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Re: Float overflowing behavior!

From: Vadim Plessky <lucy-ples@mtu-net.ru>
Date: Mon, 19 Aug 2002 18:09:43 +0400
To: www-style@w3.org, Coises <Randy@Coises.com>
Message-Id: <200208191809.43352.lucy-ples@mtu-net.ru>

On Monday 19 August 2002 2:34 am, Coises wrote:
|  [Sun, 18 Aug 2002 11:43:33 +0000 (GMT)] Ian Hickson:
|  >On Sat, 17 Aug 2002, C. Bottelier wrote:
|  >> To summarize an element can be made float inorder to achieve the
|  >> 6 cases seen in this thread.
|  >
|  >For the benefits of the working group, could you summarise these 6 cases
|  >as well?
|
|  The six cases given in this thread were:
|

testcase (or picture demonstrating supposed rendering) would help

|  1. Box floats to the left content edge of the containing block; subsequent
|  text flows around it.
|
|  2. Box floats to the left content edge of the containing block; text from
|  the containing block flows around it, but the containing block is extended
|  at the bottom, if necessary, to encompass the float.
|
|  3. Box floats to the left content edge of the containing block; some
|  subsequent text flows around it, but either a subsequent block or an
|  ancestor of the containing block is extended at the bottom, if necessary,
|  so that the float does not run past it.
|
|  4. Box floats to the left content edge of a specified ancestor of the
|  containing block.
|
|  5. Box floats to the left content edge of the containing block and second
|  box floats to the right edge of the first.  The containing block is
|  extended at the bottom to encompass the first float, but not the second.
|
|  6. Text flows around the irregular edge of inclusions and/or line boxes in
|  the float (rather than around the float box itself).
|
|  >At least one of the six cases can be done using CSS1 (see
|  >http://lists.w3.org/Archives/Public/www-style/2002Aug/0137.html) so it's
|  >not completely clear that all the proposed properties are needed.
|
|  Case 1 is the only one of these handled *naturally* by CSS2.
|
|  Cases 2 and 3 can be accomplished in CSS2 by adding a "dummy" element at
|  the end of the block to be extended and setting the "clear" property on
| it.
|
|  Case 4 can be accomplished in CSS2 by using a negative value for the
|  margin-left property so long as the required value can be computed
|  when the style sheet is written.  (E.g., suppose the block containing the
|  box to be floated has "font-size: small"; the block containing it has
|  "font-size: large"; both blocks have non-zero padding-left which is
|  expressed in em spaces; and the box is to be floated to the content edge
| of the parent of the latter block.  As far as I can see, there would be no
| way to specify the necessary margin-left value, as it would be the sum of
| em-space measures from two different entries in the font size tables.)
|
|  Cases 5 and 6 probably cannot be accomplished at all using CSS2.
|
|  >While some of the suggested properties look very interesting, we are of
|  >course very wary of adding 3 new properties without looking very
|  > carefully at the requirements. Also, changing 'float', a property that
|  > was introduced in CSS1 and still has no completely correct
|  > implementation, is something that would have to be considered very
|  > carefully indeed.
|
|  The "float-contour" property was specifically suggested for case 6;
|  it does nothing to help in the other cases, and appears unrelated to the
|  other proposed changes.  I believe it can be considered independently.
|
|
|  The "float-overflow" property as proposed by the original poster in this
|  thread was meant to handle cases 2 and 3 in a more natural way.  It would
|  do nothing to help in cases 4, 5 and 6.
|
|  It was noted that "float-overflow" could be defined to apply to floats
|  themselves (instead of to blocks to be extended by floats, as in the
|  original proposal).  This would handle cases 2 and 5 in a straightforward
|  fashion; it would do nothing to help in cases 3, 4 and 6.
|
|
|  I suggested some extensions to the "float" property syntax and the
| addition of the "float-bounds" property as an alternative to
| "float-overflow."
|
|  The additional values I suggested for the float property were intended to
|  open discussion as to the underlying logic of floats, and possible ways
|  floats could be used.  They do not directly address any of the problem
|  cases yet discussed in this thread, but rather (with the "float-bounds"
|  property) were meant to suggest a fuller model of "what a float is."
|
|  The "float-bounds" property directly addresses cases 1-5 --- though case 3
|  can be handled only when the block to be extended is an ancestor of the
|  float, not a subsequent block.  (In practical cases, I do not expect this
|  to be a problem; however, it is a limitation which is not shared by the
|  original "float-overflow" proposal.)  "Float-bounds" won't help in case 6.
|
|  "Float-bounds" can be thought of as (in part) a way to combine the
| original and variant versions of "float-overflow," taking the best points
| of each:
|
|  * Extended element doesn't have to be the float's parent.  (original)
|  * Different floats in same context can be handled differently.  (variant)
|  * Applies to the floats, where one would expect to find it.  (variant)
|
|  as well as adding the ability to float to an edge of an ancestor element
|  other than the immediate parent without having to calculate a negative
|  margin property to achieve the effect.

-- 

Vadim Plessky
http://kde2.newmail.ru  (English)
33 Window Decorations and 6 Widget Styles for KDE
http://kde2.newmail.ru/kde_themes.html
KDE mini-Themes
http://kde2.newmail.ru/themes/
Received on Monday, 19 August 2002 10:59:12 GMT

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