I'm calling the Win32 DrawText function to output some text into a device context. The text is long and wraps nicely onto a second line. The problem is I need to decrease the space between lines a bit (I guess decrease the line height?). Any ideas on how to do this?
I would just call DrawText twice (one for each line) but then I have to do my own word wrap.
Is there any other way?
Thanks
It's been quite a while since I dealt with this on Win32, but I believe the font itself defines the "expected" spacing by defining empty space below the character. Drawtext uses this full "height to position the next line when wrapping. If you want to do something which is not in alignment with this sizing, I believe you will have to do your own wrapping calculations and multiple DrawText() calls.
One possibility is to put the text into a disabled Rich Edit Control. I think that gives you a lot of control over formatting.
If you do write your own word wrap, you probably want to use GetTextExtentExPoint() for measuring how much will fit in each line.
Related
I have a variable-width container (screen width) and fixed left and right margins. Remaining area gives me a constraint for maximum text width, where I'm placing text of variable content (multiple languages). I want text to fit into that width without truncation, wrapping if needed. Text is relatively short - it may fit into single line, likely to fit into 2 lines and will fit into 3 lines for sure.
I want to avoid cases like (2) - where text wraps into long and a short line. It does not look nice. Instead I would like it to wrap more evenly, like in case (3).
For the demo purposes I've hardcoded hand-picked margins, but I want solution to work automatically for any text content and any container width.
Is it achievable using built-in Flutter widgets, or I need to implement something custom, similar to https://pub.dartlang.org/packages/auto_size_text?
Using HitTestTextPosition style API from IDWriteTextLayout I did not managed to handle properly text positions inside "ti", "ffi" or other ligatures with fonts like Calibri. It always returns position after or before ligature not inside like t|i or f|f|i.
What is the recommended way to do a caret movement inside ligatures with DirectWrite API?
There... is no "inside" position if you have GSUB replacements turned on?
Opentype GSUB ligatures are single glyph replacements for codepoint sequences, rather than being "several glyphs, smushed together". They are literally distinct, single glyphs, with single bounding boxes, and a single left and right side bearing for cursor placement/alignment. If you have the text A + E and the font has a ligature replacement that turns it into Ӕ then with ligatures enabled there really are only two cursor positions in that code sequence: |Ӕ and Ӕ|. You can't place the cursor "in the middle", because there is no "middle"; it's a single, atomic, indivisible element.
The same goes for f. ligatures like ff, fi, fl, ffi, ffl, or ſt: these are single glyphs once shaped with GSUB turned on. This is in fact what's supposed to happen: having GSUB ligatures enabled means you expressly want text to be presented—for all intents and purposes—as having atomic glyphs for many-to-one substitutions, like turning the full phrase "صلى الله عليه وعلى آله وسلم", as well as variations of that, into the single glyph ﷺ.
If you want to work with the base codepoint sequences (so that if you have a text with f + f + i it doesn't turn that into ffi) you will need to load the font with the liga OpenType feature disabled.
The text editors I know of use the simple hack of (1) dividing the width of the glyph cluster by the number of code points within the cluster (excluding any zero width combining marks), rather than use the GDEF caret positioning information. This includes even Word, which you can tell if you look closely enough below. It's not precise, but since it's simple and close enough at ordinary reading sizes, it's what many do:
(2) I've heard that some may (but don't know which) also use the original glyph advances of the unshaped characters (pre-ligation) and scale them proportionally to the ligature cluster width.
(3) Some text editors may use the GDEF table, but I never knew of any for sure (possibly Adobe In-Design?).
The most challenging aspect of using methods 2 or 3 with IDWriteTextLayout is that accessing the corresponding IDWriteFontFace in that run requires quite the indirection because the specific IDWriteFontFace used (after resolving font family name+WWS+variable font axes) is stored in the layout but not publicly accessible via any "getter" API. The only way you can extract them is by "drawing" the glyph runs via IDWriteTextLayout::Draw into a user-defined IDWriteTextRenderer interface to record all the DWRITE_GLYPH_RUN::fontFace's. Then you could call IDWriteFontFace::GetDesignGlyphAdvances on the code points or IDWriteFontFace::TryGetFontTable to read the OpenType GDEF table (which is complex to read). It's a lot of work, and that's because...
The official PadWrite example has the same issue
IDWriteTextLayout was designed for displaying text rather than editing it. It has some functionality for hit-testing which is useful if you want to display an underlined link in a paragraph and test for it being clicked (in which case the ligature would be whole anyway within a word), or if you want to draw some decorations around some text, but it wasn't really intended for the full editing experience, which includes caret navigation. It was always intended that actual text editing engines (e.g. those used in Word, PowerPoint, OpenOffice, ...) would call the lower level API's, which they do.
The PadWrite sample I wrote is a little misleading because although it supports basic editing, that was just so you can play around with the formatting and see how things worked. It had a long way to go before it could really be an interactive editor. For one (the big one), it completely recreated the IDWriteTextLayout each edit, which is why the sample only presented a few paragraphs of text, because a full editor with several pages of text would want to incrementally update the text. I don't work on that team anymore, but I've thought of creating a DWrite helper library on GitHub to fill in some hindsight gaps, and if I ever did, I'd probably just ... use method 1 :b.
I wanted to allow the Emacs cursor to move around freely outside of actual text (similar to virtualedit=all in Vim).
"Oh," I thought, "I'll just keep track of a virtual cursor and draw it to the screen myself."
But it turns out the actual native C drawing routines (such as draw_glyphs) seem to refer back to the buffer contents to decide what to draw (I could be wrong though).
My next idea was to make a giant overlay of all spaces so I'd have complete freedom where to put stuff. But an overlay only goes over ranges of actual text, so again, this does not seem to give me what I'm looking for.
Is this a reasonable goal without hacking the C code?
I believe the writeable area of a window is intrinsically limited to the buffer with which it is associated, i.e. you have to draw in an area where buffer content exists.
(One example of this limitation is the impossibility of drawing a vertical guide line in the 80th column to help the user identify long lines; currently the best possible implementation of such a feature is to highlight the "overflow" of each too-long line.)
You can do the same as what artist-mode does without adding spaces to the buffer:
when trying to place the cursor after the end of the line, just use an overlay with an after-string property which adds the spaces in the display without modifying the buffer.
Have a look at "artist-mode" (M-xartist-modeRET) - it allows you to draw in Emacs.
From the function documentation: "Artist lets you draw lines, squares, rectangles and poly-lines, ellipses and circles with your mouse and/or keyboard."
You can look at popup.el from the auto-complete package, which can pop up tooltips and menus and such at any position, including positions outside the contents of the buffer. Maybe that will show you how you can do it.
I have a view that draws multicolored text inside UITableViewCell. To draw multicolored text I'm using NSAttributedString However, I would like to make it so that if the text is too long to fit into the view, the last visible line is truncated to display an ellipsis at its end.
Obviously this is very easy to do when drawing only a single line, as you can just set
kCTLineBreakByTruncatingTail for the line break mode of the paragraph style. The problem is that I want my text to wrap to fill the rectangle, and then only have the last line truncated with an ellipsis - setting the line break mode confines the whole text to one line.
Does anybody have any ideas of how I would go about this?
Many thanks in advance for any suggestions,
JC.
Create your CTFrame from your CTFrameSetter with the rectangle of your UITableViewCell. Then, you can get all the CTLines of your CTFrame and determine when they will cut off. To swap out the ellipsis, you could keep that drawn with a separate CTFrame and draw it over the overflowing text on the last line.
You can find working code here: https://stackoverflow.com/a/14612598/473067
It's a similar approach to what Heath suggested. But then all wrapped up in a shiny package.
Well, to activate text truncating in UILabel, you should re-set lineBreakMode parameter to NSLineBreakByTruncatingTail after setting attributedText.
textLabel.attributedText = attributedText;
textLabel.lineBreakMode = NSLineBreakByTruncatingTail;
Ok, I am beat. I tried a few things but I am unable to make this happen. I need some help now.
I want to be able to have some text and picture side by side (only one line, thus no need for wrapping or other fun. The picture is small enough to fit in a text line):
This is a text <temp.jpg placed center to the textline>
Problem is, when I use
This is a text \includegraphics{temp.jpg}
the pictures baseline is alligned with the text baseline. I want the picture (vertical) center to be aligned with the text baseline. How can I make this possible?
This is a text $\vcenter{\hbox{\includegraphics{temp.jpg}}}$
It sounds like you want \raisebox (see the raisebox section of the LaTeX wikibook), with a negative argument. Use dimensions ex (the notional height of an 'x' in the current font) or \baselineskip (the size between text baselines) as your units.
If you want to do more complicated things, such as move the graphics box down by half its height, you can, but it gets fiddly. If the graphic size isn't unpredictable, you're probably better off tuning this by hand anyway.
In my opinion, most simple answer \raisebox{-0.5\totalheight}{<your graphic here>}
This is a text \raisebox{-0.5\totalheight}{\includegraphics{temp.jpg}}
Explanation:
\raisebox moves vertically the whole text/picture given as second argument. The first argument is the vertical shift as a length. This command provides the length \totalheight which is, self-explanatory, the height of the whole text/picture that you want to raise. The factor -0.5 lowers exactly at the half of the length(as the question demands). For aesthetic adjustments just modify the factor's value.
By the way, with this method there is no need to get into math mode as in #AlexeiMalistov answer, and no need of double command \vcenter + \hbox