HID/src/ImprovedKeyboard.cpp

/*
Copyright (c) 2014-2015 NicoHood
See the readme for credit to other people.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

#include "ImprovedKeyboard.h"

#if defined(_USING_HID)

//================================================================================
//================================================================================
//	Keyboard

static const u8 _hidReportDescriptor[] PROGMEM = {

  //  Keyboard
    0x05, 0x01,                    // USAGE_PAGE (Generic Desktop)  // 47
    0x09, 0x06,                    // USAGE (Keyboard)
    0xa1, 0x01,                    // COLLECTION (Application)
    0x85, HID_REPORTID_KEYBOARD,   //   REPORT_ID
    0x05, 0x07,                    //   USAGE_PAGE (Keyboard)
   
  0x19, 0xe0,                    //   USAGE_MINIMUM (Keyboard LeftControl)
    0x29, 0xe7,                    //   USAGE_MAXIMUM (Keyboard Right GUI)
    0x15, 0x00,                    //   LOGICAL_MINIMUM (0)
    0x25, 0x01,                    //   LOGICAL_MAXIMUM (1)
    0x75, 0x01,                    //   REPORT_SIZE (1)
    
  0x95, 0x08,                    //   REPORT_COUNT (8)
    0x81, 0x02,                    //   INPUT (Data,Var,Abs)
    0x95, 0x01,                    //   REPORT_COUNT (1)
    0x75, 0x08,                    //   REPORT_SIZE (8)
    0x81, 0x03,                    //   INPUT (Cnst,Var,Abs)
    
  0x95, 0x06,                    //   REPORT_COUNT (6)
    0x75, 0x08,                    //   REPORT_SIZE (8)
    0x15, 0x00,                    //   LOGICAL_MINIMUM (0)
    0x25, 0x65,                    //   LOGICAL_MAXIMUM (101)
    0x05, 0x07,                    //   USAGE_PAGE (Keyboard)
    
  0x19, 0x00,                    //   USAGE_MINIMUM (Reserved (no event indicated))
    0x29, 0x65,                    //   USAGE_MAXIMUM (Keyboard Application)
    0x81, 0x00,                    //   INPUT (Data,Ary,Abs)
    0xc0,                          // END_COLLECTION
};

Keyboard_::Keyboard_(void) 
{
	static HID_Descriptor cb = {
		.length = sizeof(_hidReportDescriptor),
		.descriptor = _hidReportDescriptor,
	};
	static HIDDescriptorListNode node(&cb);
	HID.AppendDescriptor(&node);
}

void Keyboard_::begin(void)
{
}

void Keyboard_::end(void)
{
}

void Keyboard_::sendReport(KeyReport* keys)
{
	HID.SendReport(HID_REPORTID_KEYBOARD,keys,sizeof(KeyReport));
}

// press() adds the specified key (printing, non-printing, or modifier)
// to the persistent key report and sends the report.  Because of the way 
// USB HID works, the host acts like the key remains pressed until we 
// call release(), releaseAll(), or otherwise clear the report and resend.
size_t Keyboard_::press(uint8_t k) 
{
	uint8_t i;
	if (k >= 136) {			// it's a non-printing key (not a modifier)
		k = k - 136;
	} else if (k >= 128) {	// it's a modifier key
		_keyReport.modifiers |= (1<<(k-128));
		k = 0;
	} else {				// it's a printing key
		k = pgm_read_byte(_asciimap + k);
		if (!k) {
			setWriteError();
			return 0;
		}
		if (k & 0x80) {						// it's a capital letter or other character reached with shift
			_keyReport.modifiers |= 0x02;	// the left shift modifier
			k &= 0x7F;
		}
	}
	
	// Add k to the key report only if it's not already present
	// and if there is an empty slot.
	if (_keyReport.keys[0] != k && _keyReport.keys[1] != k && 
		_keyReport.keys[2] != k && _keyReport.keys[3] != k &&
		_keyReport.keys[4] != k && _keyReport.keys[5] != k) {
		
		for (i=0; i<6; i++) {
			if (_keyReport.keys[i] == 0x00) {
				_keyReport.keys[i] = k;
				break;
			}
		}
		if (i == 6) {
			setWriteError();
			return 0;
		}	
	}
	sendReport(&_keyReport);
	return 1;
}

// release() takes the specified key out of the persistent key report and
// sends the report.  This tells the OS the key is no longer pressed and that
// it shouldn't be repeated any more.
size_t Keyboard_::release(uint8_t k) 
{
	uint8_t i;
	if (k >= 136) {			// it's a non-printing key (not a modifier)
		k = k - 136;
	} else if (k >= 128) {	// it's a modifier key
		_keyReport.modifiers &= ~(1<<(k-128));
		k = 0;
	} else {				// it's a printing key
		k = pgm_read_byte(_asciimap + k);
		if (!k) {
			return 0;
		}
		if (k & 0x80) {							// it's a capital letter or other character reached with shift
			_keyReport.modifiers &= ~(0x02);	// the left shift modifier
			k &= 0x7F;
		}
	}
	
	// Test the key report to see if k is present.  Clear it if it exists.
	// Check all positions in case the key is present more than once (which it shouldn't be)
	for (i=0; i<6; i++) {
		if (0 != k && _keyReport.keys[i] == k) {
			_keyReport.keys[i] = 0x00;
		}
	}

	sendReport(&_keyReport);
	return 1;
}

void Keyboard_::releaseAll(void)
{
	_keyReport.keys[0] = 0;
	_keyReport.keys[1] = 0;	
	_keyReport.keys[2] = 0;
	_keyReport.keys[3] = 0;	
	_keyReport.keys[4] = 0;
	_keyReport.keys[5] = 0;	
	_keyReport.modifiers = 0;
	sendReport(&_keyReport);
}

size_t Keyboard_::write(uint8_t c)
{	
	uint8_t p = press(c);  // Keydown
	release(c);            // Keyup
	return p;              // just return the result of press() since release() almost always returns 1
}

Keyboard_ Keyboard;

#endif