modules/interactive.js

   1 /**
   2  * (C) Copyright 2007-2009 John J. Foerch
   3  * (C) Copyright 2007-2008 Jeremy Maitin-Shepard
   4  *
   5  * Use, modification, and distribution are subject to the terms specified in the
   6  * COPYING file.
   7 **/
   8
   9 require("utils.js");
  10
  11 var interactive_commands = {};
  12
  13 /**
  14  * name: string name of the command.
  15  *
  16  * doc: Documentation string, may be null.
  17  *
  18  * handler: A function to handle the command.
  19  *
  20  * The $prefix keyword, when true, means that the command
  21  * is a prefix-command.
  22  */
  23 define_keywords("$prefix", "$browser_object", "$prompt");
  24 function interactive (name, doc, handler) {
  25     keywords(arguments);
  26     var cmd = {
  27         name: name,
  28         handler: handler,
  29         browser_object: arguments.$browser_object,
  30         prefix: arguments.$prefix,
  31         doc: doc,
  32         shortdoc: get_shortdoc_string(doc),
  33         prompt: arguments.$prompt,
  34         source_code_reference: get_caller_source_code_reference() };
  35     interactive_commands[name] = cmd;
  36     return name;
  37 }
  38
  39 function interactive_error (str) {
  40     var e = new Error(str);
  41     e.__proto__ = interactive_error.prototype;
  42     return e;
  43 }
  44 interactive_error.prototype.__proto__ = Error.prototype;
  45
  46
  47 function interactive_context (buffer) {
  48     this.local = conkeror;
  49     this.buffer = buffer;
  50     if (buffer) {
  51         this.window = this.buffer.window;
  52         if (buffer.page) {
  53             this.local = buffer.page.local;
  54         } else {
  55             this.local = buffer.local;
  56         }
  57     }
  58 }
  59 interactive_context.prototype = {
  60     constructor: interactive_context,
  61     toString: function () "#<interactive_context>",
  62     get P () this.prefix_argument,
  63     get p () univ_arg_to_number(this.prefix_argument),
  64     set p (default_value) univ_arg_to_number(this.prefix_argument, default_value),
  65     get minibuffer () this.window.minibuffer,
  66     prefix_argument: null,
  67     repeat: null
  68 };
  69
  70
  71 function handle_interactive_error (window, e) {
  72     if (! window)
  73         throw e;
  74     if (e instanceof interactive_error) {
  75         window.minibuffer.message(e.message);
  76     } else if (e instanceof abort) {
  77         window.minibuffer.message("Quit");
  78     } else {
  79         dump_error(e);
  80         window.minibuffer.message("call interactively: " + e);
  81     }
  82 }
  83
  84 function call_interactively (I, command) {
  85     var handler;
  86     var window = I.window;
  87
  88     if (typeof command == "function") {
  89         // Special interactive command
  90         command(I);
  91         yield co_return();
  92     }
  93
  94     var cmd = interactive_commands[command];
  95     if (!cmd) {
  96         handle_interactive_error(
  97             window,
  98             interactive_error("Invalid command: " + command));
  99         yield co_return();
 100     }
 101
 102     I.command = cmd;
 103     handler = cmd.handler;
 104
 105     try {
 106         while (typeof handler == "string") {
 107             let parent = interactive_commands[handler];
 108             handler = parent.handler;
 109             if (handler == command) {
 110                 throw (interactive_error("circular command alias, "+command));
 111             }
 112         }
 113
 114         try {
 115             yield handler(I);
 116         } catch (e) {
 117             handle_interactive_error(window, e);
 118         }
 119     } catch (e) {
 120         handle_interactive_error(window, e);
 121     }
 122 }
 123
 124
 125 function alternates () {
 126     let alts = Array.prototype.slice.call(arguments, 0);
 127     return function (I) {
 128         var index = 0;
 129         if (array_p(I.prefix_argument)) {
 130             let num = I.prefix_argument = I.prefix_argument[0];
 131             while (num >= 4 && index + 1 < alts.length) {
 132                 num = num / 4;
 133                 index++;
 134             }
 135         }
 136         yield alts[index](I);
 137     };
 138 }
 139
 140
 141 /*
 142  * Utility functions for use in the rc to alter the behavior
 143  * of interactive commands.
 144  */
 145 function set_handler (name, handler) {
 146     var cmd = interactive_commands[name];
 147     cmd.handler = handler;
 148 }
 149
 150 function set_default_browser_object (name, browser_object) {
 151     var cmd = interactive_commands[name];
 152     cmd.browser_object = browser_object;
 153 }
 154
 155 provide("interactive");