Hi,

This is a corner case that is not considered in Spec design: In fact what you are doing is changing the content of the model and you need the presenter to react to it.

Indeed, as Stef says the solution is to re-set the image to the image presenter when performing the change:

You may think something like that should be done in the `updatePresenter` message (but updatePresenter does not has a mean in "widget" presenters).... or like the `refresh` message for lists/tables, and you would be right (I will add a refresh message to SpImagePresenter). But at the end, it will end up doing exactly that, so you are safe workaround it the thing :)

Esteban

Hi Mikael

I do not know the answer so I tried to find it.��

Indeed the superclass>>updatePresenter is empty :(

Let us see what esteban will reply.��

Now I tried to check the morphic back end.��

Now writing directly on the canvas this way does not look the right way.��

Did you try with��

SpMorphPresenter

or��

SpRoassalPresenter because you have access to the cairo canvas.��

While browsing the code of the SpMorphicROassalAdapter I saw

widget sessionChanged.

SpAbstractMorphicAdapter I saw changed.

changed

^ self widgetDo: [ :w | w changed ]

I also saw in SpAbstractAdapter isRedrawable so I wonder if it should not be true on the Adapter corresponding to the SpImagePresenter (if any)

BTW the SpMorphicAthensAdapter defines a method redraw (Athens is the cairo wrapper used also in Roassal)

Reading the code of SpMorphicImageAdapter >> buildWidget

| alphaImage |

alphaImage := AlphaImageMorph new.

alphaImage model: self.

alphaImage

getImageSelector: #getImage;

vResizing: #spaceFill;

hResizing: #spaceFill;

layout: self layoutValue;

dragEnabled: self dragEnabled;

dropEnabled: self dropEnabled;

setBalloonText: self help;

update: #getImage.

self model

whenImageChangeDo: [

alphaImage image:

(self getImage ifNil: [ Form extent: 1 @ 1 depth: 32 ]) ];

whenAutoScaleChangeDo: [ widget layout: self layoutValue ].

^ alphaImage

It feels like we should reassign the image:

Did you try something like��

updatePresenter��

��

�� self image: self image?

On 7 Mar 2025, at 18:11, Mikael Svane <mikael.svane@fridhem.org> wrote:

I have a Form where I change pixel colours using Form>>pixelValueAt:put:. The Form exists inside an SpImagePresenter. After having changed the pixels, I want to redraw the Form in an #updatePresenters method to show the changes, but I haven��t been able to figure out how to do this. If I inspect the Form it is clear that the pixels have been changed, so the problem is in the #updatePresenters mwthod. I have tried different variations on this theme without success:

��

updatePresenter��

�� | canvas |

�� Get the canvas of the Form:��

�� canvas := imagePresenter image form getCanvas.

��

�� adapter widget drawSubmorphsOn: canvas

��

Any suggestions would be very welcome.

��

Kind regards,

Mikael