Rem
bbdoc: noddybox.simplegui
EndRem
Module noddybox.simplegui

ModuleInfo "Framework: (Very) Simple GUI"
ModuleInfo "Copyright: Public Domain"
ModuleInfo "Author: Ian Cowburn"
ModuleInfo "Version: $Revision$"

' $Id$

Strict
Import brl.max2d
Import brl.filesystem
Import brl.basic
Import noddybox.bitmapfont

Rem
bbdoc: Defines the @TBitmapFont to be used by the GUI.
EndRem
Type TGUIFont
	Rem
	bbdoc: The font to use.
	EndRem
	Global font:TBitmapFont
End Type

Rem
bbdoc: The base widget type.
EndRem
Type TWidget Abstract

	Rem
	bbdoc: This widget consumes click events
	EndRem
	Const	HAS_CLICK:Int=1
	Rem
	bbdoc: This widget consumes drag events
	EndRem
	Const	HAS_DRAG:Int=2
	Rem
	bbdoc: This widget consumes key events
	EndRem
	Const	HAS_KEY:Int=4

	Rem
	bbdoc: If true the widget is displayed.
	EndRem
	Field	displayed:Int
	Rem
	bbdoc: If true the widget can be interacted with.
	EndRem
	Field	enabled:Int
	Rem
	bbdoc: The text displayed in the widget.
	EndRem
	Field	text:String
	Rem
	bbdoc: The X co-ordinate of the widget.
	EndRem
	Field	x:Int
	Rem
	bbdoc: The Y co-ordinate of the widget.
	EndRem
	Field	y:Int
	Rem
	bbdoc: The width of the widget.
	EndRem
	Field	w:Int
	Rem
	bbdoc: The height of the widget.
	EndRem
	Field	h:Int
	Rem
	bbdoc: Callback to call when clicked.
	EndRem
	Field	callback(w:TWidget)
	Rem
	bbdoc: True if the mouse is over this widget, False otherwise.
	EndRem
	Field	mouse_over:Int
	Rem
	bbdoc: The @TGUIHandler that owns this widget.
	EndRem
	Field	owner:TGUIHandler
	Rem
	bbdoc: The mask of consumed events, zero otherwise.
	EndRem
	Field	consumes:Int

	Rem
	bbdoc: Override this accept keypresses
	EndRem	
	Method HandleKey(k:Int)
	End Method
	
	Rem
	bbdoc: Override this for when the mouse enters.  Call this parent version to handle @mouse_over too.
	EndRem
	Method MouseEnter()
		If displayed And enabled
			mouse_over=True
		EndIf
	End Method

	Rem
	bbdoc: Override this for when the mouse leaves.  Call this parent version to handle @mouse_over too.
	EndRem
	Method MouseLeave()
		mouse_over=False
	End Method

	Rem
	bbdoc: Override to handle a mouse button press.
	EndRem
	Method HandleClick()
	End Method
	
	Rem
	bbdoc: Handles mouse dragging.
	about: @mx and @my are the changes in mouse co-ordinates since the last drag.
	EndRem
	Method HandleDrag(mx:Int, my:Int)
	End Method
	
	Rem
	bbdoc: Must be provided by a widget to draw itself.
	EndRem
	Method Draw() Abstract
	
	Rem
	bbdoc: Helper to draw a wireframe rectangle.
	EndRem
	Function DrawBox(x:Int, y:Int, w:Int, h:Int)
		DrawLine(x,y,x+w-1,y)
		DrawLine(x+w-1,y,x+w-1,y+h-1)
		DrawLine(x+w-1,y+h-1,x,y+h-1)
		DrawLine(x,y+h-1,x,y)
	End Function

	Rem
	bbdoc: Helper to draw a 3D rectangle.
	EndRem
	Function Draw3DBox(x:Int, y:Int, w:Int, h:Int, invert:Int, size:Int=2)
		Local f:Int
		
		SetColor(200,200,200)
		DrawRect(x,y,w,h)

		If invert
			SetColor(170,170,170)
		Else
			SetColor(230,230,230)
		EndIf

		For f=0 Until size
			DrawLine(x+f,y+f,x+w-1-f,y+f)
			DrawLine(x+w-1-f,y+f,x+w-1-f,y+h-1-f)
		Next

		If invert
			SetColor(230,230,230)
		Else
			SetColor(170,170,170)
		EndIf

		For f=0 Until size
			DrawLine(x+w-1-f,y+h-1-f,x+f,y+h-1-f)
			DrawLine(x+f,y+h-1-f,x+f,y+f)
		Next
	End Function

End Type

Rem
bbdoc: The panel widget (simply displays itself as a white bordered black box)
EndRem
Type TPanel Extends TWidget
	
	Rem
	bbdoc: Create a TPanel widget.
	returns: The created widget.
	about: @gui is the @TGUIHandler object managing this wiget. @x, @y, @x and @h are its position and size.  If @x or @y is -1 they are centered.
	EndRem
	Function Create:TPanel(gui:TGUIHandler,x:Int, y:Int, w:Int, h:Int)
		Local o:TPanel=New TPanel
		o.displayed=True
		o.enabled=True
		o.consumes=0
		
		If x=-1
			x=(GraphicsWidth()-w)/2
		EndIf
		
		If y=-1
			y=(GraphicsHeight()-h)/2
		EndIf

		o.x=x
		o.y=y
		o.w=w
		o.h=h
		gui.Register(o)
		Return o
	End Function
	
	Method Draw()
		SetColor(0,0,0)
		DrawRect(x,y,w,h)
		SetColor(255,255,255)
		DrawBox(x,y,w,h)
	End Method

End Type

Rem
bbdoc: The label widget (simply displays the supplied string)
EndRem
Type TLabel Extends TWidget
	Rem
	bbdoc: Create a TLabel widget.
	returns: The created widget.
	about: @gui is the @TGUIHandler object managing this wiget. @x and @y are its position and @text is the text to display in the label.
	EndRem
	Function Create:TLabel(gui:TGUIHandler,x:Int, y:Int, text:String)
		Local o:TLabel=New TLabel
		o.displayed=True
		o.enabled=True
		o.consumes=0
		o.x=x
		o.y=y
		o.w=TGUIFont.font.TextWidth(text)+2
		o.h=TGUIFont.font.MaxHeight()+1
		o.text=text
		gui.Register(o)
		Return o
	End Function
	
	Method Draw()
		TGUIFont.font.Draw(text,x+1,y+1)
	End Method

End Type

Rem
bbdoc: The text entry widget
EndRem
Type TText Extends TWidget
	Field maxlen:Int
	Field mode:Int
	
	Rem
	bbdoc: The text box handles any text
	EndRem
	Const NORMAL:Int=0

	Rem
	bbdoc: The text box handles a number
	EndRem
	Const NUMERIC:Int=1
	
	Rem
	bbdoc: The text box handles only integer numbers
	EndRem
	Const INTEGER:Int=2
	
	Rem
	bbdoc: The text box handles only positive numbers
	EndRem
	Const POSITIVE:Int=4
	
	Rem
	bbdoc: The text box handles a basic set of filename characters (alphanumerics, periods, spaces and underscores)
	EndRem
	Const FILENAME:Int=8
	
	Rem
	bbdoc: The text box is readonly
	EndRem
	Const READONLY:Int=256
	
	
	Rem
	bbdoc: Create a TText widget.
	returns: The created widget.
	about: @gui is the @TGUIHandler object managing this wiget. @x and @y are its position and @text is the initial text in the widget.
	@maxlen is the maximum number of characters allowed.  @mode defines the valid characters that can be entered.
	@callback is called when RETURN is pressed in the text field.
	EndRem
	Function Create:TText(gui:TGUIHandler,x:Int, y:Int, text:String, maxlen:Int, mode:Int=0, callback(w:TWidget)=Null)
		Local o:TText=New TText
		o.displayed=True
		o.enabled=True
		o.consumes=HAS_CLICK|HAS_KEY
		o.x=x
		o.y=y
		o.maxlen=maxlen
		o.w=TGUIFont.font.MaxWidth()*(maxlen+1)+2
		o.h=TGUIFont.font.MaxHeight()+2
		o.text=text
		o.callback=callback
		o.mode=mode
		gui.Register(o)
		Return o
	End Function

	Rem
	bbdoc: Set the text to a floating point value.
	about: @v is the floating point value (a double to cover both types).  This value will be placed in the text
	field with trailing zeros (and trailing dot if an integer) removed.
	EndRem
	Method SetFloat(v:Double)
		Local s:String=v
		
		If s.Find(".")<>-1
			While s.length>1 And s[s.length-1]=Asc("0")
				s=s[..s.length-1]
			Wend
			
			While s.length>1 And s[s.length-1]=Asc(".")
				s=s[..s.length-1]
			Wend
		EndIf
		
		text=s
	End Method
	
	Method HandleClick()
		If Not(mode & READONLY)
			owner.SetFocus(Self)
		EndIf
	End Method
	
	Method HandleKey(k:Int)
		If (mode & READONLY)
			Return
		EndIf
		
		If k=27
			text=""
		Else If k=8
			If text.length>0
				text=text[0..text.length-1]
			EndIf
		Else If k=13
			If callback<>Null
				callback(Self)
				owner.SetFocus(Null)
			EndIf
		Else If k>31 And k<127 And text.length<maxlen
			If (mode & NUMERIC)
				If k=Asc("-") And (Not (mode & POSITIVE)) And text.length=0
					text:+Chr(k)
				EndIf
				
				If k>=Asc("0") And k<=Asc("9")
					text:+Chr(k)
				EndIf
				
				If k=Asc(".") And (Not (mode & INTEGER)) And text.Find(".")=-1
					text:+Chr(k)
				EndIf
			Else
				If (mode & FILENAME)
					If (k>=Asc("a") And k<=Asc("z")) Or (k>=Asc("A") And k<=Asc("Z")) Or (k>=Asc("0") And k<=Asc("9")) Or k=Asc(" ") Or k=Asc(".") Or k=Asc("_")
						text:+Chr(k)
					EndIf
				Else
					text:+Chr(k)
				EndIf
			EndIf
		EndIf
	End Method
	
	Method Draw()
		Local s:String=text
		
		If owner.GetFocus()=Self And Not (mode & READONLY)
			SetColor(128,128,128)
			s:+"_"
		Else
			SetColor(64,64,64)
		EndIf
		
		DrawRect(x,y,w,h)
		
		TGUIFont.font.Draw(s,x+1,y+1)
	End Method
End Type

Rem
bbdoc: The checkbox widget
EndRem
Type TCheckbox Extends TWidget

	Rem
	bbdoc: True if the box is checked, False otherwise.
	EndRem
	Field	checked:Int
	
	Rem
	bbdoc: Create a TCheckox widget.
	returns: The created widget.
	about: @gui is the @TGUIHandler object managing this wiget. @x and @y are its position and @text is the text to display by the checkbox.
	@callback is called when the checkbox is toggled.
	EndRem
	Function Create:TCheckbox(gui:TGUIHandler, x:Int, y:Int, text:String, callback(w:TWidget)=Null)
		Local o:TCheckbox=New TCheckbox
		o.displayed=True
		o.enabled=True
		o.consumes=HAS_CLICK
		o.x=x
		o.y=y
		o.w=TGUIFont.font.TextWidth(" "+text)+4+TGUIFont.font.MaxHeight()
		o.h=TGUIFont.font.MaxHeight()+2
		o.text=text
		o.callback=callback
		gui.Register(o)
		Return o
	End Function
	
	Method HandleClick()
		checked=Not checked
		
		If callback<>Null
			callback(Self)
		EndIf
	End Method
	
	Method Draw()
		If (mouse_over)
			SetColor(255,255,255)
		Else
			SetColor(200,200,200)
		EndIf

		DrawBox(x,y,TGUIFont.font.MaxHeight(),TGUIFont.font.MaxHeight())
		
		If checked
			SetColor(255,100,100)
			DrawRect(x+1,y+1,TGUIFont.font.MaxHeight()-2,TGUIFont.font.MaxHeight()-2)
		EndIf
		
		TGUIFont.font.Draw(" "+text,x+2+TGUIFont.font.MaxHeight(),y+1)
	End Method
End Type

Rem
bbdoc: The button widget
EndRem
Type TButton Extends TWidget

	Field ox:Int
	Field oy:Int
	
	Rem
	bbdoc: Create a TButton widget.
	returns: The created widget.
	about: @gui is the @TGUIHandler object managing this wiget. @x, @y, @w and @h are its position and size, and @text is the text to display in the button.
	@callback is called when the button is pressed.
	EndRem
	Function Create:TButton(gui:TGUIHandler, x:Int, y:Int, w:Int, h:Int, text:String, callback(w:TWidget))
		Local o:TButton=New TButton
		o.displayed=True
		o.enabled=True
		o.consumes=HAS_CLICK
		o.x=x
		o.y=y
		o.w=w
		o.h=h
		o.text=text
		o.ox=x+w/2-TGUIFont.font.TextWidth(text)/2
		o.oy=y+h/2-TGUIFont.font.TextHeight(text)/2
		o.callback=callback
		gui.Register(o)
		Return o
	End Function
	
	Method HandleClick()
		If callback<>Null
			callback(Self)
		EndIf
	End Method

	Method Draw()
		If (mouse_over)
			SetColor(255,255,255)
			DrawBox(x,y,w,h)
		EndIf
		
		Draw3DBox(x+1,y+1,w-2,h-2,False,2)
		
		TGUIFont.font.Draw(text,ox,oy)
	End Method
End Type

Rem
bbdoc: A drop down list type widget
EndRem
Type TButtonList Extends TWidget

	Field options:String[]
	
	Rem
	bbdoc: The selected item.
	EndRem
	Field selected:Int
	
	Rem
	bbdoc: Create a TButtonList widget.
	returns: The created widget.
	about: @gui is the @TGUIHandler object managing this wiget. @x and @y are its position. @options are the options for the list and
	@selected is the currently selected item. @callback is called when the selection changes.
	EndRem
	Function Create:TButtonList(gui:TGUIHandler, x:Int, y:Int, options:String[], selected:Int, callback(w:TWidget))
		Local o:TButtonList=New TButtonList
		Local maxw:Int=0
		o.displayed=True
		o.enabled=True
		o.consumes=HAS_CLICK
		o.x=x
		o.y=y
		o.options=options
		o.selected=selected
		o.text=options[selected]
		
		For Local s:String=EachIn options
			maxw=Max(maxw,TGUIFont.font.TextWidth(s))
		Next
		
		o.w=maxw+TGUIFont.font.MaxHeight()+4
		o.h=TGUIFont.font.MaxHeight()+2
		o.callback=callback
		gui.Register(o)
		Return o
	End Function
	
	Method HandleClick()
		Local sel:Int=GUIMenu("Select value",options,x,y)
		
		If sel<>-1
			selected=sel
			text=options[selected]
			If callback<>Null
				callback(Self)
			EndIf
		EndIf
	End Method

	Method Draw()
		If (mouse_over)
			SetColor(128,128,128)
		Else
			SetColor(64,64,64)
		EndIf

		DrawRect(x,y,w,h)				
		Draw3DBox(x+2,y+2,h-4,h-4,False,1)

		TGUIFont.font.Draw(text,x+TGUIFont.font.MaxHeight()+3,y+1)
	End Method
End Type

Rem
bbdoc: Optional type to use for TTextList
about: If the objects stored as TTextList options are derived from this type then tabular lists can be created.
EndRem
Type TTextListItem Abstract
	Rem
	bbdoc: The number of columns.
	returns: The number of columns
	EndRem
	Method Columns:Int() Abstract
	
	Rem
	bbdoc: A column offset.
	returns: The column offset for column @i (numbered from zero).
	EndRem
	Method ColumnOffset:Int(i:Int) Abstract

	Rem
	bbdoc: Column data.
	returns: The column data for column @i (numbered from zero).
	EndRem
	Method ColumnData:String(i:Int) Abstract
End Type

Rem
bbdoc: A widget that displays text items as a list.
EndRem
Type TTextList Extends TWidget

	Field options:Object[]
	Field selected:Int
	Field num:Int
	Field top:Int
	Field rows:Int
	
	Rem
	bbdoc: Create a TTextList widget.
	returns: The created widget.
	about: @gui is the @TGUIHandler object managing this wiget. @x, @y, and @w are its position and width.
	@rows are the number of items to display at a time.
	@callback is called when the selection changes.
	EndRem
	Function Create:TTextList(gui:TGUIHandler, x:Int, y:Int, w:Int, rows:Int, callback(w:TWidget)=Null)
		Local o:TTextList=New TTextList
		Local maxw:Int=0
		o.displayed=True
		o.enabled=True
		o.consumes=HAS_CLICK
		o.x=x
		o.y=y
		o.options=Null
		o.selected=-1
		o.num=0
		o.top=0
		o.rows=rows
		
		o.w=w
		o.h=TGUIFont.font.MaxHeight()*rows
		o.callback=callback
		gui.Register(o)
		Return o
	End Function
	
	Rem
	bbdoc: Sets the options to display in the list.
	about: @opts is an array of objects.  <i>Note</i>: If the objects passed are derived from TTextListItem then tabular output is generated.
	If they are not derived, ToString() is called on the objects to display them, so you are not restricted to the type of object that
	can be passed.
	EndRem
	Method SetOptions(opts:Object[])
		options=opts
		num=opts.length
		selected=-1
		top=0
	End Method
	
	Rem
	bbdoc: Gets the selected item's index.
	returns: The selected item's index, or -1 if nothing is selected.
	EndRem
	Method GetSelectedIndex:Int()
		Return selected
	End Method
	
	Rem
	bbdoc: Gets the selected item.
	returns: The selected item, or null if nothing is selected.
	EndRem
	Method GetSelectedItem:Object()
		If options<>Null And selected<>-1
			Return options[selected]
		Else
			Return Null
		EndIf
	End Method
	
	Rem
	bbdoc: Set the top row.
	about: @i is the index of the item to display in the first row of the widget.
	EndRem
	Method SetTopRow(i:Int)
		If options<>Null And i<num
			top=i
		EndIf
	End Method
	
	Rem
	bbdoc: Get the top row.
	returns: The index of the item displayed in the first row of the widget.  -1 if no options are set.
	EndRem
	Method GetTopRow:Int()
		If options<>Null
			Return top
		Else
			Return -1
		EndIf
	End Method
	
	Rem
	bbdoc: Ensure an item is visible.
	about: @i is the index of the item that is to be made visible.
	EndRem
	Method EnsureVisible(i:Int)
		If options<>Null And i<num
			If i<top
				top=i
			ElseIf i>=top+rows
				top=Max(0,i-rows+1)
			EndIf
		EndIf
	End Method
	
	Method HandleClick()
		If options<>Null
			Local sel:Int=top+(MouseY()-y)/TGUIFont.font.MaxHeight()
			
			If sel<num
				selected=sel
				If callback<>Null
					callback(Self)
				EndIf
			EndIf
		EndIf
	End Method

	Method Draw()
		SetColor(64,64,64)
		DrawRect(x,y,w,h)
		
		If options<>Null
			Local vx:Int
			Local vy:Int
			Local vw:Int
			Local vh:Int
			
			GetViewport(vx,vy,vw,vh)
			
			Local ty:Int=y
			For Local f:Int=top Until top+rows
				SetViewport(x,ty,w,TGUIFont.font.MaxHeight())

				If f=selected
					If mouse_over And MouseY()>=ty And MouseY()<ty+TGUIFont.font.MaxHeight()
						SetColor(200,128,128)
					Else
						SetColor(128,128,128)
					EndIf
					DrawRect(x,ty,w,TGUIFont.font.MaxHeight())
				Else
					If mouse_over And MouseY()>=ty And MouseY()<ty+TGUIFont.font.MaxHeight() And f<num
						SetColor(128,0,0)
						DrawRect(x,ty,w,TGUIFont.font.MaxHeight())
					EndIf
				EndIf
				
				If f<num
					Local li:TTextListItem=TTextListItem(options[f])
					
					If li<>Null
						For Local f:Int=0 Until li.Columns()
							TGUIFont.font.Draw(li.ColumnData(f),x+li.ColumnOffset(f),ty)
						Next
					Else
						TGUIFont.font.Draw(options[f].ToString(),x,ty)
					EndIf
				EndIf
				
				ty:+TGUIFont.font.MaxHeight()
			Next
			
			SetViewport(vx,vy,vw,vh)
		EndIf
	End Method
End Type

Rem
bbdoc: A number up/down widget for doubles
EndRem
Type TNumberDouble Extends TWidget

	Rem
	bbdoc: The value
	EndRem
	Field value:Double
	
	Rem
	bbdoc: The increment/decrement
	EndRem
	Field change:Double
	
	Rem
	bbdoc: The maximum value
	EndRem
	Field maxval:Double
	
	Rem
	bbdoc: The minimum value
	EndRem
	Field minval:Double
	
	Rem
	bbdoc: Create a TNumber widget.
	returns: The created widget.
	about: @gui is the @TGUIHandler object managing this wiget. @x and @y are its position. @callback is called when the value changes.
	EndRem
	Function Create:TNumberDouble(gui:TGUIHandler, x:Int, y:Int, callback(w:TWidget)=Null)
		Local o:TNumberDouble=New TNumberDouble
		o.displayed=True
		o.enabled=True
		o.consumes=HAS_CLICK
		o.value=0
		o.minval=0
		o.maxval=100
		o.change=10
		o.x=x
		o.y=y
		o.w=TGUIFont.font.MaxHeight()*2+8
		o.h=TGUIFont.font.MaxHeight()+2
		o.callback=callback
		gui.Register(o)
		Return o
	End Function
	
	Method HandleClick()
		Local old:Double=value

		If MouseX()<x+w/2
			value=Min(value+change,maxval)
		Else
			value=Max(value-change,minval)
		EndIf
		
		If value<>old And callback<>Null
			callback(Self)
		EndIf
	End Method

	Method Draw()
		If mouse_over
			If MouseX()<x+w/2
				SetColor(128,128,128)
				DrawRect(x,y,w/2,h)
				SetColor(64,64,64)
				DrawRect(x+w/2,y,w/2,h)
			Else
				SetColor(64,64,64)
				DrawRect(x,y,w/2,h)
				SetColor(128,128,128)
				DrawRect(x+w/2,y,w/2,h)
			EndIf
		Else
			SetColor(64,64,64)
			DrawRect(x,y,w,h)
		EndIf
	
		Draw3DBox(x+2,y+2,h-4,h-4,False,1)
		Draw3DBox(x+w-h,y+2,h-4,h-4,False,1)

		TGUIFont.font.Draw(value,x+w+2,y+1)
	End Method
End Type

Rem
bbdoc: A number up/down widget for ints
EndRem
Type TNumberInt Extends TWidget

	Rem
	bbdoc: The value
	EndRem
	Field value:Int
	
	Rem
	bbdoc: The increment/decrement
	EndRem
	Field change:Int
	
	Rem
	bbdoc: The maximum value
	EndRem
	Field maxval:Int
	
	Rem
	bbdoc: The minimum value
	EndRem
	Field minval:Int
	
	Rem
	bbdoc: Create a TNumber widget.
	returns: The created widget.
	about: @gui is the @TGUIHandler object managing this wiget. @x and @y are its position.
	@callback is called when the value changes.
	EndRem
	Function Create:TNumberInt(gui:TGUIHandler, x:Int, y:Int, callback(w:TWidget)=Null)
		Local o:TNumberInt=New TNumberInt
		o.displayed=True
		o.enabled=True
		o.consumes=HAS_CLICK
		o.value=0
		o.minval=0
		o.maxval=100
		o.change=10
		o.x=x
		o.y=y
		o.w=TGUIFont.font.MaxHeight()*2+8
		o.h=TGUIFont.font.MaxHeight()+2
		o.callback=callback
		gui.Register(o)
		Return o
	End Function
	
	Method HandleClick()
		Local old:Int=value

		If MouseX()<x+w/2
			value=Min(value+change,maxval)
		Else
			value=Max(value-change,minval)
		EndIf
		
		If value<>old And callback<>Null
			callback(Self)
		EndIf
	End Method

	Method Draw()
		If mouse_over
			If MouseX()<x+w/2
				SetColor(128,128,128)
				DrawRect(x,y,w/2,h)
				SetColor(64,64,64)
				DrawRect(x+w/2,y,w/2,h)
			Else
				SetColor(64,64,64)
				DrawRect(x,y,w/2,h)
				SetColor(128,128,128)
				DrawRect(x+w/2,y,w/2,h)
			EndIf
		Else
			SetColor(64,64,64)
			DrawRect(x,y,w,h)
		EndIf

		Draw3DBox(x+2,y+2,h-4,h-4,False,1)
		Draw3DBox(x+w-h,y+2,h-4,h-4,False,1)

		TGUIFont.font.Draw(value,x+w+2,y+1)
	End Method
End Type

Rem
bbdoc: A scrollbar widget
EndRem
Type TScrollbar Extends TWidget

	Field horiz:Int
	Field bc:Int
	Field page:Double
	Field maxval:Double
	Field minval:Double
	Field stepsize:Double
	Field blocksize:Int
	
	Rem
	bbdoc: Create a TVerticalScrollbar widget.
	returns: The created widget.
	about: @gui is the @TGUIHandler object managing this wiget. @x, @y, @w and @h are its position and size.
	If @w is greater than height then an horizontal scrollbar is created, otherwise its vertical.  @callback is called when the scrollbar moves.
	EndRem
	Function Create:TScrollbar(gui:TGUIHandler, x:Int, y:Int, w:Int, h:Int, callback(w:TWidget)=Null)
		Local o:TScrollbar=New TScrollbar
		o.displayed=True
		o.enabled=True
		o.consumes=HAS_CLICK|HAS_DRAG
		o.x=x
		o.y=y
		o.w=w
		o.h=h
		o.horiz=(w>h)
		o.SetBar(0,100,10)
		o.callback=callback
		gui.Register(o)
		Return o
	End Function
	
	Rem
	bbdoc: Set parameters for scroll bar
	about: @min_val and @max_val are the values at the top and bottom of the scroll bar.  @page_size is the numbers between the two that
	is covered by the block in the scrollbar.  <i>Note</i>: The maximum value of @value is @max_val minus @page_size.
	EndRem
	Method SetBar(min_val:Double, max_val:Double, page_size:Double)
		minval=min_val
		maxval=max_val
		page=page_size
		
		If horiz
			stepsize=(maxval-minval)/w
			blocksize=Min(w,Max(1,page/stepsize))
			bc=x
		Else
			stepsize=(maxval-minval)/h
			blocksize=Min(h,Max(1,page/stepsize))
			bc=y
		EndIf
	End Method
	
	Rem
	bbdoc: Get the current value of the scrollbar.
	returns: The current position of the scrollbar inbetween the minimum and maximum values.
	EndRem
	Method GetValue:Double()
		If horiz
			Return minval+(bc-x)*stepsize
		Else
			Return minval+(bc-y)*stepsize
		EndIf
	End Method
	
	Rem
	bbdoc: Sets the current value of the scrollbar.
	EndRem
	Method SetValue(val:Double)
		If horiz
			bc=Max(x,Min(x+w-blocksize,x+(val-minval)/stepsize))
		Else
			bc=Max(y,Min(y+h-blocksize,y+(val-minval)/stepsize))
		EndIf
	End Method
	
	Method HandleClick()
		Local old:Double=GetValue()
		
		If horiz
			bc=Max(x,Min(x+w-blocksize,MouseX()))
		Else
			bc=Max(y,Min(y+h-blocksize,MouseY()))
		EndIf
		
		If GetValue()<>old And callback<>Null
			callback(Self)
		EndIf
	End Method
	
	Method HandleDrag(mx:Int, my:Int)
		Local old:Double=GetValue()

		If horiz
			bc=Max(x,Min(x+w-blocksize,bc+mx))
		Else
			bc=Max(y,Min(y+h-blocksize,bc+my))
		EndIf
		
		If GetValue()<>old And callback<>Null
			callback(Self)
		EndIf
	End Method

	Method Draw()
		SetColor(64,64,64)
		DrawRect(x,y,w,h)
		If horiz
			Draw3DBox(bc,y,blocksize,h,False,1)
		Else
			Draw3DBox(x,bc,w,blocksize,False,1)
		EndIf
	End Method
End Type

Rem
bbdoc: Handles the GUI.
EndRem
Type TGUIHandler

	' These are private
	'
	Field 	m_widgets:TList
	Field	m_focus:TWidget
	Field	m_over:TWidget
	Field	m_clicked:TWidget
	Field	m_dragging:Int
	Field	m_dragx:Int
	Field	m_dragy:Int
	Field	m_dragobj:TWidget

	Rem
	bbdoc: Create a GUI Handler.
	returns: The GUI Hanbler.
	EndRem
	Function Create:TGUIHandler()
		Local o:TGUIHandler
		
		o=New TGUIHandler
		
		o.m_widgets=CreateList()
		o.m_focus=Null
		o.m_over=Null
		o.m_clicked=Null
		o.m_dragging=False
		o.m_dragx=0
		o.m_dragy=0
		o.m_dragobj=Null

		Return o
	End Function
	
	Rem
	bbdoc: Register a widget.
	about: Widgets in the library call this themselves when creating.
	EndRem
	Method Register(w:TWidget)
		m_widgets.AddLast(w)
		w.owner=Self
	End Method
	
	Rem
	bbdoc: Remove all widgets.
	EndRem
	Method Clear()
		m_widgets.Clear()
	End Method
	
	Rem
	bbdoc: Sets the enable state of all widgets.
	about: If @state is true then all widgets are enabled, otherwise all widgets are disabled.
	EndRem
	Method SetEnable(state:Int)
		For Local w:TWidget=EachIn m_widgets
			w.enabled=state
		Next
	End Method
	
	Rem
	bbdoc: Sets the displayed state of all widgets.
	about: If @state is true then all widgets are displayed, otherwise all widgets are hidden.
	EndRem
	Method SetDisplay(state:Int)
		For Local w:TWidget=EachIn m_widgets
			w.displayed=state
		Next
	End Method
	
	Rem
	bbdoc: Sets the keyboard focus to the supplied widget.  Pass null for no focus.
	EndRem
	Method SetFocus(w:TWidget)
		m_focus=w
	End Method
	
	Rem
	bbdoc: Gets the keyboard focus.
	returns: The currently focused TWidget, or null for no focus.
	EndRem
	Method GetFocus:TWidget()
		Return m_focus
	End Method
	
	Rem
	bbdoc: Gets the last clicked widget.
	returns: The last clicked TWidget.  Null is returned if this is called again before another widget is clicked.
	EndRem
	Method Clicked:TWidget()
		Local last:TWidget=m_clicked
		m_clicked=Null
		Return last
	End Method
	
	Rem
	bbdoc: Whether a widget is dragging
	returns: True if a widget is consuming a mouse drag.
	EndRem
	Method IsDragging:Int()
		Return m_dragging
	End Method
	
	Rem
	bbdoc: Perform the event loop and pass any necessary events.
	about: KeyHit(KEY_MOUSELEFT) and GetChar() are used to consume events for the interface.
	EndRem
	Method EventLoop()
		Local x:Int=MouseX()
		Local y:Int=MouseY()
		Local b:Int=MouseHit(1)>0
		Local drag:Int=MouseDown(1)
		
		Local w:TWidget=LocateWidget(x,y)
		
		For Local wid:TWidget=EachIn m_widgets
			If wid.displayed
				If wid.enabled
					wid.Draw()
				Else
					SetAlpha(0.3)
					wid.Draw()
					SetAlpha(1)
				EndIf
			EndIf
		Next
		
		If w<>m_over
			If m_over<>Null
				m_over.MouseLeave()
			EndIf
			m_over=w
			If m_over<>Null
				m_over.MouseEnter()
			EndIf
		EndIf
		
		If w<>Null And w.enabled And w.consumes&TWidget.HAS_CLICK=TWidget.HAS_CLICK And b And Not m_dragging
			w.HandleClick()
			m_clicked=w
		EndIf
		
		Local k:Int=GetChar()
		
		If k<>0 And m_focus<>Null And m_focus.enabled And m_focus.consumes&TWidget.HAS_KEY=TWidget.HAS_KEY
			m_focus.HandleKey(k)
		EndIf
		
		If drag
			If m_dragging
				m_dragobj.HandleDrag(MouseX()-m_dragx,MouseY()-m_dragy)
				m_dragx=MouseX()
				m_dragy=MouseY()
			Else
				If w<>Null And w.consumes&TWidget.HAS_DRAG=TWidget.HAS_DRAG
					m_dragging=True
					m_dragx=MouseX()
					m_dragy=MouseY()
					m_dragobj=w
				EndIf
			EndIf
		Else
			m_dragging=False
			m_dragobj=Null
		EndIf
	End Method
	
	' Private method
	'
	Method LocateWidget:TWidget(x:Int,y:Int)
		For Local w:TWidget=EachIn m_widgets
			If x>=w.x And y>=w.y And x<w.x+w.w And y<w.y+w.h And w.consumes
				Return w
			EndIf
		Next
		Return Null
	End Method
End Type


Rem
bbdoc: Displays a notification alert with the supplied string.
about: The string @s can be split into multiple lines using the '|' character.  If @i is not null then this image is drawn as a mouse cursor.
EndRem
Function GUINotify(s:String, i:TImage=Null)
	Local back:TImage=CreateImage(GraphicsWidth(),GraphicsHeight(),1,0)
	GrabImage(back,0,0)
	
	Local txt:TSplitText=TSplitText.Create(s)
	
	Local w:Int=Max(txt.width+10,GraphicsWidth()/4)
	Local h:Int=txt.Height+TGUIFont.font.MaxHeight()*4
	Local x:Int=GraphicsWidth()/2-w/2
	Local y=GraphicsHeight()/2-h/2
	Local by=y+h-TGUIFont.font.MaxHeight()*2.5
	
	Local gui:TGUIHandler=TGUIHandler.Create()
	
	Local ty:Int=y+5
	
	For Local t:String=EachIn txt.lines
		Local label:TLabel=TLabel.Create(gui,x+5,ty,t)
		ty:+TGUIFont.font.TextHeight(t)
	Next
	
	Local button:TButton=TButton.Create(gui,x+5,by,w-10,TGUIFont.font.MaxHeight()*2,"OK",Null)
	
	Local click:TWidget=Null
	
	While click<>button
		Cls
		SetAlpha(0.5)
		DrawImage(back,0,0)
		SetAlpha(1)
		TWidget.Draw3DBox(x,y,w,h,False,2)
		gui.EventLoop()
		click=gui.Clicked()

		If i<>Null
			SetColor(255,255,255)
			DrawImage(i,MouseX(),MouseY())
		EndIf
		
		Flip
	Wend
End Function

Rem
bbdoc: Displays a yes/no alert with the supplied string.
returns: True if Yes selected, otherwise False.
about: The string @s can be split into multiple lines using the '|' character.  If @i is not null then this image is drawn as a mouse cursor.
EndRem
Function GUIYesNo:Int(s:String, i:TImage=Null)
	Local back:TImage=CreateImage(GraphicsWidth(),GraphicsHeight(),1,0)
	GrabImage(back,0,0)
	
	Local txt:TSplitText=TSplitText.Create(s)
	
	Local w:Int=Max(txt.width+10,GraphicsWidth()/4)
	Local h:Int=txt.Height+TGUIFont.font.MaxHeight()*4
	Local x:Int=GraphicsWidth()/2-w/2
	Local y=GraphicsHeight()/2-h/2
	Local by=y+h-TGUIFont.font.MaxHeight()*2.5
	
	Local gui:TGUIHandler=TGUIHandler.Create()
	
	Local ty:Int=y+5
	
	For Local t:String=EachIn txt.lines
		Local label:TLabel=TLabel.Create(gui,x+5,ty,t)
		ty:+TGUIFont.font.TextHeight(t)
	Next

	Local yes:TButton=TButton.Create(gui,x+5,by,w/2-10,TGUIFont.font.MaxHeight()*2,"Yes",Null)
	Local no:TButton=TButton.Create(gui,x+w/2+5,by,w/2-10,TGUIFont.font.MaxHeight()*2,"No",Null)
	
	Local click:TWidget=Null
	
	While click=Null
		Cls
		SetAlpha(0.5)
		DrawImage(back,0,0)
		SetAlpha(1)
		TWidget.Draw3DBox(x,y,w,h,False,2)
		gui.EventLoop()
		click=gui.Clicked()

		If i<>Null
			SetColor(255,255,255)
			DrawImage(i,MouseX(),MouseY())
		EndIf
		
		Flip
	Wend
	
	Return click=yes
End Function


Rem
bbdoc: Displays a pop-up menu.
returns: The index of the selected option, -1 for none.
about: @title is the menu title, @options the options to display and @x and @y specify its position.
If @i is not null then this image is drawn as a mouse cursor.
EndRem
Function GUIMenu(title:String, options:String[], x:Int, y:Int, i:TImage=Null)
	Local f:Int
	Local back:TImage=CreateImage(GraphicsWidth(),GraphicsHeight(),1,0)
	GrabImage(back,0,0)
	
	Local st:Int=TGUIFont.font.MaxHeight()*2
	Local h:Int=TGUIFont.font.MaxHeight()*3
	Local w:Int=TGUIFont.font.TextWidth(title)+30
	
	For f=0 Until options.length
		w=Max(w,TGUIFont.font.TextWidth(options[f])+30)
		h:+st
	Next
	
	Local gui:TGUIHandler=TGUIHandler.Create()
	
	x=Max(0,Min(x,GraphicsWidth()-w))
	y=Max(0,Min(y,GraphicsHeight()-h))
	
	Local label:TLabel=TLabel.Create(gui,x+5,y+2,title)
	Local button:TButton[]=New TButton[options.length]
	
	For f=0 Until options.length
		button[f]=TButton.Create(gui,x+5,y+TGUIFont.font.MaxHeight()*2+f*st,w-10,st-2,options[f],Null)
	Next
	
	Local click:TWidget=Null
	
	While click=Null And MouseHit(2)=0
		Cls
		SetAlpha(0.5)
		DrawImage(back,0,0)
		SetAlpha(1)
		TWidget.Draw3DBox(x,y,w,h,False,2)
		gui.EventLoop()
		click=gui.Clicked()
		
		If i<>Null
			SetColor(255,255,255)
			DrawImage(i,MouseX(),MouseY())
		EndIf
		
		Flip
	Wend
	
	For f=0 Until options.length
		If button[f]=click
			Return f
		EndIf
	Next
	
	Return -1
End Function

Rem
bbdoc: Displays a basic file selector.
returns: The selected file, or null for none.
about: @title is the title.  @file is the initially selected file, and f set to null then no file is selected and the current directory displayed.
Set @save to true for a save dialog (the filename can be altered).
If @i is not null then this image is drawn as a mouse cursor.
EndRem
Function GUIFileSelect:String(title:String, file:String, save:Int, i:TImage=Null)
	FlushKeys()

	Local oldpwd:String=CurrentDir()
	Local dir:String
	Local fn:String
	Local sw:Int=GraphicsWidth()
	Local sh:Int=GraphicsHeight()
	Local fh:Int=TGUIFont.font.MaxHeight()
	Local fw:Int=TGUIFont.font.MaxWidth()
	Local rows:Int=(sh-fh*10)/fh
	
	If file<>Null And file<>""
		dir=ExtractDir(file)
		
		If dir=""
			dir=oldpwd
		EndIf
		
		If FileType(file)=FILETYPE_FILE
			fn=StripDir(file)
		Else
			fn=""
		EndIf
	Else
		dir=oldpwd
		fn=""
	EndIf
	
	Local gui:TGUIHandler=TGUIHandler.Create()
	
	TPanel.Create(gui,0,0,sw,sh)
	TLabel.Create(gui,10,fh*0.5,title)
	
	Local list:TTextList=TTextList.Create(gui,20,fh*2,sw-40,rows)
	Local scroll:TScrollbar=TScrollbar.Create(gui,list.x+list.w+5,list.y,10,list.h)
	
	Local fntext:TText
	
	If save
		fntext=TText.Create(gui,20,sh-fh*6,fn,(sw-40)/fw,TText.FILENAME)
	Else
		fntext=TText.Create(gui,20,sh-fh*6,fn,(sw-40)/fw,TText.READONLY)
	EndIf
	
	Local bw:Int=TGUIFont.font.MaxWidth()*9
	
	Local cancel:TButton=TButton.Create(gui,sw-bw-20,sh-fh*3.5,bw,fh*2.5,"Cancel",Null)
	Local ok:Tbutton=TButton.Create(gui,cancel.x-bw-10,cancel.y,bw,fh*2.5,"OK",Null)
	
	Local last:TDirEntry=Null
	
	ChangeDir(dir)
	LoadDirEnts(list,scroll,rows)

	Repeat
		Cls

		gui.EventLoop()
		
		TGUIFont.font.Draw(CurrentDir(),list.x,list.y+list.h+3)
		
		Local click:TWidget=gui.Clicked()
		
		If click=ok
			Local ret:String=CurrentDir()+"/"+fntext.text
			ChangeDir(oldpwd)
			FlushKeys()
			Return ret
		EndIf
		
		If click=cancel Or (KeyHit(KEY_ESCAPE) And gui.GetFocus()=Null)
			ChangeDir(oldpwd)
			FlushKeys()
			Return Null
		EndIf
		
		If list.GetSelectedItem()<>last
			last=TDirEntry(list.GetSelectedItem())
			
			If last.is_dir
				ChangeDir(last.filename)
				LoadDirEnts(list,scroll,rows)
				fntext.text=""
				last=Null
			Else
				fntext.text=last.filename
			EndIf
		EndIf
		
		ok.enabled=(fntext.text<>"")
		
		list.SetTopRow(scroll.GetValue())

		If i<>Null
			SetColor(255,255,255)
			DrawImage(i,MouseX(),MouseY())
		EndIf
		
		Flip
	Forever
End Function

Rem
bbdoc: Handles a TGUIHandler as if it's a modal dialog.
returns: True if @ok is pressed, False if @cancel or the ESCAPE key is pressed.  ESCAPE is only allowed if nothing has the text focus.
about: @gui is the GUI handler and widgets to display as a dialog., @ok is the clickable widget that OK's the dialog, @cancel the widget that cancels it.
If @i is not null then this image is drawn as a mouse cursor.
EndRem
Function GUIDialog(gui:TGUIHandler, ok:TWidget, cancel:TWidget, i:TImage=Null)
	FlushKeys()
	
	Local back:TImage=CreateImage(GraphicsWidth(),GraphicsHeight(),1,0)
	GrabImage(back,0,0)
	
	Local done:Int=False
	Local ok_pressed:Int
	Local click:TWidget
	
	While done=False
		Cls
		SetAlpha(0.5)
		DrawImage(back,0,0)
		SetAlpha(1)
		gui.EventLoop()
		click=gui.Clicked()
		
		If click=ok
			done=True
			ok_pressed=True
		EndIf
		
		If click=cancel Or (KeyHit(KEY_ESCAPE) And gui.GetFocus()=Null)
			done=True
			ok_pressed=False
		EndIf
		
		If i<>Null
			SetColor(255,255,255)
			DrawImage(i,MouseX(),MouseY())
		EndIf
		
		Flip
	Wend
	
	FlushKeys()
	Return ok_pressed
End Function

Private

Type TSplitText
	Field lines:TList
	Field width:Int
	Field height:Int
	
	Function Create:TSplitText(s:String)
		Local o:TSplitText=New TSplitText

		o.lines=CreateList()
		o.width=0
		o.height=0
		
		Local sub:String=""
		
		For Local f:Int=0 Until s.length
			Local c:Int=s[f]
			If c=Asc("|")
				o.lines.AddLast(sub)
				o.width=Max(o.width,TGUIFont.font.TextWidth(sub))
				o.height:+TGUIFont.font.TextHeight(sub)
				sub=""
			Else
				sub:+Chr(c)
			EndIf
		Next
		
		If sub.length>0
			o.lines.AddLast(sub)
			o.width=Max(o.width,TGUIFont.font.TextWidth(sub))
			o.height:+TGUIFont.font.TextHeight(sub)
		EndIf
		
		Return o
	End Function
EndType

Type TDirEntry Extends TTextListItem
	Field path:String
	Field dir:String
	Field filename:String
	Field size:Int
	Field is_dir:Int
	
	Function Create:TDirEntry(path:String)
		Local o:TDirEntry=New TDirEntry
		o.path=path
		o.dir=ExtractDir(path)
		o.filename=StripDir(path)
		o.is_dir=(FileType(path)=FILETYPE_DIR)
		o.size=FileSize(path)
		Return o
	End Function
	
	Method Compare:Int(o:Object)
		Local d:TDirEntry=TDirEntry(o)
		
		If d=Null
			Return 0
		EndIf
		
		If is_dir=d.is_dir
			Return filename.Compare(d.filename)
		Else
			If is_dir
				Return -1
			Else
				Return 1
			EndIf
		EndIf
		
		Return 0
	End Method
	
	Method Columns:Int()
		Return 2
	End Method
	
	Method ColumnOffset:Int(i:Int)
		If i=0
			Return 0
		Else
			Return GraphicsWidth()-TGUIFont.font.MaxWidth()*20
		EndIf
	End Method
	
	Method ColumnData:String(i:Int)
		If i=0
			Return filename
		Else
			If is_dir
				Return "DIR"
			Else
				Return size+" bytes"
			EndIf
		EndIf
	End Method
End Type

Function LoadDirEnts(list:TTextList, scroll:TScrollbar, rows:Int)
	Local d:TList=CreateList()
	
	For Local s:String=EachIn LoadDir(CurrentDir(),False)
		d.AddLast(TDirEntry.Create(CurrentDir()+"/"+s))
	Next
	
	d.Sort()
	
	list.SetOptions(d.ToArray())
	scroll.SetBar(0,Max(1,d.Count()-rows/2),1)
End Function