save-window-positions

#! /usr/bin/env node

/* 
 * Copyright (C) 2015 Rafael Vega <contacto@rafaelvega.co> 
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

// Libraries
var shell = require('child_process');
var fs = require('fs');

// Config variables
var window_list_command = 'wmctrl -lpG';
var window_properties_command = 'xprop -id {1}'

function print(a, params){
   var s = JSON.stringify(a, null, "\t");
   
   fs.writeFileSync(params.output_filename, s); 
}

function get_window_info(window, callback){
   if(window == ''){
      callback(true, null);
      return;
   }

   win= window.split(' ');
   win= win.filter(function(n){ return n; }); // Get rid of extra whitespace within the split array

   var info = {};
   info.wid = win[0];
   info.workspace = Number(win[1]);
   info.pid = Number(win[2]);
   info.x = Number(win[3]);
   info.y = Number(win[4]);
   info.w = Number(win[5]);
   info.h = Number(win[6]);

   // Title must be handled differently because it might contain several consecutive spaces
   var title_start = win.splice(8, win.length)[0];
   var title_pos = window.search(title_start);
   info.title = window.substring(title_pos);

   if(info.workspace == -1){ 
      // This is the Desktop "window"
      callback(true, null); 
      return;
   }

   // The above info does not include window decorations or maximization
   // state, get them with xprop.
   var command = window_properties_command.replace('{1}', info.wid);
   shell.exec(command, function(err, stdout, stderr){
      var window_properties = stdout.split('\n');

      var decorations = window_properties.filter(function(i){
         return i.search('_NET_FRAME_EXTENTS') != -1;
      });

      try{
         decorations = decorations[0].split(' = ')[1].split(',')
         info.decorations = {
            left: Number(decorations[0]),
            right: Number(decorations[1]),
            top: Number(decorations[2]),
            bottom: Number(decorations[3])
         };
      }
      catch(e){
         info.decorations = {
            top: 0,
            right: 0,
            bottom: 0,
            left: 0
         };
      }

      var maximized = window_properties.filter(function(i){
         return i.search('_NET_WM_STATE') != -1;
      });
      try{
         info.states = [];
         maximized = maximized[0].split(' = ')[1].split(',');
         maximized.forEach(function(state){
            state = state.trim();
            if(state == '_NET_WM_STATE_HIDDEN'){
               info.states.push('hidden');
            }
            if(state == '_NET_WM_STATE_MAXIMIZED_HORZ'){
               info.states.push('maximized_horz');
            }
            if(state == '_NET_WM_STATE_MAXIMIZED_VERT'){
               info.states.push('maximized_vert');
            }
         });
      }
      catch(e){
         info.states = [];
      }

      /*
       * Not sure if this is where the magic number used in 
       * the set-geometries script comes from...
       */
         // var shadows = window_properties.filter(function(i){
         //    return i.search('_NET_WM_OPAQUE_REGION') != -1;
         // });
         // try{
         //    shadows = shadows[0].split(' = ')[1].split(',');
         //    info.shadows = shadows;
         // }
         // catch(e){
         //    info.shadows = [0,0,0,0,0,0,0,0];
         // }

      callback(false, info);
   });
}

function get_windows_info(parameters){
   shell.exec(window_list_command, function(err, stdout, stderr){
      if(err){
         console.error(err);
         return;
      }
      var windows = stdout.split('\n');
      var window_count = windows.length;
      var infos = [];
      windows.forEach(function(window){
         get_window_info(window, function(err, info){
            if(!err){
               infos.push(info);
            }

            window_count--;
            if(window_count <= 0){
               print(infos, parameters);
            }
         });
      });
   });
}

function parse_parameters(){
   var params = {
      output_filename : process.env['HOME']+'/.config/window_positions/window_positions.json'
   };

  if(typeof(process.argv[2]) != 'undefined'){
     params.output_filename = process.argv[2];
  }
  else{
     // User is not setting a filename, let's create the directory
     // to put the default savefile
      fs.mkdir(process.env['HOME']+'/.config/window_positions', function(){});
  }

  return params;
}

var parameters = parse_parameters();
get_windows_info(parameters);


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