Fixes extra canvas create calls.
Fixes unnecessary call of `new DOMCanvasFactory`.
Fixes undefined error of DOMCanvasFactory.
Fixes failures in some of the tests.
Fixes expected behaviour.
Remove unused vars.
See http://eslint.org/docs/rules/brace-style.
Having the opening/closing braces on the same line can often make the code slightly more difficult to read, in particular for `if`/`else if` statements, compared to using new lines.
This patch also, for consistency with `mozilla-central`, enables the [`no-iterator`](http://eslint.org/docs/rules/no-iterator) rule. Note that this rule didn't require a single code change.
This property was added all the way back in PR 542, but hasn't actually been relied upon ever since PR 692.
Note that there's a `isStream()` utility function which replaced the property years ago, hence the `isStream` property is now dead code.
Other PDF viewers, e.g. Adobe Reader, seem to append `FileAttachment`s to their attachments views.
One obvious difference in PDF.js is that we cannot append all the annotations on document load, since that would require parsing *every* page. Despite that, it still seems like a good idea to add `FileAttachment`s, since it's thus possible to access all the various types of attachments from a single place.
*Note:* With the previous patch we display a notification when a `FileAttachment` is added to the sidebar, which thus makes appending the contents of these annotations to the sidebar slightly more visible/useful.
Please see http://eslint.org/docs/rules/no-unused-vars; note that this patch purposely uses the same rule options as in `mozilla-central`, such that it fixes part of issue 7957.
It wasn't, in my opinion, entirely straightforward to enable this rule compared to the already existing rules. In many cases a `var descriptiveName = ...` format was used (more or less) to document the code, and I choose to place the old variable name in a trailing comment to not lose that information.
I welcome feedback on these changes, since it wasn't always entirely easy to know what changes made the most sense in every situation.
Given the nature of `EOF` and `isEOF`, it seems to me that they really ought to be placed in `core/primitives.js` instead.
In general, it doesn't seem great to have to depend on the entire `core/parser.js` file for such simple primitives/helper functions.
In particular, while `core/ps_parser.js` is completely separate from `core/parser.js` with regards to its function, it still depends on the latter for just *one* primitive.
Note that compared to e.g. PR 7389, this will not reduce the number of dependencies for `core/ps_parser`, however the new dependency IMHO makes more sense.
PR 7322 added the `PdfJsNetwork.jsm` file, instead of the general `src/core/network.js` file for the Firefox addon. However, `make.js` wasn't updated to actually stop including the now obsolete network file.
Please see http://eslint.org/docs/rules/spaced-comment.
Note that the exceptions added for `line` comments are intended to still allow use of the old preprocessor without linting errors.
Also, I took the opportunity to improve the grammar slightly (w.r.t. capitalization and punctuation) for comments touched in the patch.
Further adjust the heuristics used to detect OpenType font files with CFF data, to ensure that all Type0 fonts are handled the same way regardless of font Subtype (issue 7901)
We're currently making use of `uniquePrefix`/`idCounters` in multiple files, to create unique object id's, and adding a new occurrence of them requires some care to ensure that an object id isn't accidentally reused.
Furthermore, having to pass around multiple parameters as we currently do seem like something you want to avoid.
Instead, this patch adds a factory which means that there's only *one* thing that needs to be passed around. And since it's now only necessary to call a method in order to obtain a unique object id, the details are thus abstracted away at the call-sites which avoids accidental reuse of object id's.
To test that this works as expected a very simple `Page` unit-test is added, and the existing `Annotation layer` tests are also adjusted slightly.
Using `else` after `return` is not necessary, and can often lead to unnecessarily cluttered code. By using the `no-else-return` rule in ESLint we can avoid this pattern, see http://eslint.org/docs/rules/no-else-return.
We're already passing in a, currently unused, `PdfManager` instance when initializing the `XRef`. To avoid having to pass a single `password` parameter around, we could thus simply get the `password` through the `PdfManager` instance instead.
This patch also removes the `UpdatePassword` message, in favour of using the `sendWithPromise` method of `MessageHandler`.
Furthermore, the patch also refactors the `BasePdfManager_updatePassword`/`BasePdfManager_passwordChanged` methods (in pdf_manager.js), and the `pdfManagerReady` function (in worker.js).
I recently happened to look at the code I wrote for PR 5964, which fixed [bug 1157493](https://bugzilla.mozilla.org/show_bug.cgi?id=1157493), and I quickly realized that the solution is way too simplistic.
The fact that only using the `length` of a `Differences` array worked seems more like a happy accident for a particular set of font data, but could just as easily be incorrect for other PDF files.
Note that in practice, the case where the `Encoding` entry is a regular `Dict` (and not a `Ref` or `Name`) is very rare, hence I don't think that we really need to worry about having to reparse this data.
Also, the performance of this code-block is quite a bit better by updating the `hash` with the data from the *entire* `Differences` array, instead of at every loop iteration.
Changing this particular code makes me somewhat nervous about regressions, since PR 5770 necessitated the follow-up PR 6270.
However, the patch passes all tests added in those PRs (and obviously all other tests). Furthermore, I've manually checked all the issues/bugs referenced in PRs 5770 and 6270 without finding any issues.
**Please note:** This patch fixes *only* the font bug, not the SVG conversion, present on pages two and three of the PDF file in issue 7901.
Modern browsers support styling radio buttons and checkboxes with CSS.
This makes the implementation much easier, and the fallback for older
browsers is still decent.
I haven't got an example where the current code breaks, but given all the previous cases we've seen where PDF generators use indirect objects in Arrays it makes sense to fix this pro-actively.
I've modified the relevant unit-tests slightly, and they would *not* pass without the code changes in this patch.
*Note:* `Dict_getArray` only dereferences Array elements on the "top-level", to avoid recursion issues. Furthermore if you have to loop through the Array at the call-site anyway, then using `Dict_get` in combination with `XRef_fetchIfRef` is a tiny bit more efficient.
*Please note that most of the necessary code adjustments were made in PR 7890.*
ESLint has a number of advantageous properties, compared to JSHint. Among those are:
- The ability to find subtle bugs, thanks to more rules (e.g. PR 7881).
- Much more customizable in general, and many rules allow fine-tuned behaviour rather than the just the on/off rules in JSHint.
- Many more rules that can help developers avoid bugs, and a lot of rules that can be used to enforce a consistent coding style. The latter should be particularily useful for new contributors (and reduce the amount of stylistic review comments necessary).
- The ability to easily specify exactly what rules to use/not to use, as opposed to JSHint which has a default set. *Note:* in future JSHint version some of the rules we depend on will be removed, according to warnings in http://jshint.com/docs/options/, so we wouldn't be able to update without losing lint coverage.
- More easily disable one, or more, rules temporarily. In JSHint this requires using a numeric code, which isn't very user friendly, whereas in ESLint the rule name is simply used instead.
By default there's no rules enabled in ESLint, but there are some default rule sets available. However, to prevent linting failures if we update ESLint in the future, it seemed easier to just explicitly specify what rules we want.
Obviously this makes the ESLint config file somewhat bigger than the old JSHint config file, but given how rarely that one has been updated over the years I don't think that matters too much.
I've tried, to the best of my ability, to ensure that we enable the same rules for ESLint that we had for JSHint. Furthermore, I've also enabled a number of rules that seemed to make sense, both to catch possible errors *and* various style guide violations.
Despite the ESLint README claiming that it's slower that JSHint, https://github.com/eslint/eslint#how-does-eslint-performance-compare-to-jshint, locally this patch actually reduces the runtime for `gulp` lint (by approximately 20-25%).
A couple of stylistic rules that would have been nice to enable, but where our code currently differs to much to make it feasible:
- `comma-dangle`, controls trailing commas in Objects and Arrays (among others).
- `object-curly-spacing`, controls spacing inside of Objects.
- `spaced-comment`, used to enforce spaces after `//` and `/*. (This is made difficult by the fact that there's still some usage of the old preprocessor left.)
Rules that I indend to look into possibly enabling in follow-ups, if it seems to make sense: `no-else-return`, `no-lonely-if`, `brace-style` with the `allowSingleLine` parameter removed.
Useful links:
- http://eslint.org/docs/user-guide/configuring
- http://eslint.org/docs/rules/
