Standard - Revision history

Shachar: logical to visual conversion

2016-06-04T17:03:51Z

logical to visual conversion

Shachar: Introduce logical positions of visual carets

2016-06-04T16:42:50Z

Introduce logical positions of visual carets

Shachar: 51 revisions

2012-04-03T03:57:07Z

51 revisions

Shachar: Spelling mistake at title

2010-08-19T12:23:49Z

Spelling mistake at title

Shachar: Place holder further discussion

2010-08-17T12:11:11Z

Place holder further discussion

Shachar: Ambiguous Logical Caret

2010-08-17T09:46:28Z

Ambiguous Logical Caret

Shachar: /* Ambiguous Caret */

2010-08-17T08:57:38Z

‎Ambiguous Caret

Shachar: When is the caret ambiguous

2010-08-17T08:55:56Z

When is the caret ambiguous

Shachar: Write section intro

2010-08-17T08:47:11Z

Write section intro

Shachar: Add ambiguous caret section

2010-08-17T08:44:27Z

Add ambiguous caret section

@@ Line 148: / Line 148: @@
 ====Choosing Correct Visual Position====
 The visual location a specific logical position translates MUST be one of the locations determined above. Selecting which one should be done according to the following criteria in descending order of precedence:
 '''''See [[Talk:Standard#Logical_Caret_Location|open issues]] for discussion'''''

@@ Line 111: / Line 111: @@
 This document also defines a new type of caret, called a "'''visual caret'''". A visual caret has a definite and well
 defined visual position. That visual position may, under some circumstances, translate to more than one positions in the
-logical buffer.
+logical buffer. A visual caret shall, sometimes, also have a logical position.
-Throughout this document, almost any operation will affect the caret. After each operation the caret will either be a visual caret or a logical caret. In other words, the operation will either leave a well defined logical caret position or a visual caret position. An operation that sets the logical caret position is called a "'''logical operation'''", and the caret after the operation is a logical caret. An operation that sets the visual caret position is called a "'''visual operation'''", and the caret after it is a visual caret.
+Throughout this document, almost any operation will affect the caret. After each operation the caret will either be a visual caret or a logical caret. In other words, the operation will either leave a well defined logical caret position or a visual caret position. An operation that sets the logical caret position is called a "'''logical operation'''", and the caret after the operation is a logical caret. An operation that sets the visual caret position is called a "'''visual operation'''", and the caret after it is a visual caret. Certain operations are visual operations, which result in a visual caret, but also set the logical position.
 References like "before", "after", "first" and "last" rely on the order of characters in the logical buffer, and thus imply
-a logical caret. For example, the sentence "Pressing the END key MUST bring the caret to the last character of the line"
+logical placement. For example, the sentence "Pressing the END key MUST bring the caret to the last character of the line"
-means that the caret following pressing "END" is a logical caret. Likewise, references such as "left" and "right" rely on
+means that the caret following pressing "END" is a logical caret. Likewise, references such as "left", "right", "up" and "down" rely on
 the visual arrangement of the characters on screen.  The sentence "Pressing the LEFT key SHOULD move the caret one character
 to the left" means that the caret following pressing "LEFT" is a visual caret.

@@ Line 146: / Line 146: @@
 <pre style="text-align: right;">.more english WERBEH |english|</pre>
-====Choosing Correct Visual Positition====
+====Choosing Correct Visual Position====
 The visual location a specific logical position translates MUST be one of the locations determined above. Selecting which one should be done according to the following criteria in descending order of precedence:
 '''''See [[Talk:Standard#Logical_Caret_Location|open issues]] for discussion'''''

← Older revision		Revision as of 12:11, 17 August 2010
Line 147:		Line 147:

	====Choosing Correct Visual Positition====		====Choosing Correct Visual Positition====
		+	The visual location a specific logical position translates MUST be one of the locations determined above. Selecting which one should be done according to the following criteria in descending order of precedence:
		+	'''''See [[Talk:Standard#Logical_Caret_Location\|open issues]] for discussion'''''

	===Ambiguous Visual Caret===		===Ambiguous Visual Caret===

← Older revision		Revision as of 09:46, 17 August 2010
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	===Ambiguous Logical Caret===		===Ambiguous Logical Caret===
		+	An ambiguous logical caret will have two visual positions. One position is right after the character before the caret, and the other is right before the character after the caret. In this sentence, "after" and "before" do not bear their usual meaning, as visual positions are involved. Instead, "after a character" means to the right of the character if that character's BiDi level is LTR (even), or to the left of the character if that character's BiDi level is RTL (odd).
		+
		+	Examples:
		+	<pre>english \|ARABIC more english.
		+	00000000 11111100000000000000</pre>
		+
		+	Where the caret is represented by the horizontal line. The caret might, visually, be in the following positions:
		+	<pre>english \|CIBARA\| more english.</pre>
		+
		+	Another example. In an RTL paragraph, the following logical text:
		+	<pre>\|english HEBREW more english.
		+	2222222111111112222222222221</pre>
		+
		+	The caret may be in the following positions:
		+
		+	<pre style="text-align: right;">.more english WERBEH \|english\|</pre>
		+
		+	====Choosing Correct Visual Positition====

	===Ambiguous Visual Caret===		===Ambiguous Visual Caret===

← Older revision	Revision as of 03:57, 3 April 2012
(No difference)

@@ Line 126: / Line 126: @@
 An ambiguous caret is a caret, either logical or visual, that is not located on an unambiguous position. The practical upshot of this is that the implementation needs to choose where on screen to draw the logical caret, or when in the buffer to perform the operation for a visual caret. This section deals with how to determine the different points, and explains how to resolve the ambiguity.
-An ambiguous caret will happen if and only if the character before/to the left of the caret has a different BiDi level than the character after/to the right of the caret. If the caret is before the first or after the last character of the paragraph, the missing character's BiDi level is sor or eor respectively, where sor and eor are defined by the UBA. For all practical purposes, sor and eor are at either level 0 or 1, depending on the paragraph base direction (0 for left to right, 1 for right to left). The difference between the BiDi levels on both sides of the caret is called the '''level differential'''.
+An ambiguous caret will happen if and only if the character before/to the left of the caret has a different BiDi level than the character after/to the right of the caret. If the caret is before the first or after the last character of the paragraph, the missing character's BiDi level is ''sor'' or ''eor'' respectively, where sor and eor are defined by the UBA. For all practical purposes, sor and eor are at either level 0 or 1, depending on the paragraph base direction (0 for left to right, 1 for right to left). The difference between the BiDi levels on both sides of the caret is called the '''level differential'''.
 ===Ambiguous Logical Caret===

← Older revision		Revision as of 08:47, 17 August 2010
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	==Ambiguous Caret==		==Ambiguous Caret==
		+	An ambiguous caret is a caret, either logical or visual, that is not located on an unambiguous position. The practical upshot of this is that the implementation needs to choose where on screen to draw the logical caret, or when in the buffer to perform the operation for a visual caret. This section deals with how to determine the different points, and explains how to resolve the ambiguity.
		+
		+	===Ambiguous Logical Caret===
		+
		+	===Ambiguous Visual Caret===

	=Caret Movement=		=Caret Movement=

← Older revision		Revision as of 08:44, 17 August 2010
Line 122:		Line 122:

	A position set by a logical operation is called a "'''logical position'''". Likewise, a position set by a visual operation is called a "'''visual position'''". A logical position that has only one visual representation can also be said to be a visual position that has only one logical representation. Such a position is agnostic to whether the operation that set it was a visual operation or a logical operation. We call such an agnostic position an "'''unambiguous position'''".		A position set by a logical operation is called a "'''logical position'''". Likewise, a position set by a visual operation is called a "'''visual position'''". A logical position that has only one visual representation can also be said to be a visual position that has only one logical representation. Such a position is agnostic to whether the operation that set it was a visual operation or a logical operation. We call such an agnostic position an "'''unambiguous position'''".
		+
		+	==Ambiguous Caret==

	=Caret Movement=		=Caret Movement=