generalize scroll offset prevention

This commit is contained in:
Hakim El Hattab 2016-04-07 09:07:19 +02:00
parent 00b9c2b929
commit 520fa4986e

View file

@ -410,8 +410,8 @@
// Listen to messages posted to this window // Listen to messages posted to this window
setupPostMessage(); setupPostMessage();
// Prevent iframes from scrolling the slides out of view // Prevent the slides from being scrolled out of view
setupIframeScrollPrevention(); setupScrollPrevention();
// Resets all vertical slides so that only the first is visible // Resets all vertical slides so that only the first is visible
resetVerticalSlides(); resetVerticalSlides();
@ -642,22 +642,22 @@
} }
/** /**
* This is an unfortunate necessity. Iframes can trigger the * This is an unfortunate necessity. Some actions such as
* parent window to scroll, for example by focusing an input. * an input field being focused in an iframe or using the
* keyboard to expand text selection beyond the bounds of
* a slide can trigger our content to be pushed out of view.
* This scrolling can not be prevented by hiding overflow in * This scrolling can not be prevented by hiding overflow in
* CSS so we have to resort to repeatedly checking if the * CSS (we already do) so we have to resort to repeatedly
* browser has decided to offset our slides :( * checking if the slides have been offset :(
*/ */
function setupIframeScrollPrevention() { function setupScrollPrevention() {
if( dom.slides.querySelector( 'iframe' ) ) { setInterval( function() {
setInterval( function() { if( dom.wrapper.scrollTop !== 0 || dom.wrapper.scrollLeft !== 0 ) {
if( dom.wrapper.scrollTop !== 0 || dom.wrapper.scrollLeft !== 0 ) { dom.wrapper.scrollTop = 0;
dom.wrapper.scrollTop = 0; dom.wrapper.scrollLeft = 0;
dom.wrapper.scrollLeft = 0; }
} }, 1000 );
}, 500 );
}
} }