[css-nav-1] Disambiguate between two similar terms

Closes #3389

Author: frivoal

css-nav-1/Overview.bs

@@ -1025,25 +1025,25 @@ Issue(23): The focusing steps should probably reset the <a>spatial navigation st
 <div algorithm="to run the spatial navigation steps">
 To run the <dfn>spatial navigation steps</dfn> in <var>direction</var>, do the following:
 
-1. Let <var>startingPoint</var> be the <a>DOM anchor</a> of the <a>currently focused area of a top-level browsing context</a>.
+1. Let <var>searchOrigin</var> be the <a>DOM anchor</a> of the <a>currently focused area of a top-level browsing context</a>.
 2. If the <a>spatial navigation starting point</a> is not <code>null</code>
-    and it is inside <var>startingPoint</var>
-    then set <var>startingPoint</var> to the <a>spatial navigation starting point</a>
+    and it is inside <var>searchOrigin</var>
+    then set <var>searchOrigin</var> to the <a>spatial navigation starting point</a>
 3.
-    * If <var>startingPoint</var> is an <a>node</a>,
-        let <var>eventTarget</var> be <var>startingPoint</var>
-    * else (<a>assert</a>: the starting point is a position)
-        let <var>eventTarget</var> be the <a>node</a> which contains <var>startingPoint</var>
+    * If <var>searchOrigin</var> is an <a>node</a>,
+        let <var>eventTarget</var> be <var>searchOrigin</var>
+    * else (<a>assert</a>: <var>searchOrigin</var> is a position)
+        let <var>eventTarget</var> be the <a>node</a> which contains <var>searchOrigin</var>
 4. If <var>eventTarget</var> is the <a>Document</a> or the <a>document element</a>,
         set <var>eventTarget</var> be <a>the body element</a> if it is not <code>null</code>
         or to the <a>document element</a> otherwise.
-5. If <var>startingPoint</var> is either a <a>scroll container</a> or the <a>document</a>
+5. If <var>searchOrigin</var> is either a <a>scroll container</a> or the <a>document</a>
     1. Let <var>candidates</var> be the result of <a>finding focusable areas</a>
-        within <var>startingPoint</var>
+        within <var>searchOrigin</var>
     2.
         * If <var>candidates</var> contains at least 1 item:
             1. Let <var>bestCandidate</var> be the result of <a>selecting the best candidate</a>
-                within <var>candidates</var> in <var>direction</var> starting from <var>startingPoint</var>
+                within <var>candidates</var> in <var>direction</var> starting from <var>searchOrigin</var>
             2. <span class=api><a>Fire an event</a> named <a event>navbeforefocus</a> at <var>eventTarget</var> using {{NavigationEvent}}
                 with its {{NavigationEvent/dir}} set to <var>direction</var> and {{NavigationEvent/relatedTarget}} set to <var>bestCandidate</var>
                 and with it's <code>bubbles</code> and <code>cancelable</code> attributes set to <code>true</code>,
@@ -1059,7 +1059,7 @@ To run the <dfn>spatial navigation steps</dfn> in <var>direction</var>, do the f
         * Else, fallback to the next step
 6. Let <var>container</var> be the nearest ancestor of <var>eventTarget</var> that is a <a>spatial navigation container</a>.
 7. <i>Loop</i>: Let <var>candidates</var> be the result of <a>finding focusable areas</a>
-    within <var>container</var>, excluding <var>startingPoint</var>
+    within <var>container</var>, excluding <var>searchOrigin</var>
 8. If <var>candidates</var> is empty:
     * If <var>container</var> is a <a>scroll container</a> that <a>can be manually scrolled</a>:
             1. <span class=api><a>Fire an event</a> named <a event>navbeforescroll</a> at <var>eventTarget</var> using {{NavigationEvent}}
@@ -1078,16 +1078,16 @@ To run the <dfn>spatial navigation steps</dfn> in <var>direction</var>, do the f
                 then return.
                 The User Agent may transfer focus to its own controls (if any) honouring <var>direction</var>.
             * Else, if <var>container</var> is the <a>document element</a> of a <a>nested browsing context</a> then:
-                1. Set <var>startingPoint</var> to <var>container</var>'s <a>browsing context container</a>
-                2. Set <var>eventTarget</var> be <var>startingPoint</var>
-                3. Set <var>container</var> to the nearest ancestor of <var>startingPoint</var> that is a <a>spatial navigation container</a>.
+                1. Set <var>searchOrigin</var> to <var>container</var>'s <a>browsing context container</a>
+                2. Set <var>eventTarget</var> be <var>searchOrigin</var>
+                3. Set <var>container</var> to the nearest ancestor of <var>searchOrigin</var> that is a <a>spatial navigation container</a>.
                 4. Return to the step labeled <i>loop</i>.
 
                 Issue(28): is it sane from a security standpoint that this propagates up from iframes?
             * Else, set <var>container</var> to its closest ancestor that is itself a <a>spatial navigation container</a>
                 and return to the step labeled <i>loop</i>.
 9. Let <var>bestCandidate</var> be the result of <a>selecting the best candidate</a>
-    within <var>candidates</var> in <var>direction</var> starting from <var>startingPoint</var>
+    within <var>candidates</var> in <var>direction</var> starting from <var>searchOrigin</var>
 10. <span class=api><a>Fire an event</a> named <a event>navbeforefocus</a> at <var>eventTarget</var> using {{NavigationEvent}}
     with its {{NavigationEvent/dir}} set to <var>direction</var> and {{NavigationEvent/relatedTarget}} set to <var>bestCandidate</var>
     and with it's <code>bubbles</code> and <code>cancelable</code> attributes set to <code>true</code>,
@@ -1167,17 +1167,17 @@ follow the following steps:
 To <dfn lt="select the best candidate | selecting the best candidate">select the best candidate</dfn>
 within a <a spec=infra for="/">set</a> of <var>candidates</var>
 in a direction <var>dir</var>,
-starting from <var>starting point</var>,
+starting from <var>searchOrigin</var>,
 follow the following steps:
 
 1. If <var>candidates</var> is <a spec=infra for=set>empty</a>, return <code>null</code>
 2. If <var>candidates</var> contains a single item, return that item
 3. Let <var>insideArea</var> be
-    * the <a>optimal viewing region</a> of <var>starting point</var> if <var>starting point</var> is a <a>scroll container</a>,
-    * the viewport if <var>starting point</var> is a <a>Document</a>,
-    * the <a>border box</a> of <var>starting point</var> otherwise.
+    * the <a>optimal viewing region</a> of <var>searchOrigin</var> if <var>searchOrigin</var> is a <a>scroll container</a>,
+    * the viewport if <var>searchOrigin</var> is a <a>Document</a>,
+    * the <a>border box</a> of <var>searchOrigin</var> otherwise.
 4. Let <var>insiders</var> be the subset of <var>candidates</var> items
-    whose [=DOM anchor=] are descendants of <var>starting point</var>
+    whose [=DOM anchor=] are descendants of <var>searchOrigin</var>
     and whose <a>boundary box</a>'s
     * top edge is below the top edge of <var>insideArea</var> if <var>D</var> is <code>down</code>
     * bottom edge is above the bottom edge of <var>insideArea</var> if <var>D</var> is <code>up</code>
@@ -1203,10 +1203,10 @@ follow the following steps:
     * Else
         1. Set <var>candidates</var> be the subset of its items
             whose <a>boundary box</a>'s geometric center is within the closed half plane
-            whose boundary goes through the geometric center of the <var>starting point</var>
+            whose boundary goes through the geometric center of the <var>searchOrigin</var>
             and is perpendicular to <var>D</var>.
         2. For each <var>candidate</var> in <var>candidates</var>,
-            find the points <var>P1</var> inside the <a>boundary box</a> of <var>starting point</var>
+            find the points <var>P1</var> inside the <a>boundary box</a> of <var>searchOrigin</var>
             and <var>P2</var> inside the <a>boundary box</a> of <var>candidate</var>
             that minimize the <var>distance</var> between these two points,
             when <var>distance</var> is defined as follows:
@@ -1225,7 +1225,7 @@ follow the following steps:
                 <dd>The absolute distance in the direction which is orthogonal to <var>dir</var> between <var>P1</var> and <var>P2</var>
 
               <dt><var>D</var>:
-                <dd>The square root of the area of intersection between the <a>boundary boxes</a> of <var>candidate</var> and <var>starting point</var>
+                <dd>The square root of the area of intersection between the <a>boundary boxes</a> of <var>candidate</var> and <var>searchOrigin</var>
             </dl>
         3. Return the item of the <var>candidates</var> set that has the smallest <var>distance</var>.
             If several have the same distance,