dvm.dvm.CommandManager source code

1 /**
2  * Copyright: Copyright (c) 2010-2011 Jacob Carlborg. All rights reserved.
3  * Authors: Jacob Carlborg
4  * Version: Initial created: Nov 8, 2010
5  * License: $(LINK2 http://www.boost.org/LICENSE_1_0.txt, Boost Software License 1.0)
6  */
7 module dvm.dvm.CommandManager;
8 
9 import std.algorithm : sort;
10 import std.array : array;
11 import std.format : format;
12 import std.range : join, repeat;
13 import std.conv : to;
14 
15 import dvm.commands.Command;
16 import dvm.dvm.Options;
17 
18 class CommandManager
19 {
20 	private static CommandManager instance_;
21     private Command[string] commands;
22 
23 	private this () {}
24 
25 	static CommandManager instance ()
26 	{
27 		if (instance_)
28 			return instance_;
29 
30 		return instance_ = new typeof(this);
31 	}
32 
33     void register (string command)
34     {
35         commands[command] = null;
36     }
37 
38     Command opIndex (string command)
39     {
40         if (auto c = command in commands)
41             if (*c)
42                 return *c;
43 
44         auto c = createCommand(command);
45         commands[command] = c;
46 
47         return c;
48     }
49 
50     string[] names ()
51     {
52         return commands.keys.sort.array;
53     }
54 
55     string summary ()
56     {
57         string result;
58 
59         auto len = lenghtOfLongestCommand;
60         auto options = Options.instance;
61 
62         foreach (name, _ ; commands)
63         {
64             auto command = this[name];
65             result ~= format("%s%s%s%s%s\n",
66                         options.indentation,
67                         command.name,
68                         " ".repeat(len - command.name.length).join,
69                         options.indentation.repeat(options.numberOfIndentations).join,
70                         command.summary);
71         }
72 
73         return result;
74     }
75 
76     private Command createCommand (string command)
77     {
78         return cast(Command) ClassInfo.find(command).create;
79     }
80 
81     private size_t lenghtOfLongestCommand ()
82     {
83         size_t len;
84 
85         foreach (name, _ ; commands)
86         {
87             auto command = this[name];
88 
89             if (command.name.length > len)
90                 len = command.name.length;
91         }
92 
93         return len;
94     }
95 }