GNU PGM

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