Is it possible to click through a movable div? - javascript

I am working on some jQuery/JavaScript that makes it possible to drag a div around and simultaneously be able to manipulate other divs (specifically images) on the page. The movable div is basically a transparent rectangle that is meant to simulate a lens. The problem I am having is that I cannot figure out how to pass clicks through to the images below the movable div. I have read up on the pointer-events CSS property and tried setting that to none for the movable div, but that makes the movable div no longer movable. Is there a way for me to pass clicks through this movable div while keeping it movable?
EDIT: To all those asking for my current code, here is the JavaScript that I have so far:
<script>
$(document).ready(function(){
$('img').click(function(e) {
$(document).unbind('keypress');
$(document).keypress(function(event) {
if ( event.which == 115) {
$(e.target).css('width', '+=25').css('height', '+=25');
};
if ( event.which == 97) {
$(e.target).css('width', '-=25').css('height', '-=25');
};
});
});
//code to drag the lens around with the mouse
$("#draggableLens").mousemove(function(e){
var lensPositionX = e.pageX - 75;
var lensPositionY = e.pageY - 75;
$('.lens').css({top: lensPositionY, left: lensPositionX});
});
});
</script>

I created a demo that is proof of concept using document.elementFromPoint to locate the nearest image the moveable element is over. I used jQueryUI draggable to simplify event handling.
The trick with using document.elementFromPoint is you must hide the element you are dragging just long enough to look for other elements, or the draggging element is itself the closest element.
Adding an active class to the closest element allows clicking on the viewer to access the active element
Demo code uses LI tags instead of IMG
var $images = $('#list li');
timer = false;
$('#viewer').draggable({
drag: function(event, ui) {
if (!timer) {
timer = true;
var $self = $(this);
/* use a timeout to throttle checking for the closest*/
setTimeout(function() {
/* must hide the viewer so it isn't returned as "elementFromPoint"*/
$self.hide()
var el = $(document.elementFromPoint(event.pageX, event.pageY));
$('.active').removeClass('active');
if ($el.is('li')) {
$el.addClass('active')
}
$self.show()
timer = false;
}, 100);
}
}
}).click(function() {
if ($('.active').length) {
msg = 'Clicked on: ' + $('.active').text();
} else {
msg = 'Click - No active image';
}
$('#log').html(msg + '<br>');
})
DEMO: http://jsfiddle.net/nfjjV/4/
document.elementFromPoint is not be supported in older browsers. You could also use jQuery position or offset methods to compare coordinates of elements with the current position of the viewer for full browser compatibility

Related

How do I detect the Keyboard show/hide event occurence on Android browser

I am in a fix. I am not able to identify a way to capture the keyboard show/hide status on a mobile device browser.
Problem :
I have a popup on a form in which a Text Field is present. When the user taps on the text field the keyboard shows up pushing the popup on the form and eventually making the text field invisible.
Is there a way to identify the key board show/hide status???
No, there is no way to reliably know when a keyboard is showing. The one level of control you do have is you can set your app to pan or resize when the keyboard shows up. If you set it to resize, it will recalculate your layout and shrink things so if fits the remaining screen. If you choose pan, it will keep the same size and just slide up the entire app.
you can find out keyboard show/hide inside your application,Try following code inside oncreate method,and pass your parent layout to view.
final View activityRootView = rellayLoginParent;
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener()
{
#Override
public void onGlobalLayout()
{
Rect r = new Rect();
// r will be populated with the coordinates of your view that area still visible.
activityRootView.getWindowVisibleDisplayFrame(r);
int heightDiff = activityRootView.getRootView().getHeight() - (r.bottom - r.top);
//MyLog.w("height difference is", "" + heightDiff);
if (heightDiff > 100)
{ // if more than 100 pixels, its probably a keyboard...
if(lytAppHeader.getVisibility() == View.VISIBLE)
{
lytAppHeader.setVisibility(View.GONE);
}
}
else
{
if(lytAppHeader.getVisibility() == View.GONE)
{
lytAppHeader.setVisibility(View.VISIBLE);
}
}
}
});
It seems there is no reliable way to do this in the browser. The closest I have come is to listen for focus events and then temporarily listen for resize events. If a resize occurs in the next < 1 second, it's very likely that the keyboard is up.
Apologies for the jQuery...
onDocumentReady = function() {
var $document = $(document);
var $window = $(window);
var initialHeight = window.outerHeight;
var currentHeight = initialHeight;
// Listen to all future text inputs
// If it's a focus, listen for a resize.
$document.on("focus.keyboard", "input[type='text'],textarea", function(event) {
// If there is a resize immediately after, we assume the keyboard is in.
$window.on("resize.keyboard", function() {
$window.off("resize.keyboard");
currentHeight = window.outerHeight;
if (currentHeight < initialHeight) {
window.isKeyboardIn = true;
}
});
// Only listen for half a second.
setTimeout($window.off.bind($window, "resize.keyboard"), 500);
});
// On blur, check whether the screen has returned to normal
$document.on("blur.keyboard", "input[type="text"],textarea", function() {
if (window.isKeyboardIn) {
setTimeout(function() {
currentHeight = window.outerHeight;
if (currentHeight === initialHeight) {
window.isKeyboardIn = false;
}, 500);
}
});
};

Get divs within viewport inside a wrapper div

Is there a way to get elements which is:
Inside a div with overflow: scroll
Is in viewport
Just like the following picture, where active div (5,6,7,8,9) is orange, and the others is green (1-4 and >10) :
I just want the mousewheel event to add "active" class to div 5,6,7,8,9 (currently in viewport). View my JSFiddle
$('.wrapper').bind('mousewheel', function (e) {
//addClass 'active' here
});
You could do something like this. I would have re-factored it, but only to show the concept.
Firstly I would attach this to scroll event and not mousewheel. There are those among us that likes to use keyboard for scrolling, and you also have the case of dragging the scrollbar. ;) You also have the case of touch devices.
Note that with this I have set overflow:auto; on wrapper, thus no bottom scroll-bar.
With bottom scrollbar you would either have to live with it becoming tagged as in-view a tad to early, or tumble into the world of doing a cross-browser calculating of IE's clientHeight. But the code should hopefully be OK as a starter.
»»Fiddle««
function isView(wrp, elm)
{
var wrpH = $(wrp).height(),
elmH = $(elm).height(),
elmT = $(elm).offset().top;
return elmT >= 0 &&
elmT + elmH < wrpH;
}
$('.wrapper').bind('scroll', function (e) {
$('div.box').each(function(i, e) {
if (isView(".wrapper", this)) {
$(this).addClass('active');
} else {
$(this).removeClass('active');
}
});
});
Note that you should likely refactor in such a way that .wrapper height is only retrieved once per invocation, or if it is static, at page load etc.
Update; a modified version of isView(). Taking position of container into account. This time looking at dolphins in the pool.
»»Fiddle««
function isView(pool, dolphin) {
var poolT = pool.offset().top,
poolH = pool.height(),
dolpH = dolphin.height(),
dolpT = dolphin.offset().top - poolT;
return dolpT >= 0 && dolpT + dolpH <= poolH;
}

How to disable scrolling in outer elements?

I have a vertically-scrolling div within a page that also scrolls vertically.
When the child div is scrolled with the mouse wheel and reaches the top or bottom of the scroll bar, the page (body) begins to scroll. While the mouse is over the child div, I'd like the page (body) scroll to be locked.
This SO post (scroll down to the selected answer) demonstrates the problem well.
This SO question is essentially the same as mine, but the selected answer causes my page contents to noticeably shift horizontally as the scrollbar disappears and reappears.
I thought there might be a solution that leverages event.stopPropagation(), but couldn't get anything to work. In ActionScript, this kind of thing would be solved by placing a mousewheel handler on the child div that calls stopPropagation() on the event before it reaches the body element. Since JS and AS are both ECMAScript languages, I thought the concept might translate, but it didn't seem to work.
Is there a solution that keeps my page contents from shifting around? Most likely using stopPropagation rather than a CSS fix? JQuery answers are welcome as is pure JS.
here's what i ended up with. very similar to #mrtsherman's answer here, only pure JS events instead of jQuery. i still used jQuery for selecting and moving the child div around, though.
// earlier, i have code that references my child div, as childDiv
function disableWindowScroll () {
if (window.addEventListener) {
window.addEventListener("DOMMouseScroll", onChildMouseWheel, false);
}
window.onmousewheel = document.onmousewheel = onChildMouseWheel;
}
function enableWindowScroll () {
if (window.removeEventListener) {
window.removeEventListener("DOMMouseScroll", onArticleMouseWheel, false);
}
window.onmousewheel = document.onmousewheel = null;
}
function onChildMouseWheel (event) {
var scrollTgt = 0;
event = window.event || event;
if (event.detail) {
scrollTgt = -40 * event.detail;
} else {
scrollTgt = event.wheelDeltaY;
}
if (scrollTgt) {
preventDefault(event);
$(childDiv).scrollTop($(childDiv).scrollTop() - scrollTgt);
}
}
function preventDefault (event) {
event = event || window.event;
if (event.preventDefault) {
event.preventDefault();
}
event.returnValue = false;
}
i've noticed the scrolling doesn't match normal scrolling exactly; it seems to scroll a bit faster than without this code. i assume i can fix by knocking down wheelDeltaY a bit, but it's odd that it would be reported differently by javascript than it's actually implemented by the browser...
I usually do it with a small hack listening to the scroll event on the document: it resets the scroll height back to the original one - effectively freezing the document from scrolling but any inner element with overflow: auto will still scroll nicely:
var scrollTop = $(document).scrollTop();
$(document).on('scroll.scrollLock', function() {
$(document).scrollTop(scrollTop);
});
and then when I'm done with the inner scroll lock:
$(document).off('scroll.scrollLock');
the .scrollLock event namespace makes sure I'm not messing with any other event listeners on scroll.
Although this is an old question, here is how I do it with jQuery. This allows you to scroll a list within an outer list, or you can change the outer list to the document to do what the OP asked.
window.scrollLockHolder = null;
function lockScroll(id){
if (window.scrollLockHolder == null){
window.scrollLockHolder = $('#' + id).scrollTop();
}
$('#' + id).on('scroll', function(){
$('#' + id).scrollTop(window.scrollLockHolder);
});
}
function unlockScroll(id){
$('#' + id).off('scroll');
window.scrollLockHolder = null;
}
And you can use it like this:
<ul onmousemove="lockScroll('outer-scroller-id')" onmouseout="unlockScroll('outer-scroller-id')">
<li>...</li>
<li>...</li>
</ul>
what about this:
div.onmousemove = function() { // may be onmouseover also works fine
document.body.style.overflow = "hidden";
document.documentElement.style.overflow = "hidden";
};
div.onmouseout = function() {
document.body.style.overflow = "auto";
document.documentElement.style.overflow = "auto";
};

One function to rule multiple buttons, and then some

I have 7 buttons. They are distributed on top of a background image and interacting with it. They are placed absolutely. I have created a jQuery function to animate one of the buttons height. The button expands upwards. Check it out here: http://hdpano.no/bf/newindex.html and click the top left button named Deck 8.
I wish this function to handle all the buttons, but there are some variables. The baseline of each button varies, and i need to subtract from it as i expand the height. I also wish to close any other open button if one clicks another.
Here is the jQuery code:
jQuery(document).ready(function() {
$('#link8').toggle(
function()
{
$('#deck8').animate({height: "25px",top:"202"}, 500);
},
function()
{
$('#deck8').animate({height: "150",top:"76"}, 500);
});
});
The function is quite basic and I have stripped it of all my attempts to make it work with the other buttons.
This does what you're looking for. Replace the code in your page with this...
<script type="text/javascript">
jQuery(document).ready(function() {
$('.link').click(function() {
var $me = $(this);
if ($me.height() == 150) {
$me.animate({height: "25px",top:"+=126"}, 500);
} else {
$(".link").each(function() {
if ($(this) != $me) {
if ($(this).height() == 150) {
$(this).animate({height: "25px",top:"+=126"}, 500);
}
}
});
$me.animate({height: "150px",top:"-=126"}, 500);
}
});
});
</script>
You can toggle the position with += and -= so it uses relative positioning, rather than absolute positioning, so that code affects all the divs on the page with class "link".
this in the toggle functions would be the element that is clicked.
Here is what I would do:
remove the <br/> tags. Use margin/padding to achieve spacing.
basically you want to expand/collapse the element ".link" (the container) for the height of the contained <ul>.
use "+=" or "-=" with the animate function to automatically add/remove the specified value.
as your buttons start collapsed, you should invert the two functions in the toggle
Here a code that is more general:
jQuery(document).ready(function() {
// on click of any link with class ".linkContent"
$('.linkContent').toggle(
function() {
// get the parent ".link" container
var $parent = $(this).parent(),
// get the full height of the <ul> to show/hide + the height of the link
h = $parent.find('ul').outerHeight() + $(this).outerHeight();
// animate using += and -= to avoid setting explicit values
$parent.animate({ height: '+=' + h, top: '-=' + h }, 500);
},
function() {
var $parent = $(this).parent(),
h = $parent.find('ul').outerHeight() + $(this).outerHeight();
$parent.animate({ height: '-=' + h, top: '+=' + h }, 500);
});
});
The following demo shows the code in action. You might have to tweak it a bit to get the exact height to add/remove but you get the idea:
DEMO
What you want to do is add a class eg .deck to each button, then toggle .deck'. Inside the toggle function use$(this)` to refer to the current button.

Capture first visible div id while scrolling (viewport)

I have this page:
I want to capture on which div I am while I'm scrolling.
I know If I use:
if( $(document).scrollTop() > $('#div1').position().top) {
console.log('Div1')
}
...it will capture the div1 but instead of using this code for every div I want to set 1 snippet for all divs
Something like:
var a = // The div i am at
if( $(document).scrollTop() > $(a).position().top) {
console.log($(a).attr('id'))
}
I am looking something like the viewport: http://www.appelsiini.net/projects/viewport/3x2.html
Can I achieve that without a plugin, simply 2-3 lines?
Here's a nice way to do it. You may want to optimize the '<=' with a pixel offset to improve user experience and move the div selector ($divs) outside the callback to increase performance. Have a look at my fiddle: http://jsfiddle.net/brentmn/CmpEt/
$(window).scroll(function() {
var winTop = $(this).scrollTop();
var $divs = $('div');
var top = $.grep($divs, function(item) {
return $(item).position().top <= winTop;
});
});
Just throw it into a loop.
var list = [];
$("div").each(function(index) {
if( $(document).scrollTop() > $(this).position().top)
list.push($(this));
});
alert(list);
The list will than have every div that is within your viewport.
I'd suggest using the jQuery Inview plugin:
https://github.com/protonet/jquery.inview
Well maintained Plugin that detects whatever content is in the viewer currently, enabling you to bind functions to an inview event. So as soon as your div is in view you could fire off all the relevant functions you wanted and then again when it has left the users view. Would be great for your needs.
$(window).scroll(function () {
$("#privacyContent div").each(function () {
var bottomOffset = ($(this).offset().top + $(this).height());
console.log("Botom=",bottomOffset ,"Win= ", $(window).scrollTop());
if (bottomOffset > $(window).scrollTop()) {
$("#menu a").removeClass("active");
// console.log("Div is= ",$(this).attr('id'));
$("#menu a[href='#" + $(this).attr('id') + "']").addClass("active");
$(".b").removeClass("fsActive");
var div = $(this);
div.find(".b").addClass("fsActive");
return false;
}
});
});
I do it like this it works fine it detect all div id

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