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
");  
   
      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
",  
   
                 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