Re: [webkit-dev] Ruby Text Enhancements
Thanks a lot for the review! The patch has landed and should be a much cleaner foundation for generated content (which may also have to be overlapped). Speaking of general ruby text enhancements: there is a new bug https://bugs.webkit.org/show_bug.cgi?id=47596 regarding the ruby display types. The previous consensus was that we shouldn't implement them (yet). Furthermore, the expectation in that bug description would run contrary to the spec anyway: setting rt to 'display: inline' should display it as ruby text (rather than inline). Do you guys have any suggestions on this? Cheers, - Roland On Thu, Oct 7, 2010 at 2:14 PM, Roland Steiner rolandstei...@google.comwrote: Seeing that this is progressing ad a quick pace, could I entice some kind reviewer to r+ my patch for bug https://bugs.webkit.org/show_bug.cgi?id=41040 before I get (another...) mid-air collision? ^_^; Roland On Wed, Oct 6, 2010 at 5:34 PM, Eric Mader ema...@apple.com wrote: On Oct 5, 2010, at 6:25 PM, David Hyatt wrote: On Oct 5, 2010, at 7:33 PM, Eric Mader wrote: On Sep 24, 2010, at 8:02 PM, David Hyatt wrote: This is a tough problem. It seems like you have to get involved in the line layout code e.g., findNextLineBreak in order to really do the right thing. findNextLineBreak uses an iterator that walks the objects, so it's easier to tell what text came before you and what text comes after you. You can also tell whether or not that text will even fit on the line and possibly do the margin hacking there. I just did a prototype that checks for a RenderRubyRun in the isReplaced() code inside findNextLineBreak and calls a method on the RenderRubyRun that takes the last and the next object and sets negative margins by calling setMarginLeft() and setMarginRight(). I stepped through this code and it computes the correct margins, but the margins don't seem to take - the ruby doesn't overlap the surrounding text. Guessing that some other code is resetting the margins, I modified the code to cache the computed margins in the RenderRubyRun object and return the cached values through subclassed marginLeft() and marginRight() methods. With this change, the ruby displays as I would expect. It's probably RenderBlockLineLayout line 348 getting you in trouble ( computeInlineDirectionPositionsForLine). computeLogicalWidth is called again, and that will recompute the left/right margins and blow away the changes you made to them. I have no idea why that call is there. It should not be necessary, but maybe there's something subtle I'm missing. You could try removing it, and see if that fixes the problem (it should). Yes, that did the trick! I haven't noticed any obvious problems with that line removed, but I haven't done much testing yet. dave (hy...@apple.com) Regards, Eric ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Ruby Text Enhancements
On Oct 5, 2010, at 6:25 PM, David Hyatt wrote: On Oct 5, 2010, at 7:33 PM, Eric Mader wrote: On Sep 24, 2010, at 8:02 PM, David Hyatt wrote: This is a tough problem. It seems like you have to get involved in the line layout code e.g., findNextLineBreak in order to really do the right thing. findNextLineBreak uses an iterator that walks the objects, so it's easier to tell what text came before you and what text comes after you. You can also tell whether or not that text will even fit on the line and possibly do the margin hacking there. I just did a prototype that checks for a RenderRubyRun in the isReplaced() code inside findNextLineBreak and calls a method on the RenderRubyRun that takes the last and the next object and sets negative margins by calling setMarginLeft() and setMarginRight(). I stepped through this code and it computes the correct margins, but the margins don't seem to take - the ruby doesn't overlap the surrounding text. Guessing that some other code is resetting the margins, I modified the code to cache the computed margins in the RenderRubyRun object and return the cached values through subclassed marginLeft() and marginRight() methods. With this change, the ruby displays as I would expect. It's probably RenderBlockLineLayout line 348 getting you in trouble (computeInlineDirectionPositionsForLine). computeLogicalWidth is called again, and that will recompute the left/right margins and blow away the changes you made to them. I have no idea why that call is there. It should not be necessary, but maybe there's something subtle I'm missing. You could try removing it, and see if that fixes the problem (it should). Yes, that did the trick! I haven't noticed any obvious problems with that line removed, but I haven't done much testing yet. dave (hy...@apple.com) Regards, Eric___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Ruby Text Enhancements
On Sep 24, 2010, at 8:02 PM, David Hyatt wrote: This is a tough problem. It seems like you have to get involved in the line layout code e.g., findNextLineBreak in order to really do the right thing. findNextLineBreak uses an iterator that walks the objects, so it's easier to tell what text came before you and what text comes after you. You can also tell whether or not that text will even fit on the line and possibly do the margin hacking there. I just did a prototype that checks for a RenderRubyRun in the isReplaced() code inside findNextLineBreak and calls a method on the RenderRubyRun that takes the last and the next object and sets negative margins by calling setMarginLeft() and setMarginRight(). I stepped through this code and it computes the correct margins, but the margins don't seem to take - the ruby doesn't overlap the surrounding text. Guessing that some other code is resetting the margins, I modified the code to cache the computed margins in the RenderRubyRun object and return the cached values through subclassed marginLeft() and marginRight() methods. With this change, the ruby displays as I would expect. Does anybody have any idea what code resetting the margins, and what I need to do to talk it out of doing this? Regards, Eric ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Ruby Text Enhancements
On Oct 5, 2010, at 7:33 PM, Eric Mader wrote: On Sep 24, 2010, at 8:02 PM, David Hyatt wrote: This is a tough problem. It seems like you have to get involved in the line layout code e.g., findNextLineBreak in order to really do the right thing. findNextLineBreak uses an iterator that walks the objects, so it's easier to tell what text came before you and what text comes after you. You can also tell whether or not that text will even fit on the line and possibly do the margin hacking there. I just did a prototype that checks for a RenderRubyRun in the isReplaced() code inside findNextLineBreak and calls a method on the RenderRubyRun that takes the last and the next object and sets negative margins by calling setMarginLeft() and setMarginRight(). I stepped through this code and it computes the correct margins, but the margins don't seem to take - the ruby doesn't overlap the surrounding text. Guessing that some other code is resetting the margins, I modified the code to cache the computed margins in the RenderRubyRun object and return the cached values through subclassed marginLeft() and marginRight() methods. With this change, the ruby displays as I would expect. It's probably RenderBlockLineLayout line 348 getting you in trouble (computeInlineDirectionPositionsForLine). computeLogicalWidth is called again, and that will recompute the left/right margins and blow away the changes you made to them. I have no idea why that call is there. It should not be necessary, but maybe there's something subtle I'm missing. You could try removing it, and see if that fixes the problem (it should). dave (hy...@apple.com) ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Ruby Text Enhancements
On Sep 27, 2010, at 3:40 PM, Eric Mader wrote: Are you saying that subclassing computeLogicalWidth() would still mean that I'm computing the margins at the initial calculation time? You'd be computing them whenever the ruby run's layout changed. The problem with that is if you're setting margins based off surrounding content, you're not going to get a layout just because your surroundings changed. It just doesn't seem like you can deal with all the corner cases without integrating right into line layout. I don't see how else you can know if you have adequate available space to actually overhang without knowing what you've seen so far on the line and how much space you have left on the line. This would require special-casing the ruby blocks in line layout code, right? I was trying to avoid this, hoping that I could just extend the existing ruby objects. Right. It's kind of a minor miracle that Ruby has gotten this far without having to do this though. :) This method makes several assumptions that I'm not 100% sure are always safe: * That a RenderRuby object holds only 1 RenderRubyRun object. I believe you can have multiple RenderRubyRuns inside a single RenderRuby. http://www.whatwg.org/specs/web-apps/current-work/multipage/text-level-semantics.html#the-ruby-element The ruby element allows one or more spans of phrasing content to be marked with ruby annotations. * That the text for the ruby text and ruby base are always the direct child of the RenderRubyText and RenderRubyBase object. I doubt that's a valid assumption. I assume that you can have a content tree of markup underneath a RenderRubyText and a RenderRubyBase, e.g., if you put in some i and some b. Anyway, I think you could just ask for the width() of the rubyText() and rubyBase() objects themselves rather than drilling down into their subtrees. I couldn't figure out how to ask the RenderRubyText and RenderRubyRun objects for their width. They don't support the width() method. What method should I call? They should. They are RenderBlocks, so they should have width() methods. You may have just been getting bad results because you hooked in before the width was computed. That's why computeLogicalWidth subclassing would work better for you. Let the base class set up the margins and width, and then you override. dave (hy...@apple.com) ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Ruby Text Enhancements
On 2010/09/28, at 10:11, David Hyatt wrote: On Sep 27, 2010, at 3:40 PM, Eric Mader wrote: Are you saying that subclassing computeLogicalWidth() would still mean that I'm computing the margins at the initial calculation time? You'd be computing them whenever the ruby run's layout changed. The problem with that is if you're setting margins based off surrounding content, you're not going to get a layout just because your surroundings changed. Probably a novice question but are there mechanisms or ways to trigger re-computing of the ruby's layout when the surrounding text has changed? - kida ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Ruby Text Enhancements
On Sep 28, 2010, at 7:11 AM, David Hyatt wrote: The ruby element allows one or more spans of phrasing content to be marked with ruby annotations. * That the text for the ruby text and ruby base are always the direct child of the RenderRubyText and RenderRubyBase object. I doubt that's a valid assumption. I assume that you can have a content tree of markup underneath a RenderRubyText and a RenderRubyBase, e.g., if you put in some i and some b. Anyway, I think you could just ask for the width() of the rubyText() and rubyBase() objects themselves rather than drilling down into their subtrees. I couldn't figure out how to ask the RenderRubyText and RenderRubyRun objects for their width. They don't support the width() method. What method should I call? They should. They are RenderBlocks, so they should have width() methods. You may have just been getting bad results because you hooked in before the width was computed. That's why computeLogicalWidth subclassing would work better for you. Let the base class set up the margins and width, and then you override. Doh! I was trying to call width() on RenderText objects. When I called it directly on firstChild() and lastChild() of the RenderRubyRun, it works, but returns the frame width, which isn't useful for my purposes. Instead I called maxPrefWidth() which has the values I'm after. (only, I guess, if the ruby text and ruby base is a single line…) dave (hy...@apple.com) Regards, Eric ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Ruby Text Enhancements
Thanks. Looks like hooking findNextLineBreak is something we should try. - kida On 2010/09/28, at 12:56, David Hyatt wrote: On Sep 28, 2010, at 12:20 PM, Yasuo Kida wrote: On 2010/09/28, at 10:11, David Hyatt wrote: On Sep 27, 2010, at 3:40 PM, Eric Mader wrote: Are you saying that subclassing computeLogicalWidth() would still mean that I'm computing the margins at the initial calculation time? You'd be computing them whenever the ruby run's layout changed. The problem with that is if you're setting margins based off surrounding content, you're not going to get a layout just because your surroundings changed. Probably a novice question but are there mechanisms or ways to trigger re-computing of the ruby's layout when the surrounding text has changed? In this case, you really don't need to re-layout the RenderRubyRun itself. You just need to possibly change its margins. I think hooking into findNextLineBreak is the easiest way to do this, since you can see your surroundings and figure out what it is you'd be overlapping and how much room you have on the line. dave (hy...@apple.com) ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Ruby Text Enhancements
A generic question: is there any in-depth documentation I can ready about block layout and how the various methods are supposed to be used? I've looked at the technical articles at http://webkit.org/coding/technical-articles.html but they seem to only have fairly high-level information and left me hungry for much more. Specific comments below. Regards, Eric On Sep 24, 2010, at 8:02 PM, David Hyatt wrote: It would probably be simpler to just subclass computeLogicalWidth (recently renamed from calcWidth) and modify the m_marginLeft and m_marginRight variables after calling the base class method. Then you don't have to add any new member variables. The big problem with building the overhang into margins at the initial calculation time, though, is that you may not get a relayout when objects around you change, so you won't get an opportunity to adjust your margins when that happens. Your margins are also computed before you've even know what's going on the line, so it could be really tricky to have all the information you need. Are you saying that subclassing computeLogicalWidth() would still mean that I'm computing the margins at the initial calculation time? It just doesn't seem like you can deal with all the corner cases without integrating right into line layout. I don't see how else you can know if you have adequate available space to actually overhang without knowing what you've seen so far on the line and how much space you have left on the line. This would require special-casing the ruby blocks in line layout code, right? I was trying to avoid this, hoping that I could just extend the existing ruby objects. This method makes several assumptions that I'm not 100% sure are always safe: * That a RenderRuby object holds only 1 RenderRubyRun object. I believe you can have multiple RenderRubyRuns inside a single RenderRuby. http://www.whatwg.org/specs/web-apps/current-work/multipage/text-level-semantics.html#the-ruby-element The ruby element allows one or more spans of phrasing content to be marked with ruby annotations. * That the text for the ruby text and ruby base are always the direct child of the RenderRubyText and RenderRubyBase object. I doubt that's a valid assumption. I assume that you can have a content tree of markup underneath a RenderRubyText and a RenderRubyBase, e.g., if you put in some i and some b. Anyway, I think you could just ask for the width() of the rubyText() and rubyBase() objects themselves rather than drilling down into their subtrees. I couldn't figure out how to ask the RenderRubyText and RenderRubyRun objects for their width. They don't support the width() method. What method should I call? ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Ruby Text Enhancements
On Sep 21, 2010, at 7:16 PM, Roland Steiner wrote: Hi Eric, comments inline: On Wed, Sep 22, 2010 at 6:57 AM, Eric Mader ema...@apple.com wrote: On Sep 20, 2010, at 9:52 PM, Roland Steiner wrote: Oh vey, that's ambituous! :) There's so many corner cases I foresee on this one that I was just too happy to postpone it when we originally discussed to leave out CSS3 ruby stuff from the initial implementation, which is purely based off HTML5 - including supporting multiple base/text pairs within a single ruby, and line-breaking within the ruby. Yes, it's a bit scary. ;-) I don't think I could implement the whole thing at once, so I'm looking at doing a partial implementation. Maybe the first round would only check to be sure that the neighboring blocks aren't ruby blocks. I would actually suggest cutting it down further and at first doing it only where the neighbor is plain text - this should still catch 90% of the cases where you'd want overhang and should vastly reduce the corner cases. You can verify and compute this rather easily when layouting the ruby, and you'd not need to worry about different glyph heights of neighboring inline elements, or about replaced elements interfering. Overhang would be basically be the minimum of: maximum overhang, or length of neighboring text run, or available/remaining space on the line. The latter factor may also cause you to need to break the ruby or move it to the next line altogether. I'll look at this idea too. What do I need to do to find the neighboring inline elements? I'm looking at using a RenderOverflow object to implement this. Can you point me at any documentation for this class, other than what's in the code? I'm having some trouble sorting out what all the various rectangles used in conjunction with this object represent. I have to say I'm not personally familiar with RenderOverflow, either (haven't used it with ruby). Just judging from the description it stores overflow rectangles for stuff that is actual content (layout overflow) and stuff that is pure cosmetic rendering, such as shadows or reflections (visual overflow). For ruby overhang you'd be looking at layout overflow in principle (unless the overhang text also has shadows and stuff, which may add to the visual overflow), AFAICT. But as I said, I'm not really an expert here. I've been looking at RenderOverflow, and I'm beginning to suspect that it's not the best way to proceed. Now I'm thinking that the negative margins are the way to go. My guess is that I need to set the margins on either the RenderRubyRun object or perhaps the RenderRuby object itself. To compute the correct margins, it looks to me like I'll need to access the widths of the RenderRubyText and RenderRubyBase objects. So far, I haven't been able to work out how to do that. Any clues would be greatly appreciated. Cheers, - Roland Regards, Eric ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Ruby Text Enhancements
Great to see someone else interested in doing ruby implementation! :) I did the original ruby implementation, so I'm very happy to help with any questions/problems/issues (bugs? there are not bugs!). BTW, please note that there is another ruby patch in the review pipeline: https://bugs.webkit.org/show_bug.cgi?id=41040 (had to modify and re-submit this one after in-flight clashes with another patch) that might affect the implementation. On Tue, Sep 21, 2010 at 3:12 AM, David Hyatt hy...@apple.com wrote: On Sep 17, 2010, at 8:07 PM, Eric Mader wrote: Hi, I'm working on making the following enhancements to Ruby Text: 1) Implement the behavior of ruby-overhang:auto Oh vey, that's ambituous! :) There's so many corner cases I foresee on this one that I was just too happy to postpone it when we originally discussed to leave out CSS3 ruby stuff from the initial implementation, which is purely based off HTML5 - including supporting multiple base/text pairs within a single ruby, and line-breaking within the ruby. 2) implement the behavior of ruby-line-stacking:exclude-ruby Which way do you intend to implement this? AFAICT the current consensus seems to go towards having ruby included by default rather than excluded. 3) Add some Mac OS specific character properties to the ruby text 4) Turn off the underline when the ruby text is in a link I've looked at the code enough to know that the layout or ruby text is done by the normal block stacking in BlockLayout. I'm guessing that I can do at lest the first two tasks by changing the RenderRuby code to report a different width and / or height for the ruby block. Does this seem like the right way to do what I want? Assuming for the moment that it is, I have some questions: 1) What methods should I subclass to report the adjusted width and height? I'm very hazy on the Ruby implementation. I believe it makes an inline-block with two block children vertically stacked, and then it uses text-align:center to center the ruby base. If so, this behavior has to be preserved when the ruby text is wider than the base. Yes, that's the basic layout for a single ruby text/base pair. Note that multiple such pairs may be contained within a single ruby element (which is normally an inline element, unless it's floated or positioned). A ruby may also include renderers for :before and :after content, which are outside of the inline-blocks for base/text pairs. This is implemented in the aforementioned patch for 41040, which also fixes some issues with RenderRubyAsBlock and supersedes the patch for 43722). I think a reasonable way to implement overhang therefore would be with negative margins applied to the ruby run. This way the correct layout of the Ruby object is preserved, and the surrounding text will just naturally get pushed inside the Ruby object to overlap it. Basically you can compare the delta in width between the base and the text and then apply margins to either side of the ruby run based off how you want to overhang. That's also what I'd suggest. However, there are the following additional things to consider: .) The margin on the left side may need to be reduced because of line start (setting it to 0), or neighboring elements that reduce how much it can overhand (larger text or other element, a neighboring ruby element, etc.). .) The same goes for the right margin - however, this one is vastly more tricky, since the following elements are probably not yet layouted. Depending on what follows (text you can overhang, stuff that turns out you can't overhang, the line end) you might need to increase the projected width of the whole ruby run, which in turn might push out following elements. There might even be extreme cases where ruby text overhangs multiple following objects if those are very small. You also need to be careful caching any values inside used for this inside the ruby, because whether a ruby text may/may not overhang (or by how much) may change dependent on changes inside _neighboring_ elements. Also, please note that currently the size of rt is set at 60% of the base, which is different from the standard 50%. This was chosen because it improves readability on (low dpi) screens. If you implement ruby overhang properly, esp. for the purposes of CJK rendering (see http://www.w3.org/TR/2009/NOTE-jlreq-20090604/#en-subheading2_3_3), you may want/need to reconsider this, or adjust your implementation to take the difference into consideration. 2) If the ruby text is wider than the ruby base and I report the width of the base as the width of the whole block will some of the ruby text get clipped, or will it all still draw? It would all still draw as long as you set up overflow correctly. You can look for addLayoutOverflow methods. I think you may be able to use negative margins for overhang though without altering your reported width. 3) Ruby text is only allowed to overhang the base in
Re: [webkit-dev] Ruby Text Enhancements
On Sep 21, 2010, at 2:52 AM, Roland Steiner wrote: We'd probably need to add a new value to that property if Ruby is supposed to be skipped. Ergh Looking at it, I'm not sure that's a good proposal at all - at least it has still lots to address (it doesn't address list bullets, or :before/:after generated content, for one). I think that the best approach for ruby would be to view the whole ruby run (i.e., base and text combined) as the main object for text-decoration, and not the base and text individually. That is: .) underline: line painted below the base only, over the width of base and text (but excluding any overhangs!) .) overline: overline painted above the text, same as above - note that the line width doesn't (!) change .) line-through: either just the base is decorated, or both base and text. I can see arguments for either way, although I think painting a line-through through the text may overly obscure it, since it's quite small - note that the line width for the ruby text would need to be different in this case as well, which in turn probably means amending the spec. .) blink: all blinks ;) This however means that a rule for rt would need to affect the ruby text separately, independent of the decoration of the whole thing (which IMHO would be a good thing anyway). Yeah the main point I was trying to make with text-decoration is that in the strict mode model it's the element with text-decoration on it that draws the line. So right now if you have: a[some ruby] /a It's the line boxes for the a element that draw a line, and it just cuts through the ruby no matter where the ruby happens to be (just as it might cut through any other objects like images that might have a different vertical alignment). We have no concept of making that line skip elements or do something different, so it's a fair bit of work to customize the behavior. Even more annoying is that text-decoration has two completely different code paths for quirks vs. strict mode. In quirks mode, the underlines are drawn by the elements themselves (so e.g., you get no underlines under images in quirks mode), and so customizing the line drawing behavior will be easier to do in quirks mode. ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Ruby Text Enhancements
On Sep 20, 2010, at 9:52 PM, Roland Steiner wrote: Great to see someone else interested in doing ruby implementation! :) I did the original ruby implementation, so I'm very happy to help with any questions/problems/issues (bugs? there are not bugs!). BTW, please note that there is another ruby patch in the review pipeline: https://bugs.webkit.org/show_bug.cgi?id=41040 (had to modify and re-submit this one after in-flight clashes with another patch) that might affect the implementation. On Tue, Sep 21, 2010 at 3:12 AM, David Hyatt hy...@apple.com wrote: On Sep 17, 2010, at 8:07 PM, Eric Mader wrote: Hi, I'm working on making the following enhancements to Ruby Text: 1) Implement the behavior of ruby-overhang:auto Oh vey, that's ambituous! :) There's so many corner cases I foresee on this one that I was just too happy to postpone it when we originally discussed to leave out CSS3 ruby stuff from the initial implementation, which is purely based off HTML5 - including supporting multiple base/text pairs within a single ruby, and line-breaking within the ruby. Yes, it's a bit scary. ;-) I don't think I could implement the whole thing at once, so I'm looking at doing a partial implementation. Maybe the first round would only check to be sure that the neighboring blocks aren't ruby blocks. I'm looking at using a RenderOverflow object to implement this. Can you point me at any documentation for this class, other than what's in the code? I'm having some trouble sorting out what all the various rectangles used in conjunction with this object represent. 2) implement the behavior of ruby-line-stacking:exclude-ruby Which way do you intend to implement this? AFAICT the current consensus seems to go towards having ruby included by default rather than excluded. Well, the spec. says that exclude-ruby is the default. Looking at a few example sites, it seems that they don't use big enough inter-line spacing to accommodate ruby text, so changing the exclude-ruby as the default would result in the ruby overlapping the previous line, which is probably worse than the current state where the inter-line spacing isn't uniform. (using 60% as the default size for ruby text probably makes this a bit worse) As ruby implementations with the specified default implemented become more common, I expect that sites will be updated to use correct inter-line spacing and everyone will be happy. In the near-term, though, things will look worse if we implement the default... 3) Add some Mac OS specific character properties to the ruby text 4) Turn off the underline when the ruby text is in a link I've looked at the code enough to know that the layout or ruby text is done by the normal block stacking in BlockLayout. I'm guessing that I can do at lest the first two tasks by changing the RenderRuby code to report a different width and / or height for the ruby block. Does this seem like the right way to do what I want? Assuming for the moment that it is, I have some questions: 1) What methods should I subclass to report the adjusted width and height? I'm very hazy on the Ruby implementation. I believe it makes an inline-block with two block children vertically stacked, and then it uses text-align:center to center the ruby base. If so, this behavior has to be preserved when the ruby text is wider than the base. Yes, that's the basic layout for a single ruby text/base pair. Note that multiple such pairs may be contained within a single ruby element (which is normally an inline element, unless it's floated or positioned). A ruby may also include renderers for :before and :after content, which are outside of the inline-blocks for base/text pairs. This is implemented in the aforementioned patch for 41040, which also fixes some issues with RenderRubyAsBlock and supersedes the patch for 43722). I think a reasonable way to implement overhang therefore would be with negative margins applied to the ruby run. This way the correct layout of the Ruby object is preserved, and the surrounding text will just naturally get pushed inside the Ruby object to overlap it. Basically you can compare the delta in width between the base and the text and then apply margins to either side of the ruby run based off how you want to overhang. That's also what I'd suggest. However, there are the following additional things to consider: See my comments about RenderOverflow above. Is that the right way to go? Do I set the width of the ruby block to the width of the base text, or to the width of the ruby text and then give it the appropriate margins? About turning off the underline if the ruby is in a link: I've looked at the styles and tried adding code to change the parts that I think relate to this, but haven't found anything that makes a difference. It's also occurred to me that I might be able to do this by writing
Re: [webkit-dev] Ruby Text Enhancements
Hi Eric, comments inline: On Wed, Sep 22, 2010 at 6:57 AM, Eric Mader ema...@apple.com wrote: On Sep 20, 2010, at 9:52 PM, Roland Steiner wrote: Oh vey, that's ambituous! :) There's so many corner cases I foresee on this one that I was just too happy to postpone it when we originally discussed to leave out CSS3 ruby stuff from the initial implementation, which is purely based off HTML5 - including supporting multiple base/text pairs within a single ruby, and line-breaking within the ruby. Yes, it's a bit scary. ;-) I don't think I could implement the whole thing at once, so I'm looking at doing a partial implementation. Maybe the first round would only check to be sure that the neighboring blocks aren't ruby blocks. I would actually suggest cutting it down further and at first doing it only where the neighbor is plain text - this should still catch 90% of the cases where you'd want overhang and should vastly reduce the corner cases. You can verify and compute this rather easily when layouting the ruby, and you'd not need to worry about different glyph heights of neighboring inline elements, or about replaced elements interfering. Overhang would be basically be the minimum of: maximum overhang, or length of neighboring text run, or available/remaining space on the line. The latter factor may also cause you to need to break the ruby or move it to the next line altogether. I'm looking at using a RenderOverflow object to implement this. Can you point me at any documentation for this class, other than what's in the code? I'm having some trouble sorting out what all the various rectangles used in conjunction with this object represent. I have to say I'm not personally familiar with RenderOverflow, either (haven't used it with ruby). Just judging from the description it stores overflow rectangles for stuff that is actual content (layout overflow) and stuff that is pure cosmetic rendering, such as shadows or reflections (visual overflow). For ruby overhang you'd be looking at layout overflow in principle (unless the overhang text also has shadows and stuff, which may add to the visual overflow), AFAICT. But as I said, I'm not really an expert here. Cheers, - Roland ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Ruby Text Enhancements
On Sep 17, 2010, at 8:07 PM, Eric Mader wrote: Hi, I'm working on making the following enhancements to Ruby Text: 1) Implement the behavior of ruby-overhang:auto 2) implement the behavior of ruby-line-stacking:exclude-ruby 3) Add some Mac OS specific character properties to the ruby text 4) Turn off the underline when the ruby text is in a link I've looked at the code enough to know that the layout or ruby text is done by the normal block stacking in BlockLayout. I'm guessing that I can do at lest the first two tasks by changing the RenderRuby code to report a different width and / or height for the ruby block. Does this seem like the right way to do what I want? Assuming for the moment that it is, I have some questions: 1) What methods should I subclass to report the adjusted width and height? I'm very hazy on the Ruby implementation. I believe it makes an inline-block with two block children vertically stacked, and then it uses text-align:center to center the ruby base. If so, this behavior has to be preserved when the ruby text is wider than the base. I think a reasonable way to implement overhang therefore would be with negative margins applied to the ruby run. This way the correct layout of the Ruby object is preserved, and the surrounding text will just naturally get pushed inside the Ruby object to overlap it. Basically you can compare the delta in width between the base and the text and then apply margins to either side of the ruby run based off how you want to overhang. 2) If the ruby text is wider than the ruby base and I report the width of the base as the width of the whole block will some of the ruby text get clipped, or will it all still draw? It would all still draw as long as you set up overflow correctly. You can look for addLayoutOverflow methods. I think you may be able to use negative margins for overhang though without altering your reported width. 3) Ruby text is only allowed to overhang the base in some cases. To know when it's OK, I'll need to examine the neighboring text. Can I always find the neighboring text by walking the render tree? This is going to be tricky. You basically want to walk the line box tree rather than the renderobject tree and then look at surrounding text. About turning off the underline if the ruby is in a link: I've looked at the styles and tried adding code to change the parts that I think relate to this, but haven't found anything that makes a difference. It's also occurred to me that I might be able to do this by writing a rule in WebKitWebCore/css/html.css, but I can't figure out exactly what the rule would look like. I tried adding text-decoration: none to the ruby rt section, but that doesn't do it. (at first, I thought that is was probably overkill, but now I think that turning text-decoration off for all ruby text is probably right.) There is no way to do this. The closest I see is: http://dev.w3.org/csswg/css3-text/#text-decoration-skip This is not implemented in WebKit yet. We'd probably need to add a new value to that property if Ruby is supposed to be skipped. dave (hy...@apple.com) ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Ruby Text Enhancements
On Mon, Sep 20, 2010 at 11:12 AM, David Hyatt hy...@apple.com wrote: This is going to be tricky. You basically want to walk the line box tree rather than the renderobject tree and then look at surrounding text. About turning off the underline if the ruby is in a link: I've looked at the styles and tried adding code to change the parts that I think relate to this, but haven't found anything that makes a difference. It's also occurred to me that I might be able to do this by writing a rule in WebKitWebCore/css/html.css, but I can't figure out exactly what the rule would look like. I tried adding text-decoration: none to the ruby rt section, but that doesn't do it. (at first, I thought that is was probably overkill, but now I think that turning text-decoration off for all ruby text is probably right.) There is no way to do this. The closest I see is: http://dev.w3.org/csswg/css3-text/#text-decoration-skip This is not implemented in WebKit yet. We'd probably need to add a new value to that property if Ruby is supposed to be skipped. Can't we ignore all text decorations when rendering a text node inside rt? - Ryosuke ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
[webkit-dev] Ruby Text Enhancements
Hi, I'm working on making the following enhancements to Ruby Text: 1) Implement the behavior of ruby-overhang:auto 2) implement the behavior of ruby-line-stacking:exclude-ruby 3) Add some Mac OS specific character properties to the ruby text 4) Turn off the underline when the ruby text is in a link I've looked at the code enough to know that the layout or ruby text is done by the normal block stacking in BlockLayout. I'm guessing that I can do at lest the first two tasks by changing the RenderRuby code to report a different width and / or height for the ruby block. Does this seem like the right way to do what I want? Assuming for the moment that it is, I have some questions: 1) What methods should I subclass to report the adjusted width and height? 2) If the ruby text is wider than the ruby base and I report the width of the base as the width of the whole block will some of the ruby text get clipped, or will it all still draw? 3) Ruby text is only allowed to overhang the base in some cases. To know when it's OK, I'll need to examine the neighboring text. Can I always find the neighboring text by walking the render tree? About turning off the underline if the ruby is in a link: I've looked at the styles and tried adding code to change the parts that I think relate to this, but haven't found anything that makes a difference. It's also occurred to me that I might be able to do this by writing a rule in WebKitWebCore/css/html.css, but I can't figure out exactly what the rule would look like. I tried adding text-decoration: none to the ruby rt section, but that doesn't do it. (at first, I thought that is was probably overkill, but now I think that turning text-decoration off for all ruby text is probably right.) Regards, Eric Mader ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
