[removed] Check if mouse button down?

Question

Is there a way to detect if a mouse button is currently down in JavaScript?

I know about the "mousedown" event, but that's not what I need. Some time AFTER the mouse button is pressed, I want to be able to detect if it is still pressed down.

Is this possible?

Answer 1

You can combine @Pax and my answers to also get the duration that the mouse has been down for:

var mousedownTimeout,
    mousedown = 0;

document.body.onmousedown = function() {
  mousedown = 0; 
  window.clearInterval(mousedownTimeout);
  mousedownTimeout = window.setInterval(function() { mousedown += 200 }, 200);
}

document.body.onmouseup = function() {
  mousedown = 0;
  window.clearInterval(mousedownTimeout);
}

Then later:

if (mousedown >= 2000) {
  // do something if the mousebutton has been down for at least 2 seconds
}

Answer 2

The following snippet will attempt to execute the "doStuff" function 2 seconds after the mouseDown event occurs in document.body. If the user lifts up the button, the mouseUp event will occur and cancel the delayed execution.

I'd advise using some method for cross-browser event attachment - setting the mousedown and mouseup properties explicitly was done to simplify the example.

function doStuff() {
  // does something when mouse is down in body for longer than 2 seconds
}

var mousedownTimeout;

document.body.onmousedown = function() { 
  mousedownTimeout = window.setTimeout(doStuff, 2000);
}

document.body.onmouseup = function() {
  window.clearTimeout(mousedownTimeout);
}

Answer 3

        var mousedown = 0;
        $(function(){
            document.onmousedown = function(e){
                mousedown = mousedown | getWindowStyleButton(e);
                e = e || window.event;
                console.log("Button: " + e.button + " Which: " + e.which + " MouseDown: " + mousedown);
            }

            document.onmouseup = function(e){
                mousedown = mousedown ^ getWindowStyleButton(e);
                e = e || window.event;
                console.log("Button: " + e.button + " Which: " + e.which + " MouseDown: " + mousedown);
            }

            document.oncontextmenu = function(e){
                // to suppress oncontextmenu because it blocks
                // a mouseup when two buttons are pressed and 
                // the right-mouse button is released before
                // the other button.
                return false;
            }
        });

        function getWindowStyleButton(e){
            var button = 0;
                if (e) {
                    if (e.button === 0) button = 1;
                    else if (e.button === 1) button = 4;
                    else if (e.button === 2) button = 2;  
                }else if (window.event){
                    button = window.event.button;
                }
            return button;
        }

this cross-browser version works fine for me.

Answer 4

Short and sweet

I'm not sure why none of the previous answers worked for me, but I came up with this solution during a eureka moment. It not only works, but it is also most elegant:

Add to body tag:

onmouseup="down=0;" onmousedown="down=1;"

Then test and execute myfunction() if down equals 1:

onmousemove="if (down==1) myfunction();"

Answer 5

You need to handle the MouseDown and MouseUp and set some flag or something to track it "later down the road"... :(

Answer 6

I know this is an old post, but I thought the tracking of mouse button using mouse up/down felt a bit clunky, so I found an alternative that may appeal to some.

<style>
    div.myDiv:active {
        cursor: default;
    }
</style>

<script>
    function handleMove( div ) {
        var style = getComputedStyle( div );
        if (style.getPropertyValue('cursor') == 'default')
        {
            // You're down and moving here!
        }
    }
</script>

<div class='myDiv' onmousemove='handleMove(this);'>Click and drag me!</div>

The :active selector handles the mouse click much better than mouse up/down, you just need a way of reading that state in the onmousemove event. For that I needed to cheat and relied on the fact that the default cursor is "auto" and I just change it to "default", which is what auto selects by default.

You can use anything in the object that is returned by getComputedStyle that you can use as a flag without upsetting the look of your page e.g. border-color.

I would have liked to set my own user defined style in the :active section, but I couldn't get that to work. It would be better if it's possible.