The blog entry from Victor Laszlo Moholy was written a few years ago,
and the system has changed since then. In particular, we're now case-
sensitive. There's a property unstretchedheight, not
unstretchedHeight. I'm surprised that "${unstretchedHeight}" works at
all.
Scaling the image proportionally can get a bit tricky. The
naturalimgview class in LZPIX has code to do this onload; this code
might help with your problem. From http://labs.openlaszlo.org/lzpix-
source/
<!-- naturalimg view is an image view with a one-pixel frame that
sizes
itself within its parent, preserving aspect ratio -->
<class name="naturalimgview" bgcolor="0x5b5b5b" opacity="0">
<attribute name="fadein" value="500"/>
<animator name="anm_opacity" attribute="opacity" to="1"
duration="$once{parent.fadein}"/>
<view name="interior" x="1" y="1" width="${this.parent.width
- 2}" height="${this.parent.height - 2}" stretches="both"/>
<method event="onload" reference="interior">
this.setDimensions();
this.setVisible( true );
this.anm_opacity.doStart();
</method>
<method name="setDimensions">
//Debug.write(this.name, "setDimensions");
var i = this.interior;
if (i['resourceheight'] == null) { return; }
var rh = i.resourceheight;
var rw = i.resourcewidth;
if (rw == 0) { return; }
var rar = rh / rw;
var h = this.parent.height;
var w = this.parent.width;
if (w == 0) { return; }
var par = h / w;
if (par < rar) {
this.setHeight(h);
this.setWidth( Math.round(h / rar) );
} else if (par > rar) {
this.setHeight( Math.round(w * rar) );
this.setWidth(w);
} else {
this.setHeight(h);
this.setWidth(w);
}
</method>
</class>
On Apr 12, 2006, at 11:58 AM, Mike Pence wrote:
> Here is what I need to do: I need to load some large images, then
> scale them down, proportionally, to fit within a part of the screen.
> This seems like awfully common need, so I am surprised that the answer
> is so difficult to find. Maybe I am just not looking in the right
> places.
>
> Here is what I have done: I went to this excellent site
> (http://secretartofscience.com/blog/?p=6) and tried the example that
> uses the aspect ratio property. No dice. I am on Laszlo 3.2. Here is
> as simple as I can make it:
>
> <canvas bgcolor="black" width="800" >
> <view name="demoview" clip="true" resource="2.jpg"
> height="${unstretchedHeight}"
> width="${unstretchedWidth}"
> >
> </view>
> </canvas>
>
> That works, of course. But as soon as I try to do any kind of math
> with those values, say:
>
> ${unstretchedHeight * 0.2}
>
> No image shows up. What am I missing?
>
> Best,
> Mike Pence
>
> _______________________________________________
> Laszlo-user mailing list
> [email protected]
> http://www.openlaszlo.org/mailman/listinfo/laszlo-user
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