Drawing Lines Behind Divs - javascript

I am looking at this fiddle:
http://jsfiddle.net/kDs2Q/45/
Is there a way to layer the divs/line in a way so that the line will be behind the other divs? I want to be able to draw the line from the center of one div to the center of the other but not see the line cross over the actual boxes.
This is how I would to the center-to-center:
var off1 = getOffset(div1);
var off2 = getOffset(div2);
var x1 = off1.left + off1.width/2;
var y1 = off1.top + off1.height/2;
var x2 = off2.left + off1.width/2;
var y2 = off2.top + off1.height/2;

Yes use z-index in your style.
z-index:-1
JSFiddle http://jsfiddle.net/D24uC/

Use z-indexes, the DIVs need to have a higher z-index than the 'line-div'.
Give it a try, set the DIVs z-index to 1000 or something and see the result:
http://jsfiddle.net/kDs2Q/884/
<div id="div1" style="position:absolute; z-index:1000; background-color:blue; width:100px; height: 200px;top: 200px; left: 100px;">

Related

Highlighting line of text in div while scrolling

I'm trying to highlight some text in a div, with the highlight being a fixed line in said text. So far I've got a very simple solution that uses two divs, one that houses the text, and the other acting as the highlight, and as you scroll the text, it will pass through the highlight div.
HTML is as follows:
<div id="test">
text...
</div>
<div id="highlight"></div>
CSS is:
#highlight {
position: fixed;
top: 50%;
width: 100%;
background-color: #ccff00;
height: 30px;
opacity: 0.6;
}
#test{
position: absolute;
font-size: 30px;
top: 50%;
}
A demo of it can be found here
I was wondering if anyone knows how to make it so that scrolling the text can be done in a way where as a user scrolls, the next line becomes highlighted. Currently it scrolls normally, so the highlight may miss a line, or not highlight a complete line. Additionally, I was wondering how it would be best to make the text scroll all the way to the bottom. Would adding a margin of the same size as the offset at the top work? Alternative solutions for any of this would be appreciated as well.
Try adding an event listener to the window on scroll. Then calculate the offset by taking the scrollY % line-height and set the highlight top margin to the negative of that value.
JavaScript below:
var highlight = document.querySelector("#highlight");
window.addEventListener('scroll', function(e){
var y = window.scrollY;
var offset = y % 30;
highlight.style.marginTop = - y % 30 + "px";
});
See Working Fiddle
Not sure if this
https://jsfiddle.net/ok0x3apo/6/ is what you're looking for
You can see that I'm remodifying the entered text, to get line by line highlight as page scrolls.
var el = document.getElementById("text"),
content = el.innerHTML.replace(/ |^\s+|\s+$/g,""),
lines = content.split(/\./);
var html = "";
for(var i in lines){
html+="<p class='clear_display' id='id_"+i+"'>"+lines[i]+".</p>";
};
document.getElementById("text").innerHTML=html;
You can make changes to the "clear_display" class on how you prefer to have the text block.
function calledEveryScroll() {
var scrollPosition = $(window).scrollTop();
for(var i in lines){
var currentSection = document.querySelector("#id_"+i+"");
var sectionTop = currentSection.offsetTop;
if (scrollPosition<=0){
$(".clear_display").removeClass('active');
document.querySelector("#id_0").className += " active";
}
if (scrollPosition >= sectionTop-50) {
$(".clear_display").removeClass('active');
if (!$(currentSection).hasClass('active')) {
$(currentSection).addClass('active');
if(previous){
if(currentSection.offsetTop==previous.offsetTop){
$(previous).addClass('active');
}
}
var previous = currentSection;
}
//return false;
}
}
}
function resizing(){
var offset =100;
var bottom = $(window).height()-offset;
$('#text').css('margin-bottom',bottom);
}
This function checks each line when page scrolls.For the scroll to reach the bottom I'm calculating the margin-bottom.Hope it helps.

How to draw lots of lines in html? [closed]

Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 6 years ago.
Improve this question
I have lots of images in my page and I am looking for a way to draw a line that will connect one image to the other ( it doesn't have to be an arrow, just a normal line. ).For example, let us consider ($) as an image:
$
$
Now how can I connect those 2 images ($) with a line?
Thanks!
Since you seem to be asking about basic JavaScript, HTML, and CSS, here's a simple method using only those. It's nice to understand the math and theory behind doing these kinds of graphical calculations instead of entirely relying on libraries.
Use a HTML div as a line by calculating the distance and angle between two images.
// Get the position of the first image
var imgOnePosition = document.getElementById("one").getBoundingClientRect();
// Get the position of the second image
var imgTwoPosition = document.getElementById("two").getBoundingClientRect();
// Calculate the angle between the two images' positions.
// Math.atan2() returns a value in radians so convert it to degrees as well
var angle = Math.atan2(imgOnePosition.top - imgTwoPosition.top, imgOnePosition.left - imgTwoPosition.left) * (180 / Math.PI);
// Calculate the distance, hopefully you remember this from basic algebra :)
var distance = Math.sqrt(Math.pow(imgOnePosition.top - imgTwoPosition.top, 2) + Math.pow(imgOnePosition.left - imgTwoPosition.left, 2));
// Create a new DIV to represent our line
var line = document.createElement("div");
// Now we style it
line.style.position = "absolute"; // so that we can change left and top
line.style.width = distance + "px";
line.style.height = "2px";
line.style.left = "50%"; // Center the element in its parent
line.style.top = "50%"; // Center the element in its parent
line.style.background = "#000";
line.style.transformOrigin = "0% 50%"; // Rotate around one edge instead of the middle
line.style.transform = "rotate(" + (angle) + "deg)";
// Add the line to the SECOND image's parent element.
// It's the 2nd image instead of 1st because of the order we did the math in calculating the angle
document.getElementById("two").appendChild(line);
body, img {
margin: 0;
padding: 0;
display: block;
}
#container {
position: relative;
background: #ddd;
width: 320px;
height: 240px;
}
.img-container {
position: absolute;
}
<div id="container">
<div id="one" class="img-container" style="left: 50px; top: 100px;" >
<img src="http://imgur.com/8B1rYNY.png" />
</div>
<div id="two" class="img-container" style="left: 150px; top: 190px;" >
<img src="http://imgur.com/8w6LAV6.png" />
</div>
</div>
If you want the line to appear behind the images instead of in front, you could modify their z-index values so they're ordered properly.
Edit: The above works if the images are the exact same size. If they are different sizes, calculate the center point of the images and use that instead of just the top left corner of the getBoundingClientRect().
// Get the position of the first image
var imgOneRect = document.getElementById("one").getBoundingClientRect();
var imgOnePosition = {
left: (imgOneRect.left + imgOneRect.right) / 2,
top: (imgOneRect.top + imgOneRect.bottom) / 2
}
// Get the position of the second image
var imgTwoRect = document.getElementById("two").getBoundingClientRect();
var imgTwoPosition = {
left: (imgTwoRect.left + imgTwoRect.right) / 2,
top: (imgTwoRect.top + imgTwoRect.bottom) / 2
}
div tag: with a background-color, width, height, transform: rotate(50deg) and well positioning properties
SVG tag
PNG image
Canvas

Javascript positioning center style

I wanted to set my second div element indside of my first div element center. I think somehow I managed to center it. But I think I made some mistakes and it seems to me it is not properly centered and also this JavaScript style seems to me bad. Is there any better way doing it? Is my JavaScript code is correct?
FIDDLE
HTML
<div class='first'>
<div class='second'>
</div>
</div>
JavaScript
var first = document.getElementsByClassName('first')[0];
var second = document.getElementsByClassName('second')[0];
var height = first.offsetHeight;
second.style.width = height/2+"px";
second.style.height = height/2+"px";
second.style.marginLeft = height/4+"px";
second.style.marginTop = height/4+"px";
offsetHeight will get the height of the element including borders, clientHeight won't. Instead of:
var height = first.offsetHeight;
Try:
var height = first.clientHeight;
JSFiddle
I've also used top and left with position:absolute for positioning, as this take the element out of the page flow and I assume this is the behaviour you are looking for.
References:
offsetHeight
clientHeight
(Follow the links and take a look at the box-model diagrams)
Reason is drawing round take 3px thats why not positioning but you divide 2.1 that result come that you need.
Check this Demo jsFiddle
JavaScript
var first = document.getElementsByClassName('first')[0];
var second = document.getElementsByClassName('second')[0];
var height = first.offsetHeight;
second.style.width = height/2.1+"px";
second.style.height = height/2.1+"px";
second.style.marginLeft = height/4+"px";
second.style.marginTop = height/4+"px";
var second = document.getElementsByClassName('second')[0];`
var left = (screen.width/2)-(100/2);
var top = (screen.height/2)-(100/2);
second.style.width = "100px"; //set as per your requirement
second.style.height = "100px"; //set as per your requirement
second.style.left= left +"px";
second.style.top = top +"px";
Just in case, you're interested, I tried to come up with a CSS only solution.
http://jsfiddle.net/53M6A/1/
Here's the changes I made to the .second class.
.second{
left: 50%; //move 50% to left
top: 50%; // move 50% down
margin-left: -50px; //move half of it's own size back to the left
margin-top: -50px; //move half of it's own size back to the top
position: relative; //make it relative, so it can be moved around by left/top
width:100px;
height:100px;
background: #fff;
border-radius:50%;
}
I've been playing a little in your fiddle and finally, I changed your 2 last lines for these:
first.style.display = "table-cell";
first.style.verticalAlign = "middle";
second.style.margin = "0 auto";
Fiddle
Seems perfectly centered to me.

how to center and make various images sizes fit in a container

I'm using bxslider to have a carousel of images. The thing is though, the images it receives to display are of somewhat unpredictable sizes. The container size is 243x243. And we know that no image will have a side smaller than 243. So...I'd like to center the image in the container. And either zoom in until the shorter of the two dimensions (L vs W) fills the container at 243, and the longer dimension overflow is hidden.
For the images I'm working with, doing this will be perfect for getting the important details of the picture in the frame.
But I'm having trouble...
I've tried the following to center the picture in the frame:
jQuery(".bx-container").each(function() {
var img_w = jQuery(this).children("img").width();
var img_h = jQuery(this).children("img").height();
var pos_top = (img_h - containerHeight) / 2;
var pos_left = (img_w - containerWidth) / 2;
var pos_top = (243 - img_h) / 2;
var pos_left = (243 - img_w) / 2;
jQuery(this).children("img").css({
'top' : pos_top + 'px',
'left' : pos_left + 'px'
});
});
And I've tried this to position not square images into the frame:
jQuery(".bx-container").each(function(){
var refRatio = 1;
var imgH = jQuery(this).children("img").height();
var imgW = jQuery(this).children("img").width();
if ( (imgW/imgH) < refRatio ) {
jQuery(this).addClass("bx-portrait");
} else {
jQuery(this).addClass("bx-landscape");
}
});
});
I've messed with both scripts and the css but I just can't seem to get it work. It either centers but doesn't resize right. Or resizes but centers wrong. Or does both wrong.
Here's the jsfiddle: http://jsfiddle.net/vgJ9X/298/
Could someone help me out?
Thanks!
EDIT:
New jsfiddle...the portrait ones work right. The landscape images still squish. :(
http://jsfiddle.net/vgJ9X/307/
EDIT:
I THINK it has something to do with relatively positioned elements not being allowed to overlap. Trying to find a fix. If anyone knows, edit the last fiddle I posted.
jQuery(".bx-container img").each(function () {
var w = jQuery(this).width();
var h = jQuery(this).height();
if (w > h) $(this).addClass('bx-landscape');
else $(this).addClass('bx-portrait');
});
Check this Updated JSFiddle
Update
jQuery(".bx-container img").each(function () {
var w = jQuery(this).width();
var h = jQuery(this).height();
if (w > h){
$(this).addClass('bx-landscape');
var trans= -243/2;
$(this).css('-webkit-transform','translateZ('+trans+'px)');
}
else if(h > w){
$(this).addClass('bx-portrait');
var trans= -243/2;
$(this).css('-webkit-transform','translateY('+trans+'px)');
}
});
check this JSFiddle
Update of Update
Found the issue with landscape, the plugin is setting max-width:100%; overriding it with max-width:none; fixes the issue...
Update Of Updated Fiddle
Try this:
img{
position:relative;
height:100%;
width:300px;
}
Simple an clean.
Demo: http://jsfiddle.net/vgJ9X/302/
I did a couple things to your jsfiddle.
First I changed the order of your resize and center functions, so the resize comes first. This way, the smaller images get resized, then centered. I also uncommented the first portion of your code.
You also had a couple of errors in your css. There was an extra closing bracket after img style declaration. Your .bx-portrait img and .bx-landscape img declarations were set to 100%px;.
Update:
Change the css in your two .bx classes to:
.bx-portrait img {
height: 100%;
width: auto;
}
.bx-landscape img {
height: auto;
width: 100%;
}
And add a clearfix to your ul:
.bxslider:after {
content: '';
clear: both;
display: table;
padding: 0;
margin: 0;
}
The height is clipping because .bx-viewport has a set height of 243px but also has a 5px border, which makes the actual internal height 233px. You'll need to make the height 253px to account for the 10px of border. This is why they don't look centered vertically.
DEMO
Why don't you just use background images instead and center them. Here is a demo from your original code
http://jsfiddle.net/8y8df/
If you want to show the full size image, just remove the background-size:contain; from the css.

Curved image path when scrolling page

I'm trying to create a rollercoaster ride for a project and need the rollercoaster to follow a path.
You can see my illustration on rollercoaster
I need the red box to follow the rollercoaster road in the background? The red box illustreres the image I'm going to use. Is this possible? I'm trying using this code...
<script type="text/javascript">
$(window).on('scroll', function(e) {
var scrollTop = $(window).scrollTop();
//var windowHeight = $(window).height();
var windowHeight = $('.road2').height();
//var S = scrollTop + Math.floor(windowHeight / 2);
var S = $(this).scrollTop(); // scrolled distance
var t = 0 + (S/windowHeight);
//var T = 0 + (S/36); // value for Top
//var L = 300 + Math.abs(Math.sin(S/400)*460); // value for Left
//
//$(".rollerImage").css({top: T+'%', left: L+'px'}); //set CSS
var canvas_X=400;
var canvas_Y=400;
// Increment Parameterization
t += 0.05;
// Width of Car
var car_X=150;
// Hieght of Car
var car_Y=50;
// Point A
var a_X=0;
var a_Y=0;
// Point B
var b_X=canvas_X-car_X; //Place point B at the end
var b_Y=0;
// Center of Semi Circle
var c_X=(b_X-a_X)/2;
var c_Y=(a_Y-a_Y)/2;
// Calculate X and Y point on trajectory
var x = a_X + t * (b_X- a_X);
var y = Math.sqrt(Math.pow((b_X - a_X),2)/4 + Math.pow((x-c_X),2));
$(".rollerImage").css({top: x+'px', left: y+'px'}); //set CSS
});
</script>
Hope someone can help with this type of path animation. Maybe it is possible to define the path in a array of coordinates?
I've tried using joel scrollpath, but can't "bind" an image to the path :(
//Graahf
I've tried to get it working with the jQuery Scrollpath using your html and css files plus the code from the demo site.
Check if this is OK for you: http://jsfiddle.net/Skr4R/6/embedded/result/
You can also check the sources of the fiddle: http://jsfiddle.net/Skr4R/6/
Important for this, is that the entire wrapper moves and rotates, that is why in my solution the train-image is outside of the wrapper, like this:
<div class="rollerCoasters">
<img src="" style="background:red; height:100px; width:50px; position:absolute; top:380px; left:50%; z-index:200; margin-left:-25px">
</div>
<div class="wrapper">
<div class="road1"><img src="base64-encoded-img" width="1434" height="539"/></div>
</div>
Hope this gets you started. It might not be the best solution, if you want the train to move, and not it's surroundings.
i am trying to achieve the same process and this has helped me along, the way forward about roating the train/object with the track could you not rotate the background(track to make the train look like it is following the track)

Categories