I would like to add text labels to my letters in FontForge, so I can refer to them by name in HTML as opposed to the actual letter or symbol. For example, the Google Material Design Font has many symbols, and you can refer to them by either a text label (cloud_queue), or a entity code (). The little material cloud icon is like this:
<i class="material-icons">cloud_queue</i>
or (for IE9 or below)
<i class="material-icons"></i>
How do you add a text label, such as cloud_queue, for a letter in FontForge?
Thanks in advance
The Material Design font achieved this using ligatures.
To do this in your own font, first add an unencoded glyph to your font (or use a code point in the Unicode private use area, if you're using unicode encoding), then change its name to c_l_o_u_d_underscore_q_u_e_u_e. This tells FontForge that you intend the glyph to be a ligature that should be substituted whenever those letters appear in that order.
Related
I use icomoon.io to create and manage my icon fonts. It's excellent and you can set "ligatures" for the text you want to display the icon.
However, I cannot find a sane way to handle missing ligatures to display a default or "missing" icon.
One insane way was I created an icon component and check the text against an array of ligatures. But this would mean that I must maintain the array to match the icons in my font.
everyDangLigature = ['star', 'arrow-up', ...]
iconText = everyDangLigature.includes(str) ? str : 'missing';
IcoMoon wrote me back with
...if you parse the CMAP table of the font, you could check if a glyph
exists by its code point.
Also asked the opentypejs group.
How does one go about parsing the CMAP table of the font?
Is there another way to elegantly handle missing ligatures in our icon fonts?
Using Material Icons, a plus icon can be added as follows:
<i class="material-icons">add</i>
The text add is no longer visible. Why does this happen and where does the plus icon come from? I know it's defined in the font file, but how?
If it's due to the word add linked with the plus icon in the font file, then why doesn't the following work in Bootstrap, with its Glyphicons?
<span style="font-family: 'Glyphicons Halflings'">\20ac</span>
EXPLANATION
When you strip all the technical information, the answer is really quite straightforward, the font file incorporates a few tables amongst which:
[MANDATORY] the list of characters
[MANDATORY] the hexadecimal codes of those characters
[OPTIONAL] one or more aliases/alternative names for those characters
The one or more aliases/alternative names are the 'ligatures' you are referring to and reside in the font file.
Essentially, when using a character/icon from a font file with ligatures, we have the option to use
the 'regular' hexadecimal code: <i class="some-font-with-ligatures">&#xxxx;</i>
or the alternative/alias/ligature name: <i class="some-font-with-ligatures">ligature-name or alias</i>
That is probably all the important info for a web designer to know.
EXTRAS
Go to CSS-Tricks: How do ligature icons work... to see usage examples and a brief explanation.
And if you want to mess around with your own icon font files I suggest you start using the IcoMoon APP:
start the APP, select an icon and select 'generate font' (bottom right)
Enable display of ligatures with the 'show ligatures'-button (top left 3rd button)
Material Icons. It is possible in a font to define special glyphs for combinations of characters. An example in English is the glyph æ, which is a combination of a and e. This is called a ligature. Other examples are special renderings of ff, ft and tt. Instead of drawing an f followed by another one, the two glyphs are drawn as a single connected glyph: f f versus ff. What the designers of the Material Icons set did is (ab)using this system to make it easy to use icons.
Let's take a step back for a moment. You'll notice in the usage of the add icon that it is possible to include it by directly using a character code that is mapped, in the font, to the correct icon.
<i class="material-icons"></i>
This refers to Unicode character U+E145, which falls in one of the Private Use Area blocks of the Unicode specification. This means that no character is usually assigned to this position and every font designer is free to put any glyph they want at that position. Google chose to put the add icon at that spot. Thus, this character, with font family Material Icons, will render as a nice icon.
In addition to that, they created a ligature in their font family that says that the combination of characters add should be rendered as the same glyph. When browsers support ligatures in their font rendering engine, this will result in the same output as using  would.
Google documents this very briefly as well.
In a nutshell: both (U+E145) and the string add will render as when using Material Icons.
<link href="https://fonts.googleapis.com/icon?family=Material+Icons"
rel="stylesheet">
As character: <span class="material-icons"></span>.<br>
As ligature: <span class="material-icons">add</span>.
Boostrap and Glyphicons. The Glyphicons font does not define ligatures, but referencing the correct characters definitely does work. This is exactly what Bootstrap does, by setting (for the plus icon from Glyphicons) content: "\002b";. This sets the content of the span it is applied on to the character represented by the escaped code point U+002B, which is the plus sign. The Glyphicons Halflings font family renders this as some sort of icon, just like Material Icons. The only difference is that the icon is represented by a different character.
Why does using \002B in a span not work, you ask? That's because escaping a Unicode character in CSS is different than in HTML. In HTML, you'd use + instead (or € to get the example you have in your question). You can read more about escaping here.
Thus, + (U+002B) renders as and € (U+20AC) renders as when using the Glyphicons Halflings font family. You'll notice that for the Glyphicons, they chose to use characters resembling the icons, whereas Material Icons use special, reserved characters.
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>
<span style="font-family: 'Glyphicons Halflings'">+ €</span>
I am converting some custom icons to web fonts (for internal use only) and I was able to use a local client tool to export to the various font formats (woff, eot, ttf, svg) needed for each icon.
I am using the character map utility in Windows to see the Unicode value for each icon. For example, an airplane icon I have has a unicode value of: U+0021 (Exclamation Mark).
So, now, in my CSS file, I am using code like so:
.myIcon-airplane:before {
content: "!"
}
This outputs an airplane icon as expected.
However, is there a way to use the unicode value (ie, U+0021) instead of the exclamation mark? Or, what's the correct way for me to map my icons using the CSS content key?
Unfortunately, I can't use a public tool due to the proprietary nature of these icons.
Use the backslash escape character followed by the unicode value, like so:
.myIcon-airplane::before{
content:"\0021";
}
<p class="myIcon-airplane"></p>
I was looking at the font-awesome source to quickly get an idea of how importing fonts and graphics works. I found the line:
.fa-spinner:before {
content: "\f110";
}
How does this refer to the spinner icon?
Where can I read about creating my own fonts and icons and using them?
That is a CSS declaration to enable you to use a shortcut like <span class="fa-spinner"> to produce a spinner icon. The content: CSS property means "place this content in this element, and the :before pseudoclass is used to place it before any content you might actually place in such a <span> in your markup.
\f110 is an escape sequence used to produce a character by its hexadecimal representation. It refers to the Unicode character at codepoint U+F110. This is in the "private use range", a range of character codes you're allowed to use for your own arbitrary symbols that don't necessarily correspond to any other character, such as a spinner icon. You can produce the same character in your markup without the assistance of CSS by simply using the equivalent HTML numeric character reference,
i'm trying to use İcomoon font for css icons. I downloaded and configured in css file. But i don't know icon's unicode values. How can i see all icons' unicode values to write as a value of data-icon attribute.
Go to https://icomoon.io/app/#/select.
Select the icon(s) that you need.
Click on Generate Font.
Hover on the icon and click on Get Code.
Copy the HTML/CSS which contains the unicode of the icon.