Opacity in Konqueror 3.5.1?

[Twey]

Whatever I set .style.opacity to in Konqueror 3.5.1, it displays the element at full opacity, and trying to get .style.opacity always returns 0.
Is this a Konqueror bug? Does it apply to Safari as well? Is there a way around it?

[jscheuer1]

I thought Konq used -KHTML-opacity. Somebody must. Safari (at least according to folks who use it that I have helped with the Ultimate Fade script) does respond to generic opacity, much in the same way (if not identically) as FF now does.

Back to Konq. Generally, if you set a property/value pair in a browser that doesn't support it, you can get any sort of return value when you query it later.

[mwinter]

Originally Posted by Twey

Whatever I set .style.opacity to in Konqueror 3.5.1, it displays the element at full opacity, and trying to get .style.opacity always returns 0.

According to (slightly outdated) Konqueror documentation, the opacity property isn't supported.

Does it apply to Safari as well? Is there a way around it?

Safari apparently does support opacity, though I can't confirm that. You might find better support by also using the -khtml-opacity property.

Originally Posted by jscheuer1

I thought Konq used -KHTML-opacity. Somebody must.

Don't forget that Safari is based on the KHTML engine.

Mike

[jscheuer1]

Originally Posted by mwinter

Don't forget that Safari is based on the KHTML engine.

I'm not forgetting that and, in fact earlier version may require -khtml-opacity, something I should have mentioned. But real world, recent versions don't, but do support generic opacity, at least as relayed to me in tests and other work I've done in concert with Safari users.

[Twey]

Originally Posted by Mike

According to (slightly outdated) Konqueror documentation, the opacity property isn't supported.

Slightly outdated? That documentation is from 3.4; there've been some very major changes since then. 3.5.1, at least, uses W3C opacity instead; in fact, -khtml-opacity is no longer recognised (element.style.KhtmlOpacity is undefined, but element.style.opacity isn't).

[jscheuer1]

Originally Posted by Twey

Slightly outdated? That documentation is from 3.4; there've been some very major changes since then. 3.5.1, at least, uses W3C opacity instead; in fact, -khtml-opacity is no longer recognised (element.style.KhtmlOpacity is undefined, but element.style.opacity isn't).

Is that with or without having previously defined these via script and/or style?

[mwinter]

Originally Posted by Twey

3.5.1, at least, uses W3C opacity instead

Your first post seemed to suggest otherwise, but a second reading shows a typo that I didn't notice before. You state that you set the opacity property to something, but you don't say what.

I must have subconsciously glossed over that mistake: I read that assigning any value always makes the element opaque, but reading the value returns zero.

Mike

[Twey]

Originally Posted by Mike

You state that you set the opacity property to something, but you don't say what.

I said "anything"
Examples (consecutively executed, on a document with images):

window.alert(typeof document.images[0].style.opacity); // string
window.alert(document.images[0].style.opacity); // empty string
window.alert(typeof document.images[0].style.KhtmlOpacity); // undefined
window.alert(document.images[0].style.opacity = 0.5); // 0.5, but image remains totally opaque
window.alert(document.images[0].style.opacity); // 0

[mwinter]

Originally Posted by Twey

I said "anything"

I know. I read the post again as the thread was loading. So, I was right the first time.

I noticed a long time ago that Konqueror implements the getComputedStyle method of the defaultView property of the document object. However, calling that method always returns null, irrespective of the arguments passed to it. Safari, on the other hand, omits the method altogether.

This may be a pattern that the Konqueror developers have decided to implement. To provide all of the properties of a particular interface, regardless of whether they're actually functional. I can't think of any other rational explanation, though if that is the approach they've decided to take, it's a rather stupid one.

Out of curiosity, can you alter the opacity of any element using any method (CSS rules or the DOM) in the latest Konqueror? If not, then it would seem that the 3.4 documentation isn't that out-of-date at all.

window.alert(typeof document.images[0].style.KhtmlOpacity); // undefined

Finally, are you sure that's the correct capitalisation for the property? Does

alert(typeof document.images[0].style.getPropertyValue('-khtml-opacity'));

display 'undefined' as well? Just a thought...

Mike

[Twey]

It returns a string. However, so does

window.alert(typeof document.images[0].style.getPropertyValue("Mr. Fish"));

... so I'm not going to put much store by that.

Originally Posted by Mike

can you alter the opacity of any element using any method (CSS rules or the DOM) in the latest Konqueror?

Yes, including <script> elements.