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