Put in the line-box-contain text (still needs more editing). (date: 2003/06/01 00:30:27)

Author: dbaron

css3-linebox/Overview.src.html

@@ -660,7 +660,9 @@ <h3 id="InlineBoxHeight"><span class="secno">3.4. </span>Line height adjustment:
   <dd>For inline-level elements, the element does not influence the <i>extended
   block-progression dimension</i> of the line. The computed value is the
   specified value ('none').  For block-level elements, equivalent to 'normal'
-  (and the computed value is 'normal').</dd>
+  (and the computed value is 'normal').
+  <span class="issue">This definition should be briefer, and should
+  refer to the next section.</span></dd>
 </dl>
 <div class="example">
   <p style="DISPLAY: none">Example(s):</p>
@@ -698,6 +700,179 @@ <h3 id="LineStacking"><span class="secno">3.5. </span>Line Stacking: the
  <span class="property"><a href="#line-box-contain">'line-box-contain'</a></span> property</h3>
 
 
+<table class="propdef" id="name-30">
+<tbody>
+<tr>
+<td><em>Name:</em>
+
+<td><dfn id="line-box-contain">line-box-contain</dfn>
+
+<tr>
+<td><em>Value:</em>
+
+<td>[ block || inline || font || text || replaced || inline-box ] | none |
+inherit | initial
+
+<tr>
+<td><em>Initial:</em>
+
+<td>block inline replaced
+
+<tr>
+<td><em>Applies to:</em>
+
+<td>block-level elements
+
+<tr>
+<td><em>Inherited:</em>
+
+<td>yes
+
+<tr>
+<td><em>Percentages:</em>
+
+<td>N/A
+
+<tr>
+<td><em>Media:</em>
+
+<td>visual
+
+<tr>
+<td><em>Computed value:</em>
+
+<td>specified value (except for 'inherit' and 'initial')
+</table>
+
+<p>This property enumerates which aspects of the elements in a line box
+contribute to the height height of that line box.
+
+<dl>
+<dt>block
+
+<dd>The extended block progression dimension of the root inline box
+must fit within the line box.
+
+<dt>inline
+
+<dd>The extended block progression dimension of all non-replaced
+inline boxes whose 'line-height' is not 'none' in the line box must fit within the line box.
+
+<dt>font
+
+<dd>The block progression dimension of all non-replaced inline boxes
+whose 'line-height' is not 'none'
+that directly (i.e., within the box but not within one of its
+descendants) contain non-removed text must fit within the line box,
+where non-removed text is any characters not removed based on the values
+of the 'linefeed-treatment', 'white-space-treatment', and
+'all-space-treatment' properties.  <span class="issue">[LDB: This isn't
+quite right.  What about zwnj, etc.?</span>
+
+<dt>replaced
+
+<dd>The margin box of all <span title="replaced element"><a
+href="#replaced">replaced elements</a></span> within the line
+must fit within the line box.
+
+<dt>inline-box
+
+<dd>The margin-box of all non-replaced inline elements in the
+line must fit within the line box.
+<span class="issue">Should this split into 'inline-border' and
+'inline-margin'?</span>
+
+<p>If the property has no value for all elements within a line, then the line
+box has 0 height, and the line within the anonymous inline established by the
+block that coincides with the line block is the baseline of that anonymous
+inline block (or should it be determined by the 'vertical-align' property of
+the block?). <span class="issue">[This is arbitrary. Does anyone have better
+ideas?]</span>
+
+<p class="note">Note that the CSS2 model is equivalent to 'block inline
+replaced' but the backwards-compatible HTML model is similar to (but not
+exactly) 'font replaced' [1].
+
+<p class="issue">Concerns: * How does this work with the cascade? * What
+about determining the visual size of inline boxes?
+
+<p class="issue">[1] I believe the differences are restricted to the first
+line of LI elements, the last line of LI, DD, and DT elements, and issues
+concerning whitespace around images. [DB]
+
+<p>The height of each line box is established as follows (we describe the
+case for <em><a href="#horizontal">horizontal flow</a></em>, but vertical
+flow is analogous). First align all the boxes on the line relative to each
+other according to the rules for <span
+class="property">'vertical-align'</span>. The line box must satisfy all of
+the following constraints:
+
+<ol>
+<li>For each box on the line that has <span class="css">'font'</span> in its
+value of <span class="property"><a
+href="#line-box-contain">'line-box-contain'</a></span>, the line box must be
+high enough to contain the <span title="top of the text"><a
+href="#top-of">top and bottom of that box's text</a></span>.
+
+<li>For each box that has <span class="css"><a
+href="#inline">'inline'</a></span> in <span class="property"><a
+href="#line-box-contain">'line-box-contain'</a></span>, the top of the line
+box must be at least as high as the <span title="top of the text"><a
+href="#top-of">top of the box's text</a></span> plus the box's <em><a
+href="#half-leading">half-leading</a></em>. The bottom of the line box must
+be at least as low as the bottom of the text plus the half-leading.
+
+<li>For each box that has <span class="css">'inline-box'</span> in <span
+class="property"><a href="#line-box-contain">'line-box-contain'</a></span>,
+the top of the line box must be at least as high as the margin-top of this
+box. The bottom of the line box must be at least as low as the margin-bottom.
+
+<li>For each <em>replaced box</em> that has <span
+class="css">'replaced'</span> in its <span class="property"><a
+href="#line-box-contain">'line-box-contain'</a></span>, the line box must
+contain the margin-top and margin-bottom of this box. <span
+class="issue">[The value 'replaced' is not strictly needed. 'Inline-box' also
+does the job, except that it is not automatically restricted to replaced
+elements.]</span>
+
+<li>For each box that has <span class="css">'text'</span> in <span
+class="property"><a href="#line-box-contain">'line-box-contain'</a></span>,
+the top of the line box must be at least as high as the top of each glyph in
+the box (excluding those in child elements). The bottom of the line box must
+be at least as low as the bottom of each glyph in the box (excluding child
+elements).
+
+<li>If the enclosing block for this line has <span class="css"><a
+href="#block">'block'</a></span> in <span class="property"><a
+href="#line-box-contain">'line-box-contain'</a></span>, then the top of the
+line box must be at least as high as the text top plus the half-leading of an
+<em><a href="#anonymous">anonymous inline element</a></em> and the bottom of
+the line box as low as the text bottom plus the half leading. This must hold
+whether or not this line actually contains such an element.
+</ol>
+
+<p class="note">Thus 'block' can be used to set an overall minimum line
+height (viz. the value of 'line-height' of the element itself) for all lines
+in an element, independent of the actual contents of each line. In
+particular, setting 'line-box-contain' to just 'block' and no other values
+will ensure that all lines are the same height, at the possible risk of some
+tall inline elements overlapping with lines above or below.
+
+<p>The <dfn id="half-leading">half-leading</dfn> of a box is defined as half
+the computed value of 'line-height' minus half the computed value of
+'font-size', i.e., (line-height - font-size)/2.
+
+<p>The <dfn id="top-of">top of the text</dfn> is the top of the em-box of a
+box's nominal font, whether or not there actually is any letter that tall.
+Replaced elements, for example, have no text, but still have a nominal font
+and are thus a text top. The rules above refer to the position of the text
+top after the box has been aligned with 'vertical-align'.
+
+
+
+
+<h4>Old, remove this:</h4>
+
 <p>Line stacking is the mechanism by which a line box is determined for each 
 line in a block and then these lines are stacked in the block-progression 
 direction resolving any spacing constraints between adjacent lines. The