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