I'm trying to create a game that uses buttons (and text areas) that are semi-transparent (Alpha of about 60%). I can do almost everything I want in XHTML and CSS, except for these semi-transparent items. So I'm looking for the easiest way of creating semi-transparent images on my web pages.
Ideas so far:
Create PNGs with semi-transparent pixels. This is supposed to be possible, and there are well-defined interfaces for defining an Alpha channel using PHP and the GD package. Problem: I tried this, but the images were opaque in all the browsers I tried (Chrome, IE8, FF).
Do it in Flash. I know how to use Flash(*) from some work I did before I retired. Problem: Flash is priced for the professional developer, not the hobbyist.
(*) Well, Flash 8. But as I understand it, even with newer versions I can continue to create movie clips the old way, they just get translated into a bunch of AS. And it's supposedly possible to continue using AS2, although you can't mix AS2 and AS3.
Do it in Flex. Problem: interfaces best described as arcane. Even using suggestions from experienced Flex developers, trying to include code from another mxml file (other than as a class) was a PITA.
Use SVG. This looked promising. The SVG syntax is basically XML, the element tags are reasonably obvious, and the interaction of attributes only slightly arcane, and there are plenty of examples in the tutorial. But... about half of current browsers will not support using SVG in an <img> tag. You have to use <embed> That means you can't put it inside an <a> or <button>. Even using embed, I got what look like "broken image" icons in IE8.
As I'm writing this, I notice several items under "similar questions" that look promising. But when I look at them, they use attributes that are not mentioned in the CSS spec: opacity, filter:alpha, and rgba. When working in a complex language, I really prefer to have the complete language spec open in another window, or to have the equivalent dead-trees version (e.g., the O'Reilly salmon book Cascading Style Sheets, The Definitive Guide, which sits on a bookshelf next to my desk.
So I'm asking for recommendations. If the consensus is to use SVG, I'll post my code and see if people can tell me what I'm doing wrong.
The CSS "opacity" property is perfectly valid. It is part of CSS3, and is supported in all browsers (*).
http://caniuse.com/css-opacity
Or you can use semi-transparent PNGs, as Alvaro demonstrated. They should work just fine. Not sure what happened with your attempts, but you must have done something wrong.
Note for versions of IE <= 8, you need to use the "filter" property instead.
https://developer.mozilla.org/en-US/docs/Web/CSS/opacity
I don't know what problem you have with PNG's. Imo the best and easiest option by far. And they look as they should in all browsers from my own experience.
check this out: http://jsfiddle.net/BDLYG/
(and here a code I need to add)
If you have most users with the 'modern' browsers, I would say go with SVG. If you do, post here, and I'll be glad to help.
Many thanks for all the useful answers. I'm currently using a combination of CSS and PNGs (generated via PHP). I could have gotten along with just CSS, but I decided I wanted to change the opacity of the background when the user hovers over the button -- but keep the text opaque. It's easy to change the opacity of the whole thing, but (as far as I can tell) not of just the background.
I also experimented with SVG, and it also works fine, but it requires extra computation so I chose the simpler (for me) approach of CSS and PHP. I'm already comfortable with those two languages, just needed to be introduced to the newer stuff in CSS3 and the one extra function call needed to make alpha work in PNGs generated by the PHP GD package.
Related
I have to create a pretty complex map which is divided in pieces, which themselves are each pretty complex polygonal structures. These are given to me as transparent PNGs. Obviously i can't just use the rectangular PNG itself to define each mouse-sensitive area.
First and last thing that came to my mind was using Image-Maps.
But before i go down that road, i wanted to ask whether anyone could think of a more modern solution to this?
Browser support requirements are IE >= 7, FF >= 3, newer Chrome & Opera. So usage of CANVAS might not be an option.
When designing web documents, you should always choose the thing which come closes to expressing your intent, so that your documents are most adaptable to use-cases you didn't think of.
An image map is entirely appropriate for placing links on map images. <canvas> makes your document less interpretable. SVG would be a reasonable choice if it fits your data well, but is less widely implemented than image maps.
SVG would be a good choice, there are plugins to add compatibility for ancient IE versions. There's nothing really wrong with maps, just make sure it's really clear where the links go as the status bar doesn't have the info like a normal link.
IE7 won't do SVG or Canvas (unless you like plugins as Mr. Bradshaw points out), and while VML might work there, it is a quagmire. You could use some javascript to compute point-in-polygon on mousemove. But really, image-maps (either client-side or server-side) will probably be the simplest approach.
I'm looking for a good way to implement reusable buttons in CSS on my forms. The requirements:
- Separate image and text (text is in many languages)
- Rollover effects
- Plays nicely cross browser
- No javascript (if possible)
- Rounded corners
Whats the best way to do this? Years ago I was using the sliding doors technique, but this seems out of date now. Would you use CSS3 with a fallback for older browsers? Any particularly well thought of techniques out there?
Jquery UI buttons are AWESOME. They're fully tested, completely compliant, and really look great. With one line of code, you can have a fully styled button in no time flat. Here's the thing--they can be executed without Jquery (go figure)
First, the tut
So, the standard method is to build an element (a, button, input) with an id and set it as a button in Jquery like this:$('#element').button()
However, if you do it in the manner that the tutorial shows, you just have to add some classes to an element to get a similar effect. So, to make a button out of an a tag, it would just be
Button
In this example, there's no need to set the button with the jQuery button declaration...you're doing it by style only. With the flexibility to style so many different type of elements, it opens up a ton of doors.
You would have to have the Jquery UI css loaded, which offers the added benefit of ThemeRoller, which can style elements on the page with a simple change of a file. It's really a great way to "theme" a site that has to change branding in a hurry, which has made custom themed apps my company puts out extremely profitable.
I would use css sprites for this. You can find out about them here:
http://css-tricks.com/css-sprites/
It is basically a way to make one large image that has all states of buttons(normal, hover, selected). The benefit is it is one http request and you don't see a flicker the first time a hover occurs. If you use this route, the css background property will be the image. You can then use text-align and line-height to center the text that you want to place over the image.
This library, Nifty Corners Cubed uses Javascript but is a fairly clean way to round div tags links, etc. It is tough to find a reusable solution without using a sliding doors derived technique. Otherwise you stuck making none-resuable buttons that have to fit to your size.
You can also take a look at PIE http://css3pie.com/
A sprite is a great option and I do use them from time to time.
Personally I don't mind if my websites aren't identical in all browsers and I go the CSS class route. I keep in mind what is and isn't supported by various browsers and if there is an element that needs to be a certain way I will double check with W3Schools for compatibility.
The main benefit the keeps me using CSS/CSS3 classes is if something changes it is done quickly by text in a single file, if need be I can do a quick change from a 10 year old computer with a dial-up connection (if they still exist) and no imaging software.
Where the advantage of a sprite is they are supported across all browsers and they will look identical (more or less). SpriteMe is a bookmarklet that I have heard of to help with sprites if you decide to go down this path.
I see this as a what do you prefer matter... these questions are what I ask myself when making this type of decision:
How often will it change? Big or small changes? Will it be a complete redesign job if it changes? What do you already know? How much time are you willing to spend learning something that you may not know? What does your gut say for this project?
I hope this can help you.
I'm working on a site that uses images diagonally aligned. The images are fairly simple and have some text inside so I can achieve the effect using either images or the CSS3 transform: rotate and border-radius properties, granted, with all the proprietary extensions.
However I'm wondering if there are significant advantages for using one over the other. I'm thinking maybe the CSS-only alternative would load faster, but a downside would be the use of more code for each image. Although using images I'd still have to do a lot of positioning for each element. Also, the CSS in the first case would not validate using browser-specific extensions, how important is this if I still make sure the site is correctly displayed in most browsers?
Is there a general approach for using either one of these options? What would you recommend?
The use of CSS3, versus images, is best answered by your need to support Internet Explorer (or other older, or CSS3-unaware, browsers): if a large portion of your user-base browses with IE then you should use images.
If you're only interested in the later, more standards-compliant, browsers (possibly including IE9, but I've no experience with it as yet) then CSS 3 is likely the better option, since it might involve a larger CSS file, but it does allow you to switch your layout more easily in future, without having to create/recreate a new set of images for the new design.
You could, of course, combine both approaches: use CSS 3 for the compliant browsers, but include an IE-specific stylesheet, with conditional comments, to supply the images as, perhaps, background-images to build up the design. This is, of course, likely to be a lot of work, though.
I would honestly recommend an image for this. CSS3 is cool, but browsers that don't support it might break your layout. Also (possibly more importantly), text really needs proper anti-aliasing to be readable when rotated or scaled, and you can get finer control over that with an image.
Two things I think you should consider here:
Images are a killer for those on mobile devices. So if you are targeting those with mobile or expect a large mobile audience, you may want to reconsider using a lot of images (and having your users pay a ton in bandwidth).
The text in your images (if you use images) will not be searchable by search engines and will not be accessible for those with accessibility issues, unless you are good at filling in your alt tags. ;-)
I'm trying to create a trapeze like shape using any number of techinques so that it will be as much as possible. the shape i'm trying to create a shape like this:
(there will be content inside the shape [imgs & txt])
so far, the possible ways of doing that are: masking (webkit) and SVG effects on html content (firefox). but I cant seem to find any way to make this work with IE and opera.
So if anyone could show me how to do this, it will be greatly appreciated.
There are a few options for creating non-rectangular shapes using CSS, but they are all hacks. This isn't something that you'd normally expect to do using CSS.
The most well known technique is triangles made using borders. It is very much a hack, and would require using multiple elements for a single shape. I wouldn't suggest using it on a production site.
The other CSS solution I can think of would be to use an extreme border-radius setting to modify the shape of the box. This is less hacky, but won't work in IE8 and lower, so fails your criteria.
You say you've tried the SVG approach and given up on it because it doesn't work in IE8. It's worth pointing out that while IE doesn't support SVG, it does support VML, which is a competing vector graphics format. SVG is now standardised, so VML will fade away, but older IEs will continue to support it.
Therefore the solution I'd go with would be to use SVG by default, and VML instead on IE7/8. The good news is that there are several Javascript solutions which make this easy.
One is Raphael, which allows you to draw SVG/VML images using Javascript. Commonly used for real-time graphs, etc.
There are also a number of solutions which simply convert SVG to VML. For example http://code.google.com/p/svg2vml/. But there are several others available.
Hope that helps.
As you suggest, masking and SVG are the way to go. These will be supported in future browsers. If you must be backwards compatible with IE, look into the IE "filter" for CSS (google "ie filter").
Be forewarned: It's very unintuitive (compared to CSS3) and generally a bitch to work with. If your goal is to make the page look identical to the CSS3 version, it will be difficult and you're probably better off using images.
I've been reading a lot of ways recently of how to avoid having to use Photoshop for things like gradients and shadows on buttons, when you can use CSS3 Box Shadow for such features. Now this is great, but obviously legacy browsers and most IE browsers don't yet implement CSS3 features, so my question is, why save yourself extra work in Photoshop when you can use CSS3 but then HAVE to use Photoshop for other browsers to see the desired effects? Isn't that just extra work?
you can use CSS3 but then HAVE to use Photoshop for other browsers to see the desired effects?
Often you don't really care whether the other browsers see the desired effects. If it's just a subtle background gradient effect, the site's going to work fine and still look reasonable with a flat background in downlevel browsers.
Compatibility was more of a problem when CSS 2 Positioning was at this stage: an unsupported positioning feature could lead to an unusable layout. But for essentially frivolous effects like backgrounds, borders and shadows, it's not critical if the effect goes missing.
There are a few reasons. From a developer/designers perspective, using CSS3 can be more flexible. An image is more or less just a static image. With CSS you can use script or CSS to animate or adjust the styling, and have advanced integration between the various technologies. This allows you to be able to do some things that are not possible or difficult just using images.
The page weight is also lower usually when using CSS, which allows the page to load faster, especially on slow connections or mobile devices. It also reduces HTTP requests (although you can use data uris too) which reduces latency and thus speeds up page loading.
Using CSS is often more maintainable and quicker, as you can adjust say a background colour or a shadow quickly just by changing the CSS, while with images you have to open up photoshop, edit the file, resave, etc. This is fantastic for quick tweaks.
There are also some people (myself included) that are much more comfortable in code than they are using graphics packages. For me it is easier to use CSS, but your milage may vary.
Also from the browser perspective we want to move the web platform forward and increase the capabilities. SVG is an example of another technology that doesn't work across all browser versions yet, but adds a lot of power. Although it may not be possible to deploy sites using certain CSS3 properties or SVG without fallbacks right now (depending on your audience or client) there will be a time in the future when old browsers are dead and what we are adding today works for all users. There was a time when most of CSS2.1 wasn't supported for example, while now you can rely on most of it if you don't need to design for IE6.
There are some parts of CSS3 that you can happily use without fallbacks, if you have a client that doesn't require all browsers to look the same. border-radius is an example, or giving a solid colour fallback to old browsers and applying transparency for newer browsers.
The world is moving forward, you can't ignore it. as long as old browser will show a button and new browser will show a more nice one, you are ok.
Otherwise, we were still be working on VT100... as why using "Windows" if most monitors doesn't support more than 4 color graphics and has 80X22 resolution....
If your bosses accepts the idea of having two versions of looks and feel and a warning. CSS3 is a good idea.
So, you use CSS3 features in your code and forget about the browsers that are not compatible -- they will see the "low-graphics version", you might want to issue a non-intrusive warning (like the one we get as alerts in StackOverflow), saying, "Your browser is not compatible with CSS3. To see this website in high graphics please upgrade your browser. Click the link here to update now."
But, depends on where you work. Big companies with lot of resources may like to stick with Photoshop and smaller once may like a light-weight CSS3 code that degrades silently in non-compatible browser.
Well you can always use ChromeFrame, to impose nice behavior on IE. Assuming that a lot of products will insist for it the near future (yeah we can argue against this), chances are that most IE users will have chromeFrame even before your application would insist for it. Once you take a decision on this, decision on using CSS3 properties or HTML5 elements is - well - hell yeah!!
Marvin