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深究AngularJS中ng-drag、ng-drop的用法

2017年12月12日  | 移动技术网IT编程  | 我要评论

1.相关地址:

插件下载:https://github.com/fatlinesofcode/ngdraggable/blob/master/ngdraggable.js

2.讲解

<div ng-drop="true" ng-drop-success="dropcomplete($index,$data,$event)" ng-repeat="item in content">
  <li ng-drag="true" ng-drag-data="item" >
    姓名:{{item.name}},年龄:{{item.age}}
  </li>
</div>

ng-drag : 表示该元素能够被拖动

ng-drag-data : 表示拖动元素时跟着被拖走的数据

ng-drop : 表示该元素内可放置被拖动的元素

ng-drop-success : 放置在ngd-drop所在元素里后触发,一般写事件.

ng-drop-success触发的dropcomplete方法的参数说明:

  1. $index : 表示拖动的数据所落的元素的下标
  2. $data : 被拖动的数据对象

3.拖拽排序示例

页面代码

<div ng-drop="true" ng-drop-success="dropcomplete($index,$data)" ng-repeat="item in content">
  <li ng-drag="true" ng-drag-data="item" >
    姓名:{{item.name}},年龄:{{item.age}}
  </li>
</div>

js代码

//数据
$scope.content = [{'name':'张春玲','age':28},{'name':'王晰','age':26},{'name':'吴正青','age':66}];

/** 拖拽成功触发方法
*  index 拖拽后落下时的元素的序号(下标)
*  obj被拖动数据对象
*/
$scope.dropcomplete = function(index, obj){
    //重新排序
    var idx = $scope.content.indexof(obj);       
    $scope.content.splice(idx,1);
    $scope.content.splice(index,0,obj);  

};

4.拖拽交换示例

页面代码

<div ng-drop="true" ng-drop-success="dropcomplete($index,$data)" ng-repeat="item in content">
  <li ng-drag="true" ng-drag-data="item" >
    姓名:{{item.name}},年龄:{{item.age}}
  </li>
</div>

js代码

//数据
$scope.content = [{'name':'张春玲','age':28},{'name':'王晰','age':26},{'name':'吴正青','age':66}];

/** 拖拽成功触发方法
*  index 拖拽后落下时的元素的序号(下标)
*  obj 被拖动数据对象
*/
$scope.dropcomplete = function(index, obj){
    var idx = $scope.content.indexof(obj); 
    $scope.content[idx] = $scope.content[index];
    $scope.content[index] = obj;      
};

5. ngdraggable插件代码

/*
 *
 * https://github.com/fatlinesofcode/ngdraggable
 */
angular.module("ngdraggable", [])
  .service('ngdraggable', [function() {


    var scope = this;
    scope.inputevent = function(event) {
      if (angular.isdefined(event.touches)) {
        return event.touches[0];
      }
      //checking both is not redundent. if only check if touches isdefined, angularjs isdefnied will return error and stop the remaining scripty if event.originalevent is not defined.
      else if (angular.isdefined(event.originalevent) && angular.isdefined(event.originalevent.touches)) {
        return event.originalevent.touches[0];
      }
      return event;
    };

  }])
  .directive('ngdrag', ['$rootscope', '$parse', '$document', '$window', 'ngdraggable', function ($rootscope, $parse, $document, $window, ngdraggable) {
    return {
      restrict: 'a',
      link: function (scope, element, attrs) {
        scope.value = attrs.ngdrag;
        var offset,_centeranchor=false,_mx,_my,_tx,_ty,_mrx,_mry;
        var _hastouch = ('ontouchstart' in window) || window.documenttouch && document instanceof documenttouch;
        var _pressevents = 'touchstart mousedown';
        var _moveevents = 'touchmove mousemove';
        var _releaseevents = 'touchend mouseup';
        var _draghandle;

        // to identify the element in order to prevent getting superflous events when a single element has both drag and drop directives on it.
        var _myid = scope.$id;
        var _data = null;

        var _dragoffset = null;

        var _dragenabled = false;

        var _presstimer = null;

        var ondragstartcallback = $parse(attrs.ngdragstart) || null;
        var ondragstopcallback = $parse(attrs.ngdragstop) || null;
        var ondragsuccesscallback = $parse(attrs.ngdragsuccess) || null;
        var allowtransform = angular.isdefined(attrs.allowtransform) ? scope.$eval(attrs.allowtransform) : true;

        var getdragdata = $parse(attrs.ngdragdata);

        // deregistration function for mouse move events in $rootscope triggered by jqlite trigger handler
        var _deregisterrootmovelistener = angular.noop;

        var initialize = function () {
          element.attr('draggable', 'false'); // prevent native drag
          // check to see if drag handle(s) was specified
          // if queryselectorall is available, we use this instead of find
          // as jqlite find is limited to tagnames
          if (element[0].queryselectorall) {
            var draghandles = angular.element(element[0].queryselectorall('[ng-drag-handle]'));
          } else {
            var draghandles = element.find('[ng-drag-handle]');
          }
          if (draghandles.length) {
            _draghandle = draghandles;
          }
          togglelisteners(true);
        };

        var togglelisteners = function (enable) {
          if (!enable)return;
          // add listeners.

          scope.$on('$destroy', ondestroy);
          scope.$watch(attrs.ngdrag, onenablechange);
          scope.$watch(attrs.ngcenteranchor, oncenteranchor);
          // wire up touch events
          if (_draghandle) {
            // handle(s) specified, use those to initiate drag
            _draghandle.on(_pressevents, onpress);
          } else {
            // no handle(s) specified, use the element as the handle
            element.on(_pressevents, onpress);
          }
          if(! _hastouch && element[0].nodename.tolowercase() == "img"){
            element.on('mousedown', function(){ return false;}); // prevent native drag for images
          }
        };
        var ondestroy = function (enable) {
          togglelisteners(false);
        };
        var onenablechange = function (newval, oldval) {
          _dragenabled = (newval);
        };
        var oncenteranchor = function (newval, oldval) {
          if(angular.isdefined(newval))
            _centeranchor = (newval || 'true');
        };

        var isclickableelement = function (evt) {
          return (
            angular.isdefined(angular.element(evt.target).attr("ng-cancel-drag"))
          );
        };
        /*
         * when the element is clicked start the drag behaviour
         * on touch devices as a small delay so as not to prevent native window scrolling
         */
        var onpress = function(evt) {
          if(! _dragenabled)return;

          if (isclickableelement(evt)) {
            return;
          }

          if (evt.type == "mousedown" && evt.button != 0) {
            // do not start dragging on right-click
            return;
          }

          if(_hastouch){
            cancelpress();
            _presstimer = settimeout(function(){
              cancelpress();
              onlongpress(evt);
            },100);
            $document.on(_moveevents, cancelpress);
            $document.on(_releaseevents, cancelpress);
          }else{
            onlongpress(evt);
          }

        };

        var cancelpress = function() {
          cleartimeout(_presstimer);
          $document.off(_moveevents, cancelpress);
          $document.off(_releaseevents, cancelpress);
        };

        var onlongpress = function(evt) {
          if(! _dragenabled)return;
          evt.preventdefault();

          offset = element[0].getboundingclientrect();
          if(allowtransform)
            _dragoffset = offset;
          else{
            _dragoffset = {left:document.body.scrollleft, top:document.body.scrolltop};
          }


          element.centerx = element[0].offsetwidth / 2;
          element.centery = element[0].offsetheight / 2;

          _mx = ngdraggable.inputevent(evt).pagex;//ngdraggable.geteventprop(evt, 'pagex');
          _my = ngdraggable.inputevent(evt).pagey;//ngdraggable.geteventprop(evt, 'pagey');
          _mrx = _mx - offset.left;
          _mry = _my - offset.top;
          if (_centeranchor) {
            _tx = _mx - element.centerx - $window.pagexoffset;
            _ty = _my - element.centery - $window.pageyoffset;
          } else {
            _tx = _mx - _mrx - $window.pagexoffset;
            _ty = _my - _mry - $window.pageyoffset;
          }

          $document.on(_moveevents, onmove);
          $document.on(_releaseevents, onrelease);
          // this event is used to receive manually triggered mouse move events
          // jqlite unfortunately only supports triggerhandler(...)
          // see http://api.jquery.com/triggerhandler/
          // _deregisterrootmovelistener = $rootscope.$on('draggable:_triggerhandlermove', onmove);
          _deregisterrootmovelistener = $rootscope.$on('draggable:_triggerhandlermove', function(event, origevent) {
            onmove(origevent);
          });
        };

        var onmove = function (evt) {
          if (!_dragenabled)return;
          evt.preventdefault();

          if (!element.hasclass('dragging')) {
            _data = getdragdata(scope);
            element.addclass('dragging');
            $rootscope.$broadcast('draggable:start', {x:_mx, y:_my, tx:_tx, ty:_ty, event:evt, element:element, data:_data});

            if (ondragstartcallback ){
              scope.$apply(function () {
                ondragstartcallback(scope, {$data: _data, $event: evt});
              });
            }
          }

          _mx = ngdraggable.inputevent(evt).pagex;//ngdraggable.geteventprop(evt, 'pagex');
          _my = ngdraggable.inputevent(evt).pagey;//ngdraggable.geteventprop(evt, 'pagey');

          if (_centeranchor) {
            _tx = _mx - element.centerx - _dragoffset.left;
            _ty = _my - element.centery - _dragoffset.top;
          } else {
            _tx = _mx - _mrx - _dragoffset.left;
            _ty = _my - _mry - _dragoffset.top;
          }

          moveelement(_tx, _ty);

          $rootscope.$broadcast('draggable:move', { x: _mx, y: _my, tx: _tx, ty: _ty, event: evt, element: element, data: _data, uid: _myid, dragoffset: _dragoffset });
        };

        var onrelease = function(evt) {
          if (!_dragenabled)
            return;
          evt.preventdefault();
          $rootscope.$broadcast('draggable:end', {x:_mx, y:_my, tx:_tx, ty:_ty, event:evt, element:element, data:_data, callback:ondragcomplete, uid: _myid});
          element.removeclass('dragging');
          element.parent().find('.drag-enter').removeclass('drag-enter');
          reset();
          $document.off(_moveevents, onmove);
          $document.off(_releaseevents, onrelease);

          if (ondragstopcallback ){
            scope.$apply(function () {
              ondragstopcallback(scope, {$data: _data, $event: evt});
            });
          }

          _deregisterrootmovelistener();
        };

        var ondragcomplete = function(evt) {


          if (!ondragsuccesscallback )return;

          scope.$apply(function () {
            ondragsuccesscallback(scope, {$data: _data, $event: evt});
          });
        };

        var reset = function() {
          if(allowtransform)
            element.css({transform:'', 'z-index':'', '-webkit-transform':'', '-ms-transform':''});
          else
            element.css({'position':'',top:'',left:''});
        };

        var moveelement = function (x, y) {
          if(allowtransform) {
            element.css({
              transform: 'matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, ' + x + ', ' + y + ', 0, 1)',
              'z-index': 99999,
              '-webkit-transform': 'matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, ' + x + ', ' + y + ', 0, 1)',
              '-ms-transform': 'matrix(1, 0, 0, 1, ' + x + ', ' + y + ')'
            });
          }else{
            element.css({'left':x+'px','top':y+'px', 'position':'fixed'});
          }
        };
        initialize();
      }
    };
  }])

  .directive('ngdrop', ['$parse', '$timeout', '$window', '$document', 'ngdraggable', function ($parse, $timeout, $window, $document, ngdraggable) {
    return {
      restrict: 'a',
      link: function (scope, element, attrs) {
        scope.value = attrs.ngdrop;
        scope.istouching = false;

        var _lastdroptouch=null;

        var _myid = scope.$id;

        var _dropenabled=false;

        var ondropcallback = $parse(attrs.ngdropsuccess);// || function(){};

        var ondragstartcallback = $parse(attrs.ngdragstart);
        var ondragstopcallback = $parse(attrs.ngdragstop);
        var ondragmovecallback = $parse(attrs.ngdragmove);

        var initialize = function () {
          togglelisteners(true);
        };

        var togglelisteners = function (enable) {
          // remove listeners

          if (!enable)return;
          // add listeners.
          scope.$watch(attrs.ngdrop, onenablechange);
          scope.$on('$destroy', ondestroy);
          scope.$on('draggable:start', ondragstart);
          scope.$on('draggable:move', ondragmove);
          scope.$on('draggable:end', ondragend);
        };

        var ondestroy = function (enable) {
          togglelisteners(false);
        };
        var onenablechange = function (newval, oldval) {
          _dropenabled=newval;
        };
        var ondragstart = function(evt, obj) {
          if(! _dropenabled)return;
          istouching(obj.x,obj.y,obj.element);

          if (attrs.ngdragstart) {
            $timeout(function(){
              ondragstartcallback(scope, {$data: obj.data, $event: obj});
            });
          }
        };
        var ondragmove = function(evt, obj) {
          if(! _dropenabled)return;
          istouching(obj.x,obj.y,obj.element);

          if (attrs.ngdragmove) {
            $timeout(function(){
              ondragmovecallback(scope, {$data: obj.data, $event: obj});
            });
          }
        };

        var ondragend = function (evt, obj) {

          // don't listen to drop events if this is the element being dragged
          // only update the styles and return
          if (!_dropenabled || _myid === obj.uid) {
            updatedragstyles(false, obj.element);
            return;
          }
          if (istouching(obj.x, obj.y, obj.element)) {
            // call the ngdraggable ngdragsuccess element callback
            if(obj.callback){
              obj.callback(obj);
            }

            if (attrs.ngdropsuccess) {
              $timeout(function(){
                ondropcallback(scope, {$data: obj.data, $event: obj, $target: scope.$eval(scope.value)});
              });
            }
          }

          if (attrs.ngdragstop) {
            $timeout(function(){
              ondragstopcallback(scope, {$data: obj.data, $event: obj});
            });
          }

          updatedragstyles(false, obj.element);
        };

        var istouching = function(mousex, mousey, dragelement) {
          var touching= hittest(mousex, mousey);
          scope.istouching = touching;
          if(touching){
            _lastdroptouch = element;
          }
          updatedragstyles(touching, dragelement);
          return touching;
        };

        var updatedragstyles = function(touching, dragelement) {
          if(touching){
            element.addclass('drag-enter');
            dragelement.addclass('drag-over');
          }else if(_lastdroptouch == element){
            _lastdroptouch=null;
            element.removeclass('drag-enter');
            dragelement.removeclass('drag-over');
          }
        };

        var hittest = function(x, y) {
          var bounds = element[0].getboundingclientrect();// ngdraggable.getprivoffset(element);
          x -= $document[0].body.scrollleft + $document[0].documentelement.scrollleft;
          y -= $document[0].body.scrolltop + $document[0].documentelement.scrolltop;
          return x >= bounds.left
            && x <= bounds.right
            && y <= bounds.bottom
            && y >= bounds.top;
        };

        initialize();
      }
    };
  }])
  .directive('ngdragclone', ['$parse', '$timeout', 'ngdraggable', function ($parse, $timeout, ngdraggable) {
    return {
      restrict: 'a',
      link: function (scope, element, attrs) {
        var img, _allowclone=true;
        var _dragoffset = null;
        scope.cloneddata = {};
        var initialize = function () {

          img = element.find('img');
          element.attr('draggable', 'false');
          img.attr('draggable', 'false');
          reset();
          togglelisteners(true);
        };


        var togglelisteners = function (enable) {
          // remove listeners

          if (!enable)return;
          // add listeners.
          scope.$on('draggable:start', ondragstart);
          scope.$on('draggable:move', ondragmove);
          scope.$on('draggable:end', ondragend);
          preventcontextmenu();

        };
        var preventcontextmenu = function() {
          // element.off('mousedown touchstart touchmove touchend touchcancel', absorbevent_);
          img.off('mousedown touchstart touchmove touchend touchcancel', absorbevent_);
          // element.on('mousedown touchstart touchmove touchend touchcancel', absorbevent_);
          img.on('mousedown touchstart touchmove touchend touchcancel', absorbevent_);
        };
        var ondragstart = function(evt, obj, elm) {
          _allowclone=true;
          if(angular.isdefined(obj.data.allowclone)){
            _allowclone=obj.data.allowclone;
          }
          if(_allowclone) {
            scope.$apply(function () {
              scope.cloneddata = obj.data;
            });
            element.css('width', obj.element[0].offsetwidth);
            element.css('height', obj.element[0].offsetheight);

            moveelement(obj.tx, obj.ty);
          }

        };
        var ondragmove = function(evt, obj) {
          if(_allowclone) {

            _tx = obj.tx + obj.dragoffset.left;
            _ty = obj.ty + obj.dragoffset.top;

            moveelement(_tx, _ty);
          }
        };
        var ondragend = function(evt, obj) {
          //moveelement(obj.tx,obj.ty);
          if(_allowclone) {
            reset();
          }
        };

        var reset = function() {
          element.css({left:0,top:0, position:'fixed', 'z-index':-1, visibility:'hidden'});
        };
        var moveelement = function(x,y) {
          element.css({
            transform: 'matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, '+x+', '+y+', 0, 1)', 'z-index': 99999, 'visibility': 'visible',
            '-webkit-transform': 'matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, '+x+', '+y+', 0, 1)',
            '-ms-transform': 'matrix(1, 0, 0, 1, '+x+', '+y+')'
            //,margin: '0' don't monkey with the margin,
          });
        };

        var absorbevent_ = function (event) {
          var e = event;//.originalevent;
          e.preventdefault && e.preventdefault();
          e.stoppropagation && e.stoppropagation();
          e.cancelbubble = true;
          e.returnvalue = false;
          return false;
        };

        initialize();
      }
    };
  }])
  .directive('ngpreventdrag', ['$parse', '$timeout', function ($parse, $timeout) {
    return {
      restrict: 'a',
      link: function (scope, element, attrs) {
        var initialize = function () {

          element.attr('draggable', 'false');
          togglelisteners(true);
        };


        var togglelisteners = function (enable) {
          // remove listeners

          if (!enable)return;
          // add listeners.
          element.on('mousedown touchstart touchmove touchend touchcancel', absorbevent_);
        };


        var absorbevent_ = function (event) {
          var e = event.originalevent;
          e.preventdefault && e.preventdefault();
          e.stoppropagation && e.stoppropagation();
          e.cancelbubble = true;
          e.returnvalue = false;
          return false;
        };

        initialize();
      }
    };
  }])
  .directive('ngcanceldrag', [function () {
    return {
      restrict: 'a',
      link: function (scope, element, attrs) {
        element.find('*').attr('ng-cancel-drag', 'ng-cancel-drag');
      }
    };
  }])
  .directive('ngdragscroll', ['$window', '$interval', '$timeout', '$document', '$rootscope', function($window, $interval, $timeout, $document, $rootscope) {
    return {
      restrict: 'a',
      link: function(scope, element, attrs) {
        var intervalpromise = null;
        var lastmouseevent = null;

        var config = {
          verticalscroll: attrs.verticalscroll || true,
          horizontalscroll: attrs.horizontalscroll || true,
          activationdistance: attrs.activationdistance || 75,
          scrolldistance: attrs.scrolldistance || 15
        };


        var reqanimframe = (function() {
          return window.requestanimationframe ||
            window.webkitrequestanimationframe ||
            window.mozrequestanimationframe ||
            window.orequestanimationframe ||
            window.msrequestanimationframe ||
            function( /* function framerequestcallback */ callback, /* domelement element */ element ) {
              window.settimeout(callback, 1000 / 60);
            };
        })();

        var animationison = false;
        var createinterval = function() {
          animationison = true;

          function nextframe(callback) {
            var args = array.prototype.slice.call(arguments);
            if(animationison) {
              reqanimframe(function () {
                $rootscope.$apply(function () {
                  callback.apply(null, args);
                  nextframe(callback);
                });
              })
            }
          }

          nextframe(function() {
            if (!lastmouseevent) return;

            var viewportwidth = math.max(document.documentelement.clientwidth, window.innerwidth || 0);
            var viewportheight = math.max(document.documentelement.clientheight, window.innerheight || 0);

            var scrollx = 0;
            var scrolly = 0;

            if (config.horizontalscroll) {
              // if horizontal scrolling is active.
              if (lastmouseevent.clientx < config.activationdistance) {
                // if the mouse is on the left of the viewport within the activation distance.
                scrollx = -config.scrolldistance;
              }
              else if (lastmouseevent.clientx > viewportwidth - config.activationdistance) {
                // if the mouse is on the right of the viewport within the activation distance.
                scrollx = config.scrolldistance;
              }
            }

            if (config.verticalscroll) {
              // if vertical scrolling is active.
              if (lastmouseevent.clienty < config.activationdistance) {
                // if the mouse is on the top of the viewport within the activation distance.
                scrolly = -config.scrolldistance;
              }
              else if (lastmouseevent.clienty > viewportheight - config.activationdistance) {
                // if the mouse is on the bottom of the viewport within the activation distance.
                scrolly = config.scrolldistance;
              }
            }



            if (scrollx !== 0 || scrolly !== 0) {
              // record the current scroll position.
              var currentscrollleft = ($window.pagexoffset || $document[0].documentelement.scrollleft);
              var currentscrolltop = ($window.pageyoffset || $document[0].documentelement.scrolltop);

              // remove the transformation from the element, scroll the window by the scroll distance
              // record how far we scrolled, then reapply the element transformation.
              var elementtransform = element.css('transform');
              element.css('transform', 'initial');

              $window.scrollby(scrollx, scrolly);

              var horizontalscrollamount = ($window.pagexoffset || $document[0].documentelement.scrollleft) - currentscrollleft;
              var verticalscrollamount = ($window.pageyoffset || $document[0].documentelement.scrolltop) - currentscrolltop;

              element.css('transform', elementtransform);

              lastmouseevent.pagex += horizontalscrollamount;
              lastmouseevent.pagey += verticalscrollamount;

              $rootscope.$emit('draggable:_triggerhandlermove', lastmouseevent);
            }

          });
        };

        var clearinterval = function() {
          animationison = false;
        };

        scope.$on('draggable:start', function(event, obj) {
          // ignore this event if it's not for this element.
          if (obj.element[0] !== element[0]) return;

          if (!animationison) createinterval();
        });

        scope.$on('draggable:end', function(event, obj) {
          // ignore this event if it's not for this element.
          if (obj.element[0] !== element[0]) return;

          if (animationison) clearinterval();
        });

        scope.$on('draggable:move', function(event, obj) {
          // ignore this event if it's not for this element.
          if (obj.element[0] !== element[0]) return;

          lastmouseevent = obj.event;
        });
      }
    };
  }]);

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