diff --git a/frontend/apps/filemanager/filemanagerhistory.lua b/frontend/apps/filemanager/filemanagerhistory.lua
index 479b96ac2..549eea46e 100644
--- a/frontend/apps/filemanager/filemanagerhistory.lua
+++ b/frontend/apps/filemanager/filemanagerhistory.lua
@@ -1,4 +1,6 @@
 local InputContainer = require("ui/widget/container/inputcontainer")
+local CenterContainer = require("ui/widget/container/centercontainer")
+local Menu = require("ui/widget/menu")
 local Screen = require("ui/screen")
 local UIManager = require("ui/uimanager")
 local DocSettings = require("docsettings")
diff --git a/frontend/document/credocument.lua b/frontend/document/credocument.lua
index 6f0b2e002..687ba9986 100644
--- a/frontend/document/credocument.lua
+++ b/frontend/document/credocument.lua
@@ -2,6 +2,8 @@ local Geom = require("ui/geometry")
 local CreOptions = require("ui/data/creoptions")
 local Document = require("document/document")
 local Configurable = require("ui/reader/configurable")
+local Font = require("ui/font")
+local Screen = require("ui/screen")
 -- TBD: DrawContext
 
 local CreDocument = Document:new{
@@ -22,7 +24,7 @@ local CreDocument = Document:new{
 }
 
 -- NuPogodi, 20.05.12: inspect the zipfile content
-function CreDocument:zipContentExt(fname)
+function CreDocument.zipContentExt(self, fname)
 	local outfile = "./data/zip_content"
 	local s = ""
 	os.execute("unzip ".."-l \""..fname.."\" > "..outfile)
diff --git a/frontend/document/koptinterface.lua b/frontend/document/koptinterface.lua
index f318b9c26..02455b141 100644
--- a/frontend/document/koptinterface.lua
+++ b/frontend/document/koptinterface.lua
@@ -2,6 +2,9 @@ local Document = require("document/document")
 local Cache = require("cache")
 local CacheItem = require("cacheitem")
 local Screen = require("ui/screen")
+local Geom = require("ui/geometry")
+local TileCacheItem = require("document/tilecacheitem")
+local Dbg = require("dbg")
 -- TBD: KOPTContext
 
 local KoptInterface = {
diff --git a/frontend/ui/device.lua b/frontend/ui/device.lua
index 6a8f985ff..28ba2f474 100644
--- a/frontend/ui/device.lua
+++ b/frontend/ui/device.lua
@@ -1,8 +1,7 @@
 local KindleFrontLight = require("ui/device/kindlefrontlight")
 local KoboFrontLight = require("ui/device/kobofrontlight")
 local BaseFrontLight = require("ui/device/basefrontlight")
-
--- Screen
+local Screen = require("ui/device/screen")
 -- util
 -- lfs
 
@@ -14,8 +13,11 @@ local Device = {
 	model = nil,
 	firmware_rev = nil,
 	frontlight = nil,
+	screen = Screen
 }
 
+Screen.device = Device
+
 function Device:getModel()
 	if self.model then return self.model end
 	if util.isEmulated() then
@@ -117,7 +119,7 @@ end
 function Device:intoScreenSaver()
 	--os.execute("echo 'screensaver in' >> /mnt/us/event_test.txt")
 	if self.charging_mode == false and self.screen_saver_mode == false then
-		Screen:saveCurrentBB()
+		self.screen:saveCurrentBB()
 		--UIManager:show(InfoMessage:new{
 			--text = "Going into screensaver... ",
 			--timeout = 2,
@@ -135,8 +137,8 @@ function Device:outofScreenSaver()
 		-- Blitbuffer.
 		util.usleep(1500000)
 		--os.execute("killall -stop cvm")
-		Screen:restoreFromSavedBB()
-		Screen:refresh(0)
+		self.screen:restoreFromSavedBB()
+		self.screen:refresh(0)
 		self.survive_screen_saver = true
 	end
 	self.screen_saver_mode = false
@@ -147,7 +149,7 @@ function Device:prepareSuspend() -- currently only used for kobo devices
 	if fl ~= nil then
 		fl.fl:sleep()
 	end
-	Screen:refresh(0)
+	self.screen:refresh(0)
 	self.screen_saver_mode = true
 end
 
@@ -157,7 +159,7 @@ end
 
 function Device:Resume() -- currently only used for kobo devices
 	os.execute("echo 0 > /sys/power/state-extended")
-	Screen:refresh(0)
+	self.screen:refresh(0)
 	local fl = self:getFrontlight()
 	if fl ~= nil then
 		fl.fl:restore()
@@ -168,7 +170,7 @@ end
 function Device:usbPlugIn()
 	--os.execute("echo 'usb in' >> /mnt/us/event_test.txt")
 	if self.charging_mode == false and self.screen_saver_mode == false then
-		Screen:saveCurrentBB()
+		self.screen:saveCurrentBB()
 		--UIManager:show(InfoMessage:new{
 			--text = "Going into USB mode... ",
 			--timeout = 2,
@@ -184,8 +186,8 @@ function Device:usbPlugOut()
 	if self.charging_mode == true and self.screen_saver_mode == false then
 		--util.usleep(1500000)
 		--os.execute("killall -stop cvm")
-		Screen:restoreFromSavedBB()
-		Screen:refresh(0)
+		self.screen:restoreFromSavedBB()
+		self.screen:refresh(0)
 	end
 
 	--@TODO signal filemanager for file changes  13.06 2012 (houqp)
diff --git a/frontend/ui/device/screen.lua b/frontend/ui/device/screen.lua
new file mode 100644
index 000000000..9a1b929c5
--- /dev/null
+++ b/frontend/ui/device/screen.lua
@@ -0,0 +1,211 @@
+local Geom = require("ui/geometry")
+
+-- Blitbuffer
+-- einkfb
+
+--[[
+Codes for rotation modes:
+
+1 for no rotation,
+2 for landscape with bottom on the right side of screen, etc.
+
+           2
+   +--------------+
+   | +----------+ |
+   | |          | |
+   | | Freedom! | |
+   | |          | |
+   | |          | |
+ 3 | |          | | 1
+   | |          | |
+   | |          | |
+   | +----------+ |
+   |              |
+   |              |
+   +--------------+
+          0
+--]]
+
+
+local Screen = {
+	width = 0,
+	height = 0,
+	native_rotation_mode = nil,
+	cur_rotation_mode = 0,
+
+	bb = nil,
+	saved_bb = nil,
+
+	fb = einkfb.open("/dev/fb0"),
+	-- will be set upon loading by Device class:
+	device = nil,
+}
+
+function Screen:init()
+	-- for unknown strange reason, pitch*2 is 10 px more than screen width in KPW
+	self.width, self.height = self.fb:getSize()
+	-- Blitbuffer still uses inverted 4bpp bitmap, so pitch should be
+	-- (self.width / 2)
+	self.bb = Blitbuffer.new(self.width, self.height, self.width/2)
+	if self.width > self.height then
+		-- For another unknown strange reason, self.fb:getOrientation always
+		-- return 0 in KPW, even though we are in landscape mode.
+		-- Seems like the native framework change framebuffer on the fly when
+		-- starting booklet. Starting KPV from ssh and KPVBooklet will get
+		-- different framebuffer height and width.
+		--
+		--self.native_rotation_mode = self.fb:getOrientation()
+		self.native_rotation_mode = 1
+	else
+		self.native_rotation_mode = 0
+	end
+	self.cur_rotation_mode = self.native_rotation_mode
+end
+
+function Screen:refresh(refesh_type, waveform_mode, x, y, w, h)
+	if x then x = x < 0 and 0 or math.floor(x) end
+    if y then y = y < 0 and 0 or math.floor(y) end
+    if w then w = w + x > self.width and self.width - x or math.ceil(w) end
+    if h then h = h + y > self.height and self.height - y or math.ceil(h) end
+	if self.native_rotation_mode == self.cur_rotation_mode then
+        self.fb.bb:blitFrom(self.bb, 0, 0, 0, 0, self.width, self.height)
+    elseif self.native_rotation_mode == 0 and self.cur_rotation_mode == 1 then
+        self.fb.bb:blitFromRotate(self.bb, 270)
+        if x and y and w and h then
+        	x, y = y, self.width - w - x
+        	w, h = h, w
+        end
+    elseif self.native_rotation_mode == 0 and self.cur_rotation_mode == 3 then
+        self.fb.bb:blitFromRotate(self.bb, 90)
+        if x and y and w and h then
+        	x, y = self.height - h - y, x
+        	w, h = h, w
+        end
+    elseif self.native_rotation_mode == 1 and self.cur_rotation_mode == 0 then
+        self.fb.bb:blitFromRotate(self.bb, 90)
+        if x and y and w and h then
+        	x, y = self.height - h - y, x
+        	w, h = h, w
+        end
+    elseif self.native_rotation_mode == 1 and self.cur_rotation_mode == 3 then
+        self.fb.bb:blitFromRotate(self.bb, 180)
+        if x and y and w and h then
+        	x, y = self.width - w - x, self.height - h - y
+        end
+    end
+	self.fb:refresh(refesh_type, waveform_mode, x, y, w, h)
+end
+
+function Screen:getSize()
+	return Geom:new{w = self.width, h = self.height}
+end
+
+function Screen:getWidth()
+	return self.width
+end
+
+function Screen:getHeight()
+	return self.height
+end
+
+function Screen:getDPI()
+	if(self.device:getModel() == "KindlePaperWhite") or (self.device:getModel() == "Kobo_kraken") then
+		return 212
+	elseif self.device:getModel() == "Kobo_dragon" then
+		return 265
+	elseif self.device:getModel() == "Kobo_pixie" then
+		return 200
+	else
+		return 167
+	end
+end
+
+function Screen:scaleByDPI(px)
+	return math.floor(px * self:getDPI()/167)
+end
+
+function Screen:rescaleByDPI(px)
+	return math.ceil(px * 167/self:getDPI())
+end
+
+function Screen:getPitch()
+	return self.fb:getPitch()
+end
+
+function Screen:getNativeRotationMode()
+	-- in EMU mode, you will always get 0 from getOrientation()
+	return self.fb:getOrientation()
+end
+
+function Screen:getRotationMode()
+	return self.cur_rotation_mode
+end
+
+function Screen:getScreenMode()
+	if self.width > self.height then
+		return "landscape"
+	else
+		return "portrait"
+	end
+end
+
+function Screen:setRotationMode(mode)
+	if mode > 3 or mode < 0 then
+		return
+	end
+
+	-- mode 0 and mode 2 has the same width and height, so do mode 1 and 3
+	if (self.cur_rotation_mode % 2) ~= (mode % 2) then
+		self.width, self.height = self.height, self.width
+	end
+	self.cur_rotation_mode = mode
+	self.bb:free()
+	self.bb = Blitbuffer.new(self.width, self.height, self.width/2)
+end
+
+function Screen:setScreenMode(mode)
+	if mode == "portrait" then
+		if self.cur_rotation_mode ~= 0 then
+			self:setRotationMode(0)
+		end
+	elseif mode == "landscape" then
+		if self.cur_rotation_mode == 0 or self.cur_rotation_mode == 2 then
+			self:setRotationMode(1)
+		elseif self.cur_rotation_mode == 1 or self.cur_rotation_mode == 3 then
+			self:setRotationMode((self.cur_rotation_mode + 2) % 4)
+		end
+	end
+end
+
+function Screen:saveCurrentBB()
+	local width, height = self:getWidth(), self:getHeight()
+
+	if not self.saved_bb then
+		self.saved_bb = Blitbuffer.new(width, height, self.width/2)
+	end
+	if self.saved_bb:getWidth() ~= width then
+		self.saved_bb:free()
+		self.saved_bb = Blitbuffer.new(width, height, self.width/2)
+	end
+	self.saved_bb:blitFullFrom(self.bb)
+end
+
+function Screen:restoreFromSavedBB()
+	self:restoreFromBB(self.saved_bb)
+end
+
+function Screen:getCurrentScreenBB()
+	local bb = Blitbuffer.new(self:getWidth(), self:getHeight())
+	bb:blitFullFrom(self.bb)
+	return bb
+end
+
+function Screen:restoreFromBB(bb)
+	if bb then
+		self.bb:blitFullFrom(bb)
+	else
+		DEBUG("Got nil bb in restoreFromSavedBB!")
+	end
+end
+
+return Screen
diff --git a/frontend/ui/gesturerange.lua b/frontend/ui/gesturerange.lua
index f299998b0..4b7d7363d 100644
--- a/frontend/ui/gesturerange.lua
+++ b/frontend/ui/gesturerange.lua
@@ -1,4 +1,4 @@
--- TimeVal
+local TimeVal = require("ui/timeval")
 
 local GestureRange = {
 	ges = nil,
diff --git a/frontend/ui/reader/readercoptlistener.lua b/frontend/ui/reader/readercoptlistener.lua
index 8b21b7b2c..78fd4e2fd 100644
--- a/frontend/ui/reader/readercoptlistener.lua
+++ b/frontend/ui/reader/readercoptlistener.lua
@@ -1,4 +1,5 @@
 local EventListener = require("ui/widget/eventlistener")
+local Event = require("ui/event")
 
 local ReaderCoptListener = EventListener:new{}
 
diff --git a/frontend/ui/reader/readercropping.lua b/frontend/ui/reader/readercropping.lua
index 368b7aa29..b27eb2ac7 100644
--- a/frontend/ui/reader/readercropping.lua
+++ b/frontend/ui/reader/readercropping.lua
@@ -8,8 +8,9 @@ local RightContainer = require("ui/widget/container/rightcontainer")
 local FrameContainer = require("ui/widget/container/framecontainer")
 local VerticalGroup = require("ui/widget/verticalgroup")
 local HorizontalGroup = require("ui/widget/horizontalgroup")
+local BBoxWidget = require("ui/widget/bboxwidget")
+local HorizontalSpan = require("ui/widget/horizontalspan")
 local Button = require("ui/widget/button")
-local _ = require("gettext")
 
 local PageCropDialog = VerticalGroup:new{
 	ok_text = "OK",
diff --git a/frontend/ui/reader/readerdictionary.lua b/frontend/ui/reader/readerdictionary.lua
index 731e7ae64..75de3e792 100644
--- a/frontend/ui/reader/readerdictionary.lua
+++ b/frontend/ui/reader/readerdictionary.lua
@@ -1,6 +1,7 @@
 local EventListener = require("ui/widget/eventlistener")
 local UIManager = require("ui/uimanager")
 local DictQuickLookup = require("ui/widget/dictquicklookup")
+local Screen = require("ui/screen")
 local JSON = require("JSON")
 
 local ReaderDictionary = EventListener:new{}
diff --git a/frontend/ui/reader/readerfont.lua b/frontend/ui/reader/readerfont.lua
index ae77c3db6..8078eb558 100644
--- a/frontend/ui/reader/readerfont.lua
+++ b/frontend/ui/reader/readerfont.lua
@@ -1,6 +1,11 @@
 local InputContainer = require("ui/widget/container/inputcontainer")
+local CenterContainer = require("ui/widget/container/centercontainer")
+local Menu = require("ui/widget/menu")
+local Notification = require("ui/widget/notification")
 local Device = require("ui/device")
 local Screen = require("ui/screen")
+local Input = require("ui/input")
+local Event = require("ui/event")
 local UIManager = require("ui/uimanager")
 local _ = require("gettext")
 
diff --git a/frontend/ui/reader/readerfrontlight.lua b/frontend/ui/reader/readerfrontlight.lua
index f88c3319d..6addd2072 100644
--- a/frontend/ui/reader/readerfrontlight.lua
+++ b/frontend/ui/reader/readerfrontlight.lua
@@ -3,6 +3,9 @@ local Geom = require("ui/geometry")
 local Screen = require("ui/screen")
 local Device = require("ui/device")
 local GestureRange = require("ui/gesturerange")
+local InputDialog = require("ui/widget/inputdialog")
+local UIManager = require("ui/uimanager")
+local Notification = require("ui/widget/notification")
 local _ = require("gettext")
 
 local ReaderFrontLight = InputContainer:new{
diff --git a/frontend/ui/reader/readerhighlight.lua b/frontend/ui/reader/readerhighlight.lua
index c7e043a1e..edd7e9838 100644
--- a/frontend/ui/reader/readerhighlight.lua
+++ b/frontend/ui/reader/readerhighlight.lua
@@ -1,8 +1,14 @@
 local InputContainer = require("ui/widget/container/inputcontainer")
+local CenterContainer = require("ui/widget/container/centercontainer")
+local FrameContainer = require("ui/widget/container/framecontainer")
 local GestureRange = require("ui/gesturerange")
 local Geom = require("ui/geometry")
 local Screen = require("ui/screen")
 local Device = require("ui/device")
+local Event = require("ui/event")
+local UIManager = require("ui/uimanager")
+local ButtonTable = require("ui/widget/buttontable")
+local Input = require("ui/input")
 local _ = require("gettext")
 
 local ReaderHighlight = InputContainer:new{}
diff --git a/frontend/ui/reader/readermenu.lua b/frontend/ui/reader/readermenu.lua
index 5a32c5ba7..70f0391d1 100644
--- a/frontend/ui/reader/readermenu.lua
+++ b/frontend/ui/reader/readermenu.lua
@@ -7,6 +7,8 @@ local GestureRange = require("ui/gesturerange")
 local Geom = require("ui/geometry")
 local Event = require("ui/event")
 local Screen = require("ui/screen")
+local Menu = require("ui/widget/menu")
+local InfoMessage = require("ui/widget/infomessage")
 local _ = require("gettext")
 
 local ReaderMenu = InputContainer:new{
diff --git a/frontend/ui/reader/readerrolling.lua b/frontend/ui/reader/readerrolling.lua
index 7bc2fd6eb..a89e2b35e 100644
--- a/frontend/ui/reader/readerrolling.lua
+++ b/frontend/ui/reader/readerrolling.lua
@@ -1,7 +1,9 @@
 local InputContainer = require("ui/widget/container/inputcontainer")
 local Screen = require("ui/screen")
+local Device = require("ui/device")
 local Geom = require("ui/geometry")
 local Input = require("ui/input")
+local Event = require("ui/event")
 local GestureRange = require("ui/gesturerange")
 local ReaderPanning = require("ui/reader/readerpanning")
 local _ = require("gettext")
diff --git a/frontend/ui/reader/readerrotation.lua b/frontend/ui/reader/readerrotation.lua
index 8876505cb..7cb1ae1d0 100644
--- a/frontend/ui/reader/readerrotation.lua
+++ b/frontend/ui/reader/readerrotation.lua
@@ -2,6 +2,7 @@ local InputContainer = require("ui/widget/container/inputcontainer")
 local Screen = require("ui/screen")
 local Geom = require("ui/geometry")
 local Device = require("ui/device")
+local Event = require("ui/event")
 local GestureRange = require("ui/gesturerange")
 local _ = require("gettext")
 
diff --git a/frontend/ui/reader/readertoc.lua b/frontend/ui/reader/readertoc.lua
index 8f043f1e6..57fa4f48b 100644
--- a/frontend/ui/reader/readertoc.lua
+++ b/frontend/ui/reader/readertoc.lua
@@ -4,6 +4,7 @@ local Menu = require("ui/widget/menu")
 local Screen = require("ui/screen")
 local Device = require("ui/device")
 local UIManager = require("ui/uimanager")
+local Event = require("ui/event")
 local _ = require("gettext")
 
 local ReaderToc = InputContainer:new{
diff --git a/frontend/ui/reader/readertypeset.lua b/frontend/ui/reader/readertypeset.lua
index cfd1c698a..215b1e6cf 100644
--- a/frontend/ui/reader/readertypeset.lua
+++ b/frontend/ui/reader/readertypeset.lua
@@ -1,4 +1,5 @@
 local InputContainer = require("ui/widget/container/inputcontainer")
+local Event = require("ui/event")
 local _ = require("gettext")
 -- lfs
 
diff --git a/frontend/ui/screen.lua b/frontend/ui/screen.lua
index cbb24c5ce..784a9eac9 100644
--- a/frontend/ui/screen.lua
+++ b/frontend/ui/screen.lua
@@ -1,210 +1,2 @@
-local Device = require("ui/device")
-local Geom = require("ui/geometry")
-
--- Blitbuffer
--- einkfb
-
---[[
-Codes for rotation modes:
-
-1 for no rotation,
-2 for landscape with bottom on the right side of screen, etc.
-
-           2
-   +--------------+
-   | +----------+ |
-   | |          | |
-   | | Freedom! | |
-   | |          | |
-   | |          | |
- 3 | |          | | 1
-   | |          | |
-   | |          | |
-   | +----------+ |
-   |              |
-   |              |
-   +--------------+
-          0
---]]
-
-
-local Screen = {
-	width = 0,
-	height = 0,
-	native_rotation_mode = nil,
-	cur_rotation_mode = 0,
-
-	bb = nil,
-	saved_bb = nil,
-
-	fb = einkfb.open("/dev/fb0"),
-}
-
-function Screen:init()
-	-- for unknown strange reason, pitch*2 is 10 px more than screen width in KPW
-	self.width, self.height = self.fb:getSize()
-	-- Blitbuffer still uses inverted 4bpp bitmap, so pitch should be
-	-- (self.width / 2)
-	self.bb = Blitbuffer.new(self.width, self.height, self.width/2)
-	if self.width > self.height then
-		-- For another unknown strange reason, self.fb:getOrientation always
-		-- return 0 in KPW, even though we are in landscape mode.
-		-- Seems like the native framework change framebuffer on the fly when
-		-- starting booklet. Starting KPV from ssh and KPVBooklet will get
-		-- different framebuffer height and width.
-		--
-		--self.native_rotation_mode = self.fb:getOrientation()
-		self.native_rotation_mode = 1
-	else
-		self.native_rotation_mode = 0
-	end
-	self.cur_rotation_mode = self.native_rotation_mode
-end
-
-function Screen:refresh(refesh_type, waveform_mode, x, y, w, h)
-	if x then x = x < 0 and 0 or math.floor(x) end
-    if y then y = y < 0 and 0 or math.floor(y) end
-    if w then w = w + x > self.width and self.width - x or math.ceil(w) end
-    if h then h = h + y > self.height and self.height - y or math.ceil(h) end
-	if self.native_rotation_mode == self.cur_rotation_mode then
-        self.fb.bb:blitFrom(self.bb, 0, 0, 0, 0, self.width, self.height)
-    elseif self.native_rotation_mode == 0 and self.cur_rotation_mode == 1 then
-        self.fb.bb:blitFromRotate(self.bb, 270)
-        if x and y and w and h then
-        	x, y = y, self.width - w - x
-        	w, h = h, w
-        end
-    elseif self.native_rotation_mode == 0 and self.cur_rotation_mode == 3 then
-        self.fb.bb:blitFromRotate(self.bb, 90)
-        if x and y and w and h then
-        	x, y = self.height - h - y, x
-        	w, h = h, w
-        end
-    elseif self.native_rotation_mode == 1 and self.cur_rotation_mode == 0 then
-        self.fb.bb:blitFromRotate(self.bb, 90)
-        if x and y and w and h then
-        	x, y = self.height - h - y, x
-        	w, h = h, w
-        end
-    elseif self.native_rotation_mode == 1 and self.cur_rotation_mode == 3 then
-        self.fb.bb:blitFromRotate(self.bb, 180)
-        if x and y and w and h then
-        	x, y = self.width - w - x, self.height - h - y
-        end
-    end
-	self.fb:refresh(refesh_type, waveform_mode, x, y, w, h)
-end
-
-function Screen:getSize()
-	return Geom:new{w = self.width, h = self.height}
-end
-
-function Screen:getWidth()
-	return self.width
-end
-
-function Screen:getHeight()
-	return self.height
-end
-
-function Screen:getDPI()
-	if(Device:getModel() == "KindlePaperWhite") or (Device:getModel() == "Kobo_kraken") then
-		return 212
-	elseif Device:getModel() == "Kobo_dragon" then
-		return 265
-	elseif Device:getModel() == "Kobo_pixie" then
-		return 200
-	else
-		return 167
-	end
-end
-
-function Screen:scaleByDPI(px)
-	return math.floor(px * self:getDPI()/167)
-end
-
-function Screen:rescaleByDPI(px)
-	return math.ceil(px * 167/self:getDPI())
-end
-
-function Screen:getPitch()
-	return self.fb:getPitch()
-end
-
-function Screen:getNativeRotationMode()
-	-- in EMU mode, you will always get 0 from getOrientation()
-	return self.fb:getOrientation()
-end
-
-function Screen:getRotationMode()
-	return self.cur_rotation_mode
-end
-
-function Screen:getScreenMode()
-	if self.width > self.height then
-		return "landscape"
-	else
-		return "portrait"
-	end
-end
-
-function Screen:setRotationMode(mode)
-	if mode > 3 or mode < 0 then
-		return
-	end
-
-	-- mode 0 and mode 2 has the same width and height, so do mode 1 and 3
-	if (self.cur_rotation_mode % 2) ~= (mode % 2) then
-		self.width, self.height = self.height, self.width
-	end
-	self.cur_rotation_mode = mode
-	self.bb:free()
-	self.bb = Blitbuffer.new(self.width, self.height, self.width/2)
-end
-
-function Screen:setScreenMode(mode)
-	if mode == "portrait" then
-		if self.cur_rotation_mode ~= 0 then
-			self:setRotationMode(0)
-		end
-	elseif mode == "landscape" then
-		if self.cur_rotation_mode == 0 or self.cur_rotation_mode == 2 then
-			self:setRotationMode(1)
-		elseif self.cur_rotation_mode == 1 or self.cur_rotation_mode == 3 then
-			self:setRotationMode((self.cur_rotation_mode + 2) % 4)
-		end
-	end
-end
-
-function Screen:saveCurrentBB()
-	local width, height = self:getWidth(), self:getHeight()
-
-	if not self.saved_bb then
-		self.saved_bb = Blitbuffer.new(width, height, self.width/2)
-	end
-	if self.saved_bb:getWidth() ~= width then
-		self.saved_bb:free()
-		self.saved_bb = Blitbuffer.new(width, height, self.width/2)
-	end
-	self.saved_bb:blitFullFrom(self.bb)
-end
-
-function Screen:restoreFromSavedBB()
-	self:restoreFromBB(self.saved_bb)
-end
-
-function Screen:getCurrentScreenBB()
-	local bb = Blitbuffer.new(self:getWidth(), self:getHeight())
-	bb:blitFullFrom(self.bb)
-	return bb
-end
-
-function Screen:restoreFromBB(bb)
-	if bb then
-		self.bb:blitFullFrom(bb)
-	else
-		DEBUG("Got nil bb in restoreFromSavedBB!")
-	end
-end
-
-return Screen
+-- compatibility wrapper
+return require("ui/device").screen
diff --git a/frontend/ui/widget/bboxwidget.lua b/frontend/ui/widget/bboxwidget.lua
index d164fd80c..295bc906b 100644
--- a/frontend/ui/widget/bboxwidget.lua
+++ b/frontend/ui/widget/bboxwidget.lua
@@ -1,4 +1,9 @@
 local InputContainer = require("ui/widget/container/inputcontainer")
+local Geom = require("ui/geometry")
+local Event = require("ui/event")
+local UIManager = require("ui/uimanager")
+local Device = require("ui/device")
+local GestureRange = require("ui/gesturerange")
 
 --[[
 BBoxWidget shows a bbox for page cropping
diff --git a/frontend/ui/widget/configdialog.lua b/frontend/ui/widget/configdialog.lua
index 824ec7a29..6c3589e27 100644
--- a/frontend/ui/widget/configdialog.lua
+++ b/frontend/ui/widget/configdialog.lua
@@ -7,6 +7,7 @@ local UnderlineContainer = require("ui/widget/container/underlinecontainer")
 local ImageWidget = require("ui/widget/imagewidget")
 local TextWidget = require("ui/widget/textwidget")
 local FixedTextWidget = require("ui/widget/fixedtextwidget")
+local ProgressWidget = require("ui/widget/progresswidget")
 local ToggleSwitch = require("ui/widget/toggleswitch")
 local Font = require("ui/font")
 local Device = require("ui/device")
diff --git a/frontend/ui/widget/confirmbox.lua b/frontend/ui/widget/confirmbox.lua
index 127e6b353..bed5e6322 100644
--- a/frontend/ui/widget/confirmbox.lua
+++ b/frontend/ui/widget/confirmbox.lua
@@ -2,6 +2,16 @@ local CenterContainer = require("ui/widget/container/centercontainer")
 local FrameContainer = require("ui/widget/container/centercontainer")
 local FocusManager = require("ui/widget/focusmanager")
 local Button = require("ui/widget/button")
+local VerticalGroup = require("ui/widget/verticalgroup")
+local ImageWidget = require("ui/widget/imagewidget")
+local TextBoxWidget = require("ui/widget/textboxwidget")
+local Font = require("ui/font")
+local UIManager = require("ui/uimanager")
+local Screen = require("ui/screen")
+local HorizontalGroup = require("ui/widget/horizontalgroup")
+local VerticalSpan = require("ui/widget/verticalspan")
+local HorizontalSpan = require("ui/widget/horizontalspan")
+local _ = require("gettext")
 
 -- screen
 
diff --git a/frontend/ui/widget/container/inputcontainer.lua b/frontend/ui/widget/container/inputcontainer.lua
index 2d5583abf..a7ae4925f 100644
--- a/frontend/ui/widget/container/inputcontainer.lua
+++ b/frontend/ui/widget/container/inputcontainer.lua
@@ -1,5 +1,6 @@
 local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local Event = require("ui/event")
+local Geom = require("ui/geometry")
 
 --[[
 an InputContainer is an WidgetContainer that handles input events
diff --git a/frontend/ui/widget/dictquicklookup.lua b/frontend/ui/widget/dictquicklookup.lua
index 6fc2a1e58..f02fe0174 100644
--- a/frontend/ui/widget/dictquicklookup.lua
+++ b/frontend/ui/widget/dictquicklookup.lua
@@ -9,6 +9,12 @@ local Screen = require("ui/screen")
 local GestureRange = require("ui/gesturerange")
 local Geom = require("ui/geometry")
 local Font = require("ui/font")
+local Event = require("ui/event")
+local UIManager = require("ui/uimanager")
+local ButtonTable = require("ui/widget/buttontable")
+local Device = require("ui/device")
+local VerticalGroup = require("ui/widget/verticalgroup")
+local _ = require("gettext")
 
 --[[
 Display quick lookup word definition
diff --git a/frontend/ui/widget/focusmanager.lua b/frontend/ui/widget/focusmanager.lua
index aac793c71..8de7d2532 100644
--- a/frontend/ui/widget/focusmanager.lua
+++ b/frontend/ui/widget/focusmanager.lua
@@ -1,5 +1,6 @@
 local InputContainer = require("ui/widget/container/inputcontainer")
--- UIManager
+local Event = require("ui/event")
+local UIManager = require("ui/uimanager")
 
 --[[
 Wrapper Widget that manages focus for a whole dialog
diff --git a/frontend/ui/widget/infomessage.lua b/frontend/ui/widget/infomessage.lua
index b44985f6e..e390e8afc 100644
--- a/frontend/ui/widget/infomessage.lua
+++ b/frontend/ui/widget/infomessage.lua
@@ -8,6 +8,11 @@ local ImageWidget = require("ui/widget/imagewidget")
 local TextBoxWidget = require("ui/widget/textboxwidget")
 local HorizontalSpan = require("ui/widget/horizontalspan")
 local UIManager = require("ui/uimanager")
+local Geom = require("ui/geometry")
+local CenterContainer = require("ui/widget/container/centercontainer")
+local Input = require("ui/input")
+local Screen = require("ui/screen")
+local _ = require("gettext")
 
 --[[
 Widget that displays an informational message
diff --git a/frontend/ui/widget/menu.lua b/frontend/ui/widget/menu.lua
index 0c66773b8..0e715f61c 100644
--- a/frontend/ui/widget/menu.lua
+++ b/frontend/ui/widget/menu.lua
@@ -19,6 +19,7 @@ local Screen = require("ui/screen")
 local Input = require("ui/input")
 local UIManager = require("ui/uimanager")
 local RenderText = require("ui/rendertext")
+local InfoMessage = require("ui/widget/infomessage")
 local _ = require("gettext")
 
 --[[
diff --git a/frontend/ui/widget/notification.lua b/frontend/ui/widget/notification.lua
index 59c8675ba..7414b743b 100644
--- a/frontend/ui/widget/notification.lua
+++ b/frontend/ui/widget/notification.lua
@@ -6,6 +6,9 @@ local Font = require("ui/font")
 local Geom = require("ui/geometry")
 local Device = require("ui/device")
 local UIManager = require("ui/uimanager")
+local HorizontalGroup = require("ui/widget/horizontalgroup")
+local Input = require("ui/input")
+local Screen = require("ui/screen")
 
 --[[
 Widget that displays a tiny notification on top of screen
diff --git a/frontend/ui/widget/scrolltextwidget.lua b/frontend/ui/widget/scrolltextwidget.lua
index a93fb9e45..9f9c03b23 100644
--- a/frontend/ui/widget/scrolltextwidget.lua
+++ b/frontend/ui/widget/scrolltextwidget.lua
@@ -5,6 +5,9 @@ local Geom = require("ui/geometry")
 local GestureRange = require("ui/gesturerange")
 local UIManager = require("ui/uimanager")
 local Screen = require("ui/screen")
+local HorizontalGroup = require("ui/widget/horizontalgroup")
+local HorizontalSpan = require("ui/widget/horizontalspan")
+local Device = require("ui/device")
 
 --[[
 Text widget with vertical scroll bar