Word Processing

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Word Processing
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Word Processing and the WWW

• Similarities
• Text is still text
• Basic styling of headers, bold, italic, tables
• These are inherent in how people communicate with
  text
• Similar underlying algorithms and structures

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Word Processing and the WWW

• Differences
• WWW is dynamic
• Variable window size
• Possibly non-graphical devices
• Leave decisions to the browser
• Simple implementation when building many browsers
• Word processing is static
• Fixed page size
• Exact layout
• Target is always paper

4
Microsoft Word
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Microsoft Word
Virtually every word processor has these same
features
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Word and HTML
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Word and HTML
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Word and HTML
lthtml xmlnso"urnschemas-microsoft-comofficeof
fice" xmlnsw"urnschemas-microsoft-comofficewo
rd" xmlns"http//www.w3.org/TR/REC-html40"gt lthead
gt ltmeta http-equivContent-Type
content"text/html charsetwindows-1252"gt ltmeta
nameOriginator content"Microsoft Word
9"gt lttitlegtThis is some new textlt/titlegt lt!--if
gte mso 9gtltxmlgt ltoDocumentPropertiesgt
ltoAuthorgtDan R. Olsen Jr.lt/oAuthorgt lt/oDocument
Propertiesgt lt/xmlgtlt/headgt ltbody langEN-US
style'tab-interval.5in'gt ltdiv
classSection1gt ltp classMsoNormalgtThis is
ltbgtsomelt/bgt new textlt/pgt lt/divgt lt/bodygt lt/htmlgt
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HTML in Word

• Word doesnt like JavaScript very much

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Encodings

• HTML
• This ltbgtislt/bgt text
• Word
• Use special characters beyond 128 instead of tags

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Translating Encodings

• Word encodes many more kinds of style information
  than HTML
• Paragraph indentation
• Superscript and subscript
• Embedded EXCEL tables
• Saving as HTML
• Re code similar features (bold, underline)
• Simulate the Word feature using HTML features
• Throw away the Word feature

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Translating Encodings

• What if we take a Word document and
• Convert MS Word to WordPerfect
• then, convert WordPerfect to HTML
• then, convert HTML back to MS Word.
• Each step may modify or discard some features.
• The end result will rarely be the same as the
  original document!!!

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Algorithms for Word Processing

• Insert a character
• Delete a character
• Select some characters
• Bold some characters
• Cut / Copy / Paste

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Cursor Position
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Insert a Character
Key p
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Insert a Character
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Cursor 3 Key 'p' Text.length 7
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function insertChar(text, cursor, key) For
(itext.length-1 igtcursor ii-1)
texti1 texti textcursor
key cursor cursor 1 text.length
text.length 1
Move a character up one space
Insert character
Increment cursor
Increment length
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Algorithms for Word Processing

• Insert a character
• Delete a character
• Select some characters
• Bold some characters
• Cut / Copy / Paste

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Delete a Character
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Cursor 4 Key ltbkspgt Text.length 8
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function deleteChar(text, cursor) For
(icursor Ilttext.length ii1)
texti-1texti cursor cursor -
1 text.length text.length - 1
Move a character back one space
Decrement cursor
Decrement length
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(No Transcript)
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function moveChars(text, start, end,
destination) for (i0 iltend-start ii1)
textidestinationtextistart return
moveChars
function moveChars(text, start, end,
destination) if (destinationltstart) for
(i0 iltend-start ii1) textidestinationte
xtistart else for (iend-start igt0
ii-1) textidestinationtextistart
return
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A Helpful Function

• function moveChars(text, start, end, destination)
• if (destination lt start)
• for (istart iltend ii1)
• textdestinationi-start texti
• else
• for (iend-1 igtstart ii-1)
• textdestinationi-start texti
• return

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Insert a Character
function insertChar(text, cursor, key) For
(itext.length-1 igtcursor ii-1)
texti1texti textCursor
key cursor cursor 1 text.length
text.length 1
Changed to
function insertChar(text, cursor,
key) moveChars(text, cursor, text.length,
cursor1) textcursor key cursor cursor
1 text.length text.length 1
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Delete a Character
function deleteChar(text, cursor) For
(icursor Ilttext.length ii1) texti-1
texti cursor cursor - 1 text.length
text.length - 1
Changed to
function deleteChar(text, cursor) moveChars(text
, cursor, text.length, cursor-1) cursor
cursor - 1 text.length text.length - 1
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Algorithms for Word Processing

• Insert a character
• Delete a character
• Select some characters
• Bold some characters
• Cut / Copy / Paste

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Selecting Characters
start 2 end 7
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Algorithms for Word Processing

• Insert a character
• Delete a character
• Select some characters
• Bold some characters
• Cut / Copy / Paste

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Bolding Characters
start 2 end 7
boldChars(text, 2, 7)
function boldChars(text, start,
end) moveChars(text, start, text.length,
start1) textstart ltcode for start
boldgt moveChars(text, end1, text.length1,
end2) textend1 ltcode for end boldgt end
end 2 text.length text.length 2
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Algorithms for Word Processing

• Insert a character
• Delete a character
• Select some characters
• Bold some characters
• Cut / Copy / Paste

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Cut
start 2 end 7
ClipBoard
function cutChars(text, start, end,
clipBoard) for (istart iltend ii1)
clipBoardi texti clipBoard.length
(end - start) moveChars(text, end,
text.length-1, start) text.length text.length
- clipBoard.length end start
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Paste
Start 2
ClipBoard strin
function pasteChars(text, start,
clipBoard) moveChars(text, start, text.length,
startclipBoard.length) for (i0
iltclipBoard.length ii1) textstarti
clipBoardi text.length text.length
clipBoard.length
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Review

• Other encodings besides ltbgtlt/bgt
• Translating between encodings can modify or lose
  information
• Text is just an array
• Insert a character - move characters right
• Deleting a character - move characters left
• Selecting - Start and End are array indices
• Cut - copy to clip board and move characters left
• Copy - copy to clip board
• Paste - move characters right and copy from clip
  board