Javascript How to keep DIV in window boundary - javascript

Hey I have a "box" div which can move its position based on clicking of arrows. How can I keep the Box from going outside the window's bounds or in other words just go to the borders and not cross the boundaries.
Fiddle provided:
var elementStyle = document.getElementById("divId").style;
JSFiddle

I updated your fiddle basically you need to add checks and if your check doesn't pass then set the new position to 0.
if (newPosition < 0) {
elementStyle.top = 0;
} else {
elementStyle.top = newPosition + px;
}
Fiddle here:
https://jsfiddle.net/8t9cqyqd/7/
for bottom and right the window will keep scrolling. If that's not desirable then you need to get the window size and do the same kind of check and then set the right and bottom positions to the container size minus the size of your moving box. I can update the fiddle for that if you'd like.
updated fiddle to handle the "right" direction:
https://jsfiddle.net/8t9cqyqd/9/

Something along these lines:
var x = $("#divID").position();
if(x.left > $(window).width())
//disable up arrow movement
Just do that for all positions changing out width() with height() for the Y position

Related

Center an element in middle on screen for an horizontal scroll list

I'm attempting to have the element clicked being positioned automatically at the center of the screen. The list is having a horizontal scroll with some overflow-x : scroll which is hiding what's outside of the div(screen).
I can't find out what coordinates to pass to scrollLeft().
$('#timepicker li').on('click',function(){
var maxScrollLeft= $("#timepicker").scrollLeft('#timepicker').prop('scrollWidth') - $("#timepicker").width();
$('#timepicker').animate({
scrollLeft:
});
});
Please see my codepen: codepen
thank you.
Its a little tricky, but here's the solution.
var left = $(this).offset().left
var width = $("#timepicker").width();
var diff = left - width/2
$("#timepicker").scrollLeft($("#timepicker").scrollLeft()+diff)
Basically what i've done is get the present left position of the clicked element and divide it with half of the width of the container. This gives the difference which the scroller has to move in order to take the elment to the middle. Hope you understood the logic.
Here's the codepen attached
http://codepen.io/prajnavantha/pen/eNwWgx
You can copy paste this in the code pen click handler and see it working.
try this
$('#timepicker li').on('click',function(){
var pos=$(this).position().left; //get left position of li
var currentscroll=$("#timepicker").scrollLeft(); // get current scroll position
var divwidth=$("#timepicker").width(); //get div width
pos=(pos+currentscroll)-(divwidth/2); // for center position if you want adjust then change this
$('#timepicker').animate({
scrollLeft: pos
});
});

How use JQuery/Javascript to scroll down a page when the cursor at the top or bottom edge of the screen?

Simple, I just would like to have it so when a user is dragging an item and they reach the very bottom or top of the viewport (10px or so), the page (about 3000px long) gently scrolls down or up, until they move their cursor (and thus the item being dragged) out of the region.
An item is an li tag which uses jquery to make the list items draggable. To be specific:
../jquery-ui-1.8.14.custom.min.js
http://code.jquery.com/jquery-1.6.2.min.js
I currently use window.scrollBy(x=0,y=3) to scroll the page and have the variables of:
e.pageY ... provides absolute Y-coordinates of cursor on page (not relative to screen)
$.scrollTop() ... provides offset from top of page (when scroll bar is all the way up, it is 0)
$.height()... provides the height of viewable area in the user's browser/viewport
body.offsetHeight ... height of the entire page
How can I achieve this and which event best accommodates this (currently its in mouseover)?
My ideas:
use a an if/else to check if it is in top region or bottom, scroll up if e.pageY is showing it is in the top, down if e.page& is in bottom, and then calling the $('li').mouseover() event to iterate through...
Use a do while loop... this has worked moderately well actually, but is hard to stop from scrolling to far. But I am not sure how to control the iterations....
My latest attempt:
('li').mouseover(function(e) {
totalHeight = document.body.offsetHeight;
cursor.y = e.pageY;
var papaWindow = window;
var $pxFromTop = $(papaWindow).scrollTop();
var $userScreenHeight = $(papaWindow).height();
var iterate = 0;
do {
papaWindow.scrollBy(0, 2);
iterate++;
console.log(cursor.y, $pxFromTop, $userScreenHeight);
}
while (iterate < 20);
});
Works pretty well now, user just needs to "jiggle" the mouse when dragging items sometimes to keep scrolling, but for scrolling just with mouse position its pretty solid. Here is what I finally ended up using:
$("li").mouseover(function(e) {
e = e || window.event; var cursor = { y: 0 }; cursor.y = e.pageY; //Cursor YPos
var papaWindow = parent.window;
var $pxFromTop = $(papaWindow).scrollTop();
var $userScreenHeight = $(papaWindow).height();
if (cursor.y > (($userScreenHeight + $pxFromTop) / 1.25)) {
if ($pxFromTop < ($userScreenHeight * 3.2)) {
papaWindow.scrollBy(0, ($userScreenHeight / 30));
}
}
else if (cursor.y < (($userScreenHeight + $pxFromTop) * .75)) {
papaWindow.scrollBy(0, -($userScreenHeight / 30));
}
}); //End mouseover()
This won't work as the event only fires while you're mouse is over the li.
('li').mouseover(function(e) { });
You need to be able to tell the position of the mouse relative to the viewport when an item is being dragged. When the users starts to drag an item attach an 'mousemove' event to the body and then in that check the mouse position and scroll when necessary.
$("body").on("mousemove", function(event) {
// Check mouse position - scroll if near bottom or top
});
Dont forget to remove your event when the user stops dragging.
$("body").off("mousemove", function(event) {
// Check mouse position - scroll if near bottom or top
});
This may not be exactly what you want, but it might help. It will auto-scroll when the mouse is over the 'border of the screen' (a user defined region). Say you have a 40px wide bar on the right of the screen, if the mouse reaches the first 1px, it will start scrolling. Each px you move into it, the speed will increase. It even has a nice easing animation.
http://www.smoothdivscroll.com/v1-2.htm
I get a weekly newsletter (email) from CodeProject, and it had some stuff that certainly looks like it will solve my problem... hopefully this can help others:
http://johnpolacek.github.com/scrollorama/ -- JQuery based and animates the scroll
https://github.com/IanLunn/jQuery-Parallax -- JQuery based, similar to above
http:// remysharp. com/2009/01/26/element-in-view-event-plugin/ -- JQuery, detects whether an element is currently in view of the user (super helpful for this issue!)
Also the site in #2 had some interesting code:
var windowHeight = $window.height();
var navHeight = $('#nav').height() / 2;
var windowCenter = (windowHeight / 2);
var newtop = windowCenter - navHeight;
//ToDo: Find a way to use these vars and my original ones to determine scroll regions

CSS dynamic position of tooltip on hover with jQuery

I'm writing a simple tooltip that can hold HTML tags. Please check http://jsfiddle.net/Qkwm8/ for the demo.
I want the tooltip box to show properly regardless of the position of element, in this case <a>, that shows tooltips on mouseover event.
The tooltips are shown fine except when <a> floats right (or is at the end of the line) or at the bottom of the screen where it doesn't show properly, it appears off the screen
If the <a> floats right, or at the end of the line, or is at the bottom of the screen, I want the tooltip to change position so it remains visible
Thank you.
Update demo link
here's the complete result: http://jsfiddle.net/Qkwm8/3/
You can use the document width to check how wide the html document is and adjust the left position accordingly. Say:
//set the left position
var left = $(this).offset().left + 10;
if(left + 200 > $(document).width()){
left = $(document).width() - 200;
}
I used 200 here because you are setting your tooltip to 200px wide. Something similar can be done with height.
There is also a window width but I always get confused about the difference so you should check which one gives you better results.
An example of the bottom of the page is:
//set the height, top position
var height = $(this).height();
var top = $(this).offset().top;
if(top + 200 > $(window).height()){
top = $(window).height() - 200 - height;
}
Again, using 200 since you are setting your tooltip to 200px height.
$('a.show-tooltips').mouseover(function() {
if(($(this).parent()).css('float')) =="right") add the proper class to left
else -> the proper class the right
....
}

issue with $(document).scrollLeft() as a variable

I'm trying to use the left variable to replace '1493' in this code. It works fine when it's a number but when I changed it over to use 'left' the if statement stops working.
$(document).scroll(function () {
var width = $(document).width();
var left = $(document).scrollLeft();
var postCount = $(".post").length;
var columnLength = ( width - ((postCount*743) - 1493)) - (width-(postCount*743));
if(left >= columnLength) {
$(".num").text(left);
}
});
Does anyone have any ideas where I'm going wrong with this? Any pointers would be great.
You may need to force it to be an integer:
var left = parseInt($(document).scrollLeft());
Lets take a look at the math you have really quick.
var columnLength = ( width - ((postCount*743) - 1493)) - (width-(postCount*743));
You are basically cancelling out width, and (postCount*743). It leaves you with --1493 which is positive 1493. The following would have the same effect:
var columnLength = 1493;
So, the reason the if statement fires when you put in the static value 1493, is because columnLength ALWAYS equals 1493 which, of course satisfies this condition:
if (1493 >= columnLength)
You could as easily write:
if (1493 >= 1493)
That said, it should still, theoretically fire when left becomes greater than or equal to 1493. But left is the current horizontal scroll position in pixels. It would be a HUGELY wide page to hit a scroll position of 1493.
Edit: Here's a fiddle to give an idea of how fast the scroll position increases: http://jsfiddle.net/vdQ7B/16/
EDIT 2:
Here is an update in response to your comment.
As I understand it, you were trying to get a horizontal scrollbar that would, essentially, scroll forever.
Please see the following fiddle for a demo: http://jsfiddle.net/vdQ7B/40/
The code is below:
$(document).scroll(function () {
var width = $(document).width();
var left = $(document).scrollLeft();
var viewportwidth = window.innerWidth;
// If our scrollbar gets to the end,
// add 50 more pixels. This could be set
// to anything.
if((left + viewportwidth) === width) {
$("body").css("width", width + 50);
}
});
Per the comments in the code, we simply increase the width of the body if we determine we've reached the end. scrollLeft() will only tell us the number of pixels that are currently not visible to the left of the viewable area. So, we need to know how much viewable area we have, and how much is hidden to the left to know if we've scrolled all the way to the end.
If you have a scroll bar on an inner element, like a div, you'd need to update with width of the div, not the body.
Note: You may also need to use $(window) instead of $(document) to get scrollLeft() to work across all browsers.
Note: See here about using "innerWidth". There are some compatibility issues, and you may need to expand it a bit to handle other cases (IE6).

height of an element javascript

I would like to adjust the size of an element in the opposite direction, so the code below does adjust it, but it enlarges it from current position to bottom, I want current position to top. What would be an efficient way of doing this? thanks
var ele=document.getElementById('mydiv');
ele.style.height = 500+'px';
Do what you're doing, then move the element up by its original height:
var ele=document.getElementById('mydiv');
ele.style.height = 500+'px';
ele.style.top -= 100+'px'; //or whatever the height originally was.

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