cursor.c

Go to the documentation of this file.

 
 
#include <stdlib.h>
#include <stdio.h>
 
#ifdef _MSC_VER
#include <windows.h>
#else
#include <termios.h>
#include <unistd.h>
#endif
 
#include "cursor.h"
#include "split.h"
 
static bool inputEchoDisabled = false;
 
#ifdef _MSC_VER
static HANDLE hStdIn = INVALID_HANDLE_VALUE;
static HANDLE hStdOut = INVALID_HANDLE_VALUE;
static DWORD inputMode = 0;
#else
static struct termios oldt, newt;
#endif
 
#ifdef _MSC_VER
static void _init_console_mode(void)
{
    if (hStdOut == INVALID_HANDLE_VALUE)
    {
        hStdOut = GetStdHandle(STD_OUTPUT_HANDLE);
        if (hStdOut == INVALID_HANDLE_VALUE)
        {
            DWORD lastError = GetLastError();
            printf("GetStdHandle(STD_OUTPUT_HANDLE) failed: code = 0x%x\n", lastError);
        }
    }
    if (hStdIn == INVALID_HANDLE_VALUE)
    {
        hStdIn = GetStdHandle(STD_INPUT_HANDLE);
        if (hStdIn != INVALID_HANDLE_VALUE)
        {
            GetConsoleMode(hStdIn, &inputMode);
        }
        else
        {
            DWORD lastError = GetLastError();
            printf("GetStdHandle(STD_INPUT_HANDLE) failed: code = 0x%x\n", lastError);
        }
    }
}
#endif
 
static void _disableInputEcho(void)
{
#ifdef _MSC_VER
    _init_console_mode();
    if (hStdIn != INVALID_HANDLE_VALUE)
    {
        DWORD newMode = inputMode & ~(ENABLE_LINE_INPUT | ENABLE_ECHO_INPUT);
        if (!SetConsoleMode(hStdIn, newMode))
        {
            DWORD lastError = GetLastError();
            printf("SetConsoleMode(hStdIn, newMode) failed: code = 0x%x\n", lastError);
        }
    }
#else
    tcgetattr(STDIN_FILENO, &oldt);
    newt = oldt;
    newt.c_lflag &= ~(ICANON | ECHO);
    tcsetattr(STDIN_FILENO, TCSANOW, &newt);
#endif
    inputEchoDisabled = true;
}
 
static void _enableInputEcho(void)
{
#ifdef _MSC_VER
    _init_console_mode();
    if (hStdIn != INVALID_HANDLE_VALUE)
    {
        if (!SetConsoleMode(hStdIn, inputMode))
        {
            DWORD lastError = GetLastError();
            printf("SetConsoleMode(hStdIn, inputMode) failed: code = 0x%x\n", lastError);
        }
    }
#else
    tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
#endif
    inputEchoDisabled = false;
}
 
//=============================================================================
 
// disableinputecho()
void disableinputecho(void)
{
    if (!inputEchoDisabled)
    {
        _disableInputEcho();
    }
}
 
// enableinputecho()
void enableinputecho(void)
{
    if (inputEchoDisabled)
    {
        _enableInputEcho();
    }
}
 
// setcursorposition()
void setcursorposition(int row, int column)
{
    printf("\x1b[%d;%dH", row, column);
    fflush(stdout);
}
 
// getcursorposition()
void getcursorposition(int *row, int *column)
{
    if (row != NULL && column != NULL)
    {
        // Don't disable input echo if it is already disabled.
        bool wasInputEchoDisabled = inputEchoDisabled;
        if (!wasInputEchoDisabled)
        {
            _disableInputEcho();
        }
 
        printf("\x1b[6n");
        fflush(stdout);
        char buffer[16] = { 0 };
        // Must specify a delimiter, otherwise will block until eof (ctrl-Z).
        int c = 0;
        size_t bufferIndex = 0;
        while (c != 'R' && c != EOF && bufferIndex < sizeof(buffer))
        {
            c = getc(stdin);
            buffer[bufferIndex] = (char)c;
            bufferIndex++;
        }
        // If we filled the buffer, we got some really strange input so assume
        // it's something we can't handle and ignore it.
        if (bufferIndex < sizeof(buffer))
        {
            // Expecting ESC [ <r> ; <c> R (no spaces)
            if (bufferIndex > 2 && buffer[0] == '\x1b' && buffer[1] == '[')
            {
                SplitList elements = { 0 };
                split(buffer, "[;R", &elements);
                if (elements.strings_count >= 3)
                {
                    *row = (int)strtol(elements.strings[1], NULL, 0);
                    *column = (int)strtol(elements.strings[2], NULL, 0);
                }
                SplitList_Clear(&elements);
            }
        }
        if (!wasInputEchoDisabled)
        {
            _enableInputEcho();
        }
    }
}