- From: Rik Cabanier <cabanier@gmail.com>
- Date: Wed, 27 Nov 2013 13:55:03 -0800
- To: Michael Mullany <michael@sencha.com>
- Cc: Dean Jackson <dino@apple.com>, "public-fx@w3.org" <public-fx@w3.org>, www-style list <www-style@w3.org>, Stefan Craciun <scraciun@adobe.com>
- Message-ID: <CAGN7qDA+uyOJtioXi55gDEpTC4r-swv5HMBprmPemXBO1q_WOQ@mail.gmail.com>
On Wed, Nov 27, 2013 at 10:50 AM, Michael Mullany <michael@sencha.com>wrote: > > > > On Fri, Nov 22, 2013 at 3:05 PM, Rik Cabanier <cabanier@gmail.com> wrote: > >> >> >> >> On Thu, Sep 19, 2013 at 10:08 AM, Dean Jackson <dino@apple.com> wrote: >> >>> >>> On 18 Sep 2013, at 1:05 pm, Dirk Schulze <dschulze@adobe.com> wrote: >>> >>> >>> > I suggest adding a new keyword 'backdrop' as CSS Image. This can be >>> filtered with the CSS Image filter()[3] function and blended with >>> background colors or background images and the 'background-blend-mode' >>> property. This would produce results where the backdrop directly behind the >>> element would always be blurry, but around the element it isn't. This looks >>> even nicer on scrolling and other interactions. >>> >>> I think I suggested a separate property: background-filter (I can’t >>> remember if I emailed this, or spoke up at a meeting, or just thought of it >>> in the shower). >>> >>> The reason is that I think in most cases you want to draw normally and >>> just apply the effect to the background. There is no need to consider the >>> content of the element to be filtered for this effect. However, the name is >>> a bit misleading because, as you know, it is not filtering the element’s >>> background (in CSS terms), but its backdrop. >>> >> > I think it's sort of weird that you've removed enable-background from the > SVG portion Filters because it was hard to implement (although IE does a > perfectly serviceable job of implementing BackgroundImage per SVG 1.1 > spec.), but now you're proposing to add it again but in a way that means it > can't participate in an SVG filter chain, but perhaps I misunderstand the > proposal. > The intent was always to reintroduce it, but using the 'isolation' property [1] instead of the more confusing 'enable-background' property. I'm unsure why you think that it can't participate in the filter chain. Can you explain? > I've been seeing this effect use more lately. Designers have to create >> it manually or emulate it with CSS filters and careful overlapping of >> elements. Maybe it's time to make it a simple CSS property like you propose. >> >> All cases I've seen so far, apply the background blur over a rectangular >> region. Earlier in the thread, I suggested that the effect should only >> apply to the shape/coverage area but maybe that makes it too hard to >> implement. >> > > Speaking for Sencha and the types of apps that our community creates, we > want to be able to duplicate the blend/blur styles introduced by iOS7. > Which means that a simple blur is not enough - we need finer control of the > blur opacity/falloff. I did an example of this using SVG filters and > feImage (no BackgroundImage's were harmed in the making of this demo) It > uses a feFuncA to tweak the standard Blur behavior. > > http://codepen.io/mullany/pen/diolI > I agree that just blurring is not enough. Ideally, we would define a syntax that does something reasonable by default but that you can tweak. For instance, some examples use screen or soft light blending of the backdrop and a color (typically white). We should also say that the blur area is determined by the background-clip for now [2] and is drawn before background color and images. 1: http://dev.w3.org/fxtf/compositing-1/#isolation <http://dev.w3.org/fxtf/compositing-1/#isolation> 2: http://www.w3.org/TR/css3-background/#background-clip
Received on Wednesday, 27 November 2013 21:55:35 UTC