Selection API

[`Exposed$=Window]
interface `Selection@I {
  readonly attribute `Node$I? `anchorNode$m;
  readonly attribute `unsigned long$ `anchorOffset$m;
  readonly attribute `Node$I? `focusNode$m;
  readonly attribute `unsigned long$ `focusOffset$m;
  readonly attribute `boolean$ `isCollapsed$m;
  readonly attribute `unsigned long$ `rangeCount$m;
  readonly attribute `DOMString$ `type$m;
  readonly attribute `DOMString$ `direction$m;
  `Range$I `getRangeAt$m(`unsigned long$ %index);
  `undefined$ `addRange$m(`Range$I %range);
  `undefined$ `removeRange$m(`Range$I %range);
  `undefined$ `removeAllRanges$m();
  `undefined$ `empty$m();
  `sequence$<`StaticRange$I> `getComposedRanges$m(optional `GetComposedRangesOptions$I %options = {});
  `undefined$ `collapse$m(`Node$I? %node, optional `unsigned long$ %offset = 0);
  `undefined$ `setPosition$m(`Node$I? %node, optional `unsigned long$ %offset = 0);
  `undefined$ `collapseToStart$m();
  `undefined$ `collapseToEnd$m();
  `undefined$ `extend$m(`Node$I %node, optional `unsigned long$ %offset = 0);
  `undefined$ `setBaseAndExtent$m(`Node$I %anchorNode, `unsigned long$ %anchorOffset, `Node$I %focusNode, `unsigned long$ %focusOffset);
  `undefined$ `selectAllChildren$m(`Node$I %node);
  `undefined$ `modify$m(optional `DOMString$ %alter, optional `DOMString$ %direction, optional `DOMString$ %granularity);
  [`CEReactions$] `undefined$ `deleteFromDocument$m();
  `boolean$ `containsNode$m(`Node$I %node, optional `boolean$ %allowPartialContainment = false);
  `stringifier$m;
};

dictionary `GetComposedRangesOptions@I {
  `sequence$<`ShadowRoot$I> `shadowRoots@mb = [];
};

`新たな範囲oを作成する@ ときは、 所与の ( `境界点$ %A, `境界点$ %B ) に対し，次を走らす：

1. ( %始端, %終端 ) ~LET ［ %A は %B `より前$i ならば ( %A, %B ) ／ ~ELSE_ ( %B, %A ) ］
2. %範囲o ~LET 新たな`~live範囲o$ `DOM$r
3. %範囲o の`境界点を設定する$( `始端^i, %始端 の`~node$bp, %始端 の`~offset$bp )
4. %範囲o の`境界点を設定する$( `終端^i, %終端 の`~node$bp, %終端 の`~offset$bp )
5. ~RET %範囲o

【 この~algoは、 原文の共通な記述を集約したものである。 これは、 所与の 2 つの境界点を，必要に応じて入れ替える。 】

◎ ↓

`anchorNode@m 取得子手続きは：

1. ~IF［ コレの`~anchor$sL ~NEQ ~NULL ］~AND［ コレの`~anchor$sLは`文書~tree$内に在る ］ ⇒ コレの`~anchor$sLの`~node$bp
2. ~RET ~NULL

◎ anchorNode • The attribute must return the anchor node of this, or null if the anchor is null or anchor is not in the document tree.

`anchorOffset@m 取得子手続きは：

1. ~IF［ コレの`~anchor$sL ~NEQ ~NULL ］~AND［ コレの`~anchor$sLは`文書~tree$内に在る ］ ⇒ ~RET コレの`~anchor$sLの`~offset$bp
2. ~RET 0

◎ anchorOffset • The attribute must return the anchor offset of this, or 0 if the anchor is null or anchor is not in the document tree.

`focusNode@m 取得子手続きは：

1. ~IF［ コレの`~focus$sL ~NEQ ~NULL ］~AND［ コレの`~focus$sLは`文書~tree$内に在る ］ ⇒ コレの`~focus$sLの`~node$bp
2. ~RET ~NULL

◎ focusNode • The attribute must return the focus node of this, or null if the focus is null or focus is not in the document tree.

`focusOffset@m 取得子手続きは：

1. ~IF［ コレの`~focus$sL ~NEQ ~NULL ］~AND［ コレの`~focus$sLは`文書~tree$内に在る ］ ⇒ コレの`~focus$sLの`~offset$bp
2. ~RET 0

◎ focusOffset • The attribute must return the focus offset of this, or 0 if the focus is null or focus is not in the document tree.

`isCollapsed@m 取得子手続きは： ⇒ ~RET ~IS［ コレの`~anchor$sL ~EQ コレの`~focus$sL （両者とも ~NULL の場合も含む） ］ ◎ isCollapsed • The attribute must return true if and only if the anchor and focus are the same (including if both are null). Otherwise it must return false.

`rangeCount@m 取得子手続きは： ⇒ ~RET ［ 次が満たされるならば 1 ／ ~ELSE_ 0 ］ ⇒ ［ コレの`範囲o$sL ~NEQ ~NULL ］~AND［ コレの`~anchor$sLは`文書~tree$内に在る ］~AND［ コレの`~focus$sLは`文書~tree$内に在る ］ ◎ rangeCount • The attribute must return 0 if this is empty or either focus or anchor is not in the document tree, and must return 1 otherwise.

`type@m 取得子手続きは：

1. ~IF［ コレの`範囲o$sL ~NEQ ~NULL ］~AND［ コレの`~anchor$sLは`文書~tree$内に在る ］~AND［ コレの`~focus$sLは`文書~tree$内に在る ］ ⇒ ~RET ［ コレの`範囲o$sLは`畳まれて$いるならば `Caret^l ／ ~ELSE_ `Range^l ］
2. ~RET `None^l

◎ type • The attribute must return "None" if this is empty or either focus or anchor is not in the document tree, "Caret" if this's range is collapsed, and "Range" otherwise.

`direction@m 取得子手続きは ⇒ ~RET コレの`方向$sLに応じて ⇒＃ `無方向$i ならば 空~文字列／ `前方$i ならば `forward^l ／ `後方$i ならば `backward^l ◎ direction • The attribute must return "none" if this is empty or this selection is directionless. "forward" if this selection's direction is forwards and "backward" if this selection's direction is backwards.

`getRangeAt(index)@m ~method手続きは： ◎ getRangeAt() method

1. ~IF［ %index ~EQ 0 ］~AND［ コレの`範囲o$sL ~NEQ ~NULL ］~AND［ コレの`~anchor$sLは`文書~tree$内に在る ］~AND［ コレの`~focus$sLは`文書~tree$内に在る ］ ⇒ ~RET コレの`範囲o$sL ◎ ↓
2. ~THROW `IndexSizeError$E ◎ The method must throw an IndexSizeError exception if index is not 0, or if this is empty or either focus or anchor is not in the document tree.＼ Otherwise, it must return a reference to (not a copy of) this's range.

`getRangeAt$test ◎ tests: 1

注記： この~methodは、 コレの`範囲o$sLが ~NULL にされない限り，後続な~callに対し同じ~objを返し続ける。 ◎ Note Thus subsequent calls of this method returns the same range object if nothing has removed this's range in the meantime. In particular, getSelection().getRangeAt(0) === getSelection().getRangeAt(0) evaluates to true if the selection is not empty.

`addRange(range)@m ~method手続きは： ◎ addRange() method • The method must follow these steps:

1. ~IF［ %range の`始端~node$の`根$ ~NEQ コレを結付けている`文書$ ］ ⇒ ~RET ◎ If the root of the range's boundary points are not the document associated with this, abort these steps.
2. ~IF［ コレの`範囲o$sL ~NEQ ~NULL ］~AND［ コレの`~anchor$sLは`文書~tree$内に在る ］~AND［ コレの`~focus$sLは`文書~tree$内に在る ］【！rangeCount is not 0】 ⇒ ~RET ◎ If rangeCount is not 0, abort these steps.
3. コレの`範囲o$sL ~SET %range ◎ Set this's range to range by a strong reference (not by making a copy).

注記： `範囲o$sLは参照として追加されるので、 この~methodに対する後続な~callは，同じ~objを返す。 他の何かが`選択$の`範囲o$sLを ~NULL にするか置換するまで、 `選択$が追加された後における，~scriptによる`範囲o$sLに対する変更を反映することになる。 特に，次の~codeを走らせた後には、 `選択$は， %a ではなく %b を包含することになる： ◎ Note Since range is added by reference, subsequent calls to getRangeAt(0) returns the same object, and any changes that a script makes to range after it is added must be reflected in the selection, until something else removes or replaces this's range. In particular, the selection will contain b as opposed to a after running the following code:

var %r = document.createRange();
%r.selectNode(%a);
getSelection().addRange(%r);
%r.selectNode(%b);

注記： （`以下略$） ◎ Note At Step 2, Chrome 58 and Edge 25 do nothing. Firefox 51 gives you a multi-range selection. At least they keep the exisiting range. ◎ At Step 3, Chrome 58 and Firefox 51 store a reference, as described here. Edge 25 stores a copy. Firefox 51 changes its selection if the range is modified.

`removeRange(range)@m ~method手続きは：

1. ~IF［ コレの`範囲o$sL ~NEQ %range ］ ⇒ ~THROW `NotFoundError$E
2. コレの`範囲o$sL ~SET ~NULL

◎ removeRange() method • The method must make this empty by disassociating its range if this's range is range. Otherwise, it must throw a NotFoundError.

`removeAllRanges()@m ~method手続きは ⇒ コレの`範囲o$sL ~SET ~NULL ◎ removeAllRanges() method • The method must make this empty by disassociating its range if this has an associated range.

`getComposedRanges(options)@m ~method手続きは： ◎ getComposedRanges() method

1. %範囲o ~LET コレの`範囲o$sL ◎ ↓
2. ~IF［ %範囲o ~EQ ~NULL ］ ⇒ ~RET « »【！empty array】 ◎ If this is empty, return an empty array.
3. %始端~node ~LET %範囲o の`始端~node$ ◎ Otherwise, let startNode be start node of the range associated with this,＼
4. %始端~offset ~LET %範囲o の`始端~offset$ ◎ and let startOffset be start offset of the range.

5. ~WHILE 無条件：

   1. %~host ~LET %始端~node の`根$の`~host$
   2. ~IF［ %~host ~EQ ~NULL ］ ⇒ ~BREAK
   3. %options[ "`shadowRoots$mb" ] を成す ~EACH( %~shadow根 ) に対し ⇒ ~IF［ %始端~node の`根$は %~shadow根 の`~shadowも含めた広義-先祖$である ］ ⇒ ~BREAK
   4. %始端~offset ~SET %~host の`~index$
   5. %始端~node ~SET %~host の`親$
   6. ~IF［ %始端~node ~EQ ~NULL ］ ⇒ ~BREAK
   ◎ While startNode is a node, startNode's root is a shadow root, and startNode's root is not a shadow-including inclusive ancestor of any of options["shadowRoots"], repeat these steps: • Set startOffset to index of startNode's root's host. • Set startNode to startNode's root's host's parent.
6. %終端~node ~LET %範囲o の`終端~node$ ◎ Let endNode be end node of the range associated with this,＼
7. %終端~offset ~LET %範囲o の`終端~offset$ ◎ and let endOffset be end offset of the range.

8. ~WHILE 無条件：

   1. %~host ~LET %終端~node の`根$の`~host$
   2. ~IF［ %~host ~EQ ~NULL ］ ⇒ ~BREAK
   3. %options[ "`shadowRoots$mb" ] を成す ~EACH( %~shadow根 ) に対し ⇒ ~EACH( %~shadow根 ) に対し ⇒ ~IF［ %終端~node の`根$は %~shadow根 の`~shadowも含めた広義-先祖$である ］ ⇒ ~BREAK
   4. %終端~offset ~SET %~host の`~index$ ~PLUS 1
   5. %終端~node ~SET %~host の`親$
   6. ~IF［ %終端~node ~EQ ~NULL ］ ⇒ ~BREAK
   ◎ While endNode is a node, endNode's root is a shadow root, and endNode's root is not a shadow-including inclusive ancestor of any of options["shadowRoots"], repeat these steps: • Set endOffset to index of endNode's root's host plus 1. • Set endNode to endNode's root's host's parent.
9. %新たな範囲o ~LET 新たな `StaticRange$I — その ⇒＃ `始端~node$ ~SET %始端~node, `終端~node$ ~SET %終端~node, `始端~offset$ ~SET %始端~offset, `終端~offset$ ~SET %終端~offset ◎ Return an array consisting of new StaticRange whose start node is startNode, start offset is startOffset, end node is endNode, and end offset is endOffset.
10. ~RET « %新たな範囲o » ◎ ↑

`collapse(node, offset)@m ~method手続きは： ◎ collapse() method • The method must follow these steps:

1. ~IF［ %node ~EQ ~NULL ］ ⇒＃ `removeAllRanges()$m と同じに挙動する； ~RET ◎ If node is null, this method must behave identically as removeAllRanges() and abort these steps.
2. ~IF［ %node は`~doctype$である ］ ⇒ ~THROW `InvalidNodeTypeError$E ◎ If node is a DocumentType, throw an InvalidNodeTypeError exception and abort these steps.
3. ~IF［ %offset ~GT %node の`長さ$ ］ ⇒ ~THROW `IndexSizeError$E ◎ The method must throw an IndexSizeError exception if offset is longer than node's length and abort these steps.
4. ~IF［ コレを結付けている`文書$は %node の`~shadowも含めた広義-先祖$でない ］ ⇒ ~RET ◎ If document associated with this is not a shadow-including inclusive ancestor of node, abort these steps.
5. %境界点 ~LET `境界点$( %node, %offset ) ◎ ↓
6. コレの`範囲o$sL ~SET `新たな範囲oを作成する$( %境界点, %境界点 ) ◎ Otherwise, let newRange be a new range. ◎ Set the start the start and the end of newRange to (node, offset). ◎ Set this's range to newRange.

`collapseToStart()@m ~method手続きは： ◎ collapseToStart() method

1. ~IF［ コレの`範囲o$sL ~EQ ~NULL ］ ⇒ ~THROW `InvalidStateError$E ◎ The method must throw InvalidStateError exception if the this is empty.＼
2. %境界点 ~LET コレの`範囲o$sLの`始端$ ◎ ↓
3. コレの`範囲o$sL ~SET `新たな範囲oを作成する$( %境界点, %境界点 ) ◎ Otherwise, it must create a new range, set the start both its start and end to the start of this's range,＼ ◎ and then set this's range to the newly-created range.

注記： （`以下略$） ◎ Note For collapseToStart/End, IE9 mutates the existing range, while Firefox 9.0a2 and Chrome 15 dev replace it with a new one. The spec follows the majority and replaces it with a new one, leaving the old Range object unchanged.

`collapseToEnd()@m ~method手続きは： ◎ collapseToEnd() method

1. ~IF［ コレの`範囲o$sL ~EQ ~NULL ］ ⇒ ~THROW `InvalidStateError$E ◎ The method must throw InvalidStateError exception if the this is empty.＼
2. %境界点 ~LET コレの`範囲o$sLの`終端$ ◎ ↓
3. コレの`範囲o$sL ~SET `新たな範囲oを作成する$( %境界点, %境界点 ) ◎ Otherwise, it must create a new range, set the start both its start and end to the end of this's range,＼ ◎ and then set this's range to the newly-created range.

`extend(node, offset)@m ~method手続きは： ◎ extend() method • The method must follow these steps:

1. ~IF［ コレを結付けている`文書$は %node の`~shadowも含めた広義-先祖$でない ］ ⇒ ~RET ◎ If the document associated with this is not a shadow-including inclusive ancestor of node, abort these steps.
2. ~IF［ コレの`範囲o$sL ~EQ ~NULL ］ ⇒ ~THROW `InvalidStateError$E ◎ If this is empty, throw an InvalidStateError exception and abort these steps.
3. %旧-~anchor ~LET コレの`~anchor$sL 【！ oldFocus 未利用】 ◎ Let oldAnchor and oldFocus be the this's anchor and focus,＼
4. %新-~focus ~LET `境界点$( %node, %offset ) ◎ and let newFocus be the boundary point (node, offset). ◎ ↓Let newRange be a new range.
5. ~IF［ %node の`根$ ~NEQ コレの`範囲o$sLの`始端~node$の`根$ ］ ⇒ %旧-~anchor ~SET %新-~focus ◎ If node's root is not the same as the this's range's root, set the start newRange's start and end to newFocus.
6. コレの`範囲o$sL ~SET `新たな範囲oを作成する$( %旧-~anchor, %新-~focus ) ◎ Otherwise, if oldAnchor is before or equal to newFocus, set the start newRange's start to oldAnchor, then set its end to newFocus. ◎ Otherwise, set the start newRange's start to newFocus, then set its end to oldAnchor. ◎ Set this's range to newRange.
7. コレの`方向$sL ~SET ［ %新-~focus は %旧-~anchor `より前$i ならば `後方$i ／ ~ELSE_ `前方$i ］ ◎ If newFocus is before oldAnchor, set this's direction to backwards. Otherwise, set it to forwards.

注記： （`以下略$） ◎ Note Reverse-engineered circa January 2011. IE doesn't support it, so I'm relying on Firefox (implemented extend() sometime before 2000) and WebKit (implemented extend() in 2007). I'm mostly ignoring Opera, because gsnedders tells me its implementation isn't compatible. Firefox 12.0a1 seems to mutate the existing range. IE9 doesn't support extend(), and it's impossible to tell whether Chrome 17 dev or Opera Next 12.00 alpha mutate or replace, because getRangeAt() returns a copy anyway. Nevertheless, I go against Gecko here, to be consistent with collapse().

`setBaseAndExtent(anchorNode, anchorOffset, focusNode, focusOffset)@m ~method手続きは： ◎ setBaseAndExtent() method • The method must follow these steps:

1. ~IF［ %anchorOffset ~GT %anchorNode の`長さ$ ］~OR［ %focusOffset ~GT %focusNode の`長さ$ ］ ⇒ ~THROW `IndexSizeError$E ◎ If anchorOffset is longer than anchorNode's length or if focusOffset is longer than focusNode's length, throw an IndexSizeError exception and abort these steps.
2. ~IF［ コレを結付けている`文書$は［ %anchorNode ／ %focusNode ］の`~shadowも含めた広義-先祖$でない ］ ⇒ ~RET ◎ If document associated with this is not a shadow-including inclusive ancestor of anchorNode or focusNode, abort these steps.
3. %~anchor ~LET `境界点$( %anchorNode, %anchorOffset ) ◎ Let anchor be the boundary point (anchorNode, anchorOffset) and＼
4. %~focus ~LET `境界点$( %focusNode, %focusOffset ) ◎ let focus be the boundary point (focusNode, focusOffset).
5. コレの`範囲o$sL ~SET `新たな範囲oを作成する$( %~anchor, %~focus ) ◎ Let newRange be a new range. ◎ If anchor is before focus, set the start the newRange's start to anchor and its end to focus. Otherwise, set the start them to focus and anchor respectively. ◎ Set this's range to newRange.
6. コレの`方向$sL ~SET ［ 次が満たされるならば `後方$i ／ ~ELSE_ `前方$i ］ ⇒ %~focus は %~anchor `より前$i ◎ If focus is before anchor, set this's direction to backwards. Otherwise, set it to forwards

`selectAllChildren(node)@m ~method手続きは： ◎ selectAllChildren() method • The method must follow these steps:

1. ~IF［ %node は`~doctype$である ］ ⇒ ~THROW `InvalidNodeTypeError$E ◎ If node is a DocumentType, throw an InvalidNodeTypeError exception and abort these steps.
2. ~IF［ %node の`根$ ~NEQ コレを結付けている`文書$ ］ ⇒ ~RET ◎ If node's root is not the document associated with this, abort these steps.
3. コレの`範囲o$sL ~SET `新たな範囲oを作成する$( `境界点$( %node, 0 ), `境界点$( %node, %~node の`子$の個数 ) ) ◎ Let newRange be a new range and childCount be the number of children of node. ◎ Set newRange's start to (node, 0). ◎ Set newRange's end to (node, childCount). ◎ Set this's range to newRange.
4. コレの`方向$sL ~SET %前方 ◎ Set this's direction to forwards.

注記： （`以下略$） ◎ Note Based mostly on Firefox 9.0a2. It has a bug that I didn't reproduce, namely that if you pass a Document as the argument, the end offset becomes 1 instead of the number of children it has. It also throws a RangeException instead of DOMException, because its implementation predated their merging. ◎ IE9 behaves similarly but with glitches. It throws "Unspecified error." if the node is detached or display:none, and apparently in some random other cases too. It throws "Invalid argument." for detached comments (only!). Finally, if you pass it a comment, it seems to select the whole comment, unlike with text nodes. ◎ Chrome 16 dev behaves as you'd expect given its Selection implementation. It refuses to select anything that's not visible, so it's almost always wrong. Opera 11.50 just does nothing in all my tests, as usual.

注記： 新たな範囲oは、 既存の範囲oを変異することなく置換する。 （`以下略$） ◎ Note The new range replaces any existing one, doesn't mutate it. This matches IE9 and Firefox 12.0a1. (Chrome 17 dev and Opera Next 12.00 alpha can't be tested, because getRangeAt() returns a copy anyway.)

`modify(alter, direction, granularity)@m ~method手続きは： ◎ modify() method ◎ The method must follow these steps:

【 いずれの引数も，~IDLにおいては省略可能と指定されているが、 以下の手続きは，省略時の取扱いを欠いている（既定~値は指定されてない）。 】【 以下における文字列の比較は， 原文では`~ASCII大小無視$が利用されているが、 この訳では，予め引数を`~ASCII小文字~化する$ことにより簡素化する。 】

1. %alter ~SET `~ASCII小文字~化する$( %alter ) ◎ ↓
2. %direction ~SET `~ASCII小文字~化する$( %direction ) ◎ ↓
3. %granularity ~SET `~ASCII小文字~化する$( %granularity ) ◎ ↓

4. ~IF［ ~OR↓ ］…

   • %alter ~NIN { `extend^l, `move^l }
   • %direction ~NIN { `forward^l, `backward^l, `left^l, `right^l }
   • %granularity ~NIN { `character^l, `word^l, `sentence^l, `line^l, `paragraph^l, `lineboundary^l, `sentenceboundary^l, `paragraphboundary^l, `documentboundary^l
   • コレの`範囲o$sL ~EQ ~NULL

   …ならば ⇒ ~RET

   ◎ If alter is not ASCII case-insensitive match with "extend" or "move", abort these steps. ◎ If direction is not ASCII case-insensitive match with "forward", "backward", "left", or "right", abort these steps. ◎ If granularity is not ASCII case-insensitive match with "character", "word", "sentence", "line", "paragraph", "lineboundary", "sentenceboundary", "paragraphboundary", "documentboundary", abort these steps. ◎ If this selection is empty, abort these steps.
5. %書字~方向 ~LET コレの`~focus$sLにおける`行内~基底~方向$に応じて ⇒＃ `ltr$v 【左から右へ】ならば `right^l `rtl$v 【右から左へ】ならば `left^l ◎ ↓
6. コレの`方向$sL ~SET ［ 次が満たされるならば `前方$i ／ ~ELSE_ `後方$i ］ ⇒ %direction ~IN { `forward^l, %書字~方向 } ◎ Let effectiveDirection be backwards. ◎ If direction is ASCII case-insensitive match with "forward", set effectiveDirection to forwards. ◎ If direction is ASCII case-insensitive match with "right" and inline base direction of this selection's focus is ltr, set effectiveDirection to forwards. ◎ If direction is ASCII case-insensitive match with "left" and inline base direction of this selection's focus is rtl, set effectiveDirection to forwards. ◎ Set this selection's direction to effectiveDirection.

7. %alter に応じて： ◎ ↓

   • `extend^l ⇒ コレの`~focus$sL ~SET ［ 利用者が選択を %granularity により拡張するよう要請した ］とするときの所在 ◎ If alter is ASCII case-insensitive match with "extend", set this selection's focus to the location as if the user had requested to extend selection by granularity.
   • `move^l ⇒ コレの［ `~focus$sL, `~anchor$sL ］~SET ［ 利用者が選択を %granularity により移動するよう要請した ］とするときの所在 ◎ Otherwise, set this selection's focus and anchor to the location as if the user had requested to move selection by granularity.

   注記： %granularity により選択を［ 拡張する／移動する ］とは何を意味するか，もっと精確に定義する必要がある。 ◎ Note We need to more precisely define what it means to extend or move selection by each granularity.

`deleteFromDocument()@m ~method手続きは ⇒ ~IF［ コレの`範囲o$sL ~NEQ ~NULL ］~AND［ コレの`~anchor$sLは`文書~tree$内に在る ］~AND［ コレの`~focus$sLは`文書~tree$内に在る ］ ⇒ コレの`範囲o$sL上で `deleteContents()$m の手続きを呼出す `DOM$r ◎ deleteFromDocument() method • The method must invoke deleteContents() on this's range if this is not empty and both focus and anchor are in the document tree. Otherwise the method must do nothing.

注記： これは、 範囲oを置換することなく，実際に変異させる~methodの一つである。 （`以下略$） ◎ Note This is the one method that actually mutates the range instead of replacing it. This matches IE9 and Firefox 12.0a1. (Chrome 17 dev and Opera Next 12.00 alpha can't be tested, because getRangeAt() returns a copy anyway.)

`containsNode(node, allowPartialContainment)@m ~method手続きは：

1. ~IF［ コレの`範囲o$sL ~EQ ~NULL ］~OR［ %node の`根$ ~NEQ コレを結付けている`文書$ ］ ⇒ ~RET ~F
2. %~node始端 ~LET `境界点$( %node, 0 )
3. %~node終端 ~LET `境界点$( %node, %node の`長さ$ )
4. %範囲o ~LET コレの`範囲o$sL

5. ~IF［ %allowPartialContainment ~EQ ~F ］ ⇒ ~RET ~IS ~AND↓：

   • %範囲o の`始端$は %~node始端 `より前$i か “視覚的に等価”
   • %範囲o の`終端$は %~node終端 `より後$i か “視覚的に等価”

   【 すなわち， %範囲o は “視覚的” には~nodeを全部的に包含している 】

6. ~ELSE ⇒ ~RET ~IS ~AND↓：

   • %範囲o の`始端$は %~node終端 `より前$i か “視覚的に等価”
   • %範囲o の`終端$は %~node始端 `より後$i か “視覚的に等価”

   【 すなわち， %範囲o は “視覚的” には~nodeを部分的に包含している 】

【 “視覚的に等価” が具体的にどう決定されるかは、 定義されていない。 “2 つの境界点は、その合間に描画される内容は無いならば視覚的に等価とされる” のような定義は考えられるが。 】

◎ containsNode() method • The method must return false if this is empty or if node's root is not the document associated with this. • Otherwise, if allowPartialContainment is false, the method must return true if and only if start of its range is before or visually equivalent to the first boundary point in the node and end of its range is after or visually equivalent to the last boundary point in the node. • If allowPartialContainment is true, the method must return true if and only if start of its range is before or visually equivalent to the last boundary point in the node and end of its range is after or visually equivalent to the first boundary point in the node.

`stringifier@m による`文字列~化の挙動$は、 次に従うモノトスル： ◎ stringifier • The stringification must＼

• ［ コレの`範囲o$sL ~NEQ ~NULL ］ならば、 【範囲oを成す内容のうち】 具現化された~textの連結を返す。 ◎ return the string, which is the concatenation of the rendered text if there is a range associated with this.
• 選択が［ `textarea$e ／ `input$e ］要素の中にある場合、 要素の値【`値＠~HTMLforms#concept-fe-value$？】内で選択された部分文字列を返す。 ◎ If the selection is within a textarea or input element, it must return the selected substring in its value.

【 これは、 まだ，きちんとした手続きとして定義されてはいない。 例えば、 コレの`範囲o$sL ~EQ ~NULL の場合の挙動は指定されていない （たぶん、空~文字列を返すことになろうが）。 】

利用者が選択を改変したときは、 ~UAは，次を走らすモノトスル： ◎ If the user makes any modification to a selection, the user agent must＼

1. ( %始端, %終端 ) ~LET 利用者による選択の ( 始端, 終端 ) を指す`境界点$ （ %始端 は %終端 `より後$i でない） ◎ ↓
2. `選択$の`範囲o$sL ~SET `新たな範囲oを作成する$( %始端, %終端 ) （既存の`範囲o$sLは改変されない） ◎ create a new range with suitable start and end of the range and associate the selection with this new range (not modify the existing range), and＼

3. `選択$の`方向$sL ~SET 利用者は［ %始端, %終端 ］どちらから選択し始めたかに応じて ⇒＃ %始端 と %終端 は一致するならば `前方$i／ %始端 から選択し始めたならば `前方$i ／ %終端 から選択し始めたならば `後方$i ／ ~platform規約に因り どちらから選択し始めたか決定できないならば `無方向$i† ◎ set update selection's direction to forwards if the start is before or equal to the end, backwards if if the end is before the start, or directionless if the start and the end cannot be ordered due to the platform convention.

   【† 例えばダブルクリック等で単語を選択したときなど。 】【 原文の記述は、［ 始端／終端 ］と［ 選択し始めた地点／選択し終えた地点 ］とが混同されていて，はっきりしない所がある。 %始端 と %終端 が一致する場合と他の場合は両立し得るが、 `方向$sLの定義の記述に従うなら，一致する場合が優先されることになる。 しかしながら，常識的には、 “決定できない場合” がそれより優先されるべきであろう。 】