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Unconvinient refresh in image presenter

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Sebastián Sastre

Unconvinient refresh in image presenter

Hi,

I'm using a image presenter and I find Gdiplus particularly
interesting because of the uality of the interpolation.

It happens to me, using #viewMode: #scaleToFit, that when I maximize
and then restore the window, when the image is wider than taller, the
parts without image (those boxes on the window that are not a
proportional part of the box of the resized image) are maintaining the
parts of the previous maximized image.

I can manually send to the presenter #hide and the #show to solve
that, but I was unable to find a way to put those messages in a
convinient place.

thanks for any help,

Sebsatian

Chris Uppal-3

Re: Unconvinient refresh in image presenter

Sebastián,

> It happens to me, using #viewMode: #scaleToFit, that when I maximize
> and then restore the window, when the image is wider than taller, the
> parts without image (those boxes on the window that are not a
> proportional part of the box of the resized image) are maintaining the
> parts of the previous maximized image.

That seems to be a bug somewhere in D6.

In D5, you can avoid that behaviour by setting the view's #isEraseBackground to
true, /and/ the #backcolor to something non-nil So the following works OK in
D5.

f := 'C:\someFile.jpg'.
i := GdiplusImage fromFile: f.
p := ImagePresenter show: 'Gdiplus view' on: i.
(p view)
backcolor: (Color yellow fadedBy: 4);
isEraseBackground: true;
viewMode: #scaleBestFit;
invalidate.

The view erases itself as you change the size or maximise it.

But that doesn't work under D6. I don't know why, but one hint is that the
view doesn't seem to have passed its background color to the underlying
control.

-- chris

Sebastián Sastre

Re: Unconvinient refresh in image presenter

As you said, it does not work for me in D6. It seems to behave
correctly when reducing size but not for increasing it.

I opted for a less elegant solution putting this loose method:

GdiplusImageView>>onPositionChanged: aPositionEvent
"Private - Handle a window position change event (move or
resize)."

aPositionEvent isResize ifTrue:[self hide; show].

^super onPositionChanged: aPositionEvent

cheers,

Sebastian

Chris Uppal escreveu:

> Sebastián,
>
> > It happens to me, using #viewMode: #scaleToFit, that when I maximize
> > and then restore the window, when the image is wider than taller, the
> > parts without image (those boxes on the window that are not a
> > proportional part of the box of the resized image) are maintaining the
> > parts of the previous maximized image.
>
> That seems to be a bug somewhere in D6.
>
> In D5, you can avoid that behaviour by setting the view's #isEraseBackground to
> true, /and/ the #backcolor to something non-nil So the following works OK in
> D5.
>
> f := 'C:\someFile.jpg'.
> i := GdiplusImage fromFile: f.
> p := ImagePresenter show: 'Gdiplus view' on: i.
> (p view)
> backcolor: (Color yellow fadedBy: 4);
> isEraseBackground: true;
> viewMode: #scaleBestFit;
> invalidate.
>
> The view erases itself as you change the size or maximise it.
>
> But that doesn't work under D6. I don't know why, but one hint is that the
> view doesn't seem to have passed its background color to the underlying
> control.
>
> -- chris

Blair

Re: Unconvinient refresh in image presenter

In reply to this post by Chris Uppal-3

"Chris Uppal" <[hidden email]> wrote in message
news:44a9120e$0$778$[hidden email]...
> Sebastián,
>
>> It happens to me, using #viewMode: #scaleToFit, that when I maximize
>> and then restore the window, when the image is wider than taller, the
>> parts without image (those boxes on the window that are not a
>> proportional part of the box of the resized image) are maintaining the
>> parts of the previous maximized image.
>
> That seems to be a bug somewhere in D6.

Yes, in GdiplusImageView. The way that control backgrounds are erased was
changed and this was not reflected into GdiplusImageView. You can fix this
by copying down the View>>onEraseRequired: method, although it will now
ignore the isEraseBackground flag.

For the forthcoming release we have rationalised things so that ImageView
and GdiplusImageView sit under a common abstract superclass.

Regards

Blair