This method is currently called from `PDFViewer._scrollUpdate` on *every* scroll event in the viewer.
However, I cannot see why this code is now necessary (assuming that it once was), since text-selection and searching still works *exactly* the same way with this patch as with the current `master`.
When `PDFPageView.updatePosition` is called, the page can be in either of these states:
1. The page hasn't been rendered, in which case the `textLayer` property doesn't exist yet.
2. The page is currently rendering, meaning that the `textLayer` property exists. Given that the `textContent` won't be fetched until the page has been successfully rendered, `TextLayerBuilder.render` will return immediately and effectively be a no-op (since there's nothing to render yet).
3. The has been been rendered, and the `textLayer` is currently rendering.
4. The page, and its `textLayer`, has been completely rendered. In this case, `TextLayerBuilder.render` will return immediately and effectively be a no-op.
Here, only the *third* case seem to require any further analysis:
When scrolling occurs while the `textLayer` is rendering, `TextLayerBuilder.render` will via a helper method call `TextLayerRenderTask.cancel` (in src/display/text_layer.js) to stop processing.
However, due to the run-to-completion nature of JavaScript, once `TextLayerRenderTask._render` has been invoked `appendText` will always run.[1]
So even though we cancel rendering of pending `textLayer`s during scrolling, via the repeated `TextLayerBuilder.render` calls from within the `PDFPageView.updatePosition` method, that does *not* prevent us from running the code inside of `TextLayerRenderTask._render` over and over for the *same* page; which all seems *very* inefficient to me.[2]
All this will thus have the effect of delaying the *actual* rendering of a `textLayer` ever so slightly while scrolling in the viewer. However, it does so at the expense of potentially hundreds of unnecessary `appendText` calls.[3]
Hence it seems to me that it's less resource intensive overall to simply let rendering of the `textLayer` complete, once it has started. Obviously, we still abort all rendering of a page, and its `textLayer`, when it's being destroyed (e.g. by being evicted from the page cache).
In case that there's any worry that the patch could affect e.g. highlighting of search results, please note that the existing code in `TextLayerBuilder.render` already calls `updateMatches` when the `TextLayerTask` resolves successfully.
*I'm sorry that this became quite long, but to try and summarize:*
`PDFPageView.updatePosition` doesn't actually do anything in *most* cases. In the one case where it matters, it seems that it's actually doing more harm than good; which is why I'm proposing that we just remove it.
---
[1] Although we may be able to skip the `render` call, provided that it happens *after* a `timeout` (as is the case in the default viewer).
[2] With current work being done to support streaming of `TextContent`, we'd also need to add just as many duplicate API calls to `PDFPageView.updatePosition`.
[3] The number of duplicate `appendText` calls is directly proportional not only to the scroll speed, but also to the number of pages in the document.
Since the localization service is now asynchronous, depending on the load the browser is under, there's a small risk that the lookup of the 'page_scale_percent' string could be delayed slightly.
If the scale would change a couple of times in *very* quick succession, there's perhaps a *theoretical* possibility that the Zoom dropdown would display an incorrect value.
Consider the following, somewhat contrived, theoretical example of two zoom commands being executed *right* after one another:
```javascript
PDFViewerApplication.pdfViewer.currentScale = 1.23;
PDFViewerApplication.pdfViewer.currentScaleValue = 'page-width';
```
Only the `currentScale` call will currently trigger a l10n lookup in `selectScaleOption`. However, as far as I understand, there's no *guarantee* that the l10n string is resolved *before* `selectScaleOption` is called again as a result of the `currentScaleValue` call.
This thus has the possibility of putting the Zoom dropdown into an inconsistent state, since it's currently updated synchronously for one code-path and asynchronously for another.
To avoid these issues, I'm proposing that we *always* update the Zoom dropdown asynchronously, such that we can guarantee that the ordering is correct.
After PR 8394, at least in Firefox, the Zoom dropdown now frequently displays an old custom scale instead of the correct one. To see this behaviour, the following STR works for me:
1. Open https://mozilla.github.io/pdf.js/web/viewer.html.
2. Zoom in, by clicking on the corresponding button in the toolbar.
3. Run `PDFViewerApplication.pdfViewer.currentScaleValue` in the console.
4. Compare what's displayed in the Zoom dropdown with what's printed in the console. (If no difference can be observed, try repeating steps 2 through 4 a couple of times.)
I really don't understand why this happens, but it seems that waiting until a custom scale has been set *before* selecting it fixes things in Firefox (and works fine in e.g. Chrome as well).
Note that this patch thus makes this particular piece of the code consistent with the state prior to PR 8394.
The click handler used in Presentation Mode didn't check if the first/last page was already reached, which after PR 7529 now causes an unnecessary console error.
Hence we should simply use the already existing `_goToPreviousPage`/`_goToNextPage` methods instead, since they do the necessary bounds checking.
Fixes 8498.
Moreover, rename `FindStates` to `FindState` since enumeration names are
usually not in plural, for readability and consistency with the ones in
`src/shared/util.js`.
This patch intends to simplify future ES6 refactoring of the thumbnail code, since the current code isn't going to work well together with proper `Class`es.
With the current way that the `HandTool` is implemented, if someone would try to also add a Zoom tool (as issue 1260 asks for) that probably wouldn't work very well given that you'd then have two cursor tools which may not play nice together.
Hence this patch, which attempts to refactor things so that it should be simpler to add e.g. a Zoom tool as well (given that that issue is marked as "good-beginner-bug", and I'm not sure if that really applies considering the current state of the code).
Note that I personally have no interest in implementing a Zoom tool (similar to Adobe Reader) since I wouldn't use it, but I figured that it can't hurt to make this code a bit more future proof.
PR 7341 added special handling for `nameddest`s that look like pageNumbers, to prevent issues since we previously *incorrectly* supported specifying a pageNumber directly in the hash; i.e. `#10` versus the correct `#page=10` format.
Since this behaviour wasn't correct, PR 7757 fixed and deprecated the old format, which means that we no longer need to maintain the `nameddest` hack in multiple files.
This patch replaces a `var self = this;` statement with arrow functions, and `var` with `let` in `PDFLinkService.navigateTo`.
Furthermore, when I started looking at this method, it quickly became clear that its code is somewhat of a mess. Since I'm one of the persons that have touched this code over the years, I figured that it'd be a good idea to try and clean it up a bit.
Also replaces `var` with `let` in code that's touched in the patch. Please note that this should be completely safe, for two separate reasons, since trying to access let in a scope where it's not defined is first of all a runtime error and second of all an ESLint error (thanks to the `no-undef` rule).
Currently this method first uses a loop to build a temporary array to hold Promises, which are then resolved from a recursive helper function once the textContent is fetched for each page.
To me, this is unncessarily complicated, since we can do everything within one loop by simply chaining the asynchronous calls to retrieve the textContent. (Note that this guarantees that the textContent of the pages is still fetched sequentially.)
Also replaces `var` with `let` in the functions/methods that are touched in the patch. Please note that this should be completely safe, for two separate reasons, since trying to access `let` in a scope where it's not defined is first of all a runtime error and second of all an ESLint error (thanks to the `no-undef` rule).
This patch contains the following improvements:
- Only fetch the various document properties *once* per PDF file opened, and cache the result (in a frozen object).
- Always update the *entire* dialog at once, to prevent inconsistent UI state (issue 8371).
- Ensure that the dialog, and all its internal properties, are reset when `PDFViewerApplication.close` is called.
- Inline, and re-factor, the `getProperties` method in `open`, since that's the only call-site.
- Always overwrite the fileSize with the value obtained from `pdfDocument.getDownloadInfo`, to ensure that it's correct.
- ES6-ify the code that's touched in this patch.
Fixes 8371.
Please see http://eslint.org/docs/rules/object-shorthand.
For the most part, these changes are of the search-and-replace kind, and the previously enabled `no-undef` rule should complement the tests in helping ensure that no stupid errors crept into to the patch.
Rather than having to manually use `initializedPromise`, which really ought to be a private property, to ensure that setting/getting values in the `ViewHistory` works as intended, this re-factoring simply changes all of its methods to be asynchronous.
Furthermore, a `getMultiple` method (mirroring the existing `setMultiple` one) is also added to `ViewHistory`.
Finally, this patch also addresses an existing issue, where certain preferences (e.g. the default zoom level) would be ignored when calling `setInitialView` if reading from the `ViewHistory` fails for some reason.
With the exception of just one test-case, all the current `ui_utils` unit-tests can run successfully on Node.js (since most of them doesn't rely on the DOM).
To get this working, I had to first of all add a new `LIB` build flag such that `gulp lib` produces a `web/pdfjs.js` file that is able to load `pdf.js` successfully.
Second of all, since neither `document` nor `navigator` is available in Node.js, `web/ui_utils.js` was adjusted slightly to avoid errors.
[Firefox addon] Remove the `window.FirefoxCom` hack from `web/viewer.js`, since it was made redunant by the `setExternalLocalizerServices` refactoring (PR 7202 follow-up)
This prevents issues with the filename detection being skipped, when trying to download the opened PDF attachment, since `getPDFFileNameFromURL` ignores `data:` URLs for performance reasons.
The patch also changes the `defaultFilename` to use the ES6 default parameter notation, and fixes the formatting of the JSDoc comment.
Finally, since `getPDFFileNameFromURL` currently has no unit-tests, a few basic ones are added to avoid regressions.
In the first commit in PR 8203, I changed how the `DownloadManager` was included/initialized in `GENERIC`/`CHROME` builds.
The change was prompted by the fact that you cannot have conditional `import`s with ES6 modules, and I wanted to avoid bundling the general `DownloadManager` into the various Firefox specific build targets.
What I completely missed though, is that the new code meant that `download_manager.js` will now be pulling in the *entire* viewer (through `app.js`).
This is a *really* stupid mistake on my part, since it causes the `dist/build/pdf_viewer.js` used with the viewer components to now include basically the entire default viewer.
The simplest solution that I could come up with, is to add a `genericcom.js` file (similar to the `firefoxcom.js`/`chromecom.js` files) which will be responsible for importing/initializing the `DownloadManager`.
The browsers have become smarter and made this hack no longer
functional. Since this is now enforced by practically all browsers,
there is nothing more we can do about this. It is up to the user to
serve the viewer over HTTPS or deal with the warning.
Note that this is in no way specific for PDF.js. Any site with password
inputs served over HTTP has this problem right now. This hack was
provided as a convenience for the users, but nothing more than that.
Since calling `PDFPageView.setPdfPage` will in turn call `PDFPageView.reset`, which cancels all rendering and completely resets the page, it's thus possible that we currently cause some unnecessary re-rendering during the initial loading phase of the viewer.
Depending on the order in which data arrives, it's possible (and in practice always seem to happen) that the `pdfPage` property of the *second* page has already been set during `PDFViewer.setDocument`, by the time that the request for the `pdfPage` is resolved in `PDFViewer._ensurePdfPageLoaded`.
Also, note how the `setPdfPage` call in `PDFViewer.setDocument` is already guarded by this kind of check.
In various viewer files, there's a number of cases where we basically duplicate the functionality of `createPromiseCapability` manually.
As far as I can tell, a couple of these cases have existed for a very long time, and notable even before the `createPromiseCapability` utility function existed.
Also, since we can write ES6 code now, the patch also replaces a couple of `bind` usages with arrow functions in code that's touched in the patch.
This patch implements support for line annotations. Other viewers only
show the popup annotation when hovering over the line, which may have
any orientation. To make this possible, we render an invisible line (SVG
element) over the line on the canvas that acts as the trigger for the
popup annotation. This invisible line has the same starting coordinates,
ending coordinates and width of the line on the canvas.
Note that as discussed on IRC, this makes the viewer slightly slower to load *only* in `gulp server` mode, however the difference seem slight enough that I think it will be fine.
This patch gets rid of the only case in the code-base where we're throwing a plain `string`, rather than an `Error`, which besides better/more consistent error handling also allows us to enable the [`no-throw-literal`](http://eslint.org/docs/rules/no-throw-literal) ESLint rule.
The point of this patch is to fix a couple of inconsistencies in `viewer.html`, compared to the locale files, such that the viewer would work correctly even without the `l10n/` files present.
*Note:* Since this isn't changing any of the locale files, we should *not* need to update any of the string names.
Looking through the history of the findbar code, it seems that the `findPrevious`/`findNext` buttons have never had a `title` set (note PR 2168, which was the initial findbar implementation).
Furthermore, the `placeholder` of the `findInput` didn't agree 100% with locale file either, so this is also adjusted.
I noticed that we have a `.toolbarButton.group` CSS class, which is currently applied to some buttons in the viewer. Since it attempts to adjust the `margin-right` property, I was initially a bit puzzled as to why there wasn't different rules for LTR/RTL locales.
However, checking the viewer with the DevTools inspector, in both LTR and RTL locales, I quickly found that the rule in question is *always* being overridden by other CSS rules.
It thus seem to me that while this rule was probably useful at some point, it has been dead for years and could now be removed.
The find functionality is currently not available for small devices
because the find dialog is not responsive. This patch fixes that.
To achieve this goal, the HTML is changed to always show the find
button. To prevent issues because of the addition of an extra button for
small views, the previous/next page buttons are hidden if the view
becomes small. These buttons are not useful anyway because on small
devices navigation is usually done via scrolling. The find functionality
is much more useful to have in this case. Moreover, we wrap the existing
elements into separate `div`s so that the browser can position the
elements itself when the view becomes smaller and logically connected
elements stay together when this happens.
In the CSS, extra rules for the find bar have been added to ensure that
the dialog's doorhanger is always below the find button. All findbar
`div`s are forced to be 32 pixels high to prevent the find message text
being aligned under the checkboxes. Finally, the find message is only
visible when there is actually text to display. This prevents wrapping
issues because, by default, the label has padding and margin even if
there is no text.
Instead of just upstreaming the changes from [bug 1345253](https://bugzilla.mozilla.org/show_bug.cgi?id=1345253) as-is, it seemed better to simply get rid of the loops altogether and use the same approach as in `PDFViewer`/`PDFThumbnailViewer`.
This patch is another step towards enabling Babel. Since we're moving
towards ES6 modules, we will not be using UMD headers anymore, so we can
remove the validation.
The download button in pdf.js doesn't work in iOS Chrome.
- It appears to be an issue with URLs from URL.createObjectURL.
The URL is correct, but iOS Chrome won't even load the URL
when `a.click()` is called in `download_manager.js`. Even
if you manually visit the URL, you get a blank page.
- Fix this by detecting iOS Chrome and disabling createObjectURL.
The `download_manager.js` `download` method wasn't checking
`PDFJS.disableCreateObjectURL`, so check it there, too.
- Move the navigator.msSaveBlob check earlier, so that
this doesn't change IE10 / IE11 behavior.
- Remove the !URL check since pdf.js has a URL polyfill
now.
