jQuery implements the drag and drop effects plug in method
- 2020-05-17 04:49:18
- OfStack
This article illustrates how jQuery implements the drag-and-drop effect plug-in. Share with you for your reference. The details are as follows:
The jQuery plugin below allows you to right-click and drag the overflow element to run on a mobile device
/**
* jQuery Drag and Scroll
*
* Copyright (c) 2012 Ryan Naddy (ryannaddy.com)
* Dual licensed under the MIT and GPL licenses:
* http://www.opensource.org/licenses/mit-license.php
* http://www.gnu.org/licenses/gpl.html
*/
(function($){
var down = false;
var prevX = 0;
var prevY = 0;
var x = 0;
var y = 0;
var px = 0;
var py = 0;
var lastPX = -1;
var lastPY = -1;
var $target = null;
var $me = null;
var $selector = "";
var settings = {
mouseButton: 3,
context: false,
selectText: false
};
$.fn.dragScroll = function(options){
settings = $.extend(settings, options);
$selector = $(this).selector;
$(this).contextmenu(function(){
return false;
}).bind("mousedown touchstart", function(e){
$me = $(this);
e = event.touches ? event.touches[0] : e;
$target = $(e.target);
$target = $target.closest($selector);
if(settings.viewPort){
if(!settings.context){
$me.contextmenu(function(){
return false;
});
}
}
if(!settings.selectText){
$me.attr('unselectable', 'on').css('user-select', 'none').on('selectstart', false);
}
$me = $me.closest($selector);
if($target && $me.attr("id") != $target.attr("id")){
return false;
}
if(e.which == settings.mouseButton || event.touches){
$me.css("cursor", "move");
down = true;
}
px = $me.scrollLeft();
py = $me.scrollTop();
x = px + e.pageX;
y = py + e.pageY;
prevX = x;
prevY = y;
return true;
}).bind("mouseup touchend", function(e){
$me = $(this);
e = event.touches ? event.touches[0] : e;
$me.css("cursor", "auto");
down = false;
}).bind("mousemove touchmove", function(e){
$me = $(this);
$me = $me.closest($selector);
e = event.touches ? event.touches[0] : e;
if((e.which == settings.mouseButton || event.touches) && down){
if(event.touches){
event.preventDefault();
}
if($target && $me.attr("id") != $target.attr("id")){
return false;
}
$me.css("cursor", "move");
px = $me.scrollLeft();
py = $me.scrollTop();
x = px + e.pageX;
y = py + e.pageY;
$me.scrollLeft(px + (-(x - prevX)));
$me.scrollTop(py + (-(y - prevY)));
prevX = x - (x - prevX);
prevY = y - (y - prevY);
if(lastPX == px)
prevX = x;
if(lastPY == py)
prevY = y;
lastPX = px;
lastPY = py;
}
return true;
});
return this;
}
})(jQuery);
I hope this article has been helpful to your jQuery programming.