Beginners November 2012

beginners@lists.squeakfoundation.org

5 participants
5 discussions

Constrained Morph dragging
by Sebastian Nozzi 21 Nov '12

21 Nov '12

Hello Morphic experts, I am learning / experimenting with Morphic and have the following question: "How do I constrain the movement of a dragged Morph?" As illustrated here: http://jqueryui.com/draggable/#constrain-movement (e.g. constrain within axis/container) So far the "hack" I came up with was to aggresively re-position the dragged Morph in its "drawOn:", if it is attached to a HandMorph: drawOn: aCanvas self owner isHandMorph "is there a better way to ask: am I being dragged?" ifTrue: [ self position: (self position x) @ 400 ]. super drawOn: aCanvas. I am sure this solution is pretty bad... I also get visual artifacts when I move the mouse up/down. Are there better ways/hooks for this? Generally: is there a method that is called on submorphs whenever the parent Morph was re-positioned/re-sized? Thanks in advance! Sebastian

2 2

Re: Bag is missing items
by Joseph J Alotta 20 Nov '12

20 Nov '12

Sorry to bother you, I figured it out. Bag is not the problem. The inspector just shows the first 100 items and the last 10. I used "explore" and it showed all the missing items. Thank you, sincerely, Joe.

2 1

Bag is missing items
by Joseph J Alotta 20 Nov '12

20 Nov '12

Greetings, I have a problem with Bag. When I put stuff in it, they disappear. companies is a dictionary with 454 items. When I sort it, I first use #values to convert it to a Bag. Attached is a screen shot. See how it goes from 100 to 445. Now it is missing items? Sincerely, Joe. | bag sorted | bag := companies values. sorted := bag asSortedCollection: [ :x :y | (x at: 'points') < (y at: 'points')]. sorted inspect.

1 0

roundTo: doesn't appear to work
by Joseph J Alotta 20 Nov '12

20 Nov '12

n := 2.12435454313 n roundTo: 3. ==> 3 2 roundTo: n ==> 2.12435454313 Am I doing something wrong?

2 1

Acquiring lock, releasing in callback
by Sebastian Nozzi 02 Nov '12

02 Nov '12

Hello Dear Squeakers, threads and co. are giving me headaches :-) I wanted to ask for advice... What do I use in Squeak to prevent more than one thread entering a region, but "releasing" the exclusivity in another block/callback? For example, let's suppose there is an hypothetical class "Lock" that does that. lock acquire. longOperation performWhenFinished: [ callback code ... lock release ]. ... rest of the program ... Is there something like that? Or do I have to simulate it with something else? (Semaphore?) I am aware or Monitor/Mutex critical:, but I am not sure I can use it in my case. Thanks in advance, Sebastian

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Beginners November 2012