In article <5163d9fd.9090...@lyx.org>, Jean-Marc Lasgouttes <lasgout...@lyx.org> wrote:
> 09/04/2013 09:25, Lin Wei: > > It seems the following function decides where to break within a paragraph: > > TextMetrics.cpp: pos_type TextMetrics::rowBreakPoint(int width, > > pit_type const pit,pos_type pos) const > > Yes. > > > But still, I didn't really figure out how it works...What I'm puzzled > > about the codes is how it knows the exact breaking point as it iterates > > to then end of a row width but is still in the middle of a word. Say a > > word "itshardtowrapaword" is at the end of a line and the position > > iterator now pointing to 'p'. Then we find we are now at the end of the > > line, which means the whole words needs to be wrapped. How did the codes > > achieve that? > > As far as I understand, there is a variable named "point" that keeps > track of the last possible break point. This is what get used when the > algorithm realizes that one given word is too long. > > > Becides, I think the problem of Lyx with Chinese is that it view all > > Chinese characters as just one word so long as no space/newline appears. > > A main feature of Chinese and Japanese is that they generally don't use > > any space within words or sentences. So a sentence like "***(Bob > > 2010)***********" would be treated as two words, "**(Bob" and > > "2010)***********", thus incorrectly wrapped if the second so-called > > word is too long. > > I agree with the analysis, but I do not know what the correct algorithm > is. There is a Qt tool for that > http://doc.qt.digia.com/4.6/qtextboundaryfinder.html > but I am not sure that we can use it directly. It may be possible to use > it on strings between insets and handle insets by ourselves. > > > Btw....Sorry that I don't know the convention in developing free > > software, but should I reply only to the mailing list or cc to everyone > > replied me as well? > > You can just answer to the list. > > Regards, > JMarc Hi Jin, Jean-Marc drew my attention to this thread. I'm working on another problem (the slow scrolling problem) and this involves also the TextMetrics::rowBreakPoint() function. As Jean-Marc explained the function keeps track of the last breakpoint and then tries to add as much of the next word as possible; if there is still enough space the breakpoint is moved otherwise the function returns the last breakpoint. However if a very long word is inserted the function will break within that word. That's probably what happens if you insert chinese (without any spaces). If there are no spaces between words, I suppose "one" must understand the meaning of the words to know where to break? Or is there another way to find the possible breakpoints? Regards, P. De Visschere
