Getting notified when a morph moves

I'm trying to keep a line morph connected between two morphs
while moving one of them.
When I add the morph to the hand and start dragging the morph
no longer receives mouseMove:. I can think of several ways to get  
position updates. Is there a best/easy way?

Stephan

Le 11/02/2015 21:19, Stephan Eggermont a écrit :
> I'm trying to keep a line morph connected between two morphs
> while moving one of them.
> When I add the morph to the hand and start dragging the morph
> no longer receives mouseMove:. I can think of several ways to get  
> position updates. Is there a best/easy way?
>
> Stephan
>
>
I tried something like bellow but it did not produced any output in the
transcript.
Only "b doAnnounce: MorphChanged" produce an output in the Transcript.
Not sure how to get an anonymous morph to announce changes.

| b |
b := BorderedMorph new color: Color red.
b onAnnouncement: MorphChanged do: [ Transcript show: 'Changed' ].
b openInWorld


--
Dr. Geo - http://drgeo.eu
iStoa - http://istoa.drgeo.eu

Hi,

Here is an implementation example.
From a workspace, do:

| morphA morphB follower |
morphA := Morph new position: 10@10.
morphB := Morph new position: 100@100.
follower := FollowerLineMoprh from: morphA to: morphB.
morphA openInWorld.
morphB openInWorld.
follower openInWorld.


Frankly I don't like the idea to subscribe to the HandMorph, because at
each mouse move event, you have to check for the morph A and B if they
move. It is a waste of CPU cycles.
Ideally you will want receive event from morph A and B whenever they
changed. I am surious to know if it is possible.

Thanks

Hilaire

Le 11/02/2015 21:19, Stephan Eggermont a écrit :
> I'm trying to keep a line morph connected between two morphs
> while moving one of them.
> When I add the morph to the hand and start dragging the morph
> no longer receives mouseMove:. I can think of several ways to get  
> position updates. Is there a best/easy way?
>
> Stephan
>
>


--
Dr. Geo - http://drgeo.eu
iStoa - http://istoa.drgeo.eu

On 12/02/15 10:20, Hilaire wrote:
> Frankly I don't like the idea to subscribe to the HandMorph, because at
> each mouse move event, you have to check for the morph A and B if they
> move. It is a waste of CPU cycles.
> Ideally you will want receive event from morph A and B whenever they
> changed. I am surious to know if it is possible.

Thanks Hilaire,

This works for me. I can attach the listener when the dragging starts,
and detach it when it stops. That should do.

Stephan

Thanks Hilaire,

that works fine. I can add the listener when the actual dragging starts and remove it
on mouseUp.

MDShape>>doDrag: aMouseMoveEvent with: aMDShape
        ActiveHand addEventListener: self.
        aMouseMoveEvent hand startDrag: aMouseMoveEvent with: aMDShape.

MDShape>>handleListenEvent: anEvent
        anEvent isMouse ifFalse: [ ^self].
        anEvent isMouseUp ifTrue: [ ActiveHand removeEventListener: self ].
        anEvent isMouseMove ifTrue: [ self moved ]

MDShape>>moved
        connectors do: [ :connector | connector moved ]

Stephan

Le 12/02/2015 11:04, Stephan Eggermont a écrit :
>
> This works for me. I can attach the listener when the dragging starts,
> and detach it when it stops. That should do.

Okay if I understand correctly, the two morphs you want to link with a
line are also morphs of yours? So you can mangle into them. I was
supposing the two morphs to link could be arbitrary ones, i.e. ones you
can't modify.


--
Dr. Geo - http://drgeo.eu
iStoa - http://istoa.drgeo.eu

Hilaire wrote:
>Okay if I understand correctly, the two morphs you want to link with a
>line are also morphs of yours? So you can mangle into them. I was
>supposing the two morphs to link could be arbitrary ones, i.e. ones you
>can't modify.

I am trying to get a better understanding of Morphic by writing a
small drawing editor suitable for a tutorial.

current state:
http://smalltalkhub.com/#!/~StephanEggermont/MorphicDraw/

Stephan

Le 12/02/2015 17:12, Stephan Eggermont a écrit :
Nice :)
You may find some useful information in the collaboractive book in the
Morph chapter
http://pharo.gemtalksystems.com

Hilarie

--
Dr. Geo - http://drgeo.eu
iStoa - http://istoa.drgeo.eu