Hi Nacho, 2015-02-06 22:32 GMT+01:00 nacho <0800nacho@gmail.com>:
Hi, I've been digging and inspecting all the classes related to Morphic. But there's something that I don't happen to figure out. Morph has a method drawOn: aCanvas aCanvas fillRectangle: self bounds fillStyle: self fillStyle borderStyle: self borderStyle
Which if it's not overridden by a subclass of Morph makes it possible to still instantiate a Morph -the classic blue rectangle.
Now aCanvas is obviously an instance of FormCanvas or some other subclasses of Canvas. But the question is, where does Morph create such instance of FormCanvas?
The Morph does not care where this Canvas come from * The WorldMorph (a PasteUpMorph) has a "WorldState" instance variable and this world state controlls the update cycle. During this update it creates THE canvas from the DisplayScreen (this is now a FormCanvas for the DisplayScreen(Form)). Now it calls drawOn:canvas for all Morph(and submorphs) of the WorldMorph. (With some more or less complex computations for clipping resp. updating only the changed areas).
How does this work? I'm getting all wrong?
look at: WorldMorph>>#displayWorld WorldState>>#displayWorld:submorphs:
I read the documentation available but I can't grasp it from what I have read.
* you can create your own Form and Canvas instance and call drawOn: for a Morph with that canvas: |f canvas | f:=Form extent:300@300 depth:32. canvas := f getCanvas. EllipseMorph new extent:300@300;drawOn:canvas. f display
Thanks in advance for your help best Nacho
----- Nacho Smalltalker apprentice. Buenos Aires, Argentina. -- View this message in context: http://forum.world.st/Relationship-between-Morph-and-Canvas-tp4804251.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.