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.refresh()`
 253
 254 If you make changes to [`vimfx.modes`] directly you need to call
 255 `vimfx.refresh()` for your changes to take effect.
 256
 257 ### `vimfx.modes`
 258
 259 An object whose keys are mode names and whose values are [mode object]s.
 260
 261 This is a very low-level part of the API. It allows to:
 262
 263 - Access all commands and run them. This is the only thing that a config file
 264   user needs it for.
 265
 266   ```js
 267     let {commands} = vimfx.modes.normal
 268     // Inside a custom command:
 269     commands.tab_new.run(args)
 270   ```
 271
 272 - Adding new commands. This is intended to be used by extension authors who wish
 273   to extend VimFx, not config file users. They should use the
 274   `vimfx.addCommand()` helper instead.
 275
 276   ```js
 277   vimfx.modes.normal.commands.new_command = {
 278     pref: 'extensions.my_extension.mode.normal.new_command',
 279     category: 'misc',
 280     order: 10000,
 281     description: () => translate('mode.normal.new_command'),
 282     run: args => console.log('New command! args:', args)
 283   }
 284   ```
 285
 286 - Adding new modes. This is intended to be used by extension authors who wish to
 287   extend VimFx, not config file users.
 288
 289   ```js
 290   vimfx.modes.new_mode = {
 291     name: () => translate('mode.new_mode'),
 292     order: 10000,
 293     commands: {},
 294     onEnter(args) {},
 295     onLeave(args) {},
 296     onInput(args, match) {
 297       if (match.type === 'full') {
 298         match.command.run(args)
 299       }
 300       return (match.type !== 'none')
 301     },
 302   }
 303   ```
 304
 305 When you’re done modifying `vimfx.modes` directly, you need to call
 306 `vimfx.refresh()`. (That’s taken care of automatically in the
 307 `vimfx.addCommand()` helper.)
 308
 309 Have a look at [modes.coffee] and [commands.coffee] for more information.
 310
 311 ### `vimfx.get('categories')`
 312
 313 An object whose keys are category names and whose values are [category object]s.
 314
 315 ```js
 316 let categories = vimfx.get('categories')
 317
 318 // Add a new category.
 319 categories.custom = {
 320   name: () => 'Custom commands',
 321   order: 10000,
 322 }
 323
 324 // Swap the order of the Location and Tabs categories.
 325 ;[commands.focus_location_bar.order, categories.tabs.order] =
 326   [categories.tabs.order, commands.focus_location_bar.order]
 327 ```
 328
 329 ### Mode object
 330
 331 A mode is an object with the follwing properties:
 332
 333 - name(): `Function`. Returns a human readable name of the mode used in the help
 334   dialog and VimFx’s settings page in the Add-ons Manager.
 335 - order: `Number`. The first of the default modes has the order `100` and then
 336   they increase by `100` per mode. This allows to put new modes between two
 337   already existing ones.
 338 - commands: `Object`. The keys are command names and the values are [command
 339   object]s.
 340 - onEnter(data, ...args): `Function`. Called when the mode is entered.
 341 - onLeave(data): `Function`. Called when the mode is left.
 342 - onInput(data, match): `Function`. Called when a key is pressed.
 343
 344 #### onEnter, onLeave and onInput
 345
 346 These methods are called with an object (called `data` above) with the following
 347 properties:
 348
 349 - vim: The current [vim object].
 350 - storage: An object unique to the current [vim object] and to the current mode.
 351   Allows to share things between commands of the same mode by getting and
 352   setting keys on it.
 353
 354 ##### onEnter
 355
 356 This method is called with an object as mentioned above, and after that there
 357 may be any number of arguments (`args` in `vim.enterMode(modeName, ...args)`)
 358 that the mode is free to do whatever it wants with.
 359
 360 ##### onInput
 361
 362 The object passed to this method (see above) also has the following properties:
 363
 364 - isFrameEvent: `Boolean`. `true` if the event occured in web page content,
 365   `false` otherwise (if the event occured in the browser UI).
 366 - count: `Number`. The count for the command. `undefined` if no count. (This is
 367   simply a copy of `match.count`. `match` is defined below.)
 368
 369 The above object should be passed to commands when running them. The mode is
 370 free to do whatever it wants with the return value (if any) of the commands it
 371 runs.
 372
 373 It also receives a [match object] as the second argument.
 374
 375 `onInput` should return `true` if the current keypress should not be passed on
 376 to the browser and web pages, and `false` otherwise.
 377
 378 ### Category object
 379
 380 A category is an object with the follwing properties:
 381
 382 - name(): `Function`. Returns a human readable name of the category used in the
 383   help dialog and VimFx’s settings page in the Add-ons Manager. Config file
 384   users adding custom categories could simply return a string; extension authors
 385   are encouraged to look up the name from a locale file.
 386 - order: `Number`. The first of the default categories is the “uncategorized”
 387   category. It has the order `100` and then they increase by `100` per category.
 388   This allows to put new categories between two already existing ones.
 389
 390 ### Command object
 391
 392 A command is an object with the following properties:
 393
 394 - pref: `String`. The pref used to store the shortcuts for the command.
 395 - run(args): `Function`. Called when the command is activated.
 396 - description(): `Function`. Returns a description of the command (as a string),
 397   shown in the help dialog and VimFx’s settings page in the Add-ons Manager.
 398 - category: `String`. The category to add the command to. The value has to be
 399   one of the keys of [`vimfx.get('categories')`][categories].
 400 - order: `Number`. The first of the default commands has the order `100` and
 401   then they increase by `100` per command. This allows to put new commands
 402   between two already existing ones.
 403
 404 ### Match object
 405
 406 A `match` object has the following properties:
 407
 408 - type: `String`. It has one of the following values:
 409
 410   - `'full'`: The current keypress, together with previous keypresses, fully
 411     matches a command shortcut.
 412   - `'partial'`: The current keypress, together with previous keypresses,
 413     partially matches a command shortcut.
 414   - `'count'`: The current keypress is not part of a command shortcut, but is a
 415     digit and contributes to the count of a future matched command.
 416   - `'none'`: The current keypress is not part of a command shortcut and does
 417     not contribute to a count.
 418
 419 - focus: `String` or `null`. The type of currently focused _element_ plus
 420   current pressed _key_ combo. You might not want to run commands and suppress
 421   the event if this value is anything other than null. It has one of the
 422   following values, depending on what kind of _element_ is focused and which
 423   _key_ was pressed:
 424
 425   - `'editable'`: element: a text input or a `contenteditable` element.
 426     key: any pressed key.
 427   - `'activatable'`: element: an “activatable” element (link or button).
 428     key: see the [`activatable_element_keys`] option.
 429   - `'adjustable'`: element: an “adjustable” element (form control or video
 430     player). key: see the [`adjustable_element_keys`] option.
 431   - `'other'`: element: some other kind of element that can receive keystrokes,
 432     for example an element in fullscreen mode. key: any pressed key.
 433
 434   If none of the above criteria is met, the value is `null`, which means that
 435   the currently focused element does not appear to respond to keystrokes in any
 436   special way.
 437
 438 - command: `null` unless `type` is `'full'`. Then it is the matched command (a
 439   [command object]).
 440
 441   The matched command should usually be run at this point. It is suitable to
 442   pass on the object passed to [onInput] to the command. Some modes might choose
 443   to add extra properties to the object first. (That is favored over passing
 444   several arguments, since it makes it easier for the command to in turn pass
 445   the same data it got on to another command, if needed.)
 446
 447   Usually the return value of the command isn’t used, but that’s up to the mode.
 448
 449 - count: `Number`. The count for the command. `undefined` if no count.
 450
 451 - specialKeys: `Object`. The keys may be any of the following:
 452
 453   - `<force>`
 454   - `<late>`
 455
 456   If a key exists, its value is always `true`. The keys that exist indicate the
 457   [special keys] for the sequence used for the matched command (if any).
 458
 459 - keyStr: `String`. The current keypress represented as a string.
 460
 461 - unmodifiedKey: `String`. `keyStr` without modifiers.
 462
 463 - toplevel: `Boolean`. Whether or not the match was a toplevel match in the
 464   shortcut key tree. This is `true` unless the match is part of the tail of a
 465   multi-key shortcut.
 466
 467 ### Vim object
 468
 469 There is one `vim` object per tab.
 470
 471 A `vim` object has the following properties:
 472
 473 - window: [`Window`]. The current Firefox window object. Most commands
 474   interacting with Firefox’s UI use this.
 475
 476 - browser: [`Browser`]. The `browser` that this vim object handles.
 477
 478 - options: `Object`. Provides access to all of VimFx’s options. It is an
 479   [options object].
 480
 481 - mode: `String`. The current mode name.
 482
 483 - enterMode(modeName, ...args): `Function`. Enter mode `modeName`, passing
 484   `...args` to the mode. It is up to every mode to do whatever it wants to with
 485   `...args`.
 486
 487 - isFrameEvent(event): `Function`. Returns `true` if `event` occurred in web
 488   page content, and `false` otherwise (if it occurred in Firefox’s UI).
 489
 490 - notify(title, options = {}): `Function`. Display a notification with the title
 491   `title` (a `String`). If you need more text than a title, use `options.body`.
 492   See [`Notification`] for more information.
 493
 494 - markPageInteraction(): `Function`. Marks that the user has interacted with the
 495   page. After that [autofocus prevention] is not done anymore. Commands
 496   interacting with web page content might want to do this.
 497
 498 **Warning:** There are also properties starting with an underscore on `vim`
 499 objects. They are private, and not supposed to be used outside of VimFx’s own
 500 source code. They may change at any time.
 501
 502 ### Options object
 503
 504 An `options` object provides access to all of VimFx’s options. It is an object
 505 whose keys are VimFx pref names.
 506
 507 Note that the values are not just simply `vimfx.get(pref)` for the `pref` in
 508 question; they are _parsed_ (`parse(vimfx.get(pref))`):
 509
 510 - Space-separated prefs are parsed into arrays of strings.
 511
 512 - `black_list` and `{prev,next}_patterns` are parsed into arrays of regular
 513   expressions.
 514
 515 (See [parse-prefs.coffee] for all details.)
 516
 517 Any [option overrides] are automatically taken into account when getting an
 518 option value.
 519
 520 The [special options] are also available on this object.
 521
 522
 523 ### Location object
 524
 525 A location object is very similar to [`window.location`] in web pages.
 526 Technically, it is a [`URL`] instance. You can experient with the current
 527 location object by opening the [web console] and entering `location`.
 528
 529
 530 ## Stability
 531
 532 The public API is currently **experimental** and therefore **unstable.** Things
 533 might break with new VimFx versions.
 534
 535 As soon as VimFx 1.0.0 is released backwards compatibility will be a priority
 536 and won’t be broken until VimFx 2.0.0.
 537
 538 [option overrides]: #vimfxaddOptionOverridesrules
 539 [categories]: #vimfxgetcategories
 540 [`vimfx.modes`]: #vimfxmodes
 541 [onInput]: #oninput
 542 [mode object]: #mode-object
 543 [category object]: #category-object
 544 [command object]: #command-object
 545 [match object]: #match-object
 546 [vim object]: #vim-object
 547 [options object]: #options-object
 548 [location object]: #location-object
 549
 550 [blacklisted]: options.md#blacklist
 551 [special options]: options.md#special-options
 552 [config file]: config-file.md
 553 [bootstrap.js]: config-file.md#bootstrapjs
 554 [autofocus prevention]: options.md#prevent-autofocus
 555 [`activatable_element_keys`]: options.md#activatable_element_keys
 556 [`adjustable_element_keys`]: options.md#adjustable_element_keys
 557
 558 [special keys]: shortcuts.md#special-keys
 559
 560 [defaults.coffee]: ../extension/lib/defaults.coffee
 561 [parse-prefs.coffee]: ../extension/lib/parse-prefs.coffee
 562 [modes.coffee]: ../extension/lib/modes.coffee
 563 [commands.coffee]: ../extension/lib/commands.coffee
 564 [vim.coffee]: ../extension/lib/vim.coffee
 565
 566 [`Window`]: https://developer.mozilla.org/en-US/docs/Web/API/Window
 567 [`Browser`]: https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XUL/browser
 568 [`Notification`]: https://developer.mozilla.org/en-US/docs/Web/API/Notification
 569 [`window.location`]: https://developer.mozilla.org/en-US/docs/Web/API/Location
 570 [`URL`]: https://developer.mozilla.org/en-US/docs/Web/API/URL
 571 [TabSelect]: https://developer.mozilla.org/en-US/docs/Web/Events/TabSelect
 572 [web console]: https://developer.mozilla.org/en-US/docs/Tools/Web_Console
 573 [about:config]: http://kb.mozillazine.org/About:config