FREEDIC A SymbianOS based multilingual dictionary for the Nokia 7710 Chong Poh Kit ; Dao Yuan;...
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Transcript of FREEDIC A SymbianOS based multilingual dictionary for the Nokia 7710 Chong Poh Kit ; Dao Yuan;...
FREEDIC
A SymbianOS based multilingual dictionary for the Nokia 7710
Chong Poh Kit ; Dao Yuan; SeungHyun Whang
Contents
GUI Background monitoring Classes design Loading dictionary Lookup Function Advantages Future work
GUI Format of Dictionary fil
e The main GUI window
will be used for users to input text and to display output for dictionary searches.
Top combobox pane : word to search
Bottom textbox: Output of search function
Buttons
Clear List Clears the
searched words list Background
Sends the dictionary to the background but leave it running
Exit Permanently end the
dictionary session
Menu About
A short message about the dictionary
Copy Copy the selected
text Background
Sends the dictionary to the background but leave it running
Exit Permanently end the
dictionary session
Background monitoring
Monitor for key-press events from the background
Wakes up the dictionary and puts it to the foreground to display the text
Dictionary class design The dictionary will be divide into following classes.
Application core class contains GUI, and it generally describes all functions of the e-dictionary.
Libs class contains all dictionaries, and it handles all the function calls from AppCore, and forward them to each Dictionary.
Dict class contains everything about a particular dictionary, the INDEX file, the DATA file, and how to lookup a key word in dictionary.
Index class only deal with index file, constructing the page table, looking up words from index and return its offset in DATA file.
Load Dictionary file Format of Dictionary file
Contain three files - .ifo .idx .dict .ifo file describe general information about the
dictionary. # of word entries, etc. .idx file is a index file of .dict file. It record word s
tring and its offset in .dict file. .dict file contain the detail translation and expla
nation of each word.
Load Dictionary file How is it loaded into memory?
Very important to reduce memory consumption.
Data file: ( 4.3 MB)
offset=========word_1_data_1_dataword_1_data_2_dataword_2_data_1_dataword_2_data_2_data
......==============
like
1000==========apple [Apl]
A delicious fruit......
==============
Index file: ( 600 KB)
============== word_str; apple(a utf-8 string terminated by '\0'.) word_data_offset; 1000 // word data's offset in .dict file word_data_size; 500// word data's total size in .dict file......
==============
Memory-page table: (19 KB)
============== word_str; page number; page size;
==============
Memory-page: ( 560 B)
page 1========== word_str; word_data_offset; word_data_size; //64 entry per page.
==============
Database Lookup Function
SimpleLookup Compare the searching word in INDEX file and than read the o
ffset to the DATA file. Interface of SimpleLookup Function
TBool SimpleLookupWord(TDesC & sWordsWord, TInt32 & iWordIniWordIndexdex, TInt iLibiLib);
sWord is the string of the keyword, iWordIndex will return the offset to the DATA file iLib will determine which dictionary to search.
(Since it is will load several dictionary page table into memory.)
Lookup Function Call (Simple lookup function:)
<A word is inputed for search>
<Libs> <Dict> <offset_index><AppCore::>
for (int iLib=0; iLib<oLibs.ndicts(); iLib++) oLibs.SimpleLookupWord(word, offset of that dictionary, dictionary number);
Forward the search to the corresponding dictionary
oLib[iLib]->Lookup(word, offset)
Forward the Lookup in its index file
idx_file->lookup(str, idx)
Event: A searching key word i s entered
Look up in every dictionary:
Look up the page number in page_table
Load the page into memory
Look up the entry in the page
With the offset value to DATA file, explanation can be read from it to the memory.Then, display the explanation in textbox.
Database Lookup Function
Source code to lookup page table & entries within a page
while (iFrom<=iTo) {iThisIndex=(iFrom+iTo)/2; //divide the table into halfcmpint = stardict_strcmp(str, get_first_on_page_key(iThisIndex)); //compar
ingif (cmpint>0) // if the word is in second half,iFrom=iThisIndex+1; //reduce searching range by cutting first half else if (cmpint<0) // if the word is in first half,iTo=iThisIndex-1; //reduce searching range by cutting second half else { // if the word is foundbFound=true; //mark the flagbreak; //need no more search, break the loop}}
Future work
Loading dictionary Automatically load all possible dictionary files
from the user specified directory. For large index file (>4MB), use segmented
loading method. Change the “entry per page” according to the
total number of word entry in all dictionary.
Searching algorithm Adding rule search and fuzzy search function.