[css-inline] Make initial-letter a shorthand for initial-letter-drop and initial-letter-size. Clarify boundaries of content box for initial-letter. This is all in response to http://lists.w3.org/Archives/Public/www-style/2014Sep/0049.html

Author: dauwhe

css-inline/Overview.bs

@@ -2346,7 +2346,7 @@ The alignment constraints depend on the script used. In Japanese vertical writin
 
 
 
-<p class="issue">Add content describing constraint that the block container have a baseline grid (or fixed line-height?).</p>
+<p class="issue">Add content describing constraint that the block container have a baseline grid (or fixed line-height?). Can we say that the UA can treat other inline or replaced elements in the para as having line-height equal to zero when calculating the initial letter's alignment?</p>
 
 
 <h3 id="selecting-drop-initials">Selecting Initial Letters</h3>
@@ -2380,13 +2380,13 @@ Only the following properties can be applied to the <code>::first-letter</code>
 
 
 
-<h3 id="sizing-drop-initials">Creating Initial Letters: The 'initial-letter' Property</h3>
+<h3 id="sizing-drop-initials">Creating Initial Letters: The 'initial-letter' shorthand</h3>
 
-The 'initial-letter' property takes two positive integer values. The first argument defines the number of lines the initial letter should sink. An N-line initial letter sinks to the Nth text baseline. The optional second argument defines how many lines the initial letter occupies. If not specified, it duplicates the first argument. 
+This <i>shorthand property</i> for 'initial-letter-drop' and 'initial-letter-size' takes two positive integer values. The first argument defines the number of lines the initial letter should sink. An N-line initial letter sinks to the Nth text baseline. The optional second argument defines how many lines the initial letter occupies. If not specified, it duplicates the first argument. 
 
 <pre class="propdef">
 Name: <dfn id="propdef-initial-letter">initial-letter</dfn>
-Value: [<<integer>> <<integer>>?]
+Value: normal | [<<integer>> <<integer>>?]
 Initial: normal
 Applies to: <code>::first-letter</code> pseudo elements and inline level first child of a block container
 Inherited: no
@@ -2395,6 +2395,8 @@ Media: visual
 Computed value: ???
 </pre>
 
+<p class="note">Unlike most shorthands, omitting an argument does not result in the initial value for that argument being used.</p>
+
 
 <div class="example">
 
@@ -2413,7 +2415,47 @@ p::first-letter {
 
 
 
-Some styles of drop initials do not align with the first line of text. For example, “sunken caps” both sink below the first baseline, and extend above the first line of text. In these cases, the size of the initial cap needs to be defined. The optional second argument of 'initial-letter' specifies the size of an initial letter, as if it were an n-line drop cap.
+
+
+
+
+<h3>The initial-letter-drop property</h3>
+
+This longhand describes the line to which an initial letter “sinks.” As in the above example, the baseline of a three-line initial letter aligns to the third text baseline of the paragraph.
+
+
+
+<pre class="propdef">
+Name: <dfn id="propdef-initial-letter-drop">initial-letter-drop</dfn>
+Value: normal | <<integer>>
+Initial: normal
+Applies to: <code>::first-letter</code> pseudo elements and inline level first child of a block container
+Inherited: no
+Percentages: N/A
+Media: visual
+Computed value: ???
+</pre>
+
+<h3>The initial-letter-size property</h3>
+
+
+Some styles of drop initials do not align with the first line of text. For example, “sunken caps” both sink below the first baseline, and extend above the first line of text. In these cases, the size of the initial cap needs to be defined. The 'initial-letter-size' property specifies the size of the initial letter, as if it were an n-line drop cap.
+
+
+
+
+<pre class="propdef">
+Name: <dfn id="propdef-initial-letter-size">initial-letter-size</dfn>
+Value: normal | <<integer>>
+Initial: normal
+Applies to: <code>::first-letter</code> pseudo elements and inline level first child of a block container
+Inherited: no
+Percentages: N/A
+Media: visual
+Computed value: ???
+</pre>
+
+
 
 
 
@@ -2426,20 +2468,25 @@ Some styles of drop initials do not align with the first line of text. For examp
 
 <figure>
 <img src="SunkenCapA.png" width="480" alt="sunken drop initial"/>
-<p class="caption">Sunken cap. The letter drops two lines, but is the size of a three-line initial letter.</p>
+<p class="caption">Sunken cap. The letter drops to the second line, but is the size of a three-line initial letter.</p>
 </figure>
 <pre>
-
+/* shorthand */
 p::first-letter {
   initial-letter: 2 3;
 }
 
+/* longhand */
+p::first-letter {
+  initial-letter-drop: 2;
+  initial-letter-size: 3;
+}
 </pre>
 
 </div>
 
 
-If the first argument is ''1'', that creates a pure raised initial letter (often called “raised cap” or “stick-up cap.”
+ If 'initial-letter-drop' is ''1'', that creates a pure raised initial letter (often called a “raised cap” or “stick-up cap.” It “sinks” to the first text baseline.
 
 
 <div class="example">
@@ -2449,11 +2496,16 @@ If the first argument is ''1'', that creates a pure raised initial letter (often
 <p class="caption">Raised cap. The initial letter is the size of a 3-line initial, but does not drop.</p>
 </figure>
 <pre>
-
+/* shorthand */
 p::first-letter {
   initial-letter: 1 3;
 }
 
+/* longhand */
+p::first-letter {
+  initial-letter-drop: 1;
+  initial-letter-size: 3;
+}
 </pre>
 
 </div>
@@ -2502,11 +2554,10 @@ span.initial {
   initial-letter-alignment: ideographic;
 }
 </pre>
-
-
 </div>
 
 
+
 <h3 id="initial-letter-exclusions">Space Around Initial Letters</h3>
 
 If an initial letter has a descender, it could crash into the (n+1)th line of text. This is not desirable.
@@ -2526,6 +2577,10 @@ Text should be excluded around the glyph bounding boxes of the initial letters:
 </figure>
 
 
+<p class="note">For Western scripts, an initial letter acts as a content box bounded at the top by the cap height of the font, and at the bottom by the glyph bounding box. Borders, margins, and padding will extend from this content box.</p>
+<p class="issue">The content box will need to be different for non-Western scripts. Perhaps this should be defined as part of the 'initial-letter-alignment' property.</p>
+
+
 <h3 id="initial-letter-paragraphs">Interactions of initial letters with surrounding paragraphs</h3>
 
 <h4>Raised and sunken caps</h4>