I am trying to minimize the vertical distance between controls on a programmatically constructed Windows Form (using C#). This involves setting the Height property appropriately.
I have found that if the text of the control does not contain any letters with descenders in them (i.e. does not have any of the characters j, g, p, q or y) then the control Height can be smaller than when it does contain such letters (if it does contain letters with descenders then the descenders are chopped off if the Height isn't enough).
It will work fine to test for any of the above 5 characters as long as the language is English, or English - like, but I need to be able to cater for (just about) any language.
Is there a way, given some arbitrary Unicode character (and perhaps a font) to determine if that Unicode character has a descender or not?
There is no property defined for Unicode characters to indicate the presence of a descender, and it’s really a feature of glyph design rather than characters. For example, “Q” has a descenders in many fonts, and “J” has one in some. Besides, given the context, you should also consider diacritic marks placed below a letter, not just descenders of base letters. And probably diacritics above letters, too.
So you would need to read the font information (when available) about character dimensions, or tentatively draw characters in your software and measure their dimensions.
As a rule of thumb, any line height below 1.1 times the font size will cause problems with some characters and fonts. Using 1 (“setting solid”) is not enough, because characters may in fact extend outside the font size.
In Windows, you call GetPath() to get an array containing the X/Y coordinates of every point making up the perimeter or outline of the string of glyphs. Search the array for min/max, which will get you the rectangle exactly enclosing the string. Right to the edge of the letters.
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I'm looking at formatting a utf8 free text string to fit an exact column width on a terminal. I'm coding various truncation methods (left/middle/right) for long strings however, when the truncation break point lies over a wide character, such as an emoji, the display column counting falls apart. some form of padding is needed for the 'half wide' column placement.
Is there a suitable narrow character to show that indicates we do have valid unicode character, but insufficient display space to show it, as opposed to the special replacement character � usually used for invalid unicode ??
Example: on a fixed spacing terminal fit two smiley emojis into the space that would fit 'aaa'. e.g. "👨👨" ! so need a, preferably standardised, substitute character for the second emoji/wide character, e.g. "👨⋮" to fit that three wide space.
A side issue is trying to work out when decomposed composite characters start and end, (also are there combining prefixes?). It looks like the next code point needs to be read to see if it is still zero width (e.g. 'o' U+006F, then 'umlaut' U+0308, rather than ö U+00F6; don't stop after the plain 'o').
When a textbox, browser or other program can't display a character, or the character is not valid unicode, a white-box character is drawn instead to represent the missing glyph.
I assume that this box-glyph is a Unicode character itself, thus I am looking for its codepoint so I can use it. Does anyone know which codepoint is used, or perhaps if my assumption is wrong and it is not necessarily a member of the font?
At first I thought it might be the White Square (U+25A1), but, after I compared this glyph with an example, I found white square was smaller. There is a larger variant of it (medium and large), but these do not appear in the font under consideration, so these can not be the ones I am seeing.
I managed to find my answer, here on stackoverflow: https://stackoverflow.com/a/22636426/2718186
Particularly, the part that talks about .notdef glyph. It seems that fonts reserve a special glyph, that is not mapped to by any Unicode point, to indicate that a character has no glyph in the current font.
I want the character ⇓ with stroke, just like ⇏ but downwards, but I can't find it. Does it exist?
Edit:
If you don't see the arrows (e.g. you use IE),
I want the character [downwards double arrow] with stroke, just like [rightwards double arrow with stroke] but downwards, but I can't find it. Does it exist?
There is no such character as a precomposed character (i.e., as a single encoded character, a code point assigned to a character), but you can in principle represent it using an arrow character followed by a combining overlay character.
The character “⇏” U+21CF RIGHTWARDS DOUBLE ARROW WITH STROKE has been defined as having the canonical decomposition RIGHTWARDS DOUBLE ARROW (U+21D2) COMBINING LONG SOLIDUS OVERLAY (U+0338). In principle, a character should be expected to be rendered the same way as its canonical decomposition. In practice, things don’t always go that way.
Along the same lines, a downwards double arrow with stroke could be written as the two-character sequence DOWNWARDS DOUBLE ARROW (U+21D3) COMBINING LONG SOLIDUS OVERLAY (U+0338) or, in HTML, as ⇓̸. In practice, few fonts contain these characters, and browsers may fail to implement the combination properly. Moreover, in many fonts, the result is awkward. In Arial Unicode MS and in DejaVu Serif, the result might be acceptable, but only the latter is free (can be legally used as a downloadable font via #font-face). Here’s the combination as rendered by your browser with the SO stylesheets in effect: ⇓̸.
It doesn't seem to exist, according to this page (compared to this).
Sorry if this isn't the right overflow for this question. I need a unicode character that is as long as ⎢ (23A2, LEFT SQUARE BRACKET EXTENSION) but lines up horizontally with ⎮ (23AE, INTEGRAL EXTENSION). Is there such a character?
Take a look at shapecatcher. If you draw a straight line, it shows plenty of different codepoints resembling |.
As already pointed out, exact placement and size may depend on the font, but if you know that the font is going to be a specific one (because you supply it), you could still find the character you're looking for.
It turns out this does depend on the font. If I use DejaVu Sans Mono, INTEGRAL EXTENSION is as long as I want it to be. This font appears to be almost exactly the same as the font I was using, Menlo, except for some small differences with some characters (including this one).
Characters included in BMP as specified by 4 digits,
and those characters outside of BMP contains 5 or 6 digits.
But my doubt is:
how is the finanal character drawed from value of code point?
Are the pictures of each character restored in each computer and when displaying just show the matching picture?
Or the final glyph is a computed result of code point itself?
Each Unicode character has a code. The software displaying the character obtains a glyph for that character code - usually from a font installed onto the hosting computer. It then uses the obtained glyph to display the character.
If it can't find a glyph for that character (many fonts for Latin characters completely omit the glyphs used for East Asian languages characters) it formally can't display it. It will then either indicate error or use a supplement glyph meaning that the actual glyph can't be displayed (it can be a question mark or a square or whatever).