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allow native scroll in container during touchmove event like with drag and drop

Is there a way to allow native scrolling easily without heavy JS modifications when you reach the border of a div via custom drag and drop via touchmove listener?
When you drag the text in the div here you'll see the div inside is scrolling automatically
I provided an example with touchmove listeners but this one does not scroll, when you reach a border with your mouse
Is there an easy way to include a scrolling behavior to the 2nd example?
const element = document.body.querySelector('#draggable');
const isInContainer = (x,y) => {
const elements = document.elementsFromPoint(x, y)
return elements.find(el => el && el.classList && el.classList.contains('container')) || false;
}
const onMouseMove = (e) => {
if(isInContainer(e.pageX, e.pageY)){
element.style.top = e.pageY + 'px';
element.style.left = e.pageX + 'px';
}
}
const onMouseUp = () => {
document.removeEventListener('mousemove', onMouseMove);
document.removeEventListener('mouseup', onMouseUp)
}
element.addEventListener('mousedown', (e) => {
e.preventDefault();
document.addEventListener('mousemove', onMouseMove);
document.addEventListener('mouseup', onMouseUp)
});

In case someone has a native better solution I'm willing to accept that one... for the time being this would be my current way to solve the issue.
Note: I made a custom interval for scrolling and don't use the mousemove event so users don't have to move the mouse to trigger it. moving outside will start the interval moving inside will clear it.
// the container that should scroll
const scrollBody = document.getElementById('scrollContainer');
// parameter to check which directions should scroll
const scrollPositions = {
left: false,
right: false,
up: false,
down: false,
}
// how far should be scrolled
const nextScrollDistance = {
x: 0,
y: 0
}
// scroll interval
let scrollInterval= null;
const startScrolling = (scrollBody) => {
if (scrollInterval !== null) {
return true;
}
const intervalCallback = () => {
if (scrollInterval !== null && nextScrollDistance.x === 0 && nextScrollDistance.y === 0) {
window.clearInterval(scrollInterval);
scrollInterval = null;
} else {
scrollBody.scrollLeft += nextScrollDistance.x;
scrollBody.scrollTop += nextScrollDistance.y;
}
}
scrollInterval = window.setInterval(intervalCallback, 50);
}
const onMouseMove = (e) => {
if(isInContainer(e.pageX, e.pageY)){
element.style.top = e.pageY + 'px';
element.style.left = e.pageX + 'px';
}
const rects = scrollBody.getBoundingClientRect();
// check directions
// max x that can be scrolled
const maxX = scrollBody.scrollWidth - scrollBody.clientWidth;
// max y that can be scrolled
const maxY = scrollBody.scrollHeight - scrollBody.clientHeight;
// check all directions if it's even possible to scroll
const canScrollTop = Math.round(scrollBody.scrollTop) > 0;
const canScrollBottom = Math.round(scrollBody.scrollTop) < maxY;
const canScrollLeft = Math.round(scrollBody.scrollLeft) > 0;
const canScrollRight = Math.round(scrollBody.scrollLeft) < maxX;
// current x and y coordinates of the mouse
const x = e.pageX;
const y = e.pageY;
// dynamic value to decrease the speed.. otherwise it might scroll too fast
const minifier = 2;
// the modifiers for scrollTop and scrollLeft
nextScrollDistance.y = 0;
nextScrollDistance.x = 0;
if (canScrollBottom && y > rects.bottom) {
// distance between the right border and the mouse
const distance = Math.abs(y - rects.bottom);
// the next time it scrolls -> scroll distance / minifier
nextScrollDistance.y = Math.round(distance / minifier)
scrollPositions.down = true;
} else {
scrollPositions.down = false;
}
// all other directions...
if (canScrollTop && y < rects.top) {
const distance = Math.abs(y - rects.top);
nextScrollDistance.y = Math.round(distance / minifier) * -1;
scrollPositions.up = true;
} else {
scrollPositions.up = false;
}
if (canScrollRight && x > rects.right) {
const distance = Math.abs(x - rects.right);
nextScrollDistance.x = Math.round(distance / minifier)
scrollPositions.right = true;
} else {
scrollPositions.right = false;
}
if (canScrollLeft && x < rects.left) {
const distance = Math.abs(x - rects.left);
nextScrollDistance.x = Math.round(distance / minifier) * -1;
scrollPositions.left = true;
} else {
scrollPositions.left = false;
}
// in case one of those are set.. trigger scrolling
if (nextScrollDistance.x || nextScrollDistance.y) {
startScrolling();
}
}

JavaScript Magnifying glass

I built a magnifying glass in JavaScript, which works well when I click on it or click and dragging it, but it should not hide from the screen.
$(".menu-left-preview-box-preview").bind('click', function (e) {
window.location = "page" + ($(this).index() + 1) + ".html";
});
var native_width = 0;
var native_height = 0;
var magnifyIsMouseDown = false;
$(".magnify").parent().mousedown(function (e) {
magnifyIsMouseDown = true;
});
$(".magnify").mousemove(function (e) {
if (magnifyIsMouseDown) {
if (!native_width && !native_height) {
var image_object = new Image();
image_object.src = $(".small").attr("src");
native_width = image_object.width;
native_height = image_object.height;
} else {
var magnify_offset = $(this).offset();
var mx = e.pageX - magnify_offset.left;
var my = e.pageY - magnify_offset.top;
if (mx < $(this).width() && my < $(this).height() && mx > 0 && my > 0) {
$(".large").fadeIn(100);
} else {
$(".large").fadeOut(100);
}
if ($(".large").is(":visible")) {
var rx = Math.round(mx / $(".small").width() * native_width - $(".large").width() / 2) * -1;
var ry = Math.round(my / $(".small").height() * native_height - $(".large").height() / 2) * -1;
var bgp = rx + "px " + ry + "px";
var px = mx - $(".large").width() / 2;
var py = my - $(".large").height() / 2;
$(".large").css({ left: px, top: py, backgroundPosition: bgp });
}
}
}
});
$(".magnify").parent().mouseup(function (e) {
magnifyIsMouseDown = false;
$(".large").fadeOut(100);
});
$(".magnify").parent().mouseleave(function (e) {
$(".large").fadeOut(100);
});
manageSlide();
By default the magnifying glass must be there on the screen. The magnifying glass can be dragged and after it's dropped it must remain there at it's dropped position.
On clicking and dragging the magnify glass is working well, but it should not hide from the screen. It should be there on screen.
Provide handle of magnify glass with that circle (in design).
Working example: http://jsfiddle.net/mohsin80/4ww8efx5/

I replaced the if (magnifyIsMouseDown) { by if (isDragging) { and created the following methods:
var isDragging = false;
$(".magnify").parent().mouseup(function(e) {
isDragging = false;
});
$(".magnify").parent().mousedown(function(e) {
isDragging = true;
});
To make a simulated drag event with jQuery.
Here is the fiddle. Hope it helped :)

Draggable dot on rotatable div, dot following rotation after dragend

i'm trying to make dot that follows mouse cursor. It was all working, but when i rotated it a bit it all messed up, because bounding box has changed.
I was using this:
http://en.wikipedia.org/wiki/Rotation
(That's why i initially negated y, and than negated new value again)
I will need to read how far that dot is from center and it's angle (but related to the initial "0" rotation state)
I have to add something to rPX based on angle, but i don't know how to calculate it. Can anyone relate?
Inner div is only for creating center of coordinate system.
https://jsfiddle.net/jre86rdd/14/
var currentMousePosition = {
x:0,
y:0
}
var angle = Math.PI/6
document.addEventListener("mousemove",function(event){
currentMousePosition.x = event.clientX;
currentMousePosition.y = event.clientY;
applyMovement(event)
})
function applyMovement(event){
var rPX = event.clientX - getElementOffSetFromParentLeft(document.getElementById("light").parentNode) - 5;
var rPY = -(event.clientY - getElementOffSetFromParentTop(document.getElementById("light").parentNode) - 5);
var XinCircle = rPX*Math.cos(angle)-rPY*Math.sin(angle)
var YinCircle = rPX*Math.sin(angle)+rPY*Math.cos(angle)
if(XinCircle > -70 && XinCircle < 70)
document.getElementById("light").style.left = XinCircle + "px";
if(rPY > -70 && rPY < 70)
document.getElementById("light").style.top = -YinCircle + "px";
//console.log(rPX + " X " + XinCircle )
//console.log(rPY + " Y " + YinCircle )
}
var getElementOffSetFromParentLeft = function (htmlElement) {
var parentRect = htmlElement.parentNode.getBoundingClientRect(),
bodyRect = document.body.getBoundingClientRect();
console.log(parentRect.left)
//I need to add something here, it's 75 for 30, i have no idea how i have calculated it
return parentRect.left - bodyRect.left + 75;
}
var getElementOffSetFromParentTop = function (htmlElement) {
var parentRect = htmlElement.parentNode.getBoundingClientRect(),
bodyRect = document.body.getBoundingClientRect();
return parentRect.top - bodyRect.top;
}

For the mouse movement, it's a very simplified code using jQuery:
$('.wrapper, .outer').mousemove(function(e){
$('#light').css('left', e.pageX);
$('#light').css('top', e.pageY);
});
https://jsfiddle.net/jre86rdd/30/
Tell me if this was what you wanted.
Edit: Also you need to move the light div outside of the wrapper class because it is affected by your CSS

With your new comment, this is my answer:
HTML:
<div class="wrapper">
<div class="outer">
<div class="inner">
</div>
</div>
</div>
<div class="dot" id="light"></div>
JS:
var timeout;
var down = false;
var inside = 0; //Not a boolean because .outer can trigger false when .wrapper is true
$(document).mousedown(function() {
down = true;
}).mouseup(function() {
down = false;
}).mouseleave(function() {
down = false;
});
$('.wrapper, .outer').mouseenter(function(){
inside++;
}).mouseleave(function() {
inside--;
});
$('#light').mousedown(function () {
var x, y;
timeout = setInterval(function () {
if(down){
$(document).mousemove(function(event) {
x = event.pageX;
y = event.pageY;
});
if (inside > 0){
$('#light').css('left', x - 5);
$('#light').css('top', y - 5);
}
}
else
{
clearTimeout(timeout);
}
}, 20);
});
https://jsfiddle.net/jre86rdd/124/

How to calculate anchor point, when changing transformX value on touchmove event?

I'm creating a slider that displays a panoramic image by moving it horizontally inside a container.
Features or Intention (it's under development):
By default the animation happens automatically, changing the transformX value, in each step;
the user's able to touch the element and drag it left or right;
when touchend event's triggered, the slider resumes the animation from the user's dragged x position;
The problem is that when a user touch the element and starts dragging, the input value on transformX makes the element jumpy, apparently because the anchor point is different every time the user touches the draggable element.
What I'd like to know is, how to calculate the anchor point or position, where the user is dragging from? Or what's the best practice to always calculate from the same point, to avoid having this jumps.
I've done quite a lot of research at the moment without success. You can find a live example in the following link (http://jsbin.com/quhabi/1/edit). Please turn on the touch emulator on your brower because at the moment I'm not yet supporting mouse dragging.
You can also have a look into the code below (depends on jQuery):
sass:
html {
width: 100%;
height: 100%;
body {
width: 100%;
height: 100%;
background-color: #999;
.panorama {
width: 80%;
height: 80%;
margin: 0 auto;
overflow: hidden;
img {
height: 100%;
position: relative;
transition: opacity 0.6s ease;
transform-origin:left top;
}
}
}
}
html:
<div class="panorama">
<img src="images/panorama.jpg" alt="">
</div>
Javascript:
/*globals $, window */
'use strict';
$('document').ready(function () {
var panorama = {
// properties
$panorama: $('.panorama'),
$moveElement: $('.panorama img'),
timestart: 0,
seconds: 12,
msTotal: 0,
direction: -1,
positionX: 0,
percentage: 0,
animationFrameID: false,
myRequestAnimationFrame: (function () {
return function (callback) {
return window.setTimeout(callback, 1000 / 60);
};
})(),
touchPlayTimeout: 3000,
moveTimeoutID: null,
rightBoundary: null,
// methods
step: function (timestart) {
var self = this,
timestamp,
positionX;
timestamp = Date.now();
self.progress = timestamp - timestart;
self.percentage = (self.progress * (100 / self.msTotal));
positionX = self.direction * self.percentage;
positionX = self.positionBounderies(positionX);
positionX += '%';
self.position(positionX);
if (self.progress < self.msTotal) {
timestamp += 10;
self.animationFrameID = self.myRequestAnimationFrame(function () {
self.step.call(self, timestart);
});
}
},
positionBounderies: function (positionX) {
// move the next line to init method, after image preload done!
this.rightBoundary = 100 - (100 * (this.$panorama.width() / this.$moveElement.width()));
positionX = positionX > 0 ? 0 : positionX;
positionX = (positionX < 0 && Math.abs(positionX) > this.rightBoundary) ? this.direction * this.rightBoundary : positionX;
return positionX;
},
progressByPercentage: function (percentage) {
return percentage * (this.msTotal / 100);
},
dragIt: function (touchX) {
var positionX,
percentage = (this.progress * (100 / this.msTotal));
positionX = this.direction * percentage;
positionX = positionX + (touchX / 100);
positionX = this.positionBounderies(positionX);
positionX += '%';
// update percentage
this.percentage = Math.abs(parseFloat(positionX));
this.position(positionX);
},
position: function (posX) {
this.$moveElement.css('transform', 'translateX(' + posX + ')');
},
init: function () {
var self = this;
// set initial values
this.msTotal = this.seconds * 1000;
// set listeners
this.$moveElement.on('touchstart mousedown', function (e) {
// on mousedown prevent browser default `img` drag
e.preventDefault();
clearTimeout(self.animationFrameID);
clearTimeout(self.moveTimeoutID);
});
this.$moveElement.on('touchend mouseup', function (e) {
// on mousedown prevent browser default `img` drag
e.preventDefault();
// calculate where to play from using current progress
var playFrom = null;
self.progress = self.progressByPercentage(self.percentage);
self.moveTimeoutID = setTimeout(function () {
clearTimeout(self.moveTimeoutID);
playFrom = Date.now();
playFrom = playFrom - self.progress;
self.step(playFrom);
}, self.touchPlayTimeout);
});
this.$moveElement.on('touchmove', function (e) {
console.log(e);
var touch = e.originalEvent.touches[0],
touchPosition = touch.pageX - self.$panorama.width();
self.dragIt(touchPosition);
});
this.step(Date.now());
}
};
panorama.init();
});

I found that my problem is related with how I'm calculating the drag distance. The code above clearly shows that I'm using solely the position of pageX to calculate the transformX, which is absolutely wrong. The correct way is to store the start point from where the drag is happening from and the current dragging x value should be used to calculate the distance.
For example,
this.$moveElement.on('touchstart mousedown', function (e) {
var touch = e.originalEvent.touches[0];
self.touchDistance.start = touch.pageX;
});
this.$moveElement.on('touchmove', function (e) {
var touch = e.originalEvent.touches[0],
distance = 0;
self.touchDistance.end = touch.pageX;
distance = self.touchDistance.end - self.touchDistance.start;
self.dragIt(distance);
});
With this, I've got a working solution, as we can see here http://jsbin.com/quhabi/2/edit
Thanks for looking, hope this is useful for someone else in the future!

Javascript iPhone Scroll Effect in an iFrame / Javascript Mouse Acceleration

I'm trying to recreate the iPhone flick / scroll event in a window using JavaScript.
Starting with JQuery, I'm measuring the mouse's acceleration and offset during click - drag - release events using a timer:
var MouseY = {
init: function(context) {
var self = this;
self._context = context || window
self._down = false;
self._now = 0;
self._last = 0;
self._offset = 0;
self._timer = 0;
self._acceleration = 0;
$(self._context).mousedown(function() {self._down = true;});
$(self._context).mouseup(function() {self._down = false;});
$(self._context).mousemove(function(e) {self.move(e);});
},
move: function(e) {
var self = this;
self._timer++;
self._last = self._now;
self._now = e.clientY + window.document.body.scrollTop;
self._offset = self._now - self._last;
self._acceleration = self._offset / self._timer;
},
reset: function() {
this._offset = 0;
this._acceleration = 0;
this._timer = 0;
}
};
$(function() {
MouseY.init();
setInterval(function() {
$('#info').html(
'_acceleration:' + MouseY._acceleration + '<br />' +
'_now:' + MouseY._now + '<br />' +
'_offset:' + MouseY._offset + '<br />' +
'_timer:' + MouseY._timer + '<br />'
);
MouseY.reset();
}, 10);
});
Now the problem is translating that acceleration into screen movement - are there any algorithms (easing?) or animation libraries that could help me out on this? (I've looked into JQuery's .animate() but I'm unsure of how to apply it continuously during the drag events!
Update - final solution here:
http://johnboxall.github.com/iphone.html

Here's what I found when looking for kinetic/momentum scrolling libraries:
iScroll
Zynga Scroller
Overscroll
TouchScroll
jScrollTouch

Hit up this link for the full explanation of one approach that seems to be what you're looking for.
http://www.faqts.com/knowledge_base/view.phtml/aid/14742/fid/53
Here's an excerpt:
This handler then sets up event
capture for mouse movement and stores
mouse cursor positions in variables
mouseX and mouseY. It then starts the
timer monitorMouse() which measures
mouse cursor speed by sampling the
values in these variables at regular
intervals. The variables mouseLeft
and mouseTop hold each samplings mouse
positions and the sampling rate is
set to 100 milliseconds in the
variable monitor.timerDelay.
And some of the author's code:
nn4 = (document.layers)? true:false;
mouseLeft = mouseTop = mouseX = mouseY = 0;
monitor = {
timerDelay:100,
moveLimit:2,
sampleLimit:10
};
function startMonitor(thisText) {
if (!tip) return;
toolTipText = thisText;
writeTooltip(toolTipText);
document.captureEvents(Event.MOUSEMOVE);
document.onmousemove = function (evt) {
mouseX = evt.pageX;
mouseY = evt.pageY;
return true;
}
monitorMouse();
}
function stopMonitor() {
if (!tip) return;
hideTooltip();
if (monitor.timer) {
clearTimeout(monitor.timer);
monitor.timer = null;
}
document.releaseEvents(Event.MOUSEMOVE);
document.onmousemove = null;
monitor.slowSamples = 0;
}
function monitorMouse() {
if (Math.abs(mouseX - mouseLeft) > monitor.moveLimit
|| Math.abs(mouseY - mouseTop) > monitor.moveLimit)
{
monitor.slowSamples = 0;
}
else if (++monitor.slowSamples > monitor.sampleLimit) {
showTooltip();
return;
}
mouseLeft = mouseX;
mouseTop = mouseY;
monitor.timer = setTimeout("monitorMouse()",monitor.timerDelay);
}

You might be interested in the jQuery plugin named overscroll:
http://www.azoffdesign.com/overscroll (GitHub page)