Given the amount of work put into removing `require`-calls from the code-base, let's ensure that new ones aren't accidentally added in the future.
Note that we still have a couple of files where `require` is being used, in particular:
- The Node.js examples, however those will be updated to use `import` in PR 17081.
- The Webpack examples, and related support files, however I unfortunately don't know enough about Webpack to be able to update those. (Hopefully users of that code will help out here, once version `4` is released.)
- The `statcmp`-tool, since *some* of those `require`-calls cannot be converted to `import` without other code changes (and that file is only used during benchmarking).
Please find additional details at https://github.com/import-js/eslint-plugin-import/blob/main/docs/rules/no-commonjs.md
This has been deprecated since version `2.15.349`, which is a year ago.
Removing this will also simplify some upcoming changes, specifically outputting of JavaScript modules in the builds.
Given that the `useOnlyCssZoom` option is essentially just a special-case of the `maxCanvasPixels` functionality, we can combine the two options in order to simplify the overall implementation.
Note that the `useOnlyCssZoom` functionality was only ever used, by default, in the PDF Viewer for the B2G/FirefoxOS project (which was abandoned years ago).
Rather than repeatedly initializing a `canvasFactory`-instance for every page, move it to the document-level instead.
*Please note:* This patch is written using the GitHub UI, since I'm currently without a dev machine, so hopefully it works correctly.
Given that the `ProgressBar`-constructor was updated, we need to update the "mobile-viewer" example as well; this is yet another thing I missed during review.
This patch proposes removing the `browserify` example for the following reasons:
- The last `browserify` release was almost two years ago, according to both https://github.com/browserify/browserify/releases and https://www.npmjs.com/package/browserify?activeTab=versions
- The project no longer seems to be actively maintained, since so far this year there's only been *a single* (seemingly trivial) patch merged; see https://github.com/browserify/browserify/commits/master
- Because of the previous points `browserify` doesn't support modern and up-to-date JavaScript features, as evident from e.g. issue 14731 and multiple issues found in https://github.com/browserify/browserify/issues
- Our `browserify` example is most likely not very commonly used, judging by the very low volume of issues/PRs related to it. Looking at the `git` history of that example the only changes have been lint- or maintenance-related.[1]
- Providing an example for a framework that's no longer actively maintained doesn't seem like a good idea in general, since we probably don't want to steer users towards using (possibly) older frameworks.
- Given that we've never used `browserify` in the PDF.js project, it's also quite difficult to provide support for the example.
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[1] It's interesting to compare with the `webpack` example, since that's generated both issues *and* also PRs (for missing features) from users.
- Simplify how we look-up the DOM-element, which should also be a tiny bit more efficent.
- Use private class-fields, rather than property-names prefixed with underscores.
- Inline the `#updateBar` helper-method directly in the `percent`-setter, since having a separate method doesn't seem necessary in this case.
- Set the `indeterminate`-class on the ProgressBar DOM-element, to simplify the code.
Finally, also (slightly) re-factors the `PDFViewerApplication.progress`-method to make it a bit smaller.
The original `ProgressBar`-functionality is very old, and could thus do with some general clean-up.
In particular, while it currently accepts various options those have never really been used in either the default viewer or in any examples. The sort of "styling" that these options provided are *much better*, not to mention simpler, done directly with CSS rules.
As part of these changes, the "progress" is now updated using CSS variables rather than by directly modifying the `style` of DOM elements. This should hopefully simplify future changes to this code, see e.g. PR 14898.
Finally, this also fixes a couple of other small things in the "mobile viewer" example.
Given that Node.js doesn't support Workers, general PDF.js performance will be worse when compared to browsers. In an attempt to improve at least memory usage a little bit, update the Node.js examples to release page resources once parsing is done for that page.
Apparently Node.js has added *global* `URL.createObjectURL` support, but not done the same thing for `Blob`. Hence we also need to check for the availability of `Blob` in the `createObjectURL` helper function, and it's probably a good idea to also update `examples/node/pdf2svg.js` to work-around this until these changes reach an official PDF.js release.
Looking at the code, I do have to agree with the point made in issue 12731 about it being unexpected/unhelpful that the `PDFFindController.executeCommand`-method isn't directly usable with the "find"-event.
The reason for it being this way is, as so often, for historical reasons: The `executeCommand`-method was added (just) prior to the introduction of the `EventBus` in the viewer.
Obviously we cannot simply change the existing `PDFFindController.executeCommand`-method, since that'd be a breaking change in code which has existed for over five years.
Initially I figured that we could simply add a new method in `PDFFindController` that'd accept the state from the "find"-event, however after thinking about this and looking through the use-cases in the default viewer I settled on a slightly different approach: Let the `PDFFindController` just listen for the "find"-event (on the `EventBus`-instance) directly instead, which also removes one level of (unneeded) indirection during searching in the default viewer.
For GENERIC builds of the PDF.js library, the old `PDFFindController.executeCommand`-method is still available with a deprecation warning.
This is essentially a simplified version of the code that's used in `PDFPageView`, which will hopefully reduce the number of issues opened specifically about blurry rendering.
However, note that *ideally* users should base their implementations on the `components/` examples rather than using the API directly (the "viewer components" already support HiDPI-screens).
While e.g. the `simpleviewer` and `singlepageviewer` examples work, since they're based on the `BaseViewer`-class, the standalone `pageviewer` example currently doesn't support either XFA- or StructTree-layers. This seems like an obvious oversight, which can be easily addressed simply by exporting the necessary functionality through `pdf_viewer.component.js`, similar to the existing Text/Annotation-layers.
While working on, and testing, these changes I happened to notice a number of smaller things that's also fixed in this patch:
- Ensure that `XfaLayerBuilder.render` always have a *consistent* return type, to prevent possible run-time failures in `PDFPageView`; PR 13908 follow-up.
- Change the order of the options in the `XfaLayerBuilder`-constructor to agree with the parameter order in the `DefaultXfaLayerFactory.createXfaLayerBuilder`-method.
- Add a missing `textHighlighterFactory`-option, in the JSDocs for the `PDFPageView`-class.
- A couple of small tweaks in the `TextLayerBuilder.render`-method: Re-use an existing Array rather than creating a new one, and replace an `if` with optional chaining instead.
*Please note:* For now XFA-support is currently disabled by default, similar to the regular viewer.
Prior to PR 13042, when scripting wasn't really possible to use outside of the full viewer, the `enableScripting` option made sense.
However, at this point in time having to both pass in a `PDFScriptingManager`-instance *and* set the `enableScripting`-boolean when creating a `BaseViewer`-instance feels redundant and (mostly) annoying. Hence this patch, which removes the *separate* boolean and always enables scripting when `scriptingManager` is provided.
The relevant "viewer component" examples are also updated (with a comment), but in such a way that scripting support won't just break when used with the current PDF.js releases.
This patch is an attempt at closing an old, and seemingly trivial, issue and the SVG-files created by the `pdf2svg.js` examples still appear to work just fine when opened in browsers (tested with Firefox Nightly and Google Chrome Beta).
This resolves an issue I had when loading pdf.js with webpack. `pdfjsLib` was always `undefined` after the import, and I dug deep into pdf.js's `webpack.js` file to sort out this issue, making all sorts of changes.
I figured out that there was just something wrong with the export/import procedure. After making this change, I now have the full pdfjs object in my webpack application.
Since we really don't want to let a particular Webpack-mode dictate how we can/can't write code, let's add a note in the webpack-example README about minification instead.
A significant portion of the code-base has now been converted to use `let`/`const`, rather than `var`, hence it should be possible to simply enable the ESLint `no-var` rule globally.
This way we can ensure that new code won't accidentally use `var`, and it also removes the need to manually enable the rule in various folders.
Obviously it makes sense to continue the efforts to replace `var`, but that should probably happen on a file and/or folder basis.
Please note that this patch excludes the following code:
- The `extensions/` folder, since that seemed easiest for now (and I don't know exactly what the support situation is for the Chromium-extension).
- The entire `external/` folder is ignored, since most of it's currently excluded from linting.
For the code that isn't imported from elsewhere (and should be ignored), we should probably (at some point) bring the code up to the same linting/formatting standard as the rest of the code-base.
- Various files in the `test/` folder are ignored, as necessary, since the way that a lot of this code is loaded will require some care (or perhaps larger re-factoring) when removing `var` usage.
(This is something that I happened to notice while working on the previous patch.)
The code in the `examples/mobile-viewer/viewer.js` file is essentially copied from an older version of the default viewer, hence we can slightly simplify the `animationStarted` handling here.
