查询和设置X Window Property

用命令xprop查询窗口属性(Property)

xprop是一个命令行工具，用于查询和设置X Window的Property.

一些用法举例：

• xprop -root WM_NAME： 显示窗口名称
• xprop -id 0x200007：列出指定窗口的全部Property
• xprop -id 0x200007 -set WM_NAME "Win Title"：设定窗口的名称

用Xlib API查询窗口属性(Property)

#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xproto.h>
#include <X11/Xatom.h>

#include <iostream>
#include <list>

class XWindowPropertyPlayer {
public:
  Window window;
  Display *display;

  Display *getXDisplay(){ return display;}
  Window getXWindow() {return window;}

  XWindowPropertyPlayer(){
    connect();
  }


  void connect(){
    display = XOpenDisplay( NULL );
    if(display==NULL){
      std::cout<<"Error: connect to DISPLAY FAIL"<<std::endl;
      exit(0);
    }
  }


  void listWindowProperties(Window window){
      int nProp;
      Atom *head = XListProperties(display, window, &nProp);
      for(int i=0;i<nProp;i++){
        char *atom_name = XGetAtomName(display, *(head+i));
        std::cout<<i<<" @ "<< atom_name <<std::endl;
        XFree(atom_name);
      }
  }

  void getProperty(Window window, Atom property){
      Atom type;
      int format;
      unsigned long len, remaining;
      unsigned char* data;
      // TODO: check whether it is a X Window ID?
      int size = 64;  // 64*4=256 bytes
      int result = XGetWindowProperty( display, window, property,
                      0,               // Offset
                      size,            // Result length to return
                      false,           // Delete: false
                      AnyPropertyType, // Requested type
                      &type, &format,  // Actual return type, format
                      &len,            // Actual return length
                      &remaining,      // Bytes remaining after the return
                      &data );				
       if ( result != Success ) {
         std::cout<<"FAIL to XGetWindowProperty"<<std::endl;
         return;
       }

       if(remaining>0){
         size = size*4 + remaining;
         XFree(data);
         result = XGetWindowProperty(display, window, property,
                      0, // Offset
                      size, // Result length to return
                      false, // Delete false
                      AnyPropertyType,  // Requested type
                      &type,      // Actual return type
                      &format,    // Actual return format
                      &len,       // Actual returned length.
                      &remaining, // Bytes remaining after the return
                      &data );
       }

       char *atom_name = XGetAtomName(display,property);
       std::cout<<"INFO: "<< atom_name << " = " << data <<std::endl;
       XFree(atom_name); XFree(data);
  }

  void getProperty(Window window, const char *name){
    Atom property = XInternAtom( getXDisplay(), name, false ); 
    getProperty(window, property);
  }



  void setProperty(Window dstWnd, const char *name, const char *value){
    const unsigned char *data = (const unsigned char *) value;
    int size = strlen(value);

    Atom property = XInternAtom( getXDisplay(), name, false );
    XChangeProperty( getXDisplay(),
      dstWnd,
      property,
      XA_STRING,
      8,
      PropModeReplace,
      (unsigned char *)data,
      size);

    XFlush(getXDisplay());
  }
}; //end class

int main(int argc, char **argv){

  if(argc>=3 && strcmp(argv[1],"props")==0){
    XWindowPropertyPlayer player;
    Window wnd = (Window) atoi(argv[2]);
    player.listWindowProperties(wnd);
    return 0;
  }

  if(argc==4 && strcmp(argv[1],"prop")==0){
    XWindowPropertyPlayer player;
    Window wnd = (Window) atoi(argv[2]);
    player.getProperty(wnd, argv[3]);
    return 0;
  }

  // guit prop 12345 name value
  if(argc==5 && strcmp(argv[1],"prop")==0){
    XWindowPropertyPlayer player;
    Window wnd = (Window) atoi(argv[2]);
    player.setProperty(wnd, argv[3], argv[4]);
    return 0;
  }

  return 0;
}