Since we use states manage the input flow in McBopomofo, implementing this function becomes easy. What I did is to create a new state, Associated Phrases state, and let the key handler to emit such a state just after emitting a Committing state.
When the input method controller is under Associated Phrase state, it shows the candidate window with a tooltip, and only accept candidate keys with the shift key. The key handler uses the characters without modifiers in an NSEvent object to find if there is any matching candidate label, so I added a new member "inputTextIgnoringModifiers" to KeyHandlerInput.
I use KeyValueBlobReader to read the associated phrases. I use the cin file from OpenVanilla project but removed the head and tail of the file to pass KeyValueBlobReader's validation.
Since we have implemented the functions to add and exlcude phrases, the
commit allows users to use a table to change the output of a phrase
without changing its BPMF reading and score, when the "phrase replacement"
mode is on.
It could help users to switch a specific input scenario and the ordinary
one. For example, if a user wants to work on financial Chinese numbers
like 壹、貳、參, he or she may want the characters to have higher score
as the normal numbers like 一、二、三. The commit can let the users to
temporarily replace 一、二、三 to 壹、貳、參 by just turn on "phrase
replacement" mode and prepare a custom table.
The conversion is not done on the output phase like how we do
Traditional/Simplified Chinese conversion. What the phrase replacement
table does is to slightly modify the language model. The replacement
takes place on walking the nodes and candidates list.
A user can enable the mode and edit the table from the input menu. Since
the function is quite advanced, the menu items are hidden until the user
holds the option key.
The table is a plain text file. Each line contains a "from" and "to".
For example
```
一 壹
```
However, if the user also want all other phrase contain 一 to become 壹,
all of the phrases have to be built into the table
```
一百 壹佰
一千 壹仟
一萬 壹萬
一百萬 壹百萬
```
zonble
Lukhnos Liu