This patch avoids having to calculate the scale twice by saving it in
the properties object.
Moreover, we remove a temporary variable and place parentheses around a
calculation inside a string concatenation.
This patch improves performance by avoiding unnecessary type
conversions, which also help the JIT for optimizations.
Moreover, this patch fixes issues with the div expansion code where
`textScale` would be undefined in a division. Because of the `dataset`
usage, other comparisons evaluated to `true` while `false` would have
been correct. This makes the expansion mode now work correctly for cases
with, for example, each glyph in one div.
The polyfill for `WeakMap` has been provided by @yurydelendik.
We pass many parameters to `appendText` while we might as well pass the
`task` object that contains them. This saves a few lines of code and
makes the signature of `appendText` more clear. We do the same for
`expand`, which is useful for the next commit in which we replace
`div.dataset` with a `WeakMap`.
Furthermore, this patch adds a missing parameter to a comment block to
make it clear which parameters remain.
1. Expanding divs to improve text selection. (Yury)
2. Adding enhanceTextSelection as an option.
3. Moving feature functionality from text_layer_builder.js to text_layer.js.
4. Added expandTextDivs method to only load expanded divs on first click, and only show on subsequent clicks
These have been found using `gulp lint` in combination with the `unused:
true` parameter for JSHint. Unfortunately there are too many false
positives to enable this feature, but now that most globals have been
removed because of the conversion to UMD the results are much more
useful than before.
Some browsers render certain special characters with width 0, others with strictly positive width. (For example, the Greek Delta, Δ, has width 0 in Google Chrome, and a positive width in Firefox.) The `if` clause in operation so far results in different text layer DOM trees for different browsers.
This commit fixes that by adding the elements independently of their width.
