documentation/api.md

   1 <!--
   2 This is part of the VimFx documentation.
   3 Copyright Simon Lydell 2015.
   4 See the file README.md for copying conditions.
   5 -->
   6
   7 # Public API
   8
   9 VimFx has a public API. It is intended to be used by:
  10
  11 - Users who prefer to configure things using text files.
  12 - Users who would like to add custom commands.
  13 - Users who would like to set [special options].
  14 - Users who would like to make site-specific customizations.
  15 - Extension authors who would like to extend VimFx.
  16
  17 VimFx users who use the public API should write a so-called [config file].
  18
  19
  20 ## Getting the API
  21
  22 ```js
  23 let {classes: Cc, interfaces: Ci, utils: Cu} = Components
  24 Cu.import('resource://gre/modules/Services.jsm')
  25 let apiPref = 'extensions.VimFx.api_url'
  26 let apiUrl = Services.prefs.getComplexValue(apiPref, Ci.nsISupportsString).data
  27 Cu.import(apiUrl, {}).getAPI(vimfx => {
  28
  29   // Do things with the `vimfx` object here.
  30
  31 })
  32 ```
  33
  34 You might also want to take a look at the [config file bootstrap.js
  35 example][bootstrap.js].
  36
  37 Note that the callback passed to `getAPI` is called once every time VimFx starts
  38 up, not once per Firefox session! This means that if you update VimFx (or
  39 disable and then enable it), the callback is re-run with the new version.
  40
  41
  42 ## API
  43
  44 The following sub-sections assume that you store VimFx’s public API in a
  45 variable called `vimfx`.
  46
  47 ### `vimfx.get(pref)`, `vimfx.getDefault(pref)` and `vimfx.set(pref, value)`
  48
  49 Gets or sets the (default) value of the VimFx pref `pref`.
  50
  51 You can see all prefs in [defaults.coffee], or by opening [about:config] and
  52 filtering by `extensions.vimfx`. Note that you can also access the [special
  53 options], which may not be accessed in [about:config], using `vimfx.get()` and
  54 `vimfx.set()`—in fact, this is the _only_ way of accessing those options.
  55
  56 #### `vimfx.get(pref)`
  57
  58 Gets the value of the VimFx pref `pref`.
  59
  60 ```js
  61 // Get the value of the Hint chars option:
  62 vimfx.get('hint_chars')
  63 // Get all keyboard shortcuts (as a string) for the `f` command:
  64 vimfx.get('mode.normal.follow')
  65 ```
  66
  67 #### `vimfx.getDefault(pref)`
  68
  69 Gets the default value of the VimFx pref `pref`.
  70
  71 Useful when you wish to extend a default, rather than replacing it. See below.
  72
  73 #### `vimfx.set(pref, value)`
  74
  75 Sets the value of the VimFx pref `pref` to `value`.
  76
  77 ```js
  78 // Set the value of the Hint chars option:
  79 vimfx.set('hint_chars', 'abcdefghijklmnopqrstuvwxyz')
  80 // Add yet a keyboard shortcut for the `f` command:
  81 vimfx.set('mode.normal.follow', vimfx.getDefault('mode.normal.follow') + '  e')
  82 ```
  83
  84 When extending a pref (as in the second example above), be sure to use
  85 `vimfx.getDefault` rather than `vimfx.get`. Otherwise you get a multiplying
  86 effect. In the above example, after starting Firefox a few times the pref would
  87 be `f  e  e  e  e`. Also, if you find that example very verbose: Remember that
  88 you’re using a programming language! Write a small helper function that suits
  89 your needs.
  90
  91 Note: If you produce conflicting keyboard shortcuts, the order of your code does
  92 not matter. The command that comes first in VimFx’s settings page in the Add-ons
  93 Manager (and in the help dialog) gets the shortcut; the other one(s) do(es) not.
  94 See the notes about order in [mode object], [category object] and [command
  95 object] for more information about order.
  96
  97 ```js
  98 // Even though we set the shortcut for focusing the search bar last, the command
  99 // for focusing the location bar “wins”, because it comes first in VimFx’s
 100 // settings page in the Add-ons Manager.
 101 vimfx.set('mode.normal.focus_location_bar', 'ö')
 102 vimfx.set('mode.normal.focus_search_bar', 'ö')
 103
 104 // Swapping their orders also swaps the “winner”.
 105 let {commands} = vimfx.modes.normal
 106 ;[commands.focus_location_bar.order, commands.focus_search_bar.order] =
 107   [commands.focus_search_bar.order, commands.focus_location_bar.order]
 108 ```
 109
 110 ### `vimfx.addCommand(options, fn)`
 111
 112 Creates a new command.
 113
 114 **Note:** This should only be used by config file users, not by extension
 115 authors who wish to extend VimFx. They should add commands manually to
 116 [`vimfx.modes`] instead.
 117
 118 `options`:
 119
 120 - name: `String`. The name used when accessing the command via
 121   `vimfx.modes[options.mode].commands[options.name]`. It is also used for the
 122   pref used to store the shortcuts for the command:
 123   `` `custom.mode.${options.mode}.${options.name}` ``.
 124 - description: `String`. Shown in the help dialog and VimFx’s settings page in
 125   the Add-ons Manager.
 126 - mode: `String`. Defaults to `'normal'`. The mode to add the command to. The
 127   value has to be one of the keys of [`vimfx.modes`].
 128 - category: `String`. Defaults to `'misc'` for Normal mode and `''`
 129   (uncategorized) otherwise. The category to add the command to. The
 130   value has to be one of the keys of [`vimfx.get('categories')`][categories].
 131 - order: `Number`. Defaults to putting the command at the end of the category.
 132   The first of the default commands has the order `100` and then they increase
 133   by `100` per command. This allows to put new commands between two already
 134   existing ones.
 135
 136 `fn` is called when the command is activated. See the [onInput] documentation
 137 below for more information.
 138
 139 Note that you have to give the new command a shortcut in VimFx’s settings page
 140 in the Add-ons Manager or set one using `vimfx.set()` to able to use the new
 141 command.
 142
 143 ```js
 144 vimfx.addCommand({
 145   name: 'hello',
 146   description: 'Log Hello World',
 147 }, => {
 148   console.log('Hello World!')
 149 })
 150 // Optional:
 151 vimfx.set('custom.mode.normal.hello', 'gö')
 152 ```
 153
 154 ### `vimfx.addOptionOverrides(...rules)` and `vimfx.addKeyOverrides(...rules)`
 155
 156 These methods take any number of arguments. Each argument is a rule. The rules
 157 are added in order. The methods may be run multiple times.
 158
 159 A rule is an `Array` of length 2:
 160
 161 1. The first item is a function that returns `true` if the rule should be
 162    applied and `false` if not. This is called the matching function.
 163 2. The second item is the value that should be used if the rule is applied. This
 164    is called the override.
 165
 166 The rules are tried in the same order they were added. When a matching rule is
 167 found it is applied. No more rules will be applied.
 168
 169 #### `vimfx.addOptionOverrides(...rules)`
 170
 171 The rules are matched any time the value of a VimFx pref is needed.
 172
 173 The matching function receives a [location object].
 174
 175 The override is an object whose keys are VimFx pref names and whose values
 176 override the pref in question. The values should be formatted as in an [options
 177 object].
 178
 179 ```js
 180 vimfx.addOptionOverrides(
 181   [ ({hostname, pathname, hash}) =>
 182     `${hostname}${pathname}${hash}` === 'google.com/',
 183     {prevent_autofocus: false}
 184   ]
 185 )
 186 ```
 187
 188 #### `vimfx.addKeyOverrides(...rules)`
 189
 190 The rules are matched any time you press a key that is not part of the tail of a
 191 multi-key shortcut.
 192
 193 The matching function receives a [location object] as well as the current
 194 mode name (one of the keys of [`vimfx.modes`]).
 195
 196 The override is an array of keys which should not activate VimFx commands but be
 197 sent to the page.
 198
 199 This allows to disable commands on specific sites. To _add_ commands on specific
 200 sites, add them globally and then disable them on all _other_ sites.
 201
 202 ```js
 203 vimfx.addKeyOverrides(
 204   [ location => location.hostname === 'facebook.com',
 205     ['j', 'k']
 206   ]
 207 )
 208 ```
 209
 210 ### `vimfx.on(eventName, listener)`
 211
 212 Runs `listener(data)` when `eventName` is fired.
 213
 214 #### The `locationChange` event
 215
 216 Occurs when opening a new tab or navigating to a new URL causing a full page
 217 load. The data passed to listeners is an object with the following properties:
 218
 219 - vim: The current [vim object].
 220 - location: A [location object].
 221
 222 This can be used to enter a different mode by default on some pages (which can
 223 be used to replace the blacklist option).
 224
 225 ```js
 226 vimfx.on('load', ({vim, location}) => {
 227   if (location.hostname === 'example.com') {
 228     vim.enterMode('ignore')
 229   }
 230 })
 231 ```
 232
 233 #### The `modeChange` event
 234
 235 Occurs whenever the current mode in any tab changes. The initial entering of the
 236 default mode in new tabs also counts as a mode change. The data passed to
 237 listeners is the current [vim object].
 238
 239 ```js
 240 vimfx.on('modeChange', vim => {
 241   let mode = vimfx.modes[vim.mode].name()
 242   vim.notify(`Entering mode: ${mode}`)
 243 })
 244 ```
 245
 246 #### The `TabSelect` event
 247
 248 Occurs whenever any tab in any window is selected. This is also fired when
 249 Firefox starts for the currently selected tab. The data passed to listeners is
 250 the `event` object passed to the standard Firefox [TabSelect] event.
 251
 252 ### `vimfx.modes`
 253
 254 An object whose keys are mode names and whose values are [mode object]s.
 255
 256 This is a very low-level part of the API. It allows to:
 257
 258 - Access all commands and run them. This is the only thing that a config file
 259   user needs it for.
 260
 261   ```js
 262     let {commands} = vimfx.modes.normal
 263     // Inside a custom command:
 264     commands.tab_new.run(args)
 265   ```
 266
 267 - Adding new commands. This is intended to be used by extension authors who wish
 268   to extend VimFx, not config file users. They should use the
 269   `vimfx.addCommand()` helper instead.
 270
 271   ```js
 272   vimfx.modes.normal.commands.new_command = {
 273     pref: 'extensions.my_extension.mode.normal.new_command',
 274     category: 'misc',
 275     order: 10000,
 276     description: () => translate('mode.normal.new_command'),
 277     run: args => console.log('New command! args:', args)
 278   }
 279   ```
 280
 281 - Adding new modes. This is intended to be used by extension authors who wish to
 282   extend VimFx, not config file users.
 283
 284   ```js
 285   vimfx.modes.new_mode = {
 286     name: () => translate('mode.new_mode'),
 287     order: 10000,
 288     commands: {},
 289     onEnter(args) {},
 290     onLeave(args) {},
 291     onInput(args, match) {
 292       if (match.type === 'full') {
 293         match.command.run(args)
 294       }
 295       return (match.type !== 'none')
 296     },
 297   }
 298   ```
 299
 300 Have a look at [modes.coffee] and [commands.coffee] for more information.
 301
 302 ### `vimfx.get('categories')`
 303
 304 An object whose keys are category names and whose values are [category object]s.
 305
 306 ```js
 307 let categories = vimfx.get('categories')
 308
 309 // Add a new category.
 310 categories.custom = {
 311   name: () => 'Custom commands',
 312   order: 10000,
 313 }
 314
 315 // Swap the order of the Location and Tabs categories.
 316 ;[commands.focus_location_bar.order, categories.tabs.order] =
 317   [categories.tabs.order, commands.focus_location_bar.order]
 318 ```
 319
 320 ### Mode object
 321
 322 A mode is an object with the follwing properties:
 323
 324 - name(): `Function`. Returns a human readable name of the mode used in the help
 325   dialog and VimFx’s settings page in the Add-ons Manager.
 326 - order: `Number`. The first of the default modes has the order `100` and then
 327   they increase by `100` per mode. This allows to put new modes between two
 328   already existing ones.
 329 - commands: `Object`. The keys are command names and the values are [command
 330   object]s.
 331 - onEnter(data, ...args): `Function`. Called when the mode is entered.
 332 - onLeave(data): `Function`. Called when the mode is left.
 333 - onInput(data, match): `Function`. Called when a key is pressed.
 334
 335 #### onEnter, onLeave and onInput
 336
 337 These methods are called with an object (called `data` above) with the following
 338 properties:
 339
 340 - vim: The current [vim object].
 341 - storage: An object unique to the current [vim object] and to the current mode.
 342   Allows to share things between commands of the same mode by getting and
 343   setting keys on it.
 344
 345 ##### onEnter
 346
 347 This method is called with an object as mentioned above, and after that there
 348 may be any number of arguments (`args` in `vim.enterMode(modeName, ...args)`)
 349 that the mode is free to do whatever it wants with.
 350
 351 ##### onInput
 352
 353 The object passed to this method (see above) also has the following properties:
 354
 355 - isFrameEvent: `Boolean`. `true` if the event occured in web page content,
 356   `false` otherwise (if the event occured in the browser UI).
 357 - count: `Number`. The count for the command. `undefined` if no count. (This is
 358   simply a copy of `match.count`. `match` is defined below.)
 359
 360 The above object should be passed to commands when running them. The mode is
 361 free to do whatever it wants with the return value (if any) of the commands it
 362 runs.
 363
 364 It also receives a [match object] as the second argument.
 365
 366 `onInput` should return `true` if the current keypress should not be passed on
 367 to the browser and web pages, and `false` otherwise.
 368
 369 ### Category object
 370
 371 A category is an object with the follwing properties:
 372
 373 - name(): `Function`. Returns a human readable name of the category used in the
 374   help dialog and VimFx’s settings page in the Add-ons Manager. Config file
 375   users adding custom categories could simply return a string; extension authors
 376   are encouraged to look up the name from a locale file.
 377 - order: `Number`. The first of the default categories is the “uncategorized”
 378   category. It has the order `100` and then they increase by `100` per category.
 379   This allows to put new categories between two already existing ones.
 380
 381 ### Command object
 382
 383 A command is an object with the following properties:
 384
 385 - pref: `String`. The pref used to store the shortcuts for the command.
 386 - run(args): `Function`. Called when the command is activated.
 387 - description(): `Function`. Returns a description of the command (as a string),
 388   shown in the help dialog and VimFx’s settings page in the Add-ons Manager.
 389 - category: `String`. The category to add the command to. The value has to be
 390   one of the keys of [`vimfx.get('categories')`][categories].
 391 - order: `Number`. The first of the default commands has the order `100` and
 392   then they increase by `100` per command. This allows to put new commands
 393   between two already existing ones.
 394
 395 ### Match object
 396
 397 A `match` object has the following properties:
 398
 399 - type: `String`. It has one of the following values:
 400
 401   - `'full'`: The current keypress, together with previous keypresses, fully
 402     matches a command shortcut.
 403   - `'partial'`: The current keypress, together with previous keypresses,
 404     partially matches a command shortcut.
 405   - `'count'`: The current keypress is not part of a command shortcut, but is a
 406     digit and contributes to the count of a future matched command.
 407   - `'none'`: The current keypress is not part of a command shortcut and does
 408     not contribute to a count.
 409
 410 - focus: `String` or `null`. The type of currently focused _element_ plus
 411   current pressed _key_ combo. You might not want to run commands and suppress
 412   the event if this value is anything other than null. It has one of the
 413   following values, depending on what kind of _element_ is focused and which
 414   _key_ was pressed:
 415
 416   - `'editable'`: element: a text input or a `contenteditable` element.
 417     key: any pressed key.
 418   - `'activatable'`: element: an “activatable” element (link or button).
 419     key: see the [`activatable_element_keys`] option.
 420   - `'adjustable'`: element: an “adjustable” element (form control or video
 421     player). key: see the [`adjustable_element_keys`] option.
 422   - `'other'`: element: some other kind of element that can receive keystrokes,
 423     for example an element in fullscreen mode. key: any pressed key.
 424
 425   If none of the above criteria is met, the value is `null`, which means that
 426   the currently focused element does not appear to respond to keystrokes in any
 427   special way.
 428
 429 - command: `null` unless `type` is `'full'`. Then it is the matched command (a
 430   [command object]).
 431
 432   The matched command should usually be run at this point. It is suitable to
 433   pass on the object passed to [onInput] to the command. Some modes might choose
 434   to add extra properties to the object first. (That is favored over passing
 435   several arguments, since it makes it easier for the command to in turn pass
 436   the same data it got on to another command, if needed.)
 437
 438   Usually the return value of the command isn’t used, but that’s up to the mode.
 439
 440 - count: `Number`. The count for the command. `undefined` if no count.
 441
 442 - specialKeys: `Object`. The keys may be any of the following:
 443
 444   - `<force>`
 445   - `<late>`
 446
 447   If a key exists, its value is always `true`. The keys that exist indicate the
 448   [special keys] for the sequence used for the matched command (if any).
 449
 450 - keyStr: `String`. The current keypress represented as a string.
 451
 452 - unmodifiedKey: `String`. `keyStr` without modifiers.
 453
 454 - toplevel: `Boolean`. Whether or not the match was a toplevel match in the
 455   shortcut key tree. This is `true` unless the match is part of the tail of a
 456   multi-key shortcut.
 457
 458 ### Vim object
 459
 460 There is one `vim` object per tab.
 461
 462 A `vim` object has the following properties:
 463
 464 - window: [`Window`]. The current Firefox window object. Most commands
 465   interacting with Firefox’s UI use this.
 466
 467 - browser: [`Browser`]. The `browser` that this vim object handles.
 468
 469 - options: `Object`. Provides access to all of VimFx’s options. It is an
 470   [options object].
 471
 472 - mode: `String`. The current mode name.
 473
 474 - enterMode(modeName, ...args): `Function`. Enter mode `modeName`, passing
 475   `...args` to the mode. It is up to every mode to do whatever it wants to with
 476   `...args`.
 477
 478 - isFrameEvent(event): `Function`. Returns `true` if `event` occurred in web
 479   page content, and `false` otherwise (if it occurred in Firefox’s UI).
 480
 481 - notify(title, options = {}): `Function`. Display a notification with the title
 482   `title` (a `String`). If you need more text than a title, use `options.body`.
 483   See [`Notification`] for more information.
 484
 485 - markPageInteraction(): `Function`. Marks that the user has interacted with the
 486   page. After that [autofocus prevention] is not done anymore. Commands
 487   interacting with web page content might want to do this.
 488
 489 **Warning:** There are also properties starting with an underscore on `vim`
 490 objects. They are private, and not supposed to be used outside of VimFx’s own
 491 source code. They may change at any time.
 492
 493 ### Options object
 494
 495 An `options` object provides access to all of VimFx’s options. It is an object
 496 whose keys are VimFx pref names.
 497
 498 Note that the values are not just simply `vimfx.get(pref)` for the `pref` in
 499 question; they are _parsed_ (`parse(vimfx.get(pref))`):
 500
 501 - Space-separated prefs are parsed into arrays of strings.
 502
 503 - `black_list` and `{prev,next}_patterns` are parsed into arrays of regular
 504   expressions.
 505
 506 (See [parse-prefs.coffee] for all details.)
 507
 508 Any [option overrides] are automatically taken into account when getting an
 509 option value.
 510
 511 The [special options] are also available on this object.
 512
 513
 514 ### Location object
 515
 516 A location object is very similar to [`window.location`] in web pages.
 517 Technically, it is a [`URL`] instance. You can experient with the current
 518 location object by opening the [web console] and entering `location`.
 519
 520
 521 ## Stability
 522
 523 The public API is currently **experimental** and therefore **unstable.** Things
 524 might break with new VimFx versions.
 525
 526 As soon as VimFx 1.0.0 is released backwards compatibility will be a priority
 527 and won’t be broken until VimFx 2.0.0.
 528
 529 [option overrides]: #vimfxaddOptionOverridesrules
 530 [categories]: #vimfxgetcategories
 531 [`vimfx.modes`]: #vimfxmodes
 532 [onInput]: #oninput
 533 [mode object]: #mode-object
 534 [category object]: #category-object
 535 [command object]: #command-object
 536 [match object]: #match-object
 537 [vim object]: #vim-object
 538 [options object]: #options-object
 539 [location object]: #location-object
 540
 541 [blacklisted]: options.md#blacklist
 542 [special options]: options.md#special-options
 543 [config file]: config-file.md
 544 [bootstrap.js]: config-file.md#bootstrapjs
 545 [autofocus prevention]: options.md#prevent-autofocus
 546 [`activatable_element_keys`]: options.md#activatable_element_keys
 547 [`adjustable_element_keys`]: options.md#adjustable_element_keys
 548
 549 [special keys]: shortcuts.md#special-keys
 550
 551 [defaults.coffee]: ../extension/lib/defaults.coffee
 552 [parse-prefs.coffee]: ../extension/lib/parse-prefs.coffee
 553 [modes.coffee]: ../extension/lib/modes.coffee
 554 [commands.coffee]: ../extension/lib/commands.coffee
 555 [vim.coffee]: ../extension/lib/vim.coffee
 556
 557 [`Window`]: https://developer.mozilla.org/en-US/docs/Web/API/Window
 558 [`Browser`]: https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XUL/browser
 559 [`Notification`]: https://developer.mozilla.org/en-US/docs/Web/API/Notification
 560 [`window.location`]: https://developer.mozilla.org/en-US/docs/Web/API/Location
 561 [`URL`]: https://developer.mozilla.org/en-US/docs/Web/API/URL
 562 [TabSelect]: https://developer.mozilla.org/en-US/docs/Web/Events/TabSelect
 563 [web console]: https://developer.mozilla.org/en-US/docs/Tools/Web_Console
 564 [about:config]: http://kb.mozillazine.org/About:config