# left drag: expand
# right drag: shrink
# both drag: move
# double click: autoscale

class TkGraph
	include Tk
	def initialize(xl=300,yl=300,w=nil,side="top")
		Tk.root.cursor "arrow"
		@c=TkCanvas.new(w,
			'width'=>xl,
			'height'=>yl,
			'borderwidth'=>1,
			'relief'=>'sunken').pack('side'=>side)
		@c.bind('Double-Button-1',proc{|x,y| @auto=(not @auto);autoscale()},'%x %y')
		@c.bind('1',proc{|x,y| box_start(x,y); Tk.root.cursor "sizing"},'%x %y')
		@c.bind('B1-Motion',proc{|x,y| box_resize(x,y)},'%x %y')
		@c.bind('ButtonRelease-1',proc{|x,y| enlarge(x,y); Tk.root.cursor "arrow"},'%x %y')
		@c.bind('2',proc{|x,y| move_start(x,y); Tk.root.cursor "fleur"},'%x %y')
		@c.bind('B2-Motion',proc{|x,y| move(x,y);},'%x %y')
		@c.bind('ButtonRelease-2',proc{|x,y| redraw();Tk.root.cursor "arrow"},'%x %y')
		@c.bind('3',proc{|x,y| box_start(x,y); Tk.root.cursor "draped_box"},'%x %y')
		@c.bind('B3-Motion',proc{|x,y| box_resize(x,y)},'%x %y')
		@c.bind('ButtonRelease-3',proc{|x,y| shrink(x,y); Tk.root.cursor "arrow"},'%x %y')
		@c.bind('Double-Button-3',proc{|x,y| set_style(x,y)},'%x %y')
		@all=TkcTagAll.new(@c)
		@wave=[]
		@x,@y=nil,nil
		@xl,@yl=xl,yl	#width,height
		@x0,@y0=0,0	#origin
		@xs,@ys=1,1	#scale
		@xb,@yb=nil,nil	#box
		@xc0,@yc0,@xc1,@yc1=nil,nil,nil,nil	#coordination
		@xstyle="%.2e";@ystyle="%.2e"
		@box=nil
		@mark=false
		@auto=true
		redraw()
	end
	attr_reader :x0
	attr_reader :y0
	attr_reader :xs
	attr_reader :ys
	attr_accessor :mark
	attr_accessor :auto
	attr_accessor :xstyle
	attr_accessor :ystyle
	def scale(x,y)
		return [
		((x.to_f-@x0)/@xs*@xl).to_i,
		@yl-((y.to_f-@y0)/@ys*@yl).to_i,
		]
	end
	def unscale(x,y)
		return [
		x.to_f/@xl*@xs+@x0,
		(@yl-y).to_f/@yl*@ys+@y0,
		]
	end
	def axis()
		x,y=scale(0,0)
		@xc0.addtag("axis") if @xc0
		@xc1.addtag("axis") if @xc1
		@yc0.addtag("axis") if @yc0
		@yc1.addtag("axis") if @yc1
		TkcLine.new(@c,x,-@yl,x,@yl*2,'fill'=>'red')
		TkcLine.new(@c,-@xl,y,@xl*2,y,'fill'=>'red')
		@xc0=TkcText.new(@c,10,@yl-10,'text'=>sprintf(@xstyle,@x0),'anchor'=>'w')
		@xc1=TkcText.new(@c,@xl,@yl-10,'text'=>sprintf(@xstyle,@x0+@xs),'anchor'=>'e')
		@yc0=TkcText.new(@c,1,@yl-20,'text'=>sprintf(@ystyle,@y0),'anchor'=>'w')
		@yc1=TkcText.new(@c,1,10,'text'=>sprintf(@ystyle,@y0+@ys),'anchor'=>'w')
		@c.delete("axis")
		@c.dtag("axis")
	end
	def point(x,y,x0=@x,y0=@y)
		x1,y1=scale(x,y)
		x01,y01=scale(x0,y0)
		TkcLine.new(@c,x01,y01,x1,y1) unless @x==nil
		TkcOval.new(@c,x1-1,y1-1,x1+1,y1+1,'fill'=>'black','outline'=>'black') if @mark
		@x,@y=x,y
	end
	def redraw()
		x,y=@x,@y
		@x,@y=nil,nil
#		@wave.each{|p| point(*p)}
		w=@wave.collect{|p| scale(*p)}
		@c.addtag_all("old")
		axis()
		TkcLine.new(@c,*w.flatten) if @wave.size>1
		for p in w
			TkcOval.new(@c,p[0]-1,p[1]-1,p[0]+1,p[1]+1,'fill'=>'black','outline'=>'black')
		end if @mark
		@c.delete("old")
		@c.dtag("old")
		@x,@y=x,y
	end
	def box_start(x,y)
		@xb,@yb=x,y
		@box=TkcRectangle.new(@c,x,y,@xb,@yb,'width'=>1)
	end
	def box_resize(x,y)
		@box.coords(@xb,@yb,x,y)
	end
	def enlarge(x,y,x0=@xb,y0=@yb)
		@box.destroy
		if (x-x0).abs>@xl/20 and (y-y0).abs>@yl/20
			x1,y1=unscale(x0,y0)
			x2,y2=unscale(x,y)
			@xs=(x1-x2).abs
			@ys=(y1-y2).abs
			@x0=[x1,x2].sort[0]
			@y0=[y1,y2].sort[0]
			redraw()
		end
	end
	def shrink(x,y,x0=@xb,y0=@yb)
		@box.destroy
		if (x-x0).abs>@xl/20 and (y-y0).abs>@yl/20
			x1,y1=unscale(x0,y0)
			x2,y2=unscale(x,y)
			@xs=@xs*2-(x1-x2).abs
			@ys=@ys*2-(y1-y2).abs
			@x0=@x0*2-[x1,x2].sort[0]
			@y0=@y0*2-[y1,y2].sort[0]
			redraw()
		end
	end
	def move_start(x,y)
		@xb,@yb=x,y
	end
	def move(x,y,x0=@xb,y0=@yb)
		@all.move(x-@xb,y-@yb)
		x1,y1=unscale(x0,y0)
		x2,y2=unscale(x,y)
		@x0-=x2-x1
		@y0-=y2-y1
		@xb,@yb=x,y
		axis()
	end
	def clear()
		@wave=[]
		@x,@y=nil,nil
		redraw()
	end
	def autoscale()
		xw=@wave.collect{|xy| xy[0]}
		yw=@wave.collect{|xy| xy[1]}
		xmin=xw.sort[0]
		xmax=xw.sort.last
		ymin=yw.sort[0]
		ymax=yw.sort.last
		@xs,@ys=(xmax-xmin)*1.1,(ymax-ymin)*1.1
		@xs=1 if xmax==xmin
		@ys=1 if ymax==ymin
		@x0,@y0=(xmax+xmin-@xs)/2.0,(ymax+ymin-@ys)/2.0
		redraw()
	end
	def add(x,y)
		@wave.push([x,y])
		point(x,y)
		autoscale() if @auto
	end
	def shift(x,y)
		@wave.shift
		@wave.push([x,y])
		if @auto
			autoscale()
		else
			redraw()
		end
	end
	def size()
		return @wave.size
	end
	def set_style(x=1,y=0)
		styles=["%d","%.2f","%.2e","%.3f","%.3e"]
		xy="x"
		xy="y" if x<(@yl-y)
		w=TkToplevel.new(nil,'title'=>xy+'-axis')
		st=nil
		TkFrame.new(w){|f|
			scr=TkScrollbar.new(f).pack('side'=>'right','fill'=>'y')
			st=TkListbox.new(f).pack('side'=>'right')
			st.yscrollbar(scr)
			for e in styles
				st.insert(styles.index(e),e)
			end
			}.pack
		TkButton.new(w,'text'=>'OK',
			'command'=>proc{eval("@"+xy+"style=styles[st.curselection[0]]");w.destroy}).pack('side'=>'left')
		TkButton.new(w,'text'=>'cancel',
			'command'=>proc{w.destroy}).pack('side'=>'right')
	end

end #class