Post pobrano z: Maskable Icons: Android Adaptive Icons for Your PWA

You’ve created a Progressive Web App (PWA), designed an icon to represent it, and now you’re installing it to your Android home screen.

But, if you have a recent Android phone, your icons will show up like this:

What happened? Well, Android Oreo introduced adaptive icons, a new icon format that enforces the same shape for all icons on the home screen. Icons that don’t follow the new format are given a white background.

However, there is a new web feature called maskable icons that is coming soon to Firefox Preview and other web browsers. This new icon format will let your PWAs have their own adaptive icons on Android.

I work at Mozilla and have implemented support for maskable icons in Firefox Preview. I’ll show you how to add them to your own PWAs for Android.

What are maskable and adaptive icons?

Until a few years ago, Android app icons were freeform and could be any shape. This meant that web apps could also reuse the same transparent icon when pinned to the home screen.

However, manufacturers, like Samsung, wanted to make all icons on a device the same shape to keep things consistent. Some manufacturers even wanted different shapes. To deal with the variety of requirements from manufacturers and devices, Android introduced “adaptive icons.” You supply an image with extra space around the edges, and Android will crop it to the correct shape.

But web apps are designed to work on any platform, so they don’t have APIs to create these special Android icons. Instead, icons would get squished into white boxes like this:

Lo and behold, last September a brand new API descended upon us and was added to the W3C spec. Maskable icons allow web developers to specify a full-bleed icon that will be cropped. It’s platform agnostic, so Windows could use them for tiles or iOS could use them for icons.

How to create maskable icons

Since the maskable icon format is designed work with any platform, the size and ratios are different from the size and ratios of Android’s adaptive icons. This means you can’t reuse the same asset.

Maskable icons can be any size, and you can continue to use the same sizes that you’d use for normal transparent icons. But when designing the icon, ensure that important information is within a “safe zone” circle with a radius equal to 40% of the image’s size.

All pixels within this zone are guaranteed to be visible. Pixels outside the zone may be cropped off depending on the icon shape and the platform.

Warning: If you already have an Android app, avoid copying and pasting the icon from your Android app to your web app. The ratios are different, so your icons would look too small.

Adding the icon to your Web App Manifest

Once the icons are created, you can add an entry to your Web App Manifest similar to other icon assets. The Web App Manifest provides information about your web app in a JSON file, and includes an "icons" array.

{
  ...
  "icons": [
    ...
    {
      "src": "path/to/maskable_icon.png",
      "sizes": "196x196",
      "type": "image/png",
      "purpose": "maskable"
  ]
  ...
}

Maskable icons use a special new key, "purpose", to indicate that they are meant to be used with icon masks. Icons with transparent backgrounds have a default "purpose" of "any", and icons can be used for multiple purposes by separating each option with a space.

"purpose": "maskable any"

Preview your icons

Do you want to see what your own maskable icons will look like? I’ve created a tool, Maskable.app, to help you evaluate how the icon appears in different shapes.

The app lets you preview your icon in various shapes that can be found on Android devices. I hope this tool helps you create unique icons for your Progressive Web Apps.

Once you’re satisfied with the results, you can start testing your app with Mozilla’s Reference Browser. This special browser is a testing ground for features before they reach Firefox Preview, and you can use it to check out how your PWA looks. Chrome is working on maskable icon support too.

Tools like PWACompat also have support for maskable icons. You can automatically generate icons for iOS and other devices based on your new maskable icons!

Time to build your own icons

If you want to more control over how your PWA icons are displayed on Android, maskable icons is the way to go. With maskable icons you can customize how your icon is displayed from edge-to-edge. Hopefully this article can get you started on creating your first maskable icon.

Icon Credits:

• https://notwoods.github.io/color-breakdown/
• https://notwoods.github.io/insightful-energy/
• https://notwoods.github.io/big-island-buses/
• https://proxx.app/
• https://jakearchibald.github.io/svgomg/

The post Maskable Icons: Android Adaptive Icons for Your PWA appeared first on CSS-Tricks.

Post pobrano z: Styling Links with Real Underlines

Before we come to how to style underlines, we should answer the question: should we underline?

In graphic design, underlines are generally seen as unsophisticated. There are nicer ways to draw emphasis, to establish hierarchy, and to demarcate titles.

That’s clear in this advice from Butterick’s „Practical Typography”:

If you feel the urge to underline, use bold or italic instead. In special situations, like headings, you can also consider using all caps, small caps, or changing the point size. Not convinced? I invite you to find a book, newspaper, or magazine that underlines text. That look is mostly associated with supermarket tabloids.

But the web is different. Hyperlinks are the defining feature of the internet; and from the internet’s inception, they have been underlined. It’s a universally understood convention. The meaning is crystal clear — an underline means a link.

However, plenty of popular websites have ditched underlines: The New York Times, New York Magazine, The Washington Post, Bloomberg, Amazon, Apple, GitHub, Twitter, Wikipedia. When they removed underlines from their search results page in 2014, Google lead designer Jon Wiley argued that it created a cleaner look. Notably though, the majority of these sites have kept slight variances on the traditional lurid blue color (#0000EE) that’s been the browser default since the beginning of the web. While this provides a visual cue for the majority of users, it may not be enough to pass WCAG accessibility compliance.

Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.
— WCAG 2.1

WCAG do not strictly mandate using underlines for links, but it does recommend them. Color blind users need to be able to discern a link. You could differentiate them in other ways, such as with a bold font-weight. Or you could keep this long-established visual affordance. But if we’re going to use underlines, we want them to look nice. Marcin Wichary, a designer at Medium, described the perfect underline as:

[…] visible, but unobtrusive — allowing people to realize what’s clickable, but without drawing too much attention to itself. It should be positioned at just the right distance from the text, sitting comfortably behind it for when descenders want to occupy the same space.

Achieving this has traditionally required CSS tricks.

The hacks we’ve had

This is one trick all developers will be familiar with: border-bottom. By emulating an underline using border-bottom, we gain control over color and thickness. These pseudo-underlines have one problem: an overly large distance from the text. They are underneath the descenders of the letters. You could potentially solve this issue by using line-height, but that comes with its own issues. A similar technique utilises box-shadow. Marcin Wichary pioneered the most sophisticated technique, using background-image to simulate an underline. They were useful hacks but are thankfully no longer needed.

Styling real underlines

Finally we can demarcate links without sacrificing style thanks to two new CSS properties.

• text-underline-offset controls the position of the underline.
• text-decoration-thickness controls the thickness of underlines, as well as overlines, and line-throughs.

According to the WebKit blog:

You can also specify from-font to both of these properties which will pull the relevant metric from the used font file itself.

UX agency Clearleft make bold use of (pseudo) underlines, calling clear attention to links with colorful styling. Here’s one example of a faux underline:

a {
  text-decoration: none;
  border-bottom: #EA215A 0.125em solid;
}

Notice that this fake underline is clearly below the descender of the letter „y”:

Here’s the same paragraph, using DevTools to apply the same styling to a real underline using the new CSS properties:

a {
  text-decoration-color: #EA215A;
  text-decoration-thickness: .125em;
  text-underline-offset: 1.5px;
}

You’ll notice I’m using the em unit in my example code. The spec strongly encourages using it rather than pixels so that the thickness scales with the font.

These properties have already shipped in Safari and are coming in Firefox 70.

With the move to Chromium for Microsoft’s Edge browser, we will finally have cross browser support for the text-decoration-style property, which offers the options: solid (the default), double, dotted, dashed, and wavy. When combined, these new properties open up a whole range of possibilities.

Perhaps the biggest upgrade for underlines on the web, however, has come without developers needing to do anything. In the bad old days, descenders were unceremoniously sliced through by underlines, which was far from elegant. Developers used to hack around this shortcoming by applying a text-shadow that matched the background color. text-decoration-skip-ink brought a better way to make space for descenders.

Handily, it’s set as the new default value for underlines; meaning the look of underlines has improved while most web developers remain unaware that this property exists. Should you want an underline to cross over glyphs, you can set this property to none.

The post Styling Links with Real Underlines appeared first on CSS-Tricks.

Post pobrano z: Styling Links with Real Underlines

Before we come to how to style underlines, we should answer the question: should we underline?

In graphic design, underlines are generally seen as unsophisticated. There are nicer ways to draw emphasis, to establish hierarchy, and to demarcate titles.

That’s clear in this advice from Butterick’s „Practical Typography”:

If you feel the urge to underline, use bold or italic instead. In special situations, like headings, you can also consider using all caps, small caps, or changing the point size. Not convinced? I invite you to find a book, newspaper, or magazine that underlines text. That look is mostly associated with supermarket tabloids.

But the web is different. Hyperlinks are the defining feature of the internet; and from the internet’s inception, they have been underlined. It’s a universally understood convention. The meaning is crystal clear — an underline means a link.

However, plenty of popular websites have ditched underlines: The New York Times, New York Magazine, The Washington Post, Bloomberg, Amazon, Apple, GitHub, Twitter, Wikipedia. When they removed underlines from their search results page in 2014, Google lead designer Jon Wiley argued that it created a cleaner look. Notably though, the majority of these sites have kept slight variances on the traditional lurid blue color (#0000EE) that’s been the browser default since the beginning of the web. While this provides a visual cue for the majority of users, it may not be enough to pass WCAG accessibility compliance.

Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.
— WCAG 2.1

WCAG do not strictly mandate using underlines for links, but it does recommend them. Color blind users need to be able to discern a link. You could differentiate them in other ways, such as with a bold font-weight. Or you could keep this long-established visual affordance. But if we’re going to use underlines, we want them to look nice. Marcin Wichary, a designer at Medium, described the perfect underline as:

[…] visible, but unobtrusive — allowing people to realize what’s clickable, but without drawing too much attention to itself. It should be positioned at just the right distance from the text, sitting comfortably behind it for when descenders want to occupy the same space.

Achieving this has traditionally required CSS tricks.

The hacks we’ve had

This is one trick all developers will be familiar with: border-bottom. By emulating an underline using border-bottom, we gain control over color and thickness. These pseudo-underlines have one problem: an overly large distance from the text. They are underneath the descenders of the letters. You could potentially solve this issue by using line-height, but that comes with its own issues. A similar technique utilises box-shadow. Marcin Wichary pioneered the most sophisticated technique, using background-image to simulate an underline. They were useful hacks but are thankfully no longer needed.

Styling real underlines

Finally we can demarcate links without sacrificing style thanks to two new CSS properties.

• text-underline-offset controls the position of the underline.
• text-decoration-thickness controls the thickness of underlines, as well as overlines, and line-throughs.

According to the WebKit blog:

You can also specify from-font to both of these properties which will pull the relevant metric from the used font file itself.

UX agency Clearleft make bold use of (pseudo) underlines, calling clear attention to links with colorful styling. Here’s one example of a faux underline:

a {
  text-decoration: none;
  border-bottom: #EA215A 0.125em solid;
}

Notice that this fake underline is clearly below the descender of the letter „y”:

Here’s the same paragraph, using DevTools to apply the same styling to a real underline using the new CSS properties:

a {
  text-decoration-color: #EA215A;
  text-decoration-thickness: .125em;
  text-underline-offset: 1.5px;
}

You’ll notice I’m using the em unit in my example code. The spec strongly encourages using it rather than pixels so that the thickness scales with the font.

These properties have already shipped in Safari and are coming in Firefox 70.

With the move to Chromium for Microsoft’s Edge browser, we will finally have cross browser support for the text-decoration-style property, which offers the options: solid (the default), double, dotted, dashed, and wavy. When combined, these new properties open up a whole range of possibilities.

Perhaps the biggest upgrade for underlines on the web, however, has come without developers needing to do anything. In the bad old days, descenders were unceremoniously sliced through by underlines, which was far from elegant. Developers used to hack around this shortcoming by applying a text-shadow that matched the background color. text-decoration-skip-ink brought a better way to make space for descenders.

Handily, it’s set as the new default value for underlines; meaning the look of underlines has improved while most web developers remain unaware that this property exists. Should you want an underline to cross over glyphs, you can set this property to none.

The post Styling Links with Real Underlines appeared first on CSS-Tricks.

Post pobrano z: Working with Attributes on DOM Elements

The DOM is just a little weird about some things, and the way you deal with attributes is no exception. There are a number of ways to deal with the attributes on elements. By attributes, I mean things like the id in <div id="cool"></div>. Sometimes you need to set them. Sometimes you need to get them. Sometimes you get fancy helpers. Sometimes you don’t.

For this article, I’ll assume el is a DOM element in your JavaScript. Let’s say you’ve done something like const el = document.querySelector("#cool"); and matched <div id="cool"> or whatever.

Some attributes are also attributes of the DOM object itself, so iff you need to set an id or title, you can do:

el.id; // "cool"
el.title = "my title";
el.title; // "my title";

Others that work like that are lang, align, and all the big events, like onclick.

Then there are attributes that work similarly to that but are nested deeper. The style attribute is like that. If you log el.style you’ll see a ton of CSS style declarations. You can get and set them easily:

el.style.color = "red";
module.style.backgroundColor = "black";

You can get computed colors this way too. If you do module.style.color hoping to get the color of an element out of the gate, you probably won’t get it. For that, you’d have to do:

let style = window.getComputedStyle(el);
style.color; // whatever in CSS won out

But not all attributes are like first-class attributes like that.

el['aria-hidden'] = true; // nope

That „works” in that it sets that as a property, but it doesn’t set it in the DOM the proper way. Instead, you’ll have to use the generic setter and getter functions that work for all attributes, like:

el.setAttribute("aria-hidden", true);
el.getAttribute("aria-hidden");

Some attributes have fancy helpers. The most fancy is classList for class attributes. On an element like:

<div class="module big"></div>

You’d have:

el.classList.value; // "module big"
el.classList.length; // 2
el.classList.add("cool"); // adds the class "cool", so "module big cool"
el.classList.remove("big"); // removes "big", so "module cool"
el.classList.toggle("big"); // adds "big" back, because it was missing (goes back and forth)
el.classList.contains("module"); // true

There’s even more, and classList itself behaves like an array so you can forEach it and such. That’s a pretty strong reason to use classes, as the DOM API around them is so handy.

Another attribute type that has a somewhat fancy help is data-*. Say you’ve got:

<div data-active="true" data-placement="top right" data-extra-words="hi">test</div> 

You’ve got dataset:

el.dataset;
/*
{
  active: "true",
  "placement", "top right"
*/

el.dataset.active; // "true"
el.dataset.extraWords; // "hi", note the conversion to camelCase

el.dataset.active = "false"; // setters work like this

The post Working with Attributes on DOM Elements appeared first on CSS-Tricks.