In implementing caret browsing mode in pdf.js, I didn't notice that selectstart isn't always triggered.
So this patch removes the use of selectstart and rely only on selectionchange.
In order to simplify the selection management, the selection code is moved in the AnnotationUIManager:
- it simplifies the code;
- it allows to have only one listener for selectionchange instead of having one by visible page
for selectstart.
I had to add a delay in the integration tests for highlighting (there's a comment with an explanation),
it isn't really nice, but it's the only way I found and in real life there always is a delay between
press and release.
The function caretPositionFromPoint return the position within the last visible element
and sometimes there are some elements on top of the ones in the text layer.
So the idea is to hide the visible elements which aren't in the text layer in order
to get the right caret position.
*Please note:* This is a micro optimization, hence I fully understand if the patch is rejected.
Currently we create two temporary Arrays and have to iterate twice in total when building the final `hexNumbers` Array.
With this patch there's only one temporary Array and a single iteration required to build the final `hexNumbers` Array.
When highlighting, the annotation editor layer is disabled to get pointer events
from the text layer, but the annotation layer must be then disabled either in
order to avoid bad interactions.
As part of the changes in PR 17686 we "accidentally" enabled source-maps for the *minified* builds, which seems unnecessary since those have never been included in the `pdfjs-dist` output.
Locally this patch reduces the run-time of `gulp minified` by ~15 percent.
Rather than first building the library and then use Terser "manually" to minify the files, we can utilize a Webpack plugin to combine these steps which helps to simplify the gulpfile.
The `handler` method contained this code in two inline functions,
triggered via callbacks, which made the `handler` method big and harder
to read. Moreover, this code relied on variables from the outer scope,
which made it harder to reason about because the inputs and outputs
weren't easily visible.
This commit fixes the problems by extracting the request checking code
into a dedicated private method, and modernizing it to use e.g. `const`/
`let` instead of `var` and using template strings. The logic is now
self-contained in a single method that can be read from top to bottom
without callbacks and with comments annotating each check/section.
- Run the minification in "parallel" since that should be a *tiny* bit more efficient.
- Don't rename the minified files since that seems unnecessary, especially considering that they are only used in the `dist-pre` target where we currently change the name back manually.
After the changes in PR 17637 there's no longer any reason to invoke `tweakWebpackOutput` without an argument, since the `__non_webpack_import__` re-writing was moved into the Babel plugin.
This way we can avoid a (little) bit of unnecessary parsing during building.
