[Newbies] OrderedCollection if imageMorphs

[Christine Wolfe]

That worked!!!  Thanks - I never would have figure it out on my own.

 

I'm so confused though.  I've never had to explicitly call an initialize
method before - they seem to be invoked automatically when I use the word
"new".  Should I always call the initialize when I create a new instance?

 

@Herbert - I'm making a pinball machine in which the little ball follows the
order of execution of a student entered flowchart.at least that's what I'm
trying to do ;-)

 

From: beginners-bounces at lists.squeakfoundation.org
[mailto:beginners-bounces at lists.squeakfoundation.org] On Behalf Of Alex
Schenkman
Sent: Sunday, November 08, 2009 3:59 AM
To: A friendly place to get answers to even the most basic questions about
Squeak.
Subject: Re: [Newbies] OrderedCollection if imageMorphs

 

I think you might need to call SymbolArray>>intialize by your self.

 

If you look at the chain of message sends starting from 'SymbolArray new'

1) OrderedCollection new

2) OrderedCollection new:

3) Behavior basicNew

 

There is no call to initialize.

 

On Sat, Nov 7, 2009 at 16:28, Christine Wolfe <cwdw01 at earthlink.net> wrote:

I want to put add an imageMorph on top of another imageMorph.

 

I can do this with the following method (note SymbolBlank is an imageMorph

MyBoard>>addSymbol

|im|

im := SymbolBlank new.

self addMorph: im.

im topLeft: 2 at 2.

 

I want to enhance this so I can choose one of a collection of imageMorphs to
add.

 

I created a class, SymbolArray, that is a subclass of OrderedCollection with
the following initialize method. Each of the items I'm adding (SymbolBlank,
SymbolGet, etc) is an imageMorph.

 

SymbolArray>>initialize

super initialize.

self add: SymbolBlank new.

self add: SymbolGet new.

self add: SymbolProcess new.

self add: SymbolPut new.

self add: SymbolIf new.

self add: SymbolWhile new.

 

Then I tried to modify the addSymbol method as show below.

When I do, I get the following error message which sounds like I don't have
an element at index 1.

SymbolArray(OrderedCollection)>>errorNoSuchElement

SymbolArray(OrderedCollection)>>at:

 

| sa si |

sa := SymbolArray new.

si := sa at: 1.

self addMorph: si.

si topLeft:  2 at 2.

 

I hope someone can help me figure out how to accomplish what I want to do.

 


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