Linux程序设计入门 - gpm

  gpm是Linux console下的滑鼠驱动程序，它主要提供文字模式下的滑鼠事件处

  理。Linux下文字界面的滑鼠几乎都是用gpm来处理。


  gpm的文件在gpm原始码的doc目录中，详细的说明可叁考该目录中的文件gpm

  programming guide，此处只提供给您KickStart的一些技巧及一些叁考说明。


  特别注意到以下的范例，需在console下执行，不可在X Window的 Terminal下

  执行。


  范例 : gpm_mouse.c


  gpm原始码中有一个mev.c的程序，主要用来测试滑鼠状态。事实上，mev.c是个

  很好的范例，本范例便是取自mev.c，经过简化修改而来。


  #include <stdio.h>

  #include <stdlib.h>

  #include <unistd.h>

  #include <gpm.h>


  void main(int argc,char **argv)

  {

    fd_set readset;

    Gpm_Event event;

    Gpm_Connect conn;


    conn.eventMask   = ~0;

    conn.defaultMask = ~GPM_HARD;

    conn.maxMod      = 0;

    conn.minMod      = 0;


    if (Gpm_Open(&conn,0)==-1) {

      printf("Can not open mouse connection\n");

      exit(1);

    }


    while (1) {


      FD_ZERO(&readset);

      FD_SET(gpm_fd,&readset);

      select(gpm_fd+1,&readset,0,0,0);


      if (FD_ISSET(gpm_fd,&readset)) {

        if (Gpm_GetEvent(&event)>0) {

          printf("mouse: event 0x%02X, at %2i %2i (delta %2i %2i),"

                 "button %i, modifiers 0x%02X\r\n",

                 event.type,

                 event.x,event.y,

                 event.dx,event.dy,

                 event.buttons,

                 event.modifiers

                );

        }

      }

    }


    while (Gpm_Close());


  }


  编译


  gcc -o gpm_mouse gpm_mouse.c -lgpm


  检验结果


  mouse: event 0x01, at 15  1 (delta -2 -1),button 0, modifiers 0x00

  mouse: event 0x01, at 14  1 (delta -1  0),button 0, modifiers 0x00

  mouse: event 0x01, at 13  1 (delta -1  0),button 0, modifiers 0x00


  资料结构


  typedef struct Gpm_Connect {

    unsigned short eventMask, defaultMask;

    unsigned short minMod, maxMod;

    int pid;

    int vc;

  }              Gpm_Connect;


  enum Gpm_Etype {

    GPM_MOVE=1,

    GPM_DRAG=2,   /* exactly one of the bare ones is active at a time

  */

    GPM_DOWN=4,

    GPM_UP=  8,


    GPM_SINGLE=16,            /* at most one in three is set */

    GPM_DOUBLE=32,

    GPM_TRIPLE=64,            /* WARNING: I depend on the values */


    GPM_MFLAG=128,            /* motion during click? */

    GPM_HARD=256,             /* if set in the defaultMask, force an

  already  used event to pass over to another handler */


    GPM_ENTER=512,            /* enter event, user in Roi's */

    GPM_LEAVE=1024            /* leave event, used in Roi's */

  };


  typedef struct Gpm_Event {

    unsigned char buttons, modifiers;  /* try to be a multiple of 4 */

    unsigned short vc;

    short dx, dy, x, y;

    enum Gpm_Etype type;

    int clicks;

    enum Gpm_Margin margin;

  }              Gpm_Event;


  typedef int Gpm_Handler(Gpm_Event *event, void *clientdata);


  函数宣告


  int Gpm_Open(Gpm_Connect * CONN, int FLAGS);

  int Gpm_Close(void);

  int Gpm_GetEvent(Gpm_Event * EVENT);

  int Gpm_Getc(FILE * fp);

  #define    Gpm_Getchar() Gpm_Getc(stdin)

  int Gpm_Wgetch();

  #define Gpm_Getch() (Gpm_Wgetch(NULL))

  int Gpm_Repeat (int millisecs);

  int Gpm_DrawPointer (int X, int Y, int FD);

  int GPM_DRAWPOINTER (Gpm_Event *EPTR;)

  int Gpm_FitValuesM (int *X, int *Y, int MARGIN);

  int Gpm_FitValues (X,Y);

  Gpm_FitEvent (EPTR);

  char *Gpm_GetLibVersion (int *where);

  char *Gpm_GetServerVersion (int *where);

  int Gpm_GetSnapshot (Gpm_Event *ePtr);


  OK STATION, Webmaster, Brian Lin