9.1 Empezamos escribiendo el código del control

Crearemos nuestra clase y añadiremos una imagen relacionada al control (un eje cartesiano)

En la clase ejescartesiano copiamos el siguiente código:

' Gambas class file

'ZONA 1 Donde definimos la herencia y la orden EXPORT

INHERITS DrawingArea

EXPORT

'ZONA 2 Añadimos las propiedades que aparecerán en el cuadro de propiedades

PUBLIC CONST _Properties AS String = "*,C,B,Ap1,Ap2,colorejes"

'ZONA 3 Definimos las variables tanto Públicas como Privadas de la clase

PROPERTY C AS Float ' distancia del nuevo eje U'x medido segun eje unidades Ux (el del propio control DrawingArea

PRIVATE hC AS Float

PROPERTY B AS Float ' distancia del nuevo eje U'y medido segun unidades Uy

PRIVATE hB AS Float

PROPERTY ap1 AS Float ' Inicio del intervalo de representación eje U'x

PRIVATE hap1 AS Float

PROPERTY ap2 AS Float 'Fin del intervalo de representación eje U'x

PRIVATE hap2 AS Float

PROPERTY colorejes AS Float 'es el color en van a dibujarse los ejes

PRIVATE hcolorejes AS Float

PRIVATE FUNCTION C_Read() AS Float

RETURN hC

END

PRIVATE SUB C_Write(Value AS Float)

hC = value

END

PRIVATE FUNCTION B_Read() AS Float

RETURN hB

END

PRIVATE SUB B_Write(Value AS Float)

hb = value

END

PRIVATE FUNCTION ap1_Read() AS Float

RETURN hap1

END

PRIVATE SUB ap1_Write(Value AS Float)

hap1 = value

END

PRIVATE FUNCTION ap2_Read() AS Float

RETURN hap2

END

PRIVATE SUB ap2_Write(Value AS Float)

hap2 = value

END

PRIVATE FUNCTION colorejes_Read() AS Float

RETURN hcolorejes

END

PRIVATE SUB colorejes_Write(Value AS Float)

hcolorejes = value

END

'ZONA 4 Definirmos las subrutinas y funciones que podran ser p úblicas o privadas.

PUBLIC FUNCTION pasarUpxaUx(upx AS Float) AS Float

DIM conversion AS Float

DIM xdist AS Float

DIM escalado AS Float

xdist = ME.Width

escalado = xdist / (ME.ap2 - ME.ap1)

TRY conversion = ME.c + (upx) * escalado * 0.95

IF ERROR THEN

Message(("Se ha producido un error al convertir la coordenadas, seguramente no estan definidos los intervalos"))

RETURN 0

ELSE

RETURN conversion

ENDIF

END

PUBLIC FUNCTION pasarUpyaUy(upy AS Float) AS Float

DIM conversion AS Float

DIM xdist AS Float

DIM escalado AS Float

xdist = ME.Width

escalado = xdist / (ME.ap2 - ME.ap1)

TRY conversion = ME.B - (Upy) * escalado * 0.95

IF ERROR THEN

Message(("Se ha producido un error al convertir la coordenadas, ancho de la zona de dibujo erroneo"))

RETURN 0

ELSE

RETURN conversion

ENDIF

END

'-------------------------------------------------------------------------

' psar de ux a upx

'-------------------------------------------------------------------------

PUBLIC FUNCTION pasarUxaUpx(ux AS Float) AS Float

DIM conversion AS Float

DIM xdist AS Float

DIM escalado AS Float

xdist = ME.Width

escalado = xdist / (ME.ap2 - ME.ap1)

TRY conversion = (ux - ME.c) / escalado * 0.95

IF ERROR THEN

Message(("Se ha producido un error al convertir la coordenadas, ancho de la zona de dibujo erroneo"))

RETURN 0

ELSE

RETURN conversion

ENDIF

END

PUBLIC FUNCTION pasarUyaUpy(uy AS Float) AS Float

DIM conversion AS Float

DIM xdist AS Float

DIM escalado AS Float

xdist = ME.Width

escalado = xdist / (ME.ap2 - ME.ap1)

TRY conversion = (- uy + ME.b) / (escalado * 0.95)

IF ERROR THEN

Message(("Se ha producido un error al convertir la coordenadas, ancho de la zona de dibujo erroneo"))

RETURN 0

ELSE

RETURN conversion

ENDIF

END

PUBLIC SUB dibujarejeup()

DIM font0inicial AS String

DIM font1final AS String

' Para escribir de menor tamaño el ap1 y ap2

font0inicial = "<font size=" & Chr$(34) & "2" & Chr$(34) & "> "

font1final = "</font>"

Draw.Begin(ME)

Draw.ForeColor = ME.colorejes

Draw.Line(0, ME.pasarUpyaUy(0), ME.Width, ME.pasarUpyaUy(0))

Draw.Line(ME.pasarupxaux(0), 0, ME.pasarUpxaUx(0), ME.Height)

'escribo ap1 y ap2 eje y

Draw.ForeColor = Color.blue

Draw.RichText(font0inicial & Format$(ME.ap2, "0.00") & font1final, ME.pasarupxaux(0) + 5, ME.pasarupyauy(ME.ap2))

Draw.Line(ME.pasarupxaux(0) + 10, ME.pasarUpyaUy(ME.ap2), ME.pasarupxaux(0) - 10, ME.pasarUpyaUy(ME.ap2))

Draw.RichText(font0inicial & Format$(ME.ap1, "0.00") & font1final, ME.pasarupxaux(0) + 5, ME.pasarupyauy(ME.ap1) - 25)

Draw.Line(ME.pasarupxaux(0) + 10, ME.pasarUpyaUy(ME.ap1), ME.pasarupxaux(0) - 10, ME.pasarUpyaUy(ME.ap1))

'escribo ap1 y ap2 eje x

Draw.RichText(font0inicial & Format$(ME.ap1, "0.00") & font1final, ME.pasarupxaux(ME.ap1), ME.pasarupyauy(0) + 5)

Draw.Line(ME.pasarupxaux(ME.ap1), ME.pasarUpyaUy(0) + 10, ME.pasarupxaux(ME.ap1), ME.pasarUpyaUy(0) - 10)

Draw.RichText(font0inicial & Format$(ME.ap2, "0.00") & font1final, ME.pasarupxaux(ME.ap2) - 25, ME.pasarupyauy(0) + 5)

Draw.Line(ME.pasarupxaux(ME.ap2), ME.pasarUpyaUy(0) + 10, ME.pasarupxaux(ME.ap2), ME.pasarUpyaUy(0) - 10)

Draw.End

END