Rule-based text layout

• US 7,594,171 B2
• Filed: 10/01/2004
• Issued: 09/22/2009
• Est. Priority Date: 10/01/2004
• Status: Active Grant

• Current Assignee: Adobe Inc.
• Original Assignee: Adobe Systems Incorporated (Adobe Inc.)
• Inventors: Menninga, Eric A.
• Primary Examiner(s): Hong; Stephen S
• Assistant Examiner(s): Vaughn; Gregory J
• Application Number:
  US10/956,744
• Publication Number:
  US 20060080081A1
• Time in Patent Office: 1,817 Days
• Field of Search: 715/200, 715/243, 715/244, 715/245, 715/248, 715/256
• US Class Current: 715/245
• CPC Class Codes: G06F 40/103 Formatting, i.e. changing of presentation of documents automatic justification G06F40/189; automatic line break hyphenation G06F40/191

Abstract

The invention features systems, methods, and computer program products for typesetting a sequence of character glyphs. In on implementation, the invention provides a spacing classification file for a character set, the classification file being a text file, containing text form definitions of multiple character classes, each character class definition being structured to define a character class as having one or more arbitrary characters, the classification file further containing, in text form, multiple inter-class spacing definitions, each inter-class spacing definition defining, for an order pair of character classes, one or more spacing parameters for the ordered pair and an associated priority for each defined spacing parameter. A line of text can be compressed or expanded according to the inter-class spacing definitions for each sequential pairs of characters in the sequence of characters defined in the classification file according to their respective priorities.

Claims

1. A computer program product, tangibly embodied on a machine-readable storage device, comprising instructions operable to cause data processing apparatus to:

receive a spacing classification file specifying a classification for a Latin-based character set, the classification file being a text file containing in text form multiple character class definitions each defining a character class, each character class definition defining a character class as having one or more arbitrary Latin-based characters, the classification file further containing multiple inter-class spacing rules, in text form, each associated with an ordered pair of character classes, each inter-class spacing rule defining one or more spacing parameters for the ordered pair of character classes;

lay out a line of text comprising a sequence of Latin-based character glyphs derived from a sequence of characters using the inter-class spacing rules, the sequence of characters including one or more characters belonging to different character classes;

if the line of text needs to be compressed to a target line width, compress the line of text according to the inter-class spacing rules for each of two or more pairs of sequential characters in the sequence of characters, the inter-class spacing rules being defined in the spacing classification file, the inter-class spacing rules identifying a particular compression range for each pair of characters; and

if the line of text needs to be stretched to a target line width, decompress the line of text according to the inter-class spacing rules for each of two or more pairs of sequential characters in the sequence of characters, the inter-class spacing rules being defined in the spacing classification file, the inter-class spacing rules identifying a particular stretching range for each pair of characters.

2. The program of claim 1, wherein:

the character set includes Arabic numbers, punctuation characters, and diacritical marks; and

the inter-class spacing rules have priorities and are applied in stretching or expanding the line of text according to their respective priorities.

3. The program of claim 1, farther comprising instructions to:

receive user input applying the classification to a block of text.

4. A computer program product, tangibly embodied on a machine-readable storage device, comprising instructions operable to cause data processing apparatus to:

receive a line of Latin character text for typesetting;

receive user input defining a character classification and inter-class rules for character spacing and justification, the rules defining spacing parameters and justification parameters independent of font-specific glyph parameters, the rules further defining priorities for application of justification parameters in a justification process, the character classification defining classes including a many-to-one mapping of characters to classes, the rules defining spacing and justification parameters for ordered pairs of the class, each pair of characters in the line of text mapping to a pair of the classes, the user input being unconstrained by the program as to the number of two or more classes or the mapping of characters to classes, and where the justification parameters identify a particular compression or expansion range for each character class pair; and

lay out the line of text in accordance with the character classification and rules.

5. The program of claim 4, further comprising instructions to:

compress the line of text according to the inter-class justification rules and their respective priorities; and

stretch the line of text according to the inter-class justification rules and their respective priorities.

6. The program of claim 4, further comprising instructions to:

associate a style with a block of text, the style comprising the character classification and inter-class rules.

7. The program of claim 4, further comprising instructions to:

apply the inter-class spacing rules to a first pair of characters in addition to any kerning rules defined by a font for the first pair of characters.

8. The program of claim 4, further comprising instructions to:

apply the inter-class spacing rules to a first pair of characters in place of any kerning rules defined by a font for the first pair of characters.

9. A computer program product, tangibly embodied on a machine-readable storage device, comprising instructions operable to cause data processing apparatus to:

space a line of text comprising a sequence of characters;

then

justify the line of text by stretching or compressing, comprising instructions to collect stretch justification values or compress justification values for each sequential pair of characters in the line by priority, with all justifications of the same priority combined as one value, and starting with the highest priority, finding fractions in the range 0.0 to 1.0 for each priority until the necessary delta to a width of the line is accumulated, and applying the found fractions to the justification values of the pairs of characters by priority.

10. The program of claim 9, wherein:

the justification values are collected in a table keyed by priority.

11. The program of claim 9, wherein:

justification values for a pair of characters is defined according to respective character classes of the sequentially first and second characters of the pair.

12. The program of claim 11, further comprising instructions to:

receive user input freely defining to any granularity with which the character classes exist and which characters inhabit those classes.

13. A computer program product, tangibly embodied on a machine-readable storage device, comprising instructions operable to cause data processing apparatus to:

receive a definition of character-specific spacing rules for justification, the character-specific spacing rules including one or more character classes, the spacing rules including justification parameters identifying a range for compressing or stretching a particular pair of characters; and

apply the character-specific spacing rules for justification so that characters are spaced according to their type design in a font, or characters are spaced according to the character-specific spacing rules, or characters are spaced according to their type design in a font without regard to character-specific spacing rules, or characters are spaced according to both their type design in a font and character-specific spacing rules.

14. The program of claim 13, further comprising instructions to:

receive user input freely defining to any granularity with which the character classes exist and which characters inhabit those classes.

15. A system comprising:

a user interface device; and

one or more computers operable to interact with the user interface device and to perform operations including;

receiving a spacing classification file specifying a classification for a Latin-based character set, the classification file being a text file containing in text form multiple character class definitions each defining a character class, each character class definition defining a character class as having one or more arbitrary Latin-based characters, the classification file further containing multiple inter-class spacing rules, in text form, each associated with an ordered pair of character classes, each inter-class spacing rule defining one or more spacing parameters for the ordered pair of character classes;

laying out a line of text comprising a sequence of Latin-based character glyphs derived from a sequence of characters using the inter-class spacing rules, the sequence of characters including one or more characters belonging to different character classes;

if the line of text needs to be compressed to a target line width, compressing the line of text according to the inter-class spacing rules for each of two or more pairs of sequential characters in the sequence of characters, the inter-class spacing rules being defined in the spacing classification file, the inter-class spacing rules identifying a particular compression range for each pair of characters; and

if the line of text needs to be stretched to a target line width, decompressing the line of text according to the inter-class spacing rules for each of two or more pairs of sequential characters in the sequence of characters, the inter-class spacing rules being defined in the spacing classification file, the inter-class spacing rules identifying a particular stretching range for each pair of characters.

16. The system of claim 15, where:

the character set includes Arabic numbers, punctuation characters, and diacritical marks; and

the inter-class spacing rules have priorities and are applied in stretching or expanding the line of text according to their respective priorities.

17. The system of claim 15, further operable to perform operations comprising:

receiving user input applying the classification to a block of text.

18. A system comprising:

a user interface device; and

one or more computers operable to interact with the user interface device and to perform operations including;

receiving a line of Latin character text for typesetting;

receiving user input defining a character classification and inter-class rules for character spacing and justification, the rules defining spacing parameters and justification parameters independent of font-specific glyph parameters, the rules further defining priorities for application of justification parameters in a justification process, the character classification defining classes including a many-to-one mapping of characters to classes, the rules defining spacing and justification parameters for ordered pairs of the class, each pair of characters in the line of text mapping to a pair of the classes, the user input being unconstrained by the program as to the number of two or more classes or the mapping of characters to classes, and where the justification parameters identify a particular compression or expansion range for each character class pair; and

laying out the line of text in accordance with the character classification and rules.

19. The system of claim 18, further operable to perform operations comprising:

compressing the line of text according to the inter-class justification rules and their respective priorities; and

stretching the line of text according to the inter-class justification rules and their respective priorities.

20. The system of claim 18, further operable to perform operations comprising:

associating a style with a block of text, the style comprising the character classification and inter-class rules.

21. The system of claim 18, further operable to perform operations comprising:

applying the inter-class spacing rules to a first pair of characters in addition to any kerning rules defined by a font for the first pair of characters.

22. The system of claim 18, further operable to perform operations comprising:

applying the inter-class spacing rules to a first pair of characters in place of any kerning rules defined by a font for the first pair of characters.

23. A system comprising:

a user interface device; and

one or more computers operable to interact with the user interface device and to perform operations including;

spacing a line of text comprising a sequence of characters;

then

justifying the line of text by stretching or compressing, comprising instructions to collect stretch justification values or compress justification values for each sequential pair of characters in the line by priority, with all justifications of the same priority combined as one value, and starting with the highest priority, finding fractions in the range 0.0 to 1.0 for each priority until the necessary delta to a width of the line is accumulated, and applying the found fractions to the justification values of the pairs of characters by priority.

24. The system of claim 23, where:

the justification values are collected in a table keyed by priority.

25. The system of claim 23, where:

justification values for a pair of characters is defined according to respective character classes of the sequentially first and second characters of the pair.

26. The system of claim 25, further operable to perform operations comprising:

receiving user input freely defining to any granularity with which the character classes exist and which characters inhabit those classes.

27. A system comprising:

a user interface device; and

one or more computers operable to interact with the user interface device and to perform operations including;

receiving a definition of character-specific spacing rules for justification, the character specific spacing rules including one or more character classes, the spacing rules including justification parameters identifying a range for compressing or stretching a particular pair of characters; and

applying the character-specific spacing rules for justification so that characters are spaced according to their type design in a font, or characters are spaced according to the character-specific spacing rules, or characters are spaced according to their type design in a font without regard to character-specific spacing rules, or characters are spaced according to both their type design in a font and character-specific spacing rules.

28. The system of claim 27, further operable to perform operations comprising:

receiving user input freely defining to any granularity with which the character classes exist and which characters inhabit those classes.

29. A method comprising:

receiving a spacing classification file specifying a classification for a Latin-based character set, the classification file being a text file containing in text form multiple character class definitions each defining a character class, each character class definition defining a character class as having one or more arbitrary Latin-based characters, the classification file further containing multiple inter-class spacing rules, in text form, each associated with an ordered pair of character classes, each inter-class spacing rule defining one or more spacing parameters for the ordered pair of character classes;

laying out a line of text comprising a sequence of Latin-based character glyphs derived from a sequence of characters using the inter-class spacing rules, the sequence of characters including one or more characters belonging to different character classes;

if the line of text needs to be compressed to a target line width, compressing the line of text according to the inter-class spacing rules for each of two or more pairs of sequential characters in the sequence of characters, the inter-class spacing rules being defined in the spacing classification file, the inter-class spacing rules identifying a particular compression range for each pair of characters; and

if the line of text needs to be stretched to a target line width, decompressing the line of text according to the inter-class spacing rules for each of two or more pairs of sequential characters in the sequence of characters, the inter-class spacing rules being defined in the spacing classification file, the inter-class spacing rules identifying a particular stretching range for each pair of characters.

30. The method of claim 29, where:

the character set includes Arabic numbers, punctuation characters, and diacritical marks; and

the inter-class spacing rules have priorities and are applied in stretching or expanding the line of text according to their respective priorities.

31. The method of claim 29, further comprising:

receiving user input applying the classification to a block of text.

32. A method comprising:

receiving a line of Latin character text for typesetting;

receiving user input defining a character classification and inter-class rules for character spacing and justification, the rules defining spacing parameters and justification parameters independent of font-specific glyph parameters, the rules further defining priorities for application of justification parameters in a justification process, the character classification defining classes including a many-to-one mapping of characters to classes, the rules defining spacing and justification parameters for ordered pairs of the class, each pair of characters in the line of text mapping to a pair of the classes, the user input being unconstrained by the program as to the number of two or more classes or the mapping of characters to classes, and where the justification parameters identify a particular compression or expansion range for each character class pair; and

laying out the line of text in accordance with the character classification and rules.

33. The method of claim 32, further comprising:

compressing the line of text according to the inter-class justification rules and their respective priorities; and

stretching the line of text according to the inter-class justification rules and their respective priorities.

34. The method of claim 32, further comprising:

associating a style with a block of text, the style comprising the character classification and inter-class rules.

35. The method of claim 32, further comprising:

applying the inter-class spacing rules to a first pair of characters in addition to any kerning rules defined by a font for the first pair of characters.

36. The method of claim 32, further comprising:

applying the inter-class spacing rules to a first pair of characters in place of any kerning rules defined by a font for the first pair of characters.

37. A method comprising:

spacing a line of text comprising a sequence of characters;

then

justifying the line of text by stretching or compressing, comprising instructions to collect stretch justification values or compress justification values for each sequential pair of characters in the line by priority, with all justifications of the same priority combined as one value, and starting with the highest priority, finding fractions in the range 0.0 to 1.0 for each priority until the necessary delta to a width of the line is accumulated, and applying the found fractions to the justification values of the pairs of characters by priority.

38. The method of claim 37, where:

the justification values are collected in a table keyed by priority.

39. The method of claim 37, where:

justification values for a pair of characters is defined according to respective character classes of the sequentially first and second characters of the pair.

40. The method of claim 39, further comprising:

receiving user input freely defining to any granularity with which the character classes exist and which characters inhabit those classes.

41. A method comprising:

receiving a definition of character-specific spacing rules for justification, the character specific spacing rules including one or more character classes, the spacing rules including justification parameters identifying a range for compressing or stretching a particular pair of characters; and

applying the character-specific spacing rules for justification so that characters are spaced according to their type design in a font, or characters are spaced according to the character-specific spacing rules, or characters are spaced according to their type design in a font without regard to character-specific spacing rules, or characters are spaced according to both their type design in a font and character-specific spacing rules.

42. The method of claim 41, further comprising:

receiving user input freely defining to any granularity with which the character classes exist and which characters inhabit those classes.