1. What is the difference between reading string (CompReadStr) and
composition string (CompStr)?
The reading string only consist with basic symbols for this IME.
For exmaple, the reading string of phonetic IME is bo po mo fo.
The composition string is the string that IME want to show in
the composition window. For example, the composition string of
phonetic IME can be the following for some advance phonetic
IME -
11111
012345678901234
我們都是大ㄕˊ
2. For this advance phonetic IME, what is the clause information?
我們 (offset 0 to 4 in this string), 都是 (offset 4 to 8), and
大ㄕˊ (offset 8 to 14) are three clauses to this IME. (It may
be different ways deciding a clause to other IME) And the clause
informtion to this IME is DWORD array 0, 4, 8, and 14.
3. What is the attribute for these three clause?
The attribute for one clause should be the same. For this IME,
我們 (ATTR_CONVERTED - 2), 都是 (ATTR_CONVERTED - 2), and 大ㄕˊ
(ATTR_INPUT - 0) can be marked with different attribute as
following.
我們都是大ㄕˊ
22222222000000
The attribute is BYE array 2,2,2,2,2,2,2,2,0,0,0,0,0,0.
4. When are the ATTR_TARGET_NOTCONVERTED and ATTR_TARGET_CONVERTED
used?
The _TARGET_ is for the clause which is in the cursor position.
Most likely the Chinese should use ATTR_TARGET_CONVERTED but it is
possible we use ATTR_TARGET_NOTCONVERTED for some prediction
function.
5. If the IME do not provide the correct information. The
application or DBCS pen window may fail to function.
6. On developing Win95 IME, we should alway keep in mind the
IME conversion engine must carefully seperate with the
IME UI. Because the advance applications may not use the UI
provided by the IME, they will draw the IME UI by themself.
So it is obvious to an IME designer, we should not put IME UI
window handle into PRIVCONTEXT (data structure in imedefs.h
of the IME sample code).
7. What is the basic message flow?
1).
Before application call into GetMessage/PeekMessage, the
system will call into ImeProcessKey asking whether the IME
want to eat this key.
2).
If the function return TRUE, the system will change the virtual
key to VK_PROCESSKEY, the application will get WM_KEYDOWN with
VK_PROCESSKEY.
3).
On application calling the TranslateMessage, the system will
pass the original virtual key and other parameters to the
ImeToAsciiEx(,lpdwTransBuf,).
4).
The IME is responsible to generate WM_IME_STARTCOMPOSITION,
WM_IME_COMPOSITION, WM_IME_ENDCOMPOSITION, WM_IME_NOTIFY/
IMN_OPENCANDIDATE/IMN_CHANGECANIDATE/IMN_CLOSECANDIADTE, ...
into message buffer - lpdwTransBuf.
5).
The application can get these messages (generated by IME) from
the message loop. If the application do not handle it and
pass it to default window procedure, the system will pass it
to the default IME window. Now the IME window has chance to
handle it.
8. What is the IME window.
An IME window is a window created base on "IME" class. It is
a system class in user.exe. This window will create an onwee
window base on the UI class of an IME, system use the ImeInquire
to get this UI class name from the IME. This UI class provide
the real UI of the IME. The IME window will pass the UI related
messages to the ownee UI window and the UI window will provide
the UI feedback according to these messages for the end user.
9. How to switch to an IME or non IME in you application as the
CTRL-SPACE funtion?
// (1) switch to a non IME
hKL = GetKeyboardLayout(0);
if (ImmIsIME(hKL)) {
ImmSimulateHotKey(hAppWnd, IME_THOTKEY_IME_NONIME_TOGGLE);
}
if (ImmIsIME(hKL)) {
// switch fail handling
// P.S. If end user delete all non IMEs and only leave the IMEs
// in the system, above ImmSimulateHotKey will fail
}
// (2) switch to an IME
hKL = GetKeyboardLayout(0);
if (!ImmIsIME(hKL)) {
ImmSimulateHotKey(hAppWnd, IME_THOTKEY_IME_NONIME_TOGGLE);
}
if (!ImmIsIME(hKL)) {
// switch fail handling
// P.S. If end user delete all IMEs in the system, above
// ImmSimulateHotKey will fail
}
10. How to stick to the previos input IME for one specific field in
your application?
// Whenever focus out call ...
hPrevKL = GetKeyboardLayout(0);
:
:
// Whenever focus in call ...
ActivateKeyboradLayout(hPrevKL, 0);
11. How to change the direct switch hot key in IME configuration dialog
or control panel?
void ImeConfigureHotKeyPart(uNewModifiers, uNewVKey, hThisIMEKL)
{
DWORD dwHotKeyID;
DWORD dwAvailableHotKeyID = 0;
for (dwHotKeyID = IME_HOTKEY_DSWITCH_FIRST; dwHotKeyID <=
IME_HOTKEY_DSWITCH_LAST; dwHotKeyID++) {
BOOL fRet;
UINT uModifiers;
UINT uVKey;
UINT uTargetKL;
fRet = ImmGetHotKey(dwHotKeyID, &uModifiers, &uVKey,
&hTargetKL);
if (fRet) {
if (hTargetKL == hThisIMEKL) {
// if we want to set the hot key to a new value
ImmSetHotKey(dwHotKeyID, uNewModifiers, uNewVKey,
hThisIMEKL);
return;
}
} else if (dwAvailableHotKeyID) {
// we already find an available ID
} else {
dwAvailableHotKeyID = dwHotKeyID;
}
}
if (!dwAvailableHotKeyID) {
// no available ID case, Oh! Oh!
return;
}
// this IME does not have a direct switch hot key before
ImmSetHotKey(dwHotKeyID, uNewModifiers, uNewVKey, hThisIMEKL);
return;
}
12. An example of using property
1) Init code of RichEdit
hRichEditWnd->fdwProperty = ImmGetProperty(GetKeyboardLayout(0),
IGP_PROPERTY);
if (hRichEditWnd->fdwProperty & IME_PROP_SPECIAL_UI) {
// set composition position to init caret position
cpCompForm.dwStyle = CFS_POINT; // or CFS_RECT
cpCompForm.ptCurrentPos = ptAppCaretPosition;
// for CFS_RECT dwStyle you need to set cpCompForm.rcArea
ImmSetCompositionWindow(hIMC, cpCompForm);
} else if (hRichEditWnd->fdwProperty & IME_PROP_AT_CARET) {
// maybe application want to set the init position for
// candiadate window here
} else {
// set composition position to init caret position
cpCompForm.dwStyle = CFS_POINT; // or CFS_RECT
cpCompForm.ptCurrentPos = ptAppCaretPosition;
// for CFS_RECT dwStyle you need to set cpCompForm.rcArea
ImmSetCompositionWindow(hIMC, cpCompForm);
}
2) On message of keyboard layout change
case WM_INPUTLANGCHQANGE:
hRichEditWnd->fdwProperty = ImmGetProperty(GetKeyboardLayout(0),
IGP_PROPERTY);
hIMC = ImmGetContext(hRichEditWnd);
if (!hIMC) {
return DefWindowProc();
}
if (hRichEditWnd->fdwProperty & IME_PROP_SPECIAL_UI) {
// set composition position to init caret position
cpCompForm.dwStyle = CFS_POINT; // or CFS_RECT
cpCompForm.ptCurrentPos = ptAppCaretPosition;
// for CFS_RECT dwStyle you need to set cpCompForm.rcArea
ImmSetCompositionWindow(hIMC, cpCompForm);
} else if (hRichEditWnd->fdwProperty & IME_PROP_AT_CARET) {
// if you want to set up the candidate window position for
// an at caret IME, you may need to set here
// In the spec, we can set the 4 different candidate window
// positions for 4 level of candidate windows. Anyway the
// application may only care about the 1st level of candidate
// window
for (i = 0; i < 4; i++) {
CANDIDATEFORM cdCandForm;
cdCandForm.dwIndex = 0;
cdCandForm.dwStyle = CFS_CANDIDATEPOS;
cdCandForm.ptCUrrentPos.x = ptAppWantPosition[i].x;
cdCandForm.ptCUrrentPos.y = ptAppWantPosition[i].y;
ImmSetCandidateWindow(hIMC, &cdCandForm);
}
} else {
for (i = 0; i < 4; i++) {
CANDIDATEFORM cdCandForm;
if (!ImmGetCandiadetWindow(hIMC, i, &cdCandForm)) {
contine;
}
if (cdCandForm.dwStyle == CFS_DEFAULT) {
contine;
}
cdCandForm.dwStyle = CFS_DEFAULT;
ImmSetCandidateWindow(hIMC, &cdCandForm);
}
cpCompForm.dwStyle = CFS_POINT; // or CFS_RECT
cpCompForm.ptCurrentPos = ptAppCaretPosition;
// for CFS_RECT dwStyle you also need to set cpCompForm.rcArea field
ImmSetCompositionWindow(hIMC, cpCompForm);
}
return DefWindowProc();
3) case (all IME related messages handle by RichEdit)
if (hRichEditWnd->fdwProperty & IME_PROP_SPECIAL_UI) {
return DefWindowProc();
} else if (hRichEditWnd->fdwProperty & IME_PROP_AT_CARET) {
} else {
return DefWindowProc();
}
// original IME enable code RichEdit already implement
4) On caret movement of RichEdit, RichEdit need to set the
COMPOSITIONFORM to this new caret position by ImmSetCompositionWindow
for a near caret IME.
And for an at caret Chinese IME you need to set the CANDIDATEFORM to
the composition cursor position by ImmSetCandidateWindow.
5) On end user change font, RichEdit need to set the LOGFONT by
ImmSetCompositionFont.
Thank you
J. J. Lee (李家鈞)
