Rem
bbdoc: noddybox.gfxmenu
EndRem
Module noddybox.gfxmenu

ModuleInfo "Framework: Simple Graphical Menu"
ModuleInfo "Copyright: Public Domain"
ModuleInfo "Author: Ian Cowburn"
ModuleInfo "Version: $Revision$"

' $Id$

Strict
Import brl.linkedlist
Import brl.max2d

Rem
bbdoc: Allows a menu backdrop to be automatically processed.  Derive a class from this to use.
EndRem
Type TGfxMenuBackdrop Abstract
	Rem
	bbdoc: Create a menu backdrop element.
	returns: The created elemnt.
	about: Notice that this is a method, rather than the usual function creator.
	EndRem
	Method Create:TGfxMenuBackdrop() Abstract
	Rem
	bbdoc: Called by the menu to update the backdrop.
	EndRem
	Method Update() Abstract
End Type

Rem
bbdoc: Defines a graphical menu.
EndRem
Type TGfxMenu
	Field list:TList
	Field bdrop:TList
	Field mbdown:Int
	Field r:Int
	Field g:Int
	Field b:Int
	Field over_r:Int
	Field over_g:Int
	Field over_b:Int
	Field fade:Int

	Rem
	bbdoc: Create a menu.
	returns: The created menu.
	about: @backdrop is the backdrop to create (null for no backdrop).  @num is the number of backdrop items to create.
	about: SetColor() is called with @r, @g and @b when the mouse is not over an item, overwise SetColor() is
	about: called with @over_r, @over_g and @over_b when the item is active.  @fade is the amount colours will alter as the
	about: mouse hovers over buttons.  Set this to 255 to make colour changes instant.
	EndRem
	Function Create:TGfxMenu(r:Int=164, g:Int=164, b:Int=164, over_r:Int=255, over_g:Int=255, over_b:Int=255, fade:Int=5, backdrop:TGfxMenuBackdrop=Null, num:Int=0)
		Local menu:TGfxMenu=New TGfxMenu
		
		menu.list=New TList
		menu.bdrop=New TList
		menu.mbdown=False
		
		menu.r=r
		menu.g=g
		menu.b=b
		menu.over_r=over_r
		menu.over_g=over_g
		menu.over_b=over_b
		menu.fade=fade
		
		If backdrop
			For Local f:Int=0 Until num
				menu.bdrop.AddLast(backdrop.Create())
			Next
		EndIf
				
		Return menu
	End Function
	
	Rem
	bbdoc: Adds a menu item.
	returns: The created menu.
	about: @x and @y are the position to draw the image at.  If @x is -1 then the image is centred.  @i is the image.
	about: @id is the value returned from @Render() for this menu item.  Don't use -1 for this!
	EndRem
	Method Add(x:Int, y:Int, i:TImage, id:Int)
		list.AddLast(TGfxMenuOpt.Create(x,y,i,id,r,g,b))
	End Method
	
	Rem
	bbdoc: Renders and updates the menu.
	returns: The selected item, or -1 if nothing clicked.
	about: Set @hide to True to hide the menu (the backdrop is still updated).  SetColor() may have changed when this routine exits.
	EndRem
	Method Render:Int(hide:Int)
		For Local p:TGfxMenuBackdrop=EachIn bdrop
			p.Update()
		Next
		
		If hide
			Return -1
		EndIf
		
		Local in:Int=-1
		Local mx:Int=MouseX()
		Local my:Int=MouseY()
		Local any:Int=False
		
		For Local opt:TGfxMenuOpt=EachIn list
			If opt.InBox(mx,my)
				opt.r=Towards(over_r,opt.r)
				opt.g=Towards(over_g,opt.g)
				opt.b=Towards(over_b,opt.b)
				SetColor(opt.r,opt.g,opt.b)
		
				If KeyDown(MOUSE_LEFT)
					mbdown=True
					DrawImage(opt.i,opt.x,opt.y+2)
					any=True
				Else
					DrawImage(opt.i,opt.x,opt.y)
					If mbdown
						in=opt.id
					EndIf
					mbdown=False
				EndIf
			Else
				opt.r=Towards(r,opt.r)
				opt.g=Towards(g,opt.g)
				opt.b=Towards(b,opt.b)
				SetColor(opt.r,opt.g,opt.b)
				DrawImage(opt.i,opt.x,opt.y)
			EndIf
		Next
		
		If Not any
			mbdown=False
		EndIf
		
		Return in
	End Method
	
	Method Towards:Int(dest:Int, val:Int)
		If val<dest
			Return Min(dest,val+fade)
		ElseIf val>dest
			Return Max(dest,val-fade)
		EndIf
		
		Return val
	End Method
End Type

Private

Type TGfxMenuOpt
	Field x:Int
	Field y:Int
	Field i:TImage
	Field id:Int
	Field r:Int
	Field g:Int
	Field b:Int
	
	Function Create:TGfxMenuOpt(x:Int, y:Int, i:TImage, id:Int, r:Int, g:Int, b:Int)
		Local o:TGfxMenuOpt=New TGfxMenuOpt
		
		If x=-1
			x=(GraphicsWidth()-ImageWidth(i))/2
		EndIf
		
		o.x=x
		o.y=y
		o.i=i
		o.id=id
		o.r=r
		o.g=g
		o.b=b
		
		Return o
	End Function
	
	Method InBox:Int(mx:Int, my:Int)
		Return mx>=x And my>=y And mx<=x+ImageWidth(i) And my<=y+ImageHeight(i)
	End Method
End Type