1/* 2 * Copyright (C) 2010 Michal Hruby <michal.mhr@gmail.com> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Authored by Magnus Kulke <mkulke@gmail.com> 19 * 20 */ 21 22namespace Synapse 23{ 24 public class CalculatorPlugin : Object, Activatable, ItemProvider 25 { 26 public bool enabled { get; set; default = true; } 27 28 public void activate () 29 { 30 31 } 32 33 public void deactivate () 34 { 35 36 } 37 38 private class Result : TextMatch 39 { 40 public int default_relevancy { get; set; default = 0; } 41 42 public Result (double result, string match_string) 43 { 44 Object (title: "%g".printf (result), 45 description: "%s = %g".printf (match_string, result), 46 has_thumbnail: false, icon_name: "accessories-calculator"); 47 } 48 49 public override string get_text () 50 { 51 return title; 52 } 53 } 54 55 static void register_plugin () 56 { 57 PluginRegistry.get_default ().register_plugin ( 58 typeof (CalculatorPlugin), 59 _("Calculator"), 60 _("Calculate basic expressions."), 61 "accessories-calculator", 62 register_plugin, 63 Environment.find_program_in_path ("bc") != null, 64 _("bc is not installed") 65 ); 66 } 67 68 static construct 69 { 70 register_plugin (); 71 } 72 73 private Regex regex; 74 75 construct 76 { 77 /* The regex describes a string which *resembles* a mathematical expression. It does not 78 check for pairs of parantheses to be used correctly and only whitespace-stripped strings 79 will match. Basically it matches strings of the form: 80 "paratheses_open* number (operator paratheses_open* number paratheses_close*)+" 81 */ 82 try 83 { 84 regex = new Regex ("^\\(*(-?\\d+([.,]\\d+)?)([*/+-^]\\(*(-?\\d+([.,]\\d+)?)\\)*)+$", 85 RegexCompileFlags.OPTIMIZE); 86 } catch (Error e) { 87 critical ("Error creating regexp."); 88 } 89 } 90 91 public bool handles_query (Query query) 92 { 93 return (QueryFlags.ACTIONS in query.query_type); 94 } 95 96 public async ResultSet? search (Query query) throws SearchError 97 { 98 string input = query.query_string.replace (" ", "").replace (",", "."); 99 bool matched = regex.match (input); 100 if (!matched && input.length > 1) 101 { 102 input = input[0 : input.length - 1]; 103 matched = regex.match (input); 104 } 105 if (matched) 106 { 107 Pid pid; 108 int read_fd, write_fd; 109 string[] argv = {"bc", "-l"}; 110 string? solution = null; 111 112 try 113 { 114 Process.spawn_async_with_pipes (null, argv, null, 115 SpawnFlags.SEARCH_PATH, 116 null, out pid, out write_fd, out read_fd); 117 UnixInputStream read_stream = new UnixInputStream (read_fd, true); 118 DataInputStream bc_output = new DataInputStream (read_stream); 119 120 UnixOutputStream write_stream = new UnixOutputStream (write_fd, true); 121 DataOutputStream bc_input = new DataOutputStream (write_stream); 122 123 bc_input.put_string (input + "\n", query.cancellable); 124 yield bc_input.close_async (Priority.DEFAULT, query.cancellable); 125 solution = yield bc_output.read_line_async (Priority.DEFAULT_IDLE, query.cancellable); 126 127 if (solution != null) 128 { 129 double d = double.parse (solution); 130 Result result = new Result (d, query.query_string); 131 ResultSet results = new ResultSet (); 132 results.add (result, MatchScore.AVERAGE); 133 query.check_cancellable (); 134 return results; 135 } 136 } 137 catch (Error err) 138 { 139 if (!query.is_cancelled ()) warning ("%s", err.message); 140 } 141 } 142 143 query.check_cancellable (); 144 return null; 145 } 146 } 147} 148