new UI code

widget.lua

@@ -1,22 +1,28 @@
 require "rendertext"
 require "graphics"
 require "image"
+require "event"
+require "inputevent"
+require "font"
 
 --[[
-This is a (useless) generic Widget interface
+This is a generic Widget interface
 
 widgets can be queried about their size and can be paint.
 that's it for now. Probably we need something more elaborate
 later.
+
+if the table that was given to us as parameter has an "init"
+method, it will be called. use this to set _instance_ variables
+rather than class variables.
 ]]
-Widget = {
-	dimen = { w = 0, h = 0},
-}
+Widget = {}
 
 function Widget:new(o)
-	o = o or {}
+	local o = o or {}
 	setmetatable(o, self)
 	self.__index = self
+	if o.init then o:init() end
 	return o
 end
 
@@ -27,7 +33,17 @@ end
 function Widget:paintTo(bb, x, y)
 end
 
-function Widget:free()
+--[[
+Widgets have a rudimentary event handler/dispatcher that
+will call a method "onEventName" for an event with name
+"EventName"
+
+These methods
+]]
+function Widget:handleEvent(event)
+	if self[event.handler] then
+		return self[event.handler](self, unpack(event.args))
+	end
 end
 
 --[[
@@ -35,12 +51,56 @@ WidgetContainer is a container for another Widget
 ]]
 WidgetContainer = Widget:new()
 
-function WidgetContainer:free()
-	for _, widget in ipairs(self) do
-		widget:free()
+function WidgetContainer:getSize()
+	if self.dimen then
+		-- fixed size
+		return self.dimen
+	elseif self[1] then
+		-- return size of first child widget
+		return self[1]:getSize()
+	else
+		return { w = 0, h = 0 }
 	end
 end
 
+function WidgetContainer:paintTo(bb, x, y)
+	-- default to pass request to first child widget
+	if self[1] then
+		return self[1]:paintTo(bb, x, y)
+	end
+end
+
+function WidgetContainer:propagateEvent(event)
+	-- propagate to children
+	for _, widget in ipairs(self) do
+		if widget:handleEvent(event) then
+			-- stop propagating when an event handler returns true
+			return true
+		end
+	end
+	return false
+end
+
+--[[
+Containers will pass events to children or react on them themselves
+]]
+function WidgetContainer:handleEvent(event)
+	-- call our own standard event handler
+	if not self:propagateEvent(event) then
+		return Widget.handleEvent(self, event)
+	else
+		return true
+	end
+end
+
+function WidgetContainer:free()
+	for _, widget in ipairs(self) do
+		if widget.free then widget:free() end
+	end
+end
+
+
+
 --[[
 CenterContainer centers its content (1 widget) within its own dimensions
 ]]
@@ -49,8 +109,8 @@ CenterContainer = WidgetContainer:new()
 function CenterContainer:paintTo(bb, x, y)
 	local contentSize = self[1]:getSize()
 	if contentSize.w > self.dimen.w or contentSize.h > self.dimen.h then
-		-- throw error?
-		return
+		-- throw error? paint to scrap buffer and blit partially?
+		-- for now, we ignore this
 	end
 	self[1]:paintTo(bb,
 		x + (self.dimen.w - contentSize.w)/2,
@@ -60,16 +120,16 @@ end
 --[[
 A FrameContainer is some graphics content (1 widget) that is surrounded by a frame
 ]]
-FrameContainer = WidgetContainer:new({
+FrameContainer = WidgetContainer:new{
 	background = nil,
 	color = 15,
 	margin = 0,
 	bordersize = 2,
 	padding = 5,
-})
+}
 
 function FrameContainer:getSize()
-	local content_size = self[1]:getSize()
+	local content_size = WidgetContainer.getSize(self)
 	return {
 		w = content_size.w + ( self.margin + self.bordersize + self.padding ) * 2,
 		h = content_size.h + ( self.margin + self.bordersize + self.padding ) * 2
@@ -78,7 +138,7 @@ end
 
 function FrameContainer:paintTo(bb, x, y)
 	local my_size = self:getSize()
-	
+
 	if self.background then
 		bb:paintRect(x, y, my_size.w, my_size.h, self.background)
 	end
@@ -87,22 +147,24 @@ function FrameContainer:paintTo(bb, x, y)
 			my_size.w - self.margin * 2, my_size.h - self.margin * 2,
 			self.bordersize, self.color)
 	end
-	self[1]:paintTo(bb,
-		x + self.margin + self.bordersize + self.padding,
-		y + self.margin + self.bordersize + self.padding)
+	if self[1] then
+		self[1]:paintTo(bb,
+			x + self.margin + self.bordersize + self.padding,
+			y + self.margin + self.bordersize + self.padding)
+	end
 end
 
 --[[
 A TextWidget puts a string on a single line
 ]]
-TextWidget = Widget:new({
+TextWidget = Widget:new{
 	text = nil,
 	face = nil,
 	color = 15,
 	_bb = nil,
 	_length = 0,
 	_maxlength = 1200,
-})
+}
 
 function TextWidget:_render()
 	local h = self.face.size * 1.5
@@ -134,10 +196,10 @@ end
 --[[
 ImageWidget shows an image from a file
 ]]
-ImageWidget = Widget:new({
+ImageWidget = Widget:new{
 	file = nil,
 	_bb = nil
-})
+}
 
 function ImageWidget:_render()
 	local itype = string.lower(string.match(self.file, ".+%.([^.]+)") or "")
@@ -170,10 +232,10 @@ end
 --[[
 A Layout widget that puts objects besides each others
 ]]
-HorizontalGroup = WidgetContainer:new({
+HorizontalGroup = WidgetContainer:new{
 	align = "center",
 	_size = nil,
-})
+}
 
 function HorizontalGroup:getSize()
 	if not self._size then
@@ -217,11 +279,11 @@ end
 --[[
 A Layout widget that puts objects under each other
 ]]
-VerticalGroup = WidgetContainer:new({
+VerticalGroup = WidgetContainer:new{
 	align = "center",
 	_size = nil,
 	_offsets = {}
-})
+}
 
 function VerticalGroup:getSize()
 	if not self._size then
@@ -261,3 +323,61 @@ function VerticalGroup:free()
 	self._offsets = {}
 	WidgetContainer.free(self)
 end
+
+--[[
+an UnderlineContainer is a WidgetContainer that is able to paint
+a line under its child node
+]]
+
+UnderlineContainer = WidgetContainer:new{
+	linesize = 2,
+	padding = 1,
+	color = 0,
+}
+
+function UnderlineContainer:getSize()
+	local contentSize = self[1]:getSize()
+	return { w = contentSize.w, h = contentSize.h + self.linesize + self.padding }
+end
+
+function UnderlineContainer:paintTo(bb, x, y)
+	local contentSize = self[1]:getSize()
+	self[1]:paintTo(bb, x, y)
+	bb:paintRect(x, y + contentSize.h + self.padding,
+		contentSize.w, self.linesize, self.color)
+end
+
+
+--[[
+an InputContainer is an WidgetContainer that handles input events
+
+an example for a key_event is this:
+
+  PanBy20 = { { "Shift", Input.group.Cursor }, seqtext = "Shift+Cursor", doc = "pan by 20px", event = "Pan", args = 20, is_inactive = true },
+  PanNormal = { { Input.group.Cursor }, seqtext = "Cursor", doc = "pan by 10 px", event = "Pan", args = 10 },
+  Quit = { {"Home"} },
+
+it is suggested to reference configurable sequences from another table
+and store that table as configuration setting
+]]
+InputContainer = WidgetContainer:new{
+	key_events = {}
+}
+
+-- the following handler handles keypresses and checks
+-- if they lead to a command.
+-- if this is the case, we retransmit another event within
+-- ourselves
+function InputContainer:onKeyPress(key)
+	for name, seq in pairs(self.key_events) do
+		if not seq.is_inactive then
+			for _, oneseq in ipairs(seq) do
+				if key:match(oneseq) then
+					local eventname = seq.event or name
+					return self:handleEvent(Event:new(eventname, seq.args, key))
+				end
+			end
+		end
+	end
+end
+