Related
I setup "polish-programmers" keyboard layout
I try to:
HKL hkl=GetKeyboardLayout(0);
for(unsigned long ch=0x20; ch<=0xff ; ++ch)
{
int v = HIBYTE(VkKeyScanEx(ch,hkl));
if(v==6){
return (GetKeyState(VK_CONTROL) & 0x8000) &&(GetKeyState(VK_RMENU) & 0x8000);
}
}
return false;
I made test with GetKeyboardState - same result: always left control have same flags as right alt(altgr)
May be somebody have workaround?
I have some code I've been using to get the current keyboard layout and convert a virtual key code into a string. This works great in most situations, but I'm having trouble with some specific cases. The one that brought this to light is the accent key next to the backspace key on german QWERTZ keyboards. http://en.wikipedia.org/wiki/File:KB_Germany.svg
That key generates the VK code I'd expect kVK_ANSI_Equal but when using a QWERTZ keyboard layout I get no description back. Its ending up as a dead key because its supposed to be composed with another key. Is there any way to catch these cases and do the proper conversion?
My current code is below.
TISInputSourceRef currentKeyboard = TISCopyCurrentKeyboardInputSource();
CFDataRef uchr = (CFDataRef)TISGetInputSourceProperty(currentKeyboard, kTISPropertyUnicodeKeyLayoutData);
const UCKeyboardLayout *keyboardLayout = (const UCKeyboardLayout*)CFDataGetBytePtr(uchr);
if(keyboardLayout)
{
UInt32 deadKeyState = 0;
UniCharCount maxStringLength = 255;
UniCharCount actualStringLength = 0;
UniChar unicodeString[maxStringLength];
OSStatus status = UCKeyTranslate(keyboardLayout,
keyCode, kUCKeyActionDown, 0,
LMGetKbdType(), kUCKeyTranslateNoDeadKeysBit,
&deadKeyState,
maxStringLength,
&actualStringLength, unicodeString);
if(actualStringLength > 0 && status == noErr)
return [[NSString stringWithCharacters:unicodeString length:(NSInteger)actualStringLength] uppercaseString];
}
That key is a dead key, as you can see if you try it yourself or look at the Keyboard Viewer with the German layout active.
On the Mac, the way to enter a dead key's actual character, without composing it with another character, is to press a space after it. So try that: Turn off kUCKeyTranslateNoDeadKeysBit, and if UCKeyTranslate sets the dead-key state, translate a space after it.
EDIT (added by asker)
Just for future people, here is the fixed code with the right solution.
TISInputSourceRef currentKeyboard = TISCopyCurrentKeyboardInputSource();
CFDataRef uchr = (CFDataRef)TISGetInputSourceProperty(currentKeyboard, kTISPropertyUnicodeKeyLayoutData);
const UCKeyboardLayout *keyboardLayout = (const UCKeyboardLayout*)CFDataGetBytePtr(uchr);
if(keyboardLayout)
{
UInt32 deadKeyState = 0;
UniCharCount maxStringLength = 255;
UniCharCount actualStringLength = 0;
UniChar unicodeString[maxStringLength];
OSStatus status = UCKeyTranslate(keyboardLayout,
keyCode, kUCKeyActionDown, 0,
LMGetKbdType(), 0,
&deadKeyState,
maxStringLength,
&actualStringLength, unicodeString);
if (actualStringLength == 0 && deadKeyState)
{
status = UCKeyTranslate(keyboardLayout,
kVK_Space, kUCKeyActionDown, 0,
LMGetKbdType(), 0,
&deadKeyState,
maxStringLength,
&actualStringLength, unicodeString);
}
if(actualStringLength > 0 && status == noErr)
return [[NSString stringWithCharacters:unicodeString length:(NSUInteger)actualStringLength] uppercaseString];
}
const char IsPressed = 1; // 1
const char WasHeldDown = 2; // 10
const char IsFirstPress = 4; // 100
char* keystates[256];
Class::CalculateKeyStates()
{
for(int i = 0; i < 256; ++i)
{
if(this->IsDown(i))
{
keystates[i] |= IsPressed; // turn on
if(keystates[i] & WasHeldDown)
{
//keystates[i] |= IsFirstPress;
keystates[i] &= ~IsFirstPress; // turn off
}
else
{
keystates[i] |= WasHeldDown + IsFirstPress; // Turn on
}
}
else
{
keystates[i] = 0; // Turn ALL off
}
}
}
This function would be a member function of a class, Class. The other member function, IsDown, will return a true if the key in question is down and false if not.
Can you see any way of further improving this function?
Thanks
EDIT:
I will expand a bit as to what is done why. This is a modification of an bit of code that works through an array keyStates (which was a struct of three bools) setting IsPressed to false for all of the keys. then again setting Ispressed to the value of this->IsDown and then a third time looping through checking if the key had been held, if it has then its no longer the first press so set that to false. if it was not held down, then set first press to true and was held to true as well, so next time it is flagged as having been held.
EDIT2:
Added some comments to code and corrected one line
Personally, I would define the key-states as disjoint states and write a simple state-machine, thus:
enum keystate
{
inactive,
firstPress,
active
};
keystate keystates[256];
Class::CalculateKeyStates()
{
for (int i = 0; i < 256; ++i)
{
keystate &k = keystates[i];
switch (k)
{
inactive:
k = (isDown(i)) ? firstPress : inactive;
break;
firstPress:
k = (isDown(i)) ? active : inactive;
break;
active:
k = (isDown(i)) ? active : inactive;
break;
}
}
}
This is easier to extend, and easier to read if it gets any more complex.
You are always setting IsFirstPress if the key is down, which might not be what you want.
I'm not sure what you want to achieve with IsFirstPress, as the keystate cannot remember any previous presses anyways. If you want to mark with this bit, that it's the first time you recognized the key being down, then your logic is wrong in the corresponding if statement.
keystates[i] & WasHeldDown evaluates to true if you already set the bit WasHeldDown earlier for this keystate.
In that case, what you may want to do is actually remove the IsFirstPress bit by xor-ing it: keystates[i] ^= IsFirstPress
It seems that if you call ToAscii() or ToUnicode() while in a global WH_KEYBOARD_LL hook, and a dead-key is pressed, it will be 'destroyed'.
For example, say you've configured your input language in Windows as Spanish, and you want to type an accented letter á in a program. Normally, you'd press the single-quote key (the dead key), then the letter "a", and then on the screen an accented á would be displayed, as expected.
But this doesn't work if you call ToAscii() or ToUnicode() in a low-level keyboard hook function. It seems that the dead key is destroyed, and so no accented letter á shows up on screen. Removing a call to the above functions resolves the issue... but unfortunately, I need to be able to call those functions.
I Googled for a while, and while a lot of people seemed to have this issue, no good solution was provided.
Any help would be much appreciated!
EDIT: I'm calling ToAscii() to convert the virtual-key code and scan code received in my LowLevelKeyboardProc hook function into the resulting character that will be displayed on screen for the user.
I tried MapVirtualKey(kbHookData->vkCode, 2), but this isn't as "complete" a function as ToAscii(); for example, if you press Shift + 2, you'll get '2', not '#' (or whatever Shift + 2 will produce for the user's keyboard layout/language).
ToAscii() is perfect... until a dead-key is pressed.
EDIT2: Here's the hook function, with irrelevant info removed:
LRESULT CALLBACK keyboard_LL_hook_func(int code, WPARAM wParam, LPARAM lParam) {
LPKBDLLHOOKSTRUCT kbHookData = (LPKBDLLHOOKSTRUCT)lParam;
BYTE keyboard_state[256];
if (code < 0) {
return CallNextHookEx(keyHook, code, wParam, lParam);
}
WORD wCharacter = 0;
GetKeyboardState(&keyboard_state);
int ta = ToAscii((UINT)kbHookData->vkCode, kbHookData->scanCode,
keyboard_state, &wCharacter, 0);
/* If ta == -1, a dead-key was pressed. The dead-key will be "destroyed"
* and you'll no longer be able to create any accented characters. Remove
* the call to ToAscii() above, and you can then create accented characters. */
return CallNextHookEx(keyHook, code, wParam, lParam);
}
Quite an old thread. Unfortunately it didn't contain the answer I was looking for and none of the answers seemed to work properly. I finally solved the problem by checking the MSB of the MapVirtualKey function, before calling ToUnicode / ToAscii. Seems to be working like a charm:
if(!(MapVirtualKey(kbHookData->vkCode, MAPVK_VK_TO_CHAR)>>(sizeof(UINT)*8-1) & 1)) {
ToAscii((UINT)kbHookData->vkCode, kbHookData->scanCode,
keyboard_state, &wCharacter, 0);
}
Quoting MSDN on the return value of MapVirtualKey, if MAPVK_VK_TO_CHAR is used:
[...] Dead keys (diacritics) are indicated by setting the top bit of the return value. [...]
stop using ToAscii() and use ToUncode()
remember that ToUnicode may return you nothing on dead keys - this is why they are called dead keys.
Any key will have a scancode or a virtual key code but not necessary a character.
You shouldn't combine the buttons with characters - assuming that any key/button has a text representation (Unicode) is wrong.
So:
for input text use the characters reported by Windows
for checking button pressed (ex. games) use scancodes or virtual keys (probably virtual keys are better).
for keyboard shortcuts use virtual key codes.
Call 'ToAscii' function twice for a correct processing of dead-key, like in:
int ta = ToAscii((UINT)kbHookData->vkCode, kbHookData->scanCode,
keyboard_state, &wCharacter, 0);
int ta = ToAscii((UINT)kbHookData->vkCode, kbHookData->scanCode,
keyboard_state, &wCharacter, 0);
If (ta == -1)
...
Calling the ToAscii or ToUnicode twice is the answer.
I found this and converted it for Delphi, and it works!
cnt:=ToUnicode(VirtualKey, KeyStroke, KeyState, chars, 2, 0);
cnt:=ToUnicode(VirtualKey, KeyStroke, KeyState, chars, 2, 0); //yes call it twice
I encountered this issue while creating a key logger in C# and none of the above answers worked for me.
After a deep blog searching, I stumbled across this keyboard listener which handles dead keys perfectly.
Here is a full code which covers dead keys and shortcut keys using ALT + NUMPAD, basically a full implementation of a TextField input handling:
[DllImport("user32.dll")]
public static extern int ToUnicode(uint virtualKeyCode, uint scanCode, byte[] keyboardState, [Out, MarshalAs(UnmanagedType.LPWStr, SizeConst = 64)] StringBuilder receivingBuffer, int bufferSize, uint flags);
private StringBuilder _pressCharBuffer = new StringBuilder(256);
private byte[] _pressCharKeyboardState = new byte[256];
public bool PreFilterMessage(ref Message m)
{
var handled = false;
if (m.Msg == 0x0100 || m.Msg == 0x0102)
{
bool isShiftPressed = (ModifierKeys & Keys.Shift) != 0;
bool isControlPressed = (ModifierKeys & Keys.Control) != 0;
bool isAltPressed = (ModifierKeys & Keys.Alt) != 0;
bool isAltGrPressed = (ModifierKeys & Keys.RMenu) != 0;
for (int i = 0; i < 256; i++)
_pressCharKeyboardState[i] = 0;
if (isShiftPressed)
_pressCharKeyboardState[(int)Keys.ShiftKey] = 0xff;
if (isAltGrPressed)
{
_pressCharKeyboardState[(int)Keys.ControlKey] = 0xff;
_pressCharKeyboardState[(int)Keys.Menu] = 0xff;
}
if (Control.IsKeyLocked(Keys.CapsLock))
_pressCharKeyboardState[(int)Keys.CapsLock] = 0xff;
Char chr = (Char)0;
int ret = ToUnicode((uint)m.WParam.ToInt32(), 0, _pressCharKeyboardState, _pressCharBuffer, 256, 0);
if (ret == 0)
chr = Char.ConvertFromUtf32(m.WParam.ToInt32())[0];
if (ret == -1)
ToUnicode((uint)m.WParam.ToInt32(), 0, _pressCharKeyboardState, _pressCharBuffer, 256, 0);
else if (_pressCharBuffer.Length > 0)
chr = _pressCharBuffer[0];
if (m.Msg == 0x0102 && Char.IsWhiteSpace(chr))
chr = (Char)0;
if (ret >= 0 && chr > 0)
{
//DO YOUR STUFF using either "chr" as special key (UP, DOWN, etc..)
//either _pressCharBuffer.ToString()(can contain more than one character if dead key was pressed before)
//and don't forget to set the "handled" to true, so nobody else can use the message afterwards
}
}
return handled;
}
It is known that ToUnicode() and its older counterpart ToAscii() can change keyboard state of the current thread and thus mess with dead keys and ALT+NUMPAD keystrokes:
As ToUnicodeEx translates the virtual-key code, it also changes the
state of the kernel-mode keyboard buffer. This state-change affects
dead keys, ligatures, alt+numpad key entry, and so on. It might also
cause undesired side-effects if used in conjunction with
TranslateMessage (which also changes the state of the kernel-mode
keyboard buffer).
To avoid that you can do your ToUnicode() call in a separate thread (it will have a separate keyboard state) or use a special flag in wFlags param that is documented in ToUnicode() docs:
If bit 2 is set, keyboard state is not changed (Windows 10, version
1607 and newer)
Or you can prepare sc->char mapping table beforehand and update it on language change event.
I think it should work with ToAscii() too but better not use this old ANSI codepage-dependant method. Use ToUnicode() API instead that can even return ligatures and UTF-16 surrogate pairs - if keyboard layout have them. Some do.
See Asynchronous input vs synchronous input, a quick introduction
for the reason behind this.
I copy the vkCode in a queue and do the conversion from another thread
#HOOKPROC
def keyHookKFunc(code,wParam,lParam):
global gkeyQueue
gkeyQueue.append((code,wParam,kbd.vkCode))
return windll.user32.CallNextHookEx(0,code,wParam,lParam)
This has the advantage of not delaying key processing by the os
This works for me
byte[] keyState = new byte[256];
//Remove this if using
//GetKeyboardState(keyState);
//Add only the Keys you want
keysDown[(int)Keys.ShiftKey] = 0x80; // SHIFT down
keysDown[(int)Keys.Menu] = 0x80; // ALT down
keysDown[(int)Keys.ControlKey] = 0x80; // CONTROL down
//ToAscii should work fine
if (ToAscii(myKeyboardStruct.VirtualKeyCode, myKeyboardStruct.ScanCode, keyState, inBuffer, myKeyboardStruct.Flags) == 1)
{
//do something
}
I have a list of items (potentially large) from which the user must select one. I'd like to allow the user to type the first few letters of the desired item to jump to the correct place in the list. By default, each keypress jumps to the first item starting with that letter, so you can't type the first several letters. Is there any straightforward way to do this? Any CodeProject or other such example?
I've looked for hours, and found any number of samples for IAutocomplete, but that won't help here because I need to guarantee that the result is in the list.
The only way I can think to do this is to derive from CListBox, capture the keystrokes myself, find the item, run a timer so that new keystrokes after a sufficient pause will start a new search... since I'm not an MFC jock, this is daunting. Any tips much appreciated.
One clarifying note: my ultimate goal is actually to get this keyboard behavior for a ComboBox of DropDownList style (i.e. no edit box). The lack of an edit box rules out most autocomplete code, and the need for ComboBox functionality means I can't use CListCtrl by itself.
After much unnecessary pain, I've discovered that the real correct answer is simply to use LBS_SORT. Simply by specifying this style, the basic vanilla listbox supports the incremental search keyboard shortcut style I wanted. Without LBS_SORT (or CBS_SORT for a combobox), you get the irritating and almost-useless jump-to-first-letter-only behavior. I didn't try LBS_SORT because my list contents were added in sorted order anyway.
So the dozen or so hours of investigating custom controls, etc., all for naught because the Microsoft documentation makes no mention of this important behavioral difference in the description of LBS_SORT!!
Thanks to everyone who contributed.
I've implemented such a functionality in core Win32. Heres the code.
Somewhere in your message loop that processes the list box insert:
switch(message)
{
case WM_CHAR:
if(HandleListBoxKeyStrokes(hwnd, wParam) == FALSE)
return FALSE;
....
Heres the code (propably not fully complete):
/* ======================================================================== */
/* ======================================================================== */
#define RETURNr(a, b) // homegrown asserts
BOOLEAN HandleListBoxKeyStrokes(HWND hwnd, UINT theKey)
{
#define MAXCHARCACHEINTERVALL 600.0 // Max. milisecs time offset to consider as typed 'at once'
static char sgLastChars[255] = {'0'};
static double sgLastCharTime = 0.;
static HWND sgLasthwnd = NULL;
if(GetSecs() - sgLastCharTime > MAXCHARCACHEINTERVALL ||
sgLasthwnd != hwnd)
*sgLastChars = 0;
if(theKey == ' ' && *sgLastChars == 0)
return TRUE;
sgLastCharTime = GetSecs();
sgLasthwnd = hwnd;
AppendChar(sgLastChars, toupper(theKey));
if(strlen(sgLastChars) > 1)
{
LONG l = GetWindowLong(hwnd, GWL_STYLE);
Char255 tx;
GetClassName(hwnd, tx, sizeof(tx));
if( (! stricmp(tx, "Listbox") &&
! (l & (LBS_EXTENDEDSEL | LBS_MULTIPLESEL)) ) ||
(! stricmp(tx, "ComboBox") && // combo Box support
l & CBS_DROPDOWNLIST &&
! (l & (CBS_OWNERDRAWFIXED | CBS_OWNERDRAWVARIABLE)) ) )
{
long Count, l, BestMatch = - 1, BestMatchOff = 0;
long LBcmdSet[] = {LB_GETCOUNT, LB_GETTEXTLEN , LB_GETTEXT};
long CBcmdSet[] = {CB_GETCOUNT, CB_GETLBTEXTLEN, CB_GETLBTEXT};
long *cmdSet = (! stricmp(tx, "ComboBox")) ? CBcmdSet : LBcmdSet;
RETURNr((Count = SendMessage(hwnd, cmdSet[0], 0, 0)) != LB_ERR, 0);
for(int i = 0; i < Count; i++)
{
RETURNr((l = SendMessage(hwnd, cmdSet[1], i, 0)) != LB_ERR, TRUE);
RETURNr( l < sizeof(tx), TRUE);
RETURNr((l = SendMessage(hwnd, cmdSet[2], i, (LPARAM)&tx)) != LB_ERR, TRUE);
strupr(tx);
if(! strncmp(tx, sgLastChars, strlen(sgLastChars)))
{
SelListBoxAndNotify(hwnd, i);
return FALSE;
}
char *p;
if(p = strstr(tx, sgLastChars))
{
int off = p - tx;
if(BestMatch == -1 || off < BestMatchOff)
{
BestMatch = i;
BestMatchOff = off;
}
}
}
// If text not found at start of string see if it matches some part inside the string
if(BestMatch != -1)
SelListBoxAndNotify(hwnd, BestMatch);
// Nothing found - dont process
return FALSE;
}
}
return TRUE;
}
/* ======================================================================== */
/* ======================================================================== */
void SelListBoxAndNotify(HWND hwnd, int index)
{
// i am sorry here - this is some XVT-toolkit specific code.
// it has to be replaced with something similar for native Win32
WINDOW win = xvtwi_hwnd_to_window(hwnd);
WINDOW parent = xvt_vobj_get_parent(win);
xvt_list_set_sel(win, index, 1);
EVENT evt;
memset(&evt, 0, sizeof(evt));
evt.type = E_CONTROL;
evt.v.ctl.id = GetDlgCtrlID(hwnd);
evt.v.ctl.ci.v.lbox.dbl_click = FALSE;
xvt_win_dispatch_event(parent, &evt);
}
/* ======================================================================== */
/* ======================================================================== */
double GetSecs(void)
{
struct timeb timebuffer;
ftime(&timebuffer);
return (double)timebuffer.millitm +
((double)timebuffer.time * 1000.) - // Timezone needed for DbfGetToday
((double)timebuffer.timezone * 60. * 1000.);
}
/* ======================================================================== */
/* ======================================================================== */
char AppendChar(char *tx, char C)
{ int i;
i = strlen(tx);
tx[i ] = C;
tx[i + 1] = 0;
return(C);
}
Can you use a CListView CListCtrl instead? They work like that by default.