I'm trying to scroll into view a dummy div (id = "bottom"), which is contained inside a nested scrollbar.
But whenever the statement is executed, it just scrolled the main scrollbar (the one on the page it self.)
Below is the code, the mapped element is a list of messages, which rerenders after a new message has been sent. I've kept document.getElementById('bottom').scrollIntoView();
Which indeed works but it just scrolls the scrollbar outside the "messageList" div (the main scrollbar of the webpage.).
<div className='messageList chatRoomSubContainers'>
<br />
{data &&
data.map((msg) => {
const currentMsg = msg.data();
const messageState =
currentMsg.uid === currentUser.uid ? 'sent' : 'received';
return (
<ChatBubble
key={msg.id}
text={currentMsg.text}
// Send time stamp as well
photo={currentMsg.photo}
messageState={messageState}
/>
);
})}
<div id='bottom'>dfdsf</div>
</div>
Here is the img ref -
scrollIntoView is a method for document only, and can't be applied for a specific element.
You need to measure the distance between the #button element, and the top boundary of its parent.
You can use this method for measuring.
function scrollParentToChild(parent, child) {
// Where is the parent on page
var parentRect = parent.getBoundingClientRect();
// What can you see?
var parentViewableArea = {
height: parent.clientHeight,
width: parent.clientWidth
};
// Where is the child
var childRect = child.getBoundingClientRect();
// Is the child viewable?
var isViewable = (childRect.top >= parentRect.top) && (childRect.bottom <= parentRect.top + parentViewableArea.height);
// if you can't see the child try to scroll parent
if (!isViewable) {
// Should we scroll using top or bottom? Find the smaller ABS adjustment
const scrollTop = childRect.top - parentRect.top;
const scrollBot = childRect.bottom - parentRect.bottom;
if (Math.abs(scrollTop) < Math.abs(scrollBot)) {
// we're near the top of the list
parent.scrollTop += scrollTop;
} else {
// we're near the bottom of the list
parent.scrollTop += scrollBot;
}
}
}
Related
I need to render long list via react-window library. I can't be sure that all rows will be the same size so it forces me to use VariableSizeList. So is there a way to calculate row height when you know only index of row and actual data to be rendered?
I think it's possible to render it somehow not visible to the end user and get height from but I'm not sure is it the right way.
Yes when using VariableSizeList specify an itemSize function.
eg
itemSize = {(i) => onGetItemSize(rows[i])}
The onGetItemSize measures the content by:
returning a single line height, if content is small.
writing the content to a empty element, with the same width and properties as your row. Then measuring the element height, before emptying the element again.
For example:
onGetItemSize={((row) =>
{
let text = row.original.text;
// if no text, or text is short, don't bother measuring.
if (!text || text.length < 15)
return rowHeight;
// attempt to measure height by writting text to a, kind of hidden element.
let hiddenElement = document.getElementById(this.hiddenFieldName());
if (hiddenElement)
{
hiddenElement.textContent = text;
let ret = hiddenElement.offsetHeight;
hiddenElement.textContent = '';
if (ret > 0)
return Math.max(ret, rowHeight);
}
// fallback
return rowHeight;
})}
Then include this empty element at an appropriate place in the DOM.
<div id={this.hiddenFieldName()} style={{ visibility: 'visible', whiteSpace: 'normal' }} />
I have a Div which is as big as half of my page using CSS:
<div id="bigdiv">
CLICK ON THIS TEXT
</div>
I am trying to write a javascript or jquery code which detects click on the text and not the rest of the element. Is there a way to do that?
Since we cannot listen for events directly on the textNodes themselves, we have to take a more creative path to solving the problem. One thing we can do is look at the coordinates of the click event, and see if it overlaps with a textNode.
First, we'll need a small helper method to help us track whether a set of coordinates exists within a set of constraints. This will make it easier for us to arbitrarily determine if a set of x/y values are within the a set of dimensions:
function isInside ( x, y, rect ) {
return x >= rect.left && y >= rect.top
&& x <= rect.right && y <= rect.bottom;
}
This is fairly basic. The x and y values will be numbers, and the rect reference will be an object with at least four properties holding the absolute pixel values representing four corners of a rectangle.
Next, we need a function for cycling through all childNodes that are textNodes, and determining whether a click event took place above one of them:
function textNodeFromPoint( element, x, y ) {
var node, nodes = element.childNodes, range = document.createRange();
for ( var i = 0; node = nodes[i], i < nodes.length; i++ ) {
if ( node.nodeType !== 3 ) continue;
range.selectNodeContents(node);
if ( isInside( x, y, range.getBoundingClientRect() ) ) {
return node;
}
}
return false;
}
With all of this in place, we can now quickly determine if a textNode was directly below the clicked region, and get the value of that node:
element.addEventListener( "click", function ( event ) {
if ( event.srcElement === this ) {
var clickedNode = textNodeFromPoint( this, event.clientX, event.clientY );
if ( clickedNode ) {
alert( "You clicked: " + clickedNode.nodeValue );
}
}
});
Note that the initial condition if ( event.srcElement ) === this allows us to ignore click events originating from nested elements, such as an image or a span tag. Clicks that happen over textNodes will show the parent element as the srcElement, and as such those are the only ones we're concerned with.
You can see the results here: http://jsfiddle.net/jonathansampson/ug3w2xLc/
Quick win would be to have
<div id="bigdiv">
<span id="text">TEXT HERE</span>
</div>
Script:
$('#text').on('click', function() {
.....
});
Let's alter the content dinamically - I will make the clicking on lala available:
<div id="gig">
<div id="smthing">one</div>lala
<div id="else"></div>
</div>
Script:
var htmlText = $('#gig').text(); //the big divs text
var children = $('#gig').children(); //get dom elements so they can be ignored later
$.each(children, function (index, child) {
var txt = $(child).text().trim();
if (txt != '') { //if a child has text in him
htmlText = htmlText.replace(txt, 'xxx'); //replace it in the big text with xxx
}
});
htmlText = htmlText.split("xxx"); //split for xxx make it arrat
var counter = 0; //the part when the text is added
$.each(htmlText, function (i, el) {
htmlText[i] = el.trim();
if (htmlText[i] != "") { //if there is something here than it's my text
htmlText[i] = '<span id="text">' + htmlText[i] + '</span>'; //replace it with a HTML element personalized
counter++; //mark that you have replaced the text
} else { // if there is nothing at this point it means that I have a DOM element here
htmlText[i] = $(children[i - counter])[0].outerHTML; //add the DOM element
}
});
if (children.length >= htmlText.length) { //you might have the case when not all the HTML children were added back
for (var i = htmlText.length - 1; i < children.length; i++) {
htmlText[i + 1] = $(children[i])[0].outerHTML; //add them
}
}
htmlText = htmlText.join(""); //form a HTML markup from the altered stuff
$('#gig').html(htmlText); // replace the content of the big div
$('#text').on('click', function (data) { //add click support
alert('ok');
});
See a working example here: http://jsfiddle.net/atrifan/5qc27f9c/
P.S: sorry for the namings and stuff I am a little bit tired.
Are you able to do this, is this what you are looking for?
What the code does:
It's making only the text inside the div although the div could have other divs as well, makes only the text that has no HTML container like a div a span a p an a or something like that and alters it adding it in a span and making it available for clicking.
EDIT - Solution without adding wrapping element
Doing this without a wrapping element is quite a hassle. I managed to get it to work, however this will only work for one liners that are centered vertically AND horizontally.
To see the HTML and CSS that goes along with this, see the
jsFiddle: http://jsfiddle.net/v8jbsu3m/3/
jQuery('#bigDiv').click(function(e) {
// Get the x and y offest from the window
margin_top = jQuery(this).offset().top;
margin_left = jQuery(this).offset().left;
// Get the dimensions of the element.
height = jQuery(this).height();
width = jQuery(this).width();
// Retrieve the font_size and remove the px addition
font_size = parseInt(jQuery(this).css('font-size').replace('px', ''));
// Retrieve the position of the click
click_x = e.pageX;
click_y = e.pageY;
// These variables will be used to validate the end result
var in_text_y = false;
var in_text_x = false;
// Determine the click relative to the clicked element
relative_x = click_x - margin_left;
relative_y = click_y - margin_top;
// Determine whether the y-coordinate of the click was in the text
if (relative_y >= (parseFloat(height) / 2) - (parseFloat(font_size) / 2) &&
relative_y <= (parseFloat(height) / 2) + (parseFloat(font_size) / 2))
in_text_y = true;
// This piece of code copies the string and places it in a invisible div
// If this div has the same font styling and no paddings etc... it can
// be used to get the width of the text
text = jQuery(this).text();
text_width = jQuery('#widthTester').html(text).width();
// Determine whether the x-coordinate of the click was in the text
if (relative_x >= (parseFloat(width) / 2) - (parseFloat(text_width) / 2) &&
relative_x < (parseFloat(width) / 2) + (parseFloat(text_width) / 2))
in_text_x = true;
// If the x and y coordinates were both in the text then take action
if (in_text_x && in_text_y)
alert('You clicked the text!');
});
Also, this code can be optimized, since the same calculcation is done multiple times, but I thought that leaving the calculcations there better illustrated what was going on.
Solution by adding a wrapping element
If you put a span around the text, then you can add an onClick event handler to the span.
<div id="bigdiv">
<span>CLICK ON THIS TEXT</span>
</div>
jQuery code
jQuery('#bigdiv span').click(function() {
jquery(this).remove();
});
If you want to go straight through HTML, you can use
<div id="bigdiv" onclick="myFunction();">
and then simply apply the function afterwards in JS:
function myFunction(){
//...
}
EDIT: sorry, if you want the text to be affected, put in <p> around the text or <span> ie.
<div id="bigdiv">
<p onclick="myFuncion();"> TEXT </p>
</div>
Here is the idea behind the code: The article has an avatar object in the beginning. e.g.:
<div class="column-right">
<div class="inner">
<h3>Header of article</h3>
<div id="avatar">
<img>
<div>avatar title</div>
</div>
<p>long text</p>
</div>
</div>
When a user scrolls down, the avatar obviously disappears. So I wanted to make a clone of said avatar and put it in the left column using position fixed.
Here is the JavaScript code:
document.body.onscroll = function(e) {
var scrolled = document.documentElement.scrollTop;
var newAv;
if ( (scrolled > avatarCoords.bottom) && !newAv ) {
//check if user scrolled below the avatar. if clone of avatar exists, do anything:
newAv = avatar.cloneNode(true);
//clone actual element, whick user can't see right now
newAv.style.position = "fixed";
newAv.style.left = 2 + "px";
newAv.style.top = 10 + "px";
document.body.appendChild(newAv); //add clone in document
}
if( (scrolled < avatarCoords.bottom) && newAv ) {
newAv.parentNode.removeChild(newAv);
}
}
function getCoords(element) {
var box = element.getBoundingClientRect();
return {
bottom: box.top + avatar.offsetHeight
}
}
I don't understand why the first condition keeps responding even though the variable newAv is assigned. !newAv is supposed to be false after first cloning.
If you can answer the first question, tell me why newAv can't be removed as well.
Thank you!
You keep redefining newAV inside the onscroll function.
Make this a global variable (so this remembers the value from previous call):
var newAv;
document.body.onscroll = function(e) {
var scrolled = document.documentElement.scrollTop; // etc
I've got a problem with a script that fires 2 times and it clone some columns and append twice.
My goal is to clone the element, which is not in the viewport, and append it at the end, then delete the element from front.
It seems like the element goes of the viewport and enter twice in the condition, where I check if left of the element is greater than its width.
That means I got two clone of the same element and appended twice at the end, which is not good.
Strange thing is that the delete of the element fire once.
here's some code:
var moving = false,
$holder = $('#carousel');
$holder.on('transitionend', function (){
moving = false; // era true
});
offset = 600;
function getPosition() {
wrapper = document.getElementById('carousel');
wrapper_length = wrapper.childElementCount;
width_of_elements = wrapper.children[0].getBoundingClientRect().width;
current_left = wrapper.children[0].getBoundingClientRect().left;
positive_current_left = current_left * -1;
if(Math.round(positive_current_left) > Math.round(width_of_elements)){
// clone + set left after the last one
clone = wrapper.children[0].cloneNode(true);
clone.style.left = wrapper.children[wrapper_length - 1].getBoundingClientRect().left + (offset * 2.6) + "px";
console.log(clone);
// append child cloned
wrapper.appendChild(clone);
// delete element cloned
wrapper.removeChild(wrapper.childNodes[0]);
}
if (!moving) {
window.requestAnimationFrame(getPosition);
}
}
window.requestAnimationFrame(getPosition);
Am I wrong somewhere?
here's a fiddle to see it in action:
fiddle
If all you want to do is to move an element to the end, you can "re"-appendChild. Looks a bit wonky when it starts to come around, but that you can fix. ;)
if (Math.round(positive_current_left) > Math.round(width_of_elements)) {
// clone + set left after the last one
moveMe = wrapper.children[0];
moveMe.style.left = wrapper.children[wrapper_length - 1].getBoundingClientRect().left + (offset * 2.6) + "px";
// append child cloned
wrapper.appendChild(moveMe);
}
fiddle
I have a Div which is as big as half of my page using CSS:
<div id="bigdiv">
CLICK ON THIS TEXT
</div>
I am trying to write a javascript or jquery code which detects click on the text and not the rest of the element. Is there a way to do that?
Since we cannot listen for events directly on the textNodes themselves, we have to take a more creative path to solving the problem. One thing we can do is look at the coordinates of the click event, and see if it overlaps with a textNode.
First, we'll need a small helper method to help us track whether a set of coordinates exists within a set of constraints. This will make it easier for us to arbitrarily determine if a set of x/y values are within the a set of dimensions:
function isInside ( x, y, rect ) {
return x >= rect.left && y >= rect.top
&& x <= rect.right && y <= rect.bottom;
}
This is fairly basic. The x and y values will be numbers, and the rect reference will be an object with at least four properties holding the absolute pixel values representing four corners of a rectangle.
Next, we need a function for cycling through all childNodes that are textNodes, and determining whether a click event took place above one of them:
function textNodeFromPoint( element, x, y ) {
var node, nodes = element.childNodes, range = document.createRange();
for ( var i = 0; node = nodes[i], i < nodes.length; i++ ) {
if ( node.nodeType !== 3 ) continue;
range.selectNodeContents(node);
if ( isInside( x, y, range.getBoundingClientRect() ) ) {
return node;
}
}
return false;
}
With all of this in place, we can now quickly determine if a textNode was directly below the clicked region, and get the value of that node:
element.addEventListener( "click", function ( event ) {
if ( event.srcElement === this ) {
var clickedNode = textNodeFromPoint( this, event.clientX, event.clientY );
if ( clickedNode ) {
alert( "You clicked: " + clickedNode.nodeValue );
}
}
});
Note that the initial condition if ( event.srcElement ) === this allows us to ignore click events originating from nested elements, such as an image or a span tag. Clicks that happen over textNodes will show the parent element as the srcElement, and as such those are the only ones we're concerned with.
You can see the results here: http://jsfiddle.net/jonathansampson/ug3w2xLc/
Quick win would be to have
<div id="bigdiv">
<span id="text">TEXT HERE</span>
</div>
Script:
$('#text').on('click', function() {
.....
});
Let's alter the content dinamically - I will make the clicking on lala available:
<div id="gig">
<div id="smthing">one</div>lala
<div id="else"></div>
</div>
Script:
var htmlText = $('#gig').text(); //the big divs text
var children = $('#gig').children(); //get dom elements so they can be ignored later
$.each(children, function (index, child) {
var txt = $(child).text().trim();
if (txt != '') { //if a child has text in him
htmlText = htmlText.replace(txt, 'xxx'); //replace it in the big text with xxx
}
});
htmlText = htmlText.split("xxx"); //split for xxx make it arrat
var counter = 0; //the part when the text is added
$.each(htmlText, function (i, el) {
htmlText[i] = el.trim();
if (htmlText[i] != "") { //if there is something here than it's my text
htmlText[i] = '<span id="text">' + htmlText[i] + '</span>'; //replace it with a HTML element personalized
counter++; //mark that you have replaced the text
} else { // if there is nothing at this point it means that I have a DOM element here
htmlText[i] = $(children[i - counter])[0].outerHTML; //add the DOM element
}
});
if (children.length >= htmlText.length) { //you might have the case when not all the HTML children were added back
for (var i = htmlText.length - 1; i < children.length; i++) {
htmlText[i + 1] = $(children[i])[0].outerHTML; //add them
}
}
htmlText = htmlText.join(""); //form a HTML markup from the altered stuff
$('#gig').html(htmlText); // replace the content of the big div
$('#text').on('click', function (data) { //add click support
alert('ok');
});
See a working example here: http://jsfiddle.net/atrifan/5qc27f9c/
P.S: sorry for the namings and stuff I am a little bit tired.
Are you able to do this, is this what you are looking for?
What the code does:
It's making only the text inside the div although the div could have other divs as well, makes only the text that has no HTML container like a div a span a p an a or something like that and alters it adding it in a span and making it available for clicking.
EDIT - Solution without adding wrapping element
Doing this without a wrapping element is quite a hassle. I managed to get it to work, however this will only work for one liners that are centered vertically AND horizontally.
To see the HTML and CSS that goes along with this, see the
jsFiddle: http://jsfiddle.net/v8jbsu3m/3/
jQuery('#bigDiv').click(function(e) {
// Get the x and y offest from the window
margin_top = jQuery(this).offset().top;
margin_left = jQuery(this).offset().left;
// Get the dimensions of the element.
height = jQuery(this).height();
width = jQuery(this).width();
// Retrieve the font_size and remove the px addition
font_size = parseInt(jQuery(this).css('font-size').replace('px', ''));
// Retrieve the position of the click
click_x = e.pageX;
click_y = e.pageY;
// These variables will be used to validate the end result
var in_text_y = false;
var in_text_x = false;
// Determine the click relative to the clicked element
relative_x = click_x - margin_left;
relative_y = click_y - margin_top;
// Determine whether the y-coordinate of the click was in the text
if (relative_y >= (parseFloat(height) / 2) - (parseFloat(font_size) / 2) &&
relative_y <= (parseFloat(height) / 2) + (parseFloat(font_size) / 2))
in_text_y = true;
// This piece of code copies the string and places it in a invisible div
// If this div has the same font styling and no paddings etc... it can
// be used to get the width of the text
text = jQuery(this).text();
text_width = jQuery('#widthTester').html(text).width();
// Determine whether the x-coordinate of the click was in the text
if (relative_x >= (parseFloat(width) / 2) - (parseFloat(text_width) / 2) &&
relative_x < (parseFloat(width) / 2) + (parseFloat(text_width) / 2))
in_text_x = true;
// If the x and y coordinates were both in the text then take action
if (in_text_x && in_text_y)
alert('You clicked the text!');
});
Also, this code can be optimized, since the same calculcation is done multiple times, but I thought that leaving the calculcations there better illustrated what was going on.
Solution by adding a wrapping element
If you put a span around the text, then you can add an onClick event handler to the span.
<div id="bigdiv">
<span>CLICK ON THIS TEXT</span>
</div>
jQuery code
jQuery('#bigdiv span').click(function() {
jquery(this).remove();
});
If you want to go straight through HTML, you can use
<div id="bigdiv" onclick="myFunction();">
and then simply apply the function afterwards in JS:
function myFunction(){
//...
}
EDIT: sorry, if you want the text to be affected, put in <p> around the text or <span> ie.
<div id="bigdiv">
<p onclick="myFuncion();"> TEXT </p>
</div>