Disable specific key in WinCE
Posted by chrisryu on June 24, 2009
Keyboard driver concept
At boot time, GWES loads the keyboard driver whose name is retrieved in HKEY_LOCAL_MACHINE\Hardware\DeviceMap\KEYBD\Drivername registry.
GWES calls the PFN_KEYBD_DRIVER_INITIALIZE function that initialize hardware and IST.
The keyboard driver is responsible for converting the hardware scan code into a virtual-key code and passing both to GWES through either the PFN_KEYBD_DRIVER_INITIALIZE_EX or keybd_event API.
GEWS pulls the keyboard event from the queue and calls back to the driver’s PFN_KEYBD_DRIVER_VKEY_TO_UNICODE routine
Keyboard driver : analyzes the specified key event and the virtual-key state and generates the corresponding characters.
GWES : sends the virtual-key code and the characters to the appropriate application
Disabling the shift key
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GWES ↑ Send Keyboard events PFN _KEYBD_DRIVER_VKEY_TO_UNICODE = KeybdDriverVKeyToUnicode() ↓ Call in order to check the shift flag) KeybdDriverKeyStateToShiftFlags()
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The path for the modified source code
C:\WINCE600\PUBLIC\COMMON\OAK\DRIVERS\KEYBD\LAYMGR\LayMgr.cpp
Adding below code in end of Void KeybdDriverKeyStateToShiftFlags() function, we can set the ShiftFlags value to 0×00.
//chris
if(ShiftFlags == KeyShiftAnyShiftFlag){
ShiftFlags = 0×00000000;
}
else if(ShiftFlags == (KeyShiftAnyShiftFlag | KeyShiftLeftShiftFlag)) {
ShiftFlags = 0×00000000;
}
else if(ShiftFlags == (KeyShiftAnyShiftFlag | KeyShiftRightShiftFlag)){
ShiftFlags = 0×00000000;
}
//chris
*pShiftStateFlags = ShiftFlags | KeyState[VKey];
return;
As set the ShiftFlags’s value 0, we can disable the Shift key.
◈KeyShiftAnyShiftFlag, KeyShiftLeftShiftFlag, KeyShiftRightShiftFlag values are placed in C:\WINCE600\PUBLIC\COMMON\SDK\INC\Keybd.h
The build order
- Do Build and Sysgen C:\WINCE600\PUBLIC\COMMON\OAK\DRIVERS\KEYBD\LAYMGR
- Do ReBuild the BSP’s Keyboard driver.
- Do Make Run Time Image.
Keyboard driver concept
