This is my code
componentDidMount() {
document
.getElementsByClassName('landingScreen')[0]
.addEventListener('mousemove', this.updateDisplay, false);
document.addEventListener('scroll', this.isScrolling);
setTimeout(() => {
if (window.scrollY < 200) {
this.setState({ opacity: 1 });
}
}, 1000);
}
componentWillUnmount() {
document
.getElementsByClassName('landingScreen')[0]
.removeEventListener('mousemove', this.updateDisplay, false);
}
updateDisplay = event => {
const procentWidth = Math.round((event.pageX / this.state.width) * 100) - 50;
const procentHeight = Math.round((event.pageY / this.state.height) * 100 - 50);
const transform = `skew(${procentWidth / 5}deg,${procentHeight / 5}deg)`;
const textShadow = `${procentWidth / 1}px ${procentHeight / 1}px #5BDC94`;
const textShadow1 = `${procentWidth / 1}px ${procentHeight / 1}px #EDF5E0`;
const transform1 = `skew(${-procentWidth / 5}deg,${-procentHeight / 5}deg)`;
this.setState({ transform, textShadow, textShadow1, transform1 });
};
isScrolling = event => {
console.log(event);
if (window.scrollY >= 200) {
this.setState({ opacity: 0 });
}
if (window.scrollY <= 200) {
this.setState({ opacity: 1 });
}
};
I trigger a transform skew based on where my mouse is and it works fine when I move around my cursor but when I scroll and therefore my cursor changes position the 'mousemove' is not triggered. I tried to add a eventlistener for scroll but there I can't access these values event.pageX and event.pageY. Do you guys have any trick to trigger a 'mousemove' event after scrolling?
I've written a function in Javascript to make images draggable within a container. Even if the image is enlarged it can be dragged all over the screen without disappearing from it. My function relies heaving on using style.top and style.left. Now I've heard that using translate3d might provide better performance. This is interesting because I changed my image scale function, which uses a slider, to scale3d and the scaling is clearly smoother, no doubt. So could anyone help me convert this function I've written to use translate3d? I've tried and tried but have kept failing. Many Thanks:
EDIT: I put up a jsfiddle
https://jsfiddle.net/bx4073tr/
Please note that imgRect is the parent div while img is the image itself (it's in an img tag contained in the div).
function makeImageDraggable(event) {
// Make an image draggable but within bounds of container
let overflow_vertical = false;
let overflow_horizontal = false;
// bounding rectangles to hold image and imageContainer
let imgRect = img.getBoundingClientRect();
let imgContainerRect = imageContainer.getBoundingClientRect();
// find out if image overflows it's container div
// check for vertical overflow, getBoundingClientRect().height will get the real height after the image is scaled
if ( imgRect.height > imageContainer.offsetHeight ) {
overflow_vertical = true;
}
// check for horizontal overflow
if ( imgRect.width > imageContainer.offsetWidth ) {
overflow_horizontal = true;
}
// if there is no overflow, either horizontal or vertical, then do absolutely nothing
if (!overflow_horizontal && !overflow_vertical) {
// nothing to do
} else {
// otherwise make image draggable
event = event || window.event;
// get initial mouse position
let startX = event.clientX;
let startY = event.clientY;
// get position of image to be dragged
let offsetX = pixelToFloat(img.style.left);
let offsetY = pixelToFloat(img.style.top);
// add onmousemove event now we are sure user has initiated a mousedown event
window.onmousemove = function(mousemove_event) {
if (mousemove_event == null) {
mousemove_event = window.event;
}
// calculate bounds so that image does not go off the page
// if there is an overflow, the image will be bigger than the container
// so we need to find the maximum distance we can go upwards, downwards and sideways
// using img.getBoundingClientRect, we can get the width of the scaled image, we also get the width of the container
// divide it by 2 so we can move the same number of pixels in either direction
// max right and left
let max_right = -1 * ( ((imgRect.right - imgRect.left) - (imgContainerRect.right - imgContainerRect.left))/2 );
// should be a positive number
let max_left = -1 * (max_right);
// max bottom and top
let max_bottom = -1 * ( ((imgRect.bottom - imgRect.top) - (imgContainerRect.bottom - imgContainerRect.top))/2 );
// should be a positive number
let max_top = -1 * (max_bottom);
// Dragging image left and right
if (!overflow_horizontal) {
} else {
let scrollX = (offsetX + mousemove_event.clientX - startX);
// img.style.left will keep increasing or decreasing, check if it approaches max_left or max_right
if (scrollX >= max_left || scrollX <= max_right) {
//return false;imageContainer.style.webkitTransform = 'translate3d(' + newX + 'px,' + newY + 'px, 0)';
} else {
if (scrollX < max_left) { img.style.left = min(scrollX, max_left) + 'px'; }
if (scrollX > max_right) { img.style.left = max(scrollX, max_right) + 'px'; }
}
}
// Dragging image top to bottom
if (!overflow_vertical) {
} else {
let scrollY = (offsetY + mousemove_event.clientY - startY);
// as an expanded image is pulled downwards, img.style.top keeps increasing to approach max_top
// if it reaches max top, simply do nothing, else keep increasing
// check for both conditions, approaching max_top and approaching max_bottom
if (scrollY >= max_top || scrollY <= max_bottom) {
// return false;
} else {
if (scrollY < max_top) { img.style.top = min(scrollY, max_top) + 'px'; }
if (scrollY > max_bottom) { img.style.top = max(scrollY, max_bottom) + 'px'; }
}
}
// return
return false;
}
}
// cancel mousemove event on mouseup
window.onmouseup = function(mouseup_event) {
window.onmousemove = null;
// Should not return false as it will interfere with range slider
}
// return false
return false;
}
Works now.
See makeDraggable method in the fiddle below:
https://jsfiddle.net/daibatzu/0u74faz6/6/
All you have to do is add this function to the event listener for the image like:
var img = document.getElementById('myImage');
img.addEventListener('mousedown', function(event) { makeDraggable(event); });
Code
function makeDraggable(event) {
// get bounding rectangle
let imgRect = img.getBoundingClientRect();
let parentRect = parent.getBoundingClientRect();
// check overflow
let overflow_horizontal = (imgRect.width > parent.offsetWidth ? true : false);
let overflow_vertical = (imgRect.height > parent.offsetHeight ? true : false);
// get start position
let startX = event.pageX - translateX, startY = event.pageY - translateY;
let max_left = parentRect.left - imgRect.left;
let max_top = parentRect.top - imgRect.top;
window.onmousemove = function(evt) {
// set event object
if (evt == null) { evt = window.event; }
// Say max_left is 160px, this means we can only translate from 160px to -160px to keep the image visible
// so we check if the image moves beyond abs(160), if it does, set it to 160 or -160 depending on direction, else, let it continue
translateX = (Math.abs(evt.pageX - startX) >= max_left ? (max_left * Math.sign(evt.pageX - startX)) : (evt.pageX - startX));
translateY = (Math.abs(evt.pageY - startY) >= max_top ? (max_top * Math.sign(evt.pageY - startY)) : (evt.pageY - startY));
// check if scaled image width is greater than it's container. if it isn't set translateX to zero and so on
translateX = overflow_horizontal ? translateX : 0, translateY = overflow_vertical ? translateY : 0;
// translate parent div
parent.style['-webkit-transform'] = 'translate(' + translateX + 'px, ' + translateY + 'px)';
// return
return false;
}
window.onmouseup = function(evt) {
// set mousemove event to null
window.onmousemove = null;
}
return false;
};
I'm using slimScroll within a js project for a scroll bar on one side of the page. There are a lot of elements within the the scrollView and right now it's scrolling way to quickly and not intuitively. When I reduce the amount of wheel and/or touchScrollStep there is not change it speed.
* Version: 1.3.0
*
*/
(function($) {
jQuery.fn.extend({
slimScroll: function(options) {
var defaults = {
// width in pixels of the visible scroll area
width : 'auto',
// height in pixels of the visible scroll area
height : '250px',
// width in pixels of the scrollbar and rail
size : '7px',
// scrollbar color, accepts any hex/color value
color: '#000',
// scrollbar position - left/right
position : 'right',
// distance in pixels between the side edge and the scrollbar
distance : '1px',
// default scroll position on load - top / bottom / $('selector')
start : 'top',
// sets scrollbar opacity
opacity : .4,
// enables always-on mode for the scrollbar
alwaysVisible : false,
// check if we should hide the scrollbar when user is hovering over
disableFadeOut : false,
// sets visibility of the rail
railVisible : false,
// sets rail color
railColor : '#333',
// sets rail opacity
railOpacity : .2,
// whether we should use jQuery UI Draggable to enable bar dragging
railDraggable : true,
// defautlt CSS class of the slimscroll rail
railClass : 'slimScrollRail',
// defautlt CSS class of the slimscroll bar
barClass : 'slimScrollBar',
// defautlt CSS class of the slimscroll wrapper
wrapperClass : 'slimScrollDiv',
// check if mousewheel should scroll the window if we reach top/bottom
allowPageScroll : false,
// scroll amount applied to each mouse wheel step
wheelStep : 20,
// scroll amount applied when user is using gestures
touchScrollStep : 200,
// sets border radius
borderRadius: '7px',
// sets border radius of the rail
railBorderRadius : '7px'
};
var o = $.extend(defaults, options);
// do it for every element that matches selector
this.each(function(){
var isOverPanel, isOverBar, isDragg, queueHide, touchDif,
barHeight, percentScroll, lastScroll,
divS = '<div></div>',
minBarHeight = 30,
releaseScroll = false;
// used in event handlers and for better minification
var me = $(this);
// ensure we are not binding it again
if (me.parent().hasClass(o.wrapperClass))
{
// start from last bar position
var offset = me.scrollTop();
// find bar and rail
bar = me.parent().find('.' + o.barClass);
rail = me.parent().find('.' + o.railClass);
getBarHeight();
// check if we should scroll existing instance
if ($.isPlainObject(options))
{
// Pass height: auto to an existing slimscroll object to force a resize after contents have changed
if ( 'height' in options && options.height == 'auto' ) {
me.parent().css('height', 'auto');
me.css('height', 'auto');
var height = me.parent().parent().height();
me.parent().css('height', height);
me.css('height', height);
}
if ('scrollTo' in options)
{
// jump to a static point
offset = parseInt(o.scrollTo);
}
else if ('scrollBy' in options)
{
// jump by value pixels
offset += parseInt(o.scrollBy);
}
else if ('destroy' in options)
{
// remove slimscroll elements
bar.remove();
rail.remove();
me.unwrap();
return;
}
// scroll content by the given offset
scrollContent(offset, false, true);
}
return;
}
// optionally set height to the parent's height
o.height = (o.height == 'auto') ? me.parent().height() : o.height;
// wrap content
var wrapper = $(divS)
.addClass(o.wrapperClass)
.css({
position: 'relative',
overflow: 'hidden',
width: o.width,
height: o.height
});
// update style for the div
me.css({
overflow: 'hidden',
width: o.width,
height: o.height
});
// create scrollbar rail
var rail = $(divS)
.addClass(o.railClass)
.css({
width: o.size,
height: '100%',
position: 'absolute',
top: 0,
display: (o.alwaysVisible && o.railVisible) ? 'block' : 'none',
'border-radius': o.railBorderRadius,
background: o.railColor,
opacity: o.railOpacity,
zIndex: 90
});
// create scrollbar
var bar = $(divS)
.addClass(o.barClass)
.css({
background: o.color,
width: o.size,
position: 'absolute',
top: 0,
opacity: o.opacity,
display: o.alwaysVisible ? 'block' : 'none',
'border-radius' : o.borderRadius,
BorderRadius: o.borderRadius,
MozBorderRadius: o.borderRadius,
WebkitBorderRadius: o.borderRadius,
zIndex: 99
});
// set position
var posCss = (o.position == 'right') ? { right: o.distance } : { left: o.distance };
rail.css(posCss);
bar.css(posCss);
// wrap it
me.wrap(wrapper);
// append to parent div
me.parent().append(bar);
me.parent().append(rail);
// make it draggable and no longer dependent on the jqueryUI
if (o.railDraggable){
bar.bind("mousedown", function(e) {
var $doc = $(document);
isDragg = true;
t = parseFloat(bar.css('top'));
pageY = e.pageY;
$doc.bind("mousemove.slimscroll", function(e){
currTop = t + e.pageY - pageY;
bar.css('top', currTop);
scrollContent(0, bar.position().top, false);// scroll content
});
$doc.bind("mouseup.slimscroll", function(e) {
isDragg = false;hideBar();
$doc.unbind('.slimscroll');
});
return false;
}).bind("selectstart.slimscroll", function(e){
e.stopPropagation();
e.preventDefault();
return false;
});
}
// on rail over
rail.hover(function(){
showBar();
}, function(){
hideBar();
});
// on bar over
bar.hover(function(){
isOverBar = true;
}, function(){
isOverBar = false;
});
// show on parent mouseover
me.hover(function(){
isOverPanel = true;
showBar();
hideBar();
}, function(){
isOverPanel = false;
hideBar();
});
// support for mobile
me.bind('touchstart', function(e,b){
if (e.originalEvent.touches.length)
{
// record where touch started
touchDif = e.originalEvent.touches[0].pageY;
}
});
me.bind('touchmove', function(e){
// prevent scrolling the page if necessary
if(!releaseScroll)
{
e.originalEvent.preventDefault();
}
if (e.originalEvent.touches.length)
{
// see how far user swiped
var diff = (touchDif - e.originalEvent.touches[0].pageY) / o.touchScrollStep;
// scroll content
scrollContent(diff, true);
touchDif = e.originalEvent.touches[0].pageY;
}
});
// set up initial height
getBarHeight();
// check start position
if (o.start === 'bottom')
{
// scroll content to bottom
bar.css({ top: me.outerHeight() - bar.outerHeight() });
scrollContent(0, true);
}
else if (o.start !== 'top')
{
// assume jQuery selector
scrollContent($(o.start).position().top, null, true);
// make sure bar stays hidden
if (!o.alwaysVisible) { bar.hide(); }
}
// attach scroll events
attachWheel();
function _onWheel(e)
{
// use mouse wheel only when mouse is over
if (!isOverPanel) { return; }
var e = e || window.event;
var delta = 0;
if (e.wheelDelta) { delta = -e.wheelDelta/120; }
if (e.detail) { delta = e.detail / 3; }
var target = e.target || e.srcTarget || e.srcElement;
if ($(target).closest('.' + o.wrapperClass).is(me.parent())) {
// scroll content
scrollContent(delta, true);
}
// stop window scroll
if (e.preventDefault && !releaseScroll) { e.preventDefault(); }
if (!releaseScroll) { e.returnValue = false; }
}
function scrollContent(y, isWheel, isJump)
{
releaseScroll = false;
var delta = y;
var maxTop = me.outerHeight() - bar.outerHeight();
if (isWheel)
{
// move bar with mouse wheel
delta = parseInt(bar.css('top')) + y * parseInt(o.wheelStep) / 100 * bar.outerHeight();
// move bar, make sure it doesn't go out
delta = Math.min(Math.max(delta, 0), maxTop);
// if scrolling down, make sure a fractional change to the
// scroll position isn't rounded away when the scrollbar's CSS is set
// this flooring of delta would happened automatically when
// bar.css is set below, but we floor here for clarity
delta = (y > 0) ? Math.ceil(delta) : Math.floor(delta);
// scroll the scrollbar
bar.css({ top: delta + 'px' });
}
// calculate actual scroll amount
percentScroll = parseInt(bar.css('top')) / (me.outerHeight() - bar.outerHeight());
delta = percentScroll * (me[0].scrollHeight - me.outerHeight());
if (isJump)
{
delta = y;
var offsetTop = delta / me[0].scrollHeight * me.outerHeight();
offsetTop = Math.min(Math.max(offsetTop, 0), maxTop);
bar.css({ top: offsetTop + 'px' });
}
// scroll content
me.scrollTop(delta);
// fire scrolling event
me.trigger('slimscrolling', ~~delta);
// ensure bar is visible
showBar();
// trigger hide when scroll is stopped
hideBar();
}
function attachWheel()
{
if (window.addEventListener)
{
this.addEventListener('DOMMouseScroll', _onWheel, false );
this.addEventListener('mousewheel', _onWheel, false );
this.addEventListener('MozMousePixelScroll', _onWheel, false );
}
else
{
document.attachEvent("onmousewheel", _onWheel)
}
}
function getBarHeight()
{
// calculate scrollbar height and make sure it is not too small
barHeight = Math.max((me.outerHeight() / me[0].scrollHeight) * me.outerHeight(), minBarHeight);
bar.css({ height: barHeight + 'px' });
// hide scrollbar if content is not long enough
var display = barHeight == me.outerHeight() ? 'none' : 'block';
bar.css({ display: display });
}
function showBar()
{
// recalculate bar height
getBarHeight();
clearTimeout(queueHide);
// when bar reached top or bottom
if (percentScroll == ~~percentScroll)
{
//release wheel
releaseScroll = o.allowPageScroll;
// publish approporiate event
if (lastScroll != percentScroll)
{
var msg = (~~percentScroll == 0) ? 'top' : 'bottom';
me.trigger('slimscroll', msg);
}
}
else
{
releaseScroll = false;
}
lastScroll = percentScroll;
// show only when required
if(barHeight >= me.outerHeight()) {
//allow window scroll
releaseScroll = true;
return;
}
bar.stop(true,true).fadeIn('fast');
if (o.railVisible) { rail.stop(true,true).fadeIn('fast'); }
}
function hideBar()
{
// only hide when options allow it
if (!o.alwaysVisible)
{
queueHide = setTimeout(function(){
if (!(o.disableFadeOut && isOverPanel) && !isOverBar && !isDragg)
{
bar.fadeOut('slow');
rail.fadeOut('slow');
}
}, 1000);
}
}
});
// maintain chainability
return this;
}
});
jQuery.fn.extend({
slimscroll: jQuery.fn.slimScroll
});
})(jQuery);
I've just played around with this script and I kept adjusting the numbers and these are the numbers that felt more natural to me.
wheelStep : 10,
touchScrollStep : 75
The only thing I'm not happy with is how it doesn't understand how fast you scrolled with touch events, so it doesn't have that inertia effect like native iOS does naturally. I'm hoping they'll add that option soon.
Find
delta = (y > 0) ? Math.ceil(delta): Math.floor(delta);
and change it to the following:
var speedfix = 10;
delta = (y > 0) ? Math.ceil(delta) + speedfix : Math.floor(delta)- speedfix;
Change the value of speedfix to your requirement
I am trying to animate a video on scroll like the landing page for the new iPhone 6. I have the video animating on scroll, but I am trying to some how ease the the video once the mousewheel has been released. I'm not sure how I should approach this challenge. Should I be trying to use an actual easeOut function? Or should I do it some other way?
Here is a snippet of the JS I currently have. And a live example here.
function easeOut(t, b, c, d) {
return c * ((t = t / d - 1) * t * t * t * t + 1) + b;
};
var $win = $(window),
$video = $('video'),
frameRate = 29.97,
target = 0,
scroll = 0,
isTicking, scrollTimeout, delta, target;
var ScrollVideo = function() {
this.scrollY = 0;
$win.on('mousewheel DOMMouseScroll', this.onScroll.bind(this));
};
ScrollVideo.prototype = {
/**
* Callback for our scroll event
* keeps track of the last scroll value
*/
onScroll: function(event) {
var e = event.originalEvent ? event.originalEvent : event; // get original event if available
target += (e.wheelDelta > 0) ? -70 : 70;
if (target < 0) target = 0;
delta = Math.max(-1, Math.min(1, (e.wheelDelta || -e.detail)));
this.requestScrollTick();
},
/**
* Calls rAF if it hasn't already
* been done
*/
requestScrollTick: function() {
if( !isTicking ) {
window.requestAnimationFrame(this.scrollHandler);
}
isTicking = true;
},
/**
* Animate stuff on scroll
*/
scrollHandler: function() {
scroll += (target - scroll) * 0.1;
console.log(scroll);
if(delta < 0) {
$video[0].currentTime += (1 / frameRate);
}
else {
$video[0].currentTime -= (1 / frameRate);
}
// stop ticking
isTicking = false;
}
};
var scrollVideo = new ScrollVideo();
I'd love to be able to tackle this, any help/direction is greatly appreciated.
I've multiple, draggable divs inside of a scrollable div. When I drag them into the droppable zone (which is also a scrollable div), the doppable DIV doesn't scroll down. Just the page is moveing.
How to say, that just the droppable div should scroll while dragging?
Here is my current jquery code for making the divs draggable
$(".drag_item").draggable({
helper: 'clone',
scroll: true,
drag: function( event, ui ) {
$(this).css('z-index','100');
}
});
I came up with this solution:
var direction = {};
var bound = {};
var scrolling = false;
var container = document.getElementById("container");
$('#table-container')
.on('dragstart', draggable, function(event, ui) {
bound = {
right : $(container).offset().left + $(container).width() - 50,
left : $(container).offset().left + 50,
top : $(container).offset().top + 50,
bottom : $(container).offset().top + $(container).height() - 50
};
})
.on('dragstop', draggable, function(event, ui) {
direction = {};
})
.on('drag', draggable, function(event, ui) {
direction.right = event.clientX - bound.right;
direction.left = bound.left - event.clientX;
direction.up = bound.top - event.clientY;
direction.down = event.clientY - bound.bottom;
if ((direction.right > 0 || direction.left > 0|| direction.up > 0 || direction.down > 0) && !scrolling) {
scroll();
scrolling = true;
} else {
scrolling = false;
}
});
function scroll() {
if (direction.right > 0) {
container.scrollLeft = container.scrollLeft + (direction.right >> 1); //dividing by 2 to soften effect
}
if (direction.left > 0) {
container.scrollLeft = container.scrollLeft - (direction.left >> 1);
}
if (direction.down > 0) {
container.scrollTop = container.scrollTop + (direction.down >> 1);
}
if (direction.up > 0) {
container.scrollTop = container.scrollTop - (direction.up >> 1);
}
if (direction.right > 0 || direction.left > 0 || direction.up > 0 || direction.down > 0) {
setTimeout(scroll, 100);
}
}
Use "overflow=auto" it works for me.
<div style="overflow:auto;"></div>
OR
jQuery now supports scrollTop as an animation variable.
$("#id").animate({"scrollTop": $("#id").scrollTop() + 100});
You no longer need to setTimeout/setInterval to scroll smoothly.