LineSerial.cpp

00001 #include "LineSerial.h"
00002 
00003 LineSerial::LineSerial(PinName tx, PinName rx, const char *name) : Serial(tx, rx, name), 
00004     readBuffer(NULL),
00005     readBufferSize(0),
00006     readBufferCount(0),
00007     readLineFunc(NULL)
00008 {
00009 }
00010 
00011 LineSerial::~LineSerial()
00012 {
00013     if (this->readBuffer != NULL)
00014     {
00015         delete this->readBuffer;
00016         this->readBuffer = NULL;
00017     }
00018 }
00019 
00020 void LineSerial::allocateReadBuffer(size_t size)
00021 {
00022     // free memory.
00023     if (this->readBuffer != NULL)
00024     {
00025         delete this->readBuffer;
00026     }
00027     
00028     // allocate memory.
00029     if (size <= 0)
00030     {
00031         this->readBuffer = NULL;
00032     }
00033     else
00034     {
00035         this->readBuffer = new char[size];
00036     }
00037     
00038     // initialize related values.
00039     this->readBufferSize = size <= 0 ? 0 : size;
00040     this->readBufferCount = 0;
00041 }
00042 
00043 void LineSerial::attachReadLine(void (*func)(const char* str))
00044 {
00045     this->readLineFunc = func;
00046 }
00047 
00048 void LineSerial::task()
00049 {
00050     if (this->readable())
00051     {
00052         char c = this->getc();
00053         switch (c)
00054         {
00055         case '\r':
00056             if (this->readLineFunc != NULL)
00057             {
00058                 this->readBuffer[this->readBufferCount] = '\0';
00059                 this->readLineFunc(this->readBuffer);
00060                 this->readBufferCount = 0;
00061             }
00062             break;
00063         case '\b':
00064             if (!this->removeReadBuffer())
00065             {
00066                 this->putc('\a');
00067             }
00068             else
00069             {
00070                 this->puts("\b \b");
00071                 
00072             }
00073             break;
00074         default:
00075             if (!this->appendReadBuffer(c))
00076             {
00077                 this->putc('\a');
00078             }
00079             else
00080             {
00081                 this->putc(c);
00082             }
00083             break;
00084         }
00085     }
00086 }
00087 
00088 bool LineSerial::appendReadBuffer(char data)
00089 {
00090     if (this->readBuffer == NULL)
00091     {
00092         return false;
00093     }
00094     if (this->readBufferCount >= this->readBufferSize - 1)
00095     {
00096         return false;
00097     }
00098     
00099     this->readBuffer[this->readBufferCount++] = data;
00100     return true;
00101 }
00102 
00103 bool LineSerial::removeReadBuffer()
00104 {
00105     if (this->readBuffer == NULL)
00106     {
00107         return false;
00108     }
00109     if (this->readBufferCount <= 0)
00110     {
00111         return false;
00112     }
00113     
00114     this->readBufferCount--;
00115     return true;
00116 }