I have a div element placed on top of a canvas (with absolute positioning). Is there a way to make canvas.addEventListener('mousedown,......) work when the user clicks on the div element? I know logically it shouldn't worked as div is placed on top of canvas and user is ultimately clicking div element, not canvas. Will making div element transparent or something work? or is there any other possible solution to this problem?
For newer browsers you can use CSS pointer-events
.div_class {pointer-events : none}
FIDDLE
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I have a problem with dragging an element below the viewport. When I try to drag the element below the viewport the page will not autoscroll. As you can see in the image I have provided I am trying to drag an element below. The only way I can scroll below the viewport to drop my element in Firefox is to use the mouse wheel.
If I left click and hold while dragging down on this Stack Overflow page the viewport autoscolls downward. This is how I need my web app to perform.
I'm not really sure where to start with this as it is a paid WordPress plugin called Learndash that not properly coded.
Can anyone point me to the correct solution to this problem?
Thanks.
Checkout this link to automatically scroll the window.
https://www.bennadel.com/blog/3460-automatically-scroll-the-window-when-the-user-approaches-the-viewport-edge-in-javascript.htm
Edit:
Add a margin below your div to allow space to insert
Or add the CSS properties height:500px and overflow-y:scroll in your div
I'm trying to find a way to register a mouseover event on an element that is beneath another element. I have rows which, when moused over, make a new div appear and positions it on top of the hovered div.
Here's the page: http://www.brunobryan.com/dev/stephanebourgeois/index/
When you mouseover a row, an image appears on the right. I would like to register the mouseover event on the row even when the mouse hovers above the image.
You can permit the cursor to pass-through the image using pointer-events:
#index-hover {
pointer-events: none
}
Note, this isn't supported in all browsers. Better support if you use SVG.
This is not really possible, you have a couple of options for workarounds.
Either a) Register the hover event on a container that will contain both the row and the image.
or
b) Bind the same hover event on the image aswell.
i think the answer here is going to be that your <img> tag needs to be placed inside of the <tr> tag, and then absolutely positioned. you'll probably want to make the row relatively positioned so that you can use the row's position as context.
I've build a drag and drop interface using JavaScript where users can click and drag a link (that sometimes has a CSS background image) and drop it onto the canvas.
My problem is that the mouse cursor has the link background image beneath it during dragging. I need to add my own cursor design, so is there any way to turn this CSS background off so that it doesn't follow the mouse upon dragging?
have you tried setting :active pseudo class for anchor tags?
http://www.w3schools.com/cssref/sel_active.asp
then if that isn't work quite yet you could use !important after your deceleration possibly?
and example could be
.links:active {
background-image: none !important;
}
when the user releases the background image should return.
The best solution I found for this problem was to use jQuery to assign e.preventDefault() to the click event of the link, thus disabling the background drag effect. Then, if you want a custom cursor upon dragging, write a script to match an absolutely positioned div's (with the image as the background) x,y cords to the mouse position.
I want to write a jQuery plugin with some visual effect for selected divs.
Integrating a plugin would look like so:
$('.myclass').mypluginfunction();
Visually it would be a transparent div over the whole element, with moving background.
Is it possible to dynamically add divs without destroying e.g floated divs?
I know that the solution would be adding an absolute position to div with bigger z-index.
You don't even need to tinker with the z-index. An element lower in the source will overlay content before it. Set your elements to position: relative and append an absolutely positioned div with width and height set to 100% - this will effectively overlay it.
Get yourself Chrome (or Firebug) and play with $.append() in the console:
$('*').css('position', 'relative').append('<div style="position:absolute; width:100%; height:100%; background: #F00; opacity:0.5;"></div>');
This will position every element on your site relatively, then append an absolutely positioned div with a red background. You should see every single element on your site being overlayed by it.
Of course this is going to explode, a little, but it gives you an idea of how easy to use this technique is.
I have a container of some HTML divs and with some CSS if I hover over them, the background color changes. I want to overlay a canvas on top of the container so that I can draw lines. The problem is that when the canvas is overlaid, the hovering changes of the divs no longer works. Is there a way to overlay a canvas but still have CSS or JavaScript onmouseover events still work on the elements beneath?
So you want sort of a transparent canvas which passes all mouse events except clicks to the elements behind it?
IMHO, you'd need to use JS for that: Capture all the events on the canvas, then manually pass them on to the div behind the canvas. If you have multiple divs, you'd need some sort of lookup depending on the (x,y) coordinates of the mouse.
An alternative to going through all that hassle would be by using the pointer-events CSS attribute. Mozilla,Webkit and IE6-8(excanvas) all support this. Opera does not, but I really don't care.
<canvas style="pointer-events:none;"></canvas>