slight refactoring of filechooser so it remembers state

filechooser.lua

@@ -3,15 +3,32 @@ require "keys"
 require "graphics"
 
 FileChooser = {
+	-- Class vars:
+	
+	-- font for displaying file/dir names
+	face = freetype.newBuiltinFace("sans", 25),
+	fhash = "s25",
+	-- font for paging display
+	sface = freetype.newBuiltinFace("sans", 16),
+	sfhash = "s16",
+	-- spacing between lines
+	spacing = 40,
+
+	-- state buffer
 	dirs = nil,
-	files = nil
+	files = nil,
+	items = 0,
+	path = "",
+	page = 1,
+	current = 1,
+	oldcurrent = 0,
 }
 
-function FileChooser:readdir(path)
+function FileChooser:readdir()
 	self.dirs = {}
 	self.files = {}
-	for f in lfs.dir(path) do
-		if lfs.attributes(path.."/"..f, "mode") == "directory" and f ~= "." and not string.match(f, "^%.[^.]") then
+	for f in lfs.dir(self.path) do
+		if lfs.attributes(self.path.."/"..f, "mode") == "directory" and f ~= "." and not string.match(f, "^%.[^.]") then
 			table.insert(self.dirs, f)
 		elseif string.match(f, ".+%.[pP][dD][fF]$") then
 			table.insert(self.files, f)
@@ -21,120 +38,116 @@ function FileChooser:readdir(path)
 	table.sort(self.files)
 end
 
-function FileChooser:choose(startpath, ypos, height)
-	local face = freetype.newBuiltinFace("sans", 25)
-	local fhash = "s25"
-	local sface = freetype.newBuiltinFace("sans", 16)
-	local sfhash = "s16"
-	local path = startpath
-	local spacing = 40
-	local perpage = math.floor(height / spacing) - 1
-	local pathdirty = true
-	local pagedirty = false
-	local framebufferdirty = false
-	local markerdirty = true
-	local oldcurrent = 0
-	local page
-	local current
-	local items
+function FileChooser:setPath(newPath)
+	self.path = newPath
+	self:readdir()
+	self.items = #self.dirs + #self.files
+	if self.items == 0 then
+		return nil
+	end
+	self.page = 1
+	self.current = 1
+	return true
+end
+
+function FileChooser:choose(ypos, height)
+	local perpage = math.floor(height / self.spacing) - 1
+	local pagedirty = true
+	local markerdirty = false
 	while true do
-		if pathdirty then
-			print("showing file chooser in <"..path..">")
-			self:readdir(path)
-			items = #self.dirs + #self.files
-			if items == 0 then
-				return nil
-			end
-			page = 1
-			current = 1
-			pathdirty = false
-			pagedirty = true
-		end
 		if pagedirty then
 			fb.bb:paintRect(0, ypos, fb.bb:getWidth(), height, 0)
 			local c
 			for c = 1, perpage do
-				local i = (page - 1) * perpage + c
+				local i = (self.page - 1) * perpage + c
 				if i <= #self.dirs then
-					renderUtf8Text(fb.bb, 39, ypos + spacing*c, face, fhash, "/", true)
-					renderUtf8Text(fb.bb, 50, ypos + spacing*c, face, fhash, self.dirs[i], true)
-				elseif i <= items then
-					renderUtf8Text(fb.bb, 50, ypos + spacing*c, face, fhash, self.files[i-#self.dirs], true)
+					-- resembles display in midnight commander: adds "/" prefix for directories
+					renderUtf8Text(fb.bb, 39, ypos + self.spacing*c, self.face, self.fhash, "/", true)
+					renderUtf8Text(fb.bb, 50, ypos + self.spacing*c, self.face, self.fhash, self.dirs[i], true)
+				elseif i <= self.items then
+					renderUtf8Text(fb.bb, 50, ypos + self.spacing*c, self.face, self.fhash, self.files[i-#self.dirs], true)
 				end
 			end
-			renderUtf8Text(fb.bb, 39, ypos + spacing * perpage + 32, sface, sfhash,
-				"Page "..page.." of "..(math.floor(items / perpage)+1), true)
-			framebufferdirty = true
+			renderUtf8Text(fb.bb, 39, ypos + self.spacing * perpage + 32, self.sface, self.sfhash,
+				"Page "..self.page.." of "..(math.floor(self.items / perpage)+1), true)
 			markerdirty = true
-			pagedirty = false
 		end
 		if markerdirty then
-			if oldcurrent > 0 then
-				fb.bb:paintRect(30, ypos + spacing*oldcurrent + 10, fb.bb:getWidth() - 60, 3, 0)
-				fb:refresh(1, ypos + spacing*oldcurrent + 10, fb.bb:getWidth() - 60, 3)
+			if not pagedirty then
+				if self.oldcurrent > 0 then
+					fb.bb:paintRect(30, ypos + self.spacing*self.oldcurrent + 10, fb.bb:getWidth() - 60, 3, 0)
+						fb:refresh(1, 30, ypos + self.spacing*self.oldcurrent + 10, fb.bb:getWidth() - 60, 3)
+				end
+			end
+			fb.bb:paintRect(30, ypos + self.spacing*self.current + 10, fb.bb:getWidth() - 60, 3, 15)
+			if not pagedirty then
+				fb:refresh(1, 30, ypos + self.spacing*self.current + 10, fb.bb:getWidth() - 60, 3)
 			end
-			fb.bb:paintRect(30, ypos + spacing*current + 10, fb.bb:getWidth() - 60, 3, 15)
-			fb:refresh(1, ypos + spacing*current + 10, fb.bb:getWidth() - 60, 3)
-			oldcurrent = current
+			self.oldcurrent = self.current
 			markerdirty = false
 		end
+		if pagedirty then
+			fb:refresh(0, 0, ypos, fb.bb:getWidth(), height)
+			pagedirty = false
+		end
 		local ev = input.waitForEvent()
 		if ev.type == EV_KEY and ev.value == EVENT_VALUE_KEY_PRESS then
 			if ev.code == KEY_FW_UP then
-				if current == 1 then
-					if page > 1 then
-						current = perpage
-						page = page - 1
+				if self.current == 1 then
+					if self.page > 1 then
+						self.current = self.perpage
+						self.page = self.page - 1
 						pagedirty = true
 					end
 				else
-					current = current - 1
+					self.current = self.current - 1
 					markerdirty = true
 				end
 			elseif ev.code == KEY_FW_DOWN then
-				if current == perpage then
-					if page < (items / perpage) then
-						current = 1
-						page = page + 1
+				if self.current == perpage then
+					if self.page < (self.items / perpage) then
+						self.current = 1
+						self.page = page + 1
 						pagedirty = true
 					end
 				else
-					if page ~= math.floor(items / perpage) + 1
-						or current + (page-1)*perpage < items then
-						current = current + 1
+					if self.page ~= math.floor(self.items / perpage) + 1
+						or self.current + (self.page-1)*perpage < self.items then
+						self.current = self.current + 1
 						markerdirty = true
 					end
 				end
 			elseif ev.code == KEY_PGFWD then
-				if page < (items / perpage) then
-					if current + page*perpage > items then
-						current = items - page*perpage
+				if self.page < (self.items / perpage) then
+					if self.current + self.page*perpage > self.items then
+						self.current = self.items - self.page*perpage
 					end
-					page = page + 1
+					self.page = self.page + 1
 					pagedirty = true
 				else
-					current = items - (page-1)*perpage
+					self.current = self.items - (self.page-1)*perpage
 					markerdirty = true
 				end
 			elseif ev.code == KEY_PGBCK then
-				if page > 1 then
-					page = page - 1
+				if self.page > 1 then
+					self.page = self.page - 1
 					pagedirty = true
 				else
-					current = 1
+					self.current = 1
 					markerdirty = true
 				end
 			elseif ev.code == KEY_ENTER or ev.code == KEY_FWPRESS then
-				local newdir = self.dirs[perpage*(page-1)+current]
+				local newdir = self.dirs[perpage*(self.page-1)+self.current]
 				if newdir == ".." then
-					path = string.gsub(path, "(.*)/[^/]+/?$", "%1")
-					pathdirty = true
+					local path = string.gsub(self.path, "(.*)/[^/]+/?$", "%1")
+					self:setPath(path)
 				elseif newdir then
-					path = path.."/"..newdir
-					pathdirty = true
+					local path = self.path.."/"..newdir
+					self:setPath(path)
 				else
-					return path.."/"..self.files[perpage*(page-1)+current - #self.dirs]
+					return self.path.."/"..self.files[perpage*(self.page-1)+self.current - #self.dirs]
 				end
+				pagedirty = true
 			elseif ev.code == KEY_BACK then
 				return nil
 			end

reader.lua

@@ -74,8 +74,9 @@ width, height = fb:getSize()
 
 if lfs.attributes(ARGV[optind], "mode") == "directory" then
 	local running = true
+	FileChooser:setPath(ARGV[optind])
 	while running do
-		local pdffile = FileChooser:choose(ARGV[optind],0,height)
+		local pdffile = FileChooser:choose(0,height)
 		if pdffile ~= nil then
 			PDFReader:open(pdffile,"") -- TODO: query for password
 			PDFReader:goto(tonumber(PDFReader.settings:readsetting("last_page") or 1))