Develop Reference

Div flickers on hover

I have read a lot of the questions on here but can't find one that fixes this. I have programmed a div to follow my cursor. I only want it to appear when the cursor is over #backgroundiv. I have got it working but it sometimes randomly flickers on chrome and disappears entirely on firefox. Even more randomly is it sometimes appears to work and then starts flickering. I have tried a variety of things from hover to mouseenter/mouseover but nothing seems to work.
What I want is for #newdot to appear when the cursor is over #backgroundiv and then follow the cursor around the div. Any help would be much appreciated.
//hide dot when leaves the page
$(document).ready(function() {
$("#backgroundiv").hover(function() {
$("#newdot").removeClass("hide");
}, function() {
$("#newdot").addClass("hide");
});
});
//div follows the cursor
$("#backgroundiv").on('mousemove', function(e) {
//below centres the div
var newdotwidth = $("#newdot").width() / 2;
$('#newdot').css({
left: e.pageX - newdotwidth,
top: e.pageY - newdotwidth
});
});
//tried below too but it doesn't work
/*$(document).ready(function(){
$("#backgroundiv").mouseenter(function(){
$("#newdot").removeClass("hide");
});
$("#backgroundiv").mouseout(function(){
$("#newdot").addClass("hide");
});
}); */
#backgroundiv {
width: 400px;
height: 400px;
background-color: blue;
z-index: 1;
}
#newdot {
width: 40px;
height: 40px;
background-color: red;
position: absolute;
z-index: 2;
}
.hide {
display: none;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="newdot"></div>
<div id="backgroundiv"></div>

There is not issue but a logical behavior, when you hover on the blue div you trigger mouseenter so you remove the class and you see the red one BUT when you hover the red one you trigger mouseleave from the blue div thus you add the class and you hide the red one. Now the red is hidden you trigger again the mouseenter on the blue div and you remove the class again and the red div is shown, and so on ... this is the flicker.
To avoid this you can consider the hover on the red box to make the red box appear on its hover when you lose the hover from the blue one.
$(document).ready(function() {
$("#backgroundiv").hover(function() {
$("#newdot").removeClass("hide");
}, function() {
$("#newdot").addClass("hide");
});
});
//div follows the cursor
$("#backgroundiv").on('mousemove', function(e) {
//below centres the div
var newdotwidth = $("#newdot").width() / 2;
$('#newdot').css({
left: e.pageX - newdotwidth,
top: e.pageY - newdotwidth
});
});
#backgroundiv {
width: 400px;
height: 400px;
background-color: blue;
z-index: 1;
}
#newdot {
width: 40px;
height: 40px;
background-color: red;
position: absolute;
z-index: 2;
}
.hide {
display: none;
}
/* Added this code */
#newdot:hover {
display: block;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="newdot">
</div>
<div id="backgroundiv">
</div>

On second click, element gets moved to the edge of screen

I have a div that after I click an element(button1), expands its height. I then have another button appear which allows you to shrink the div(button2). After I click button1, the div expands and button2 shows at the bottom. I can then click button2 to shrink the div back to normal, but if I expand the div again, button2 is now off the edge of the screen, albeit in the same bottom location, just far left rather than centered.
I had to set the margin on button2 to -25px since the absolute positioning was kicking it off-center. And I need to use absolute positioning since it seemed it was only way to get the button to appear at the bottom of div after it had expanded.
$(".button1").on("click", function(){
$(".button1" ).fadeOut(200);
$("#block3").animate({
height: '800px'
}, 600, function() {
$(".button2").fadeIn(200);
});
});
$(".button2").on("click", function(){
$(".button2").fadeOut(200);
$("#block3").animate({
height: '400px'
}, 600,function(){
$(".button1" ).fadeIn(200);
});
});
.button2{
width: 50px;
height: 50px;
display:none;
position: absolute;
margin-left: 25px;
}
.button1{
width: 50px;
height: 50px;
margin-top: 25px;
image-rendering: auto;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="row">
<div class = "col-md-12" id = "block3">
<img src="https://placehold.it/120x80/00aaaa/fff/?text=scroll.png" class = "button1" />
<img src="https://placehold.it/120x80/00aaaa/fff/?text=scroll1.png" class = "button2" />
</div>
</div>
Uploaded the code.
https://jsfiddle.net/bs9xhe5e/2/

On the second click it changed the inline styling to display:block instead of display:inline, if you just add the display:inline into your jQuery it works;
https://jsfiddle.net/havL1z3m/
Added
$(".button2").css({display:"inline"});

The reason .button2 is showing up all the way to the left is that the absolute positioning gives it a default left of 0px.
Probably the easiest fix would be to remove absolute position, as well as the margin-left. Instead, to get .button2 to the bottom of the section, just set margin-top: 725px.
.button2{
width: 50px;
height: 50px;
display:none;
margin-top: 725px;
}
And then you will no longer need to use .css() to change bottom of .button2.
Check out this working fiddle: https://jsfiddle.net/gkpx7L15/

Change button2 styles like this:
.button2{
width: 50px;
height: 50px;
display:none;
position: absolute;
margin-left: -25px;
left:50%;//added style
}
https://jsfiddle.net/bs9xhe5e/3/
And everything will work fine
NOTE: Element will be positioned to the center of parent like this only when width is fixed like here. Example:
.someItem{
width: someWidth;//here we set some width to element
left: 50%; //Here we set position from the left
margin-left: -(somewidth/2);//here we set -half of the element's width for margin-left
}

css show button over image

I am making a simple reactjs app where I need to put a button over image.
My html looks like:
<div className={"panel-body"}>
<img className={"img-responsive center-block"}
src={album.photos.data[0].source} />
{(this.state.isMouseInsideID === album.id) ? <button>Your Button</button> : null}
</div>
Its all fine except button is shown below the image.
But I want to show the button over the image or in the middle of the div
How can I make this work ?

make button position relative and use z-index: maybe it will be helpful for you.

If you want to center the button in a div, while there is a background image to the div. I would suggest, to assign a background image for the div, rather than inserting an image into the div. Check out the fiddle:
http://jsfiddle.net/49s505sa/1/
HTML:
<div id="wrapper">
<button type="button">Your Button</button>
</div>
CSS:
#wrapper {
width: 100%;
height: 400px;
border: 1px solid black;
background: url('http://placehold.it/350x150') /*assign image, for demo purposes */
}
button {
height: 20px;
position: relative;
margin: -20px -50px;
width: 100px;
top: 50%;
left: 50%;
}
So, inside the render method
var style = {
backgroundImage: 'url(' + album.photos.data[0].source+ ')'
}
<div className={"panel-body"} style={style}>
{(this.state.isMouseInsideID === album.id) ? <button>Your Button</button> : null}
</div>
In this way, we will dynamically assign images to particular divs. And wont have to worry too much about styling.
Hope that helps!

Use z-index properties
The z-index property in CSS controls the vertical stacking order of
elements that overlap. As in, which one appears as if it is physically
closer to you. z-index only effects elements that have a position
value other than static (the default).. Note: z-index only works on
positioned elements
(position:absolute, position:relative, or position:fixed).
img {
position: absolute;
left: 0px;
top: 0px;
z-index: 10;
}

JQuery - show hide button when mouse enter / leave an image

In my web page I have an image that has a button positioned over it. I want to show and hide the button as mouse enter and leave the image:
$('#UserImage').mouseenter(function()
{
$('#ButtonChange').show();
}).mouseout(function()
{
$('#ButtonChange').hide();
})
It is working but as the button is contained inside the image when the mouse enters the button it is considered to leave the image so the button is hidden then at tha same moment as the button is hidden the mouseenter event is triggered again and the button is shown causing a flickering effect
any suggestion to solve this?
Edit:
$('#UserImage').mouseenter(function() {
$('#ButtonChange').show();
}).mouseout(function() {
$('#ButtonChange').hide();
})
.imageUser {
width: 150px;
height: 200px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div style="position:relative;width=150px">
<img ID="UserImage" class="imageUser" ImageUrl="~/Images/logo.jpg" />
<input type="button" ID="ButtonChange" Text="Change" style="position: absolute;top: 180px;height:25px;left:0px;width:100px;display:none">
</div>

The whole thing is also possible with pure CSS ! for such simple thing, you don't really need Jquery !
.imageUser {
width: 150px;
height: 200px;
}
.img-wrapper {
position: relative;
width: 150px
}
.img-btn {
position: absolute;
top: 180px;
height: 25px;
left: 0px;
right:0; /* gave right, to align the button in center */
margin:0 auto; /* as button as fixed width, margin aligns in center */
width: 100px;
display: none
}
.img-wrapper:hover .img-btn {display:block} /* whenever mouse hovers the image wrapper, the button is shown, other time, its hidden */
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div class="img-wrapper">
<img ID="UserImage" class="imageUser" ImageUrl="~/Images/logo.jpg" />
<input type="button" ID="ButtonChange" Text="Change" class="img-btn">
</div>

Try hover?
$("#UserImage").hover(function () {
$('#ButtonChange').show();
}, function () {
$('#ButtonChange').hide();
});
I don't have an image so I make a div instead. See Fiddle below.
Fiddle: https://jsfiddle.net/9koswww1/1

Change mouseenter to mouseover.
https://api.jquery.com/mouseenter/
Check the bottom of the page for an example.

try this
$('#UserImage').mouseenter(function()
{
$('#ButtonChange').show();
}).mouseleave(function()
{
$('#ButtonChange').hide();
})

jquery blind and exposing child div behind?

I'm trying to achieve the effect of a sliding div using the jquery animate option. I'm able to "slide" the parent div up but I'm having issues with showing the div behind the slider.
I've created this jsfiddle to show my issue.
Try uncommenting the photoOptions div. I'm trying to hide this div so it's only revealed when the parent div is slid up.
<div class="photoWrapper">
<!-- <div class="photoOptions"> This is your data. </div>-->
<div class="photoHolder">
Image Here
</div>
<div class="photoMeta">More data here</div>
<div class="photoCredits">
Trigger
</div>
</div>
Code
jQuery.fn.blindToggle = function(speed, easing, callback) {
var h = this.height() + parseInt(this.css('paddingTop')) + parseInt(this.css('paddingBottom'));
return this.animate({
marginTop: parseInt(this.css('marginTop')) < 0 ? 0 : -h
}, speed, easing, callback);
};
$(document).ready(function(){
$(".trigger").click(function(){
$('.photoHolder').blindToggle('slow');
});
});
Current CSS:
.photoWrapper {
width:200px;
border: solid 1px #ddd;
}
.photoHolder {
border: solid 1px #eee;
width:200px;
height:266px;
}
.photoOptions {
padding-top: 50px;
height: 266px;
width: 200px;
background: #eee;
position:absolute;
}
Any thoughts on how I can achieve this?

The browser renders elements based on there place in the DOM, if an element preceeds another element in the dom, it is rendered under it.
To change this default behaviour, you should use the CSS rule z-index, by defining a lower z-index on your .photoOptions div, it will be rendered below it.
as seen in this fiddle
Also be aware that z-index values may be handled differently for elements that are positioned absolute, due to the fact that they are not rendered in the normal flow.

Using the callback on .blindToggle() can achieve that effect but you're going to have to edit your CSS so that .photoCredits is visible and just start off with .photoOptions hidden:
$(document).ready(function () {
$(".trigger").click(function () {
$('.photoHolder').blindToggle('slow', function () {
$(".photoOptions").show();
});
});
});
.photoOptions {
padding-top: 50px;
height: 266px;
width: 200px;
background: #eee;
position:absolute;
display:hidden;
}