Hi Nacho, The red box with two crossing yellow lines indicates that you made a mistake in the drawOn: method. Whenever that happens, here is a tip that might help you. If you can't easily spot your error, you can debug it by evaluating:
aBall drawOn: Display getCanvas. This will bring up the debugger and hopefully give you more information. Best regards, Richo On Wed, Feb 4, 2015 at 3:00 PM, nacho <0800na...@gmail.com> wrote: > Hi, > I have the following question: > I want to draw a bouncing ball. > First thing I do is create a class: > > EllipseMorph subclass: #Ball > instanceVariableNames: 'position' > classVariableNames: '' > category: 'PBE-BouncingBall' > > > Then an initialization method that mostly do a super initialize. > Then the drawOn: > > drawOn: aCanvas > aCanvas borderWidth:10; borderColor: Color green. > > > And finally a position method: > > position: aPoint > super position: aPoint. > > position > ^ position. > > > Finally in a Playground I do: > > | aBall | > > aBall := Ball new. > aBall position: ( 10@10 ). > aBall openInWorld. > > But I get a red box with two crossing yellow lines. > What I'm missing? > > Thanks in advance. > Nacho > > > > > ----- > Nacho > Smalltalker apprentice. > Buenos Aires, Argentina. > -- > View this message in context: > http://forum.world.st/Question-on-Morphic-drawOn-method-tp4803695.html > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. > >
