S",
+		"zoom to fit content width",
+		function(unireader)
+			unireader:setGlobalZoomMode(unireader.ZOOM_FIT_TO_CONTENT_WIDTH)
+		end)
+	self.commands:add(KEY_D,nil,"D",
+		"zoom to fit page height",
+		function(unireader)
+			unireader:setGlobalZoomMode(unireader.ZOOM_FIT_TO_PAGE_HEIGHT)
+		end)
+	self.commands:add(KEY_D,MOD_SHIFT,"D",
+		"zoom to fit content height",
+		function(unireader)
+			unireader:setGlobalZoomMode(unireader.ZOOM_FIT_TO_CONTENT_HEIGHT)
+		end)
+	self.commands:add(KEY_F,nil,"F",
+		"zoom to fit margin 2-column mode",
+		function(unireader)
+			unireader:setGlobalZoomMode(unireader.ZOOM_FIT_TO_CONTENT_HALF_WIDTH_MARGIN)
+		end)
+	self.commands:add(KEY_F,MOD_SHIFT,"F",
+		"zoom to fit content 2-column mode",
+		function(unireader)
+			unireader:setGlobalZoomMode(unireader.ZOOM_FIT_TO_CONTENT_HALF_WIDTH)
+		end)
+	self.commands:add(KEY_G,nil,"G",
+		"goto page",
+		function(unireader)
+			local page = InputBox:input(height-100, 100, "Page:")
+			-- convert string to number
+			if not pcall(function () page = page + 0 end) then
+				page = unireader.pageno
+			else
+				if page < 1 or page > unireader.doc:getPages() then
+					page = unireader.pageno
+				end
+			end
+			unireader:goto(page)
+		end)
+	self.commands:add(KEY_H,nil,"H",
+		"show help page",
+		function(unireader)
+			HelpPage:show(0,height,unireader.commands)
+			unireader:goto(unireader.pageno)
+		end)
+	self.commands:add(KEY_T,nil,"T",
+		"show table of content",
+		function(unireader)
+			unireader:showTOC()
+		end)
+	self.commands:add(KEY_B,nil,"B",
+		"show jump stack",
+		function(unireader)
+			unireader:showJumpStack()
+		end)
+	self.commands:add(KEY_B,MOD_SHIFT,"B",
+		"add jump",
+		function(unireader)
+			unireader:addJump(unireader.pageno)
+		end)
+	self.commands:add(KEY_J,nil,"J",
+		"rotate 10° clockwise",
+		function(unireader)
+			unireader:setRotate( unireader.globalrotate + 10 )
+		end)
+	self.commands:add(KEY_J,MOD_SHIFT,"J",
+		"rotate screen 90° clockwise",
+		function(unireader)
+			unireader:screenRotate("clockwise")
+		end)
+	self.commands:add(KEY_K,nil,"K",
+		"rotate 10° counterclockwise",
+		function(unireader)
+			unireader:setRotate( unireader.globalrotate - 10 )
+		end)
+	self.commands:add(KEY_K,MOD_SHIFT,"K",
+		"rotate screen 90° counterclockwise",
+		function(unireader)
+			unireader:screenRotate("anticlockwise")
+		end)
+	self.commands:add(KEY_HOME,MOD_SHIFT_OR_ALT,"Home",
+		"exit application",
+		function(unireader)
+			keep_running = false
+			return "break"
+		end)
+	self.commands:add(KEY_Z,nil,"Z",
+		"set crop mode",
+		function(unireader)
+			local bbox = {}
+			bbox["x0"] = - unireader.offset_x / unireader.globalzoom
+			bbox["y0"] = - unireader.offset_y / unireader.globalzoom
+			bbox["x1"] = bbox["x0"] + width / unireader.globalzoom
+			bbox["y1"] = bbox["y0"] + height / unireader.globalzoom
+			bbox.pan_x = unireader.pan_x
+			bbox.pan_y = unireader.pan_y
+			unireader.bbox[unireader.pageno] = bbox
+			unireader.bbox[unireader:oddEven(unireader.pageno)] = bbox
+			unireader.bbox.enabled = true
+			print("# bbox " .. unireader.pageno .. dump(unireader.bbox))
+			unireader.globalzoommode = unireader.ZOOM_FIT_TO_CONTENT -- use bbox
+		end)
+	self.commands:add(KEY_Z,MOD_SHIFT,"Z",
+		"reset crop",
+		function(unireader)
+			unireader.bbox[unireader.pageno] = nil;
+			print("# bbox remove "..unireader.pageno .. dump(unireader.bbox));
+		end)
+	self.commands:add(KEY_Z,MOD_ALT,"Z",
+		"toggle crop mode",
+		function(unireader)
+			unireader.bbox.enabled = not unireader.bbox.enabled;
+			print("# bbox override: ", unireader.bbox.enabled);
+		end)
+	self.commands:add(KEY_MENU,nil,"Menu",
+		"open menu",
+		function(unireader)
+			unireader:showMenu()
+			unireader:goto(unireader.pageno)
+		end)
+	-- panning
+	local panning_keys = {Keydef:new(KEY_FW_LEFT,MOD_ANY),Keydef:new(KEY_FW_RIGHT,MOD_ANY),Keydef:new(KEY_FW_UP,MOD_ANY),Keydef:new(KEY_FW_DOWN,MOD_ANY),Keydef:new(KEY_FW_PRESS,MOD_ANY)}
+	self.commands:addGroup("[joypad]",panning_keys,
+		"pan the active view; use Shift or Alt for smaller steps",
+		function(unireader,keydef)
+			if keydef.keycode ~= KEY_FW_PRESS then
+				unireader.globalzoommode = unireader.ZOOM_BY_VALUE
+			end
+			if unireader.globalzoommode == unireader.ZOOM_BY_VALUE then
+				local x
+				local y
+				if keydef.modifier==MOD_SHIFT then -- shift always moves in small steps
+					x = unireader.shift_x / 2
+					y = unireader.shift_y / 2
+				elseif keydef.modifier==MOD_ALT then
+					x = unireader.shift_x / 5
+					y = unireader.shift_y / 5
+				elseif unireader.pan_by_page then
+					x = width;
+					y = height - unireader.pan_overlap_vertical; -- overlap for lines which didn't fit
+				else
+					x = unireader.shift_x
+					y = unireader.shift_y
+				end
+
+				print("offset "..unireader.offset_x.."*"..unireader.offset_x.." shift "..x.."*"..y.." globalzoom="..unireader.globalzoom)
+				local old_offset_x = unireader.offset_x
+				local old_offset_y = unireader.offset_y
+
+				if keydef.keycode == KEY_FW_LEFT then
+					print("# KEY_FW_LEFT "..unireader.offset_x.." + "..x.." > 0");
+					unireader.offset_x = unireader.offset_x + x
+					if unireader.pan_by_page then
+						if unireader.offset_x > 0 and unireader.pageno > 1 then
+							unireader.offset_x = unireader.pan_x
+							unireader.offset_y = unireader.min_offset_y -- bottom
+							unireader:goto(unireader.pageno - 1)
+						else
+							unireader.offset_y = unireader.min_offset_y
+						end
+					elseif unireader.offset_x > 0 then
+						unireader.offset_x = 0
+					end
+				elseif keydef.keycode == KEY_FW_RIGHT then
+					print("# KEY_FW_RIGHT "..unireader.offset_x.." - "..x.." < "..unireader.min_offset_x.." - "..unireader.pan_margin);
+					unireader.offset_x = unireader.offset_x - x
+					if unireader.pan_by_page then
+						if unireader.offset_x < unireader.min_offset_x - unireader.pan_margin and unireader.pageno < unireader.doc:getPages() then
+							unireader.offset_x = unireader.pan_x
+							unireader.offset_y = unireader.pan_y
+							unireader:goto(unireader.pageno + 1)
+						else
+							unireader.offset_y = unireader.pan_y
+						end
+					elseif unireader.offset_x < unireader.min_offset_x then
+						unireader.offset_x = unireader.min_offset_x
+					end
+				elseif keydef.keycode == KEY_FW_UP then
+					unireader.offset_y = unireader.offset_y + y
+					if unireader.offset_y > 0 then
+						unireader.offset_y = 0
+					end
+				elseif keydef.keycode == KEY_FW_DOWN then
+					unireader.offset_y = unireader.offset_y - y
+					if unireader.offset_y < unireader.min_offset_y then
+						unireader.offset_y = unireader.min_offset_y
+					end
+				elseif keydef.keycode == KEY_FW_PRESS then
+					if keydef.modifier==MOD_SHIFT then
+						if unireader.pan_by_page then
+							unireader.offset_x = unireader.pan_x
+							unireader.offset_y = unireader.pan_y
+						else
+							unireader.offset_x = 0
+							unireader.offset_y = 0
+						end
+					else
+						unireader.pan_by_page = not unireader.pan_by_page
+						if unireader.pan_by_page then
+							unireader.pan_x = unireader.offset_x
+							unireader.pan_y = unireader.offset_y
+						end
+					end
+				end
+				if old_offset_x ~= unireader.offset_x
+				or old_offset_y ~= unireader.offset_y then
+						unireader:goto(unireader.pageno)
+				end
+			end
+		end)
+	-- end panning
+	--print defined commands
+	--for k,v in pairs(self.commands.map) do print(v) end
+end