gitlab-org--gitlab-foss/app/assets/javascripts/files_comment_button.js
2018-02-20 22:20:48 +00:00

72 lines
2.8 KiB
JavaScript

/* Developer beware! Do not add logic to showButton or hideButton
* that will force a reflow. Doing so will create a signficant performance
* bottleneck for pages with large diffs. For a comprehensive list of what
* causes reflows, visit https://gist.github.com/paulirish/5d52fb081b3570c81e3a
*/
import Cookies from 'js-cookie';
const LINE_NUMBER_CLASS = 'diff-line-num';
const UNFOLDABLE_LINE_CLASS = 'js-unfold';
const NO_COMMENT_CLASS = 'no-comment-btn';
const EMPTY_CELL_CLASS = 'empty-cell';
const OLD_LINE_CLASS = 'old_line';
const LINE_COLUMN_CLASSES = `.${LINE_NUMBER_CLASS}, .line_content`;
const DIFF_CONTAINER_SELECTOR = '.files';
const DIFF_EXPANDED_CLASS = 'diff-expanded';
export default {
init($diffFile) {
/* Caching is used only when the following members are *true*.
* This is because there are likely to be
* differently configured versions of diffs in the same session.
* However if these values are true, they
* will be true in all cases */
if (!this.userCanCreateNote) {
// data-can-create-note is an empty string when true, otherwise undefined
this.userCanCreateNote = $diffFile.closest(DIFF_CONTAINER_SELECTOR).data('canCreateNote') === '';
}
this.isParallelView = Cookies.get('diff_view') === 'parallel';
if (this.userCanCreateNote) {
$diffFile.on('mouseover', LINE_COLUMN_CLASSES, e => this.showButton(this.isParallelView, e))
.on('mouseleave', LINE_COLUMN_CLASSES, e => this.hideButton(this.isParallelView, e));
}
},
showButton(isParallelView, e) {
const buttonParentElement = this.getButtonParent(e.currentTarget, isParallelView);
if (!this.validateButtonParent(buttonParentElement)) return;
buttonParentElement.classList.add('is-over');
buttonParentElement.nextElementSibling.classList.add('is-over');
},
hideButton(isParallelView, e) {
const buttonParentElement = this.getButtonParent(e.currentTarget, isParallelView);
buttonParentElement.classList.remove('is-over');
buttonParentElement.nextElementSibling.classList.remove('is-over');
},
getButtonParent(hoveredElement, isParallelView) {
if (isParallelView) {
if (!hoveredElement.classList.contains(LINE_NUMBER_CLASS)) {
return hoveredElement.previousElementSibling;
}
} else if (!hoveredElement.classList.contains(OLD_LINE_CLASS)) {
return hoveredElement.parentNode.querySelector(`.${OLD_LINE_CLASS}`);
}
return hoveredElement;
},
validateButtonParent(buttonParentElement) {
return !buttonParentElement.classList.contains(EMPTY_CELL_CLASS) &&
!buttonParentElement.classList.contains(UNFOLDABLE_LINE_CLASS) &&
!buttonParentElement.classList.contains(NO_COMMENT_CLASS) &&
!buttonParentElement.parentNode.classList.contains(DIFF_EXPANDED_CLASS);
},
};