# Class Ext.dd.DragDrop

Package: | Ext.dd
Defined In: | DDCore.js
Class: | DragDrop
Subclasses: | DD, DDTarget
Extends: | Object

Defines the interface and base operation of items that that can be dragged or can be drop targets. It was designed to be extended, overriding the event handlers for startDrag, onDrag, onDragOver and onDragOut. Up to three html elements can be associated with a DragDrop instance:

- linked element: the element that is passed into the constructor. This is the element which defines the boundaries for interaction with other DragDrop objects.
- handle element(s): The drag operation only occurs if the element that was clicked matches a handle element. By default this is the linked element, but there are times that you will want only a portion of the linked element to initiate the drag operation, and the setHandleElId() method provides a way to define this.
- drag element: this represents the element that would be moved along with the cursor during a drag operation. By default, this is the linked element itself as in Ext.dd.DD. setDragElId() lets you define a separate element that would be moved, as in Ext.dd.DDProxy.

This class should not be instantiated until the onload event to ensure that the associated elements are available. The following would define a DragDrop obj that would interact with any other DragDrop obj in the "group1" group:

    dd = new Ext.dd.DragDrop("div1", "group1");

Since none of the event handlers have been implemented, nothing would actually happen if you were to run the code above. Normally you would override this class or one of the default implementations, but you can also override the methods you want on an instance of the class...

    dd.onDragDrop = function(e, id) {
      alert("dd was dropped on " + id);
    }

## Public Properties

Property | Defined By
--- | ---
| available : boolean The available property is false until the linked dom element is accessible. | DragDrop
| config : object Configuration attributes passed into the constructor | DragDrop
| defaultPadding : Object Provides default constraint padding to "constrainTo" elements (defaults to {left: 0, right:0, top:0, bottom:0}). | DragDrop
| groups : object An object in the format {'group1':true, 'group2':true The group defines a logical collection of DragDrop objects that are related. Instances only get events when interact... The group defines a logical collection of DragDrop objects that are related. Instances only get events when interacting with other DragDrop object in the same group. This lets us define multiple groups using a single DragDrop subclass if we want. | DragDrop
| hasOuterHandles : boolean By default, drags can only be initiated if the mousedown occurs in the region the linked element is. This is done in... By default, drags can only be initiated if the mousedown occurs in the region the linked element is. This is done in part to work around a bug in some browsers that mis-report the mousedown if the previous mouseup happened outside of the window. This property is set to true if outer handles are defined. | DragDrop
| id : String The id of the element associated with this object. This is what we refer to as the "linked element" because the size... The id of the element associated with this object. This is what we refer to as the "linked element" because the size and position of this element is used to determine when the drag and drop objects have interacted. | DragDrop
| ignoreSelf : Boolean Set to false to enable a DragDrop object to fire drag events while dragging over its own Element. Defaults to true - ... Set to false to enable a DragDrop object to fire drag events while dragging over its own Element. Defaults to true - DragDrop objects do not by default fire drag events to themselves. | DragDrop
| invalidHandleClasses : Array An Array of CSS class names for elements to be considered in valid as drag handles. | DragDrop
| invalidHandleIds : Object An object who's property names identify the IDs of elements to be considered invalid as drag handles. A non-null prop... An object who's property names identify the IDs of elements to be considered invalid as drag handles. A non-null property value identifies the ID as invalid. For example, to prevent dragging from being initiated on element ID "foo", use:
    {
        foo: true
    }
| DragDrop
| invalidHandleTypes : Object An object who's property names identify HTML tags to be considered invalid as drag handles. A non-null property value... An object who's property names identify HTML tags to be considered invalid as drag handles. A non-null property value identifies the tag as invalid. Defaults to the following value which prevents drag operations from being initiated by <a> elements:
    {
        A: "A"
    }
| DragDrop
| isTarget : boolean By default, all instances can be a drop target. This can be disabled by setting isTarget to false. | DragDrop
| maintainOffset : boolean Maintain offsets when we resetconstraints. Set to true when you want the position of the element relative to its par... Maintain offsets when we resetconstraints. Set to true when you want the position of the element relative to its parent to stay the same when the page changes | DragDrop
| moveOnly : boolean When set to true, other DD objects in cooperating DDGroups do not receive notification events when this DD object is ... When set to true, other DD objects in cooperating DDGroups do not receive notification events when this DD object is dragged over them. Defaults to false. | DragDrop
| padding : int[] An array containing the 4 padding values: [top, right, bottom, left] The padding configured for this drag and drop object for calculating the drop zone intersection with this object. | DragDrop
| primaryButtonOnly : boolean By default the drag and drop instance will only respond to the primary button click (left button for a right-handed m... By default the drag and drop instance will only respond to the primary button click (left button for a right-handed mouse). Set to true to allow drag and drop to start with any mouse click that is propogated by the browser | DragDrop
| xTicks : int[] Array of pixel locations the element will snap to if we specified a horizontal graduation/interval. This array is ge... Array of pixel locations the element will snap to if we specified a horizontal graduation/interval. This array is generated automatically when you define a tick interval. | DragDrop
| yTicks : int[] Array of pixel locations the element will snap to if we specified a vertical graduation/interval. This array is gene... Array of pixel locations the element will snap to if we specified a vertical graduation/interval. This array is generated automatically when you define a tick interval. | DragDrop

## Public Methods

Method | Defined By
--- | ---
| DragDrop( String id, String sGroup, object config ) Parameters: `id` : String of the element that is linked to this instance `sGroup` : String the group of related DragDrop objects `config` : object an object containing configurable attributes Valid properties for DragDrop: padding, isTarget, maintainOffset, primaryButtonOnly Returns: void | DragDrop
| addInvalidHandleClass( string cssClass ) : void Lets you specify a css class of elements that will not initiate a drag Lets you specify a css class of elements that will not initiate a drag Parameters: `cssClass` : string the class of the elements you wish to ignore Returns: void | DragDrop
| addInvalidHandleId( string id ) : void Lets you to specify an element id for a child of a drag handle that should not initiate a drag Lets you to specify an element id for a child of a drag handle that should not initiate a drag Parameters: `id` : string the element id of the element you wish to ignore Returns: void | DragDrop
| addInvalidHandleType( string tagName ) : void Allows you to specify a tag name that should not start a drag operation when clicked. This is designed to facilitate... Allows you to specify a tag name that should not start a drag operation when clicked. This is designed to facilitate embedding links within a drag handle that do something other than start the drag. Parameters: `tagName` : string the type of element to exclude Returns: void | DragDrop
| addToGroup( sGroup {string} ) : void Add this instance to a group of related drag/drop objects. All instances belong to at least one group, and can belon... Add this instance to a group of related drag/drop objects. All instances belong to at least one group, and can belong to as many groups as needed. Parameters: `{string}` : sGroup the name of the group Returns: void | DragDrop
| applyConfig() : void Applies the configuration parameters that were passed into the constructor. This is supposed to happen at each level ... Applies the configuration parameters that were passed into the constructor. This is supposed to happen at each level through the inheritance chain. So a DDProxy implentation will execute apply config on DDProxy, DD, and DragDrop in order to get all of the parameters that are available in each object. Parameters: None. Returns: void | DragDrop
| clearConstraints() : void Clears any constraints applied to this instance. Also clears ticks since they can't exist independent of a constrain... Clears any constraints applied to this instance. Also clears ticks since they can't exist independent of a constraint at this time. Parameters: None. Returns: void | DragDrop
| clearTicks() : void Clears any tick interval defined for this instance Clears any tick interval defined for this instance Parameters: None. Returns: void | DragDrop
| constrainTo( Mixed constrainTo, [Object/Number pad], [Boolean inContent] ) : void Initializes the drag drop object's constraints to restrict movement to a certain element. Usage: var dd = new Ext.dd... Initializes the drag drop object's constraints to restrict movement to a certain element. Usage:
    var dd = new Ext.dd.DDProxy("dragDiv1", "proxytest",
                    { dragElId: "existingProxyDiv" });
     dd.startDrag = function(){
         this.constrainTo("parent-id");
     };
Or you can initalize it using the Ext.Element object:
    Ext.get("dragDiv1").initDDProxy("proxytest", {dragElId: "existingProxyDiv"}, {
         startDrag : function(){
             this.constrainTo("parent-id");
         }
     });
Parameters: `constrainTo` : Mixed The element to constrain to. `pad` : Object/Number (optional) Pad provides a way to specify "padding" of the constraints, and can be either a number for symmetrical padding (4 would be equal to {left:4, right:4, top:4, bottom:4}) or an object containing the sides to pad. For example: {right:10, bottom:10} `inContent` : Boolean (optional) Constrain the draggable in the content box of the element (inside padding and borders) Returns: void | DragDrop
| endDrag( Event e ) : void Fired when we are done dragging the object Fired when we are done dragging the object Parameters: `e` : Event the mouseup event Returns: void | DragDrop
| getDragEl() : HTMLElement Returns a reference to the actual element to drag. By default this is the same as the html element, but it can be as... Returns a reference to the actual element to drag. By default this is the same as the html element, but it can be assigned to another element. An example of this can be found in Ext.dd.DDProxy Parameters: None. Returns: `HTMLElement` the html element | DragDrop
| getEl() : HTMLElement Returns a reference to the linked element Returns a reference to the linked element Parameters: None. Returns: `HTMLElement` the html element | DragDrop
| init( id the, String sGroup, object config ) : void Sets up the DragDrop object. Must be called in the constructor of any Ext.dd.DragDrop subclass Sets up the DragDrop object. Must be called in the constructor of any Ext.dd.DragDrop subclass Parameters: `the` : id id of the linked element `sGroup` : String the group of related items `config` : object configuration attributes Returns: void | DragDrop
| initTarget( id the, String sGroup, object config ) : void Initializes Targeting functionality only... the object does not get a mousedown handler. Initializes Targeting functionality only... the object does not get a mousedown handler. Parameters: `the` : id id of the linked element `sGroup` : String the group of related items `config` : object configuration attributes Returns: void | DragDrop
| isLocked() : boolean Returns true if this instance is locked, or the drag drop mgr is locked (meaning that all drag/drop is disabled on th... Returns true if this instance is locked, or the drag drop mgr is locked (meaning that all drag/drop is disabled on the page.) Parameters: None. Returns: `boolean` true if this obj or all drag/drop is locked, else false | DragDrop
| isValidHandleChild( HTMLElement node ) : boolean Checks the tag exclusion list to see if this click should be ignored Checks the tag exclusion list to see if this click should be ignored Parameters: `node` : HTMLElement the HTMLElement to evaluate Returns: `boolean` true if this is a valid tag type, false if not | DragDrop
| lock() : void Lock this instance Lock this instance Parameters: None. Returns: void | DragDrop
| onAvailable() : void Override the onAvailable method to do what is needed after the initial position was determined. Override the onAvailable method to do what is needed after the initial position was determined. Parameters: None. Returns: void | DragDrop
| onDrag( Event e ) : void Abstract method called during the onMouseMove event while dragging an object. Abstract method called during the onMouseMove event while dragging an object. Parameters: `e` : Event the mousemove event Returns: void | DragDrop
| onDragDrop( Event e, String|DragDrop[] id ) : void Abstract method called when this item is dropped on another DragDrop obj Abstract method called when this item is dropped on another DragDrop obj Parameters: `e` : Event the mouseup event `id` : String|DragDrop[] In POINT mode, the element id this was dropped on. In INTERSECT mode, an array of dd items this was dropped on. Returns: void | DragDrop
| onDragEnter( Event e, String|DragDrop[] id ) : void Abstract method called when this element fist begins hovering over another DragDrop obj Abstract method called when this element fist begins hovering over another DragDrop obj Parameters: `e` : Event the mousemove event `id` : String|DragDrop[] In POINT mode, the element id this is hovering over. In INTERSECT mode, an array of one or more dragdrop items being hovered over. Returns: void | DragDrop
| onDragOut( Event e, String|DragDrop[] id ) : void Abstract method called when we are no longer hovering over an element Abstract method called when we are no longer hovering over an element Parameters: `e` : Event the mousemove event `id` : String|DragDrop[] In POINT mode, the element id this was hovering over. In INTERSECT mode, an array of dd items that the mouse is no longer over. Returns: void | DragDrop
| onDragOver( Event e, String|DragDrop[] id ) : void Abstract method called when this element is hovering over another DragDrop obj Abstract method called when this element is hovering over another DragDrop obj Parameters: `e` : Event the mousemove event `id` : String|DragDrop[] In POINT mode, the element id this is hovering over. In INTERSECT mode, an array of dd items being hovered over. Returns: void | DragDrop
| onInvalidDrop( Event e ) : void Abstract method called when this item is dropped on an area with no drop target Abstract method called when this item is dropped on an area with no drop target Parameters: `e` : Event the mouseup event Returns: void | DragDrop
| onMouseDown( Event e ) : void Event handler that fires when a drag/drop obj gets a mousedown Event handler that fires when a drag/drop obj gets a mousedown Parameters: `e` : Event the mousedown event Returns: void | DragDrop
| onMouseUp( Event e ) : void Event handler that fires when a drag/drop obj gets a mouseup Event handler that fires when a drag/drop obj gets a mouseup Parameters: `e` : Event the mouseup event Returns: void | DragDrop
| removeFromGroup( string sGroup ) : void Remove's this instance from the supplied interaction group Remove's this instance from the supplied interaction group Parameters: `sGroup` : string The group to drop Returns: void | DragDrop
| removeInvalidHandleClass( string cssClass ) : void Unsets an invalid css class Unsets an invalid css class Parameters: `cssClass` : string the class of the element(s) you wish to re-enable Returns: void | DragDrop
| removeInvalidHandleId( string id ) : void Unsets an invalid handle id Unsets an invalid handle id Parameters: `id` : string the id of the element to re-enable Returns: void | DragDrop
| removeInvalidHandleType( string tagName ) : void Unsets an excluded tag name set by addInvalidHandleType Unsets an excluded tag name set by addInvalidHandleType Parameters: `tagName` : string the type of element to unexclude Returns: void | DragDrop
| resetConstraints( boolean maintainOffset ) : void resetConstraints must be called if you manually reposition a dd element. resetConstraints must be called if you manually reposition a dd element. Parameters: `maintainOffset` : boolean Returns: void | DragDrop
| setDragElId( id {string} ) : void Allows you to specify that an element other than the linked element will be moved with the cursor during a drag Allows you to specify that an element other than the linked element will be moved with the cursor during a drag Parameters: `{string}` : id the id of the element that will be used to initiate the drag Returns: void | DragDrop
| setHandleElId( id {string} ) : void Allows you to specify a child of the linked element that should be used to initiate the drag operation. An example o... Allows you to specify a child of the linked element that should be used to initiate the drag operation. An example of this would be if you have a content div with text and links. Clicking anywhere in the content area would normally start the drag operation. Use this method to specify that an element inside of the content div is the element that starts the drag operation. Parameters: `{string}` : id the id of the element that will be used to initiate the drag. Returns: void | DragDrop
| setInitPosition( int diffX, int diffY ) : void Stores the initial placement of the linked element. Stores the initial placement of the linked element. Parameters: `diffX` : int the X offset, default 0 `diffY` : int the Y offset, default 0 Returns: void | DragDrop
| setOuterHandleElId( id the ) : void Allows you to set an element outside of the linked element as a drag handle Allows you to set an element outside of the linked element as a drag handle Parameters: `the` : id id of the element that will be used to initiate the drag Returns: void | DragDrop
| setPadding( int iTop, int iRight, int iBot, int iLeft ) : void Configures the padding for the target zone in px. Effectively expands (or reduces) the virtual object size for targe... Configures the padding for the target zone in px. Effectively expands (or reduces) the virtual object size for targeting calculations. Supports css-style shorthand; if only one parameter is passed, all sides will have that padding, and if only two are passed, the top and bottom will have the first param, the left and right the second. Parameters: `iTop` : int Top pad `iRight` : int Right pad `iBot` : int Bot pad `iLeft` : int Left pad Returns: void | DragDrop
| setXConstraint( int iLeft, int iRight, int iTickSize ) : void By default, the element can be dragged any place on the screen. Use this method to limit the horizontal travel of th... By default, the element can be dragged any place on the screen. Use this method to limit the horizontal travel of the element. Pass in 0,0 for the parameters if you want to lock the drag to the y axis. Parameters: `iLeft` : int the number of pixels the element can move to the left `iRight` : int the number of pixels the element can move to the right `iTickSize` : int optional parameter for specifying that the element should move iTickSize pixels at a time. Returns: void | DragDrop
| setYConstraint( int iUp, int iDown, int iTickSize ) : void By default, the element can be dragged any place on the screen. Set this to limit the vertical travel of the element... By default, the element can be dragged any place on the screen. Set this to limit the vertical travel of the element. Pass in 0,0 for the parameters if you want to lock the drag to the x axis. Parameters: `iUp` : int the number of pixels the element can move up `iDown` : int the number of pixels the element can move down `iTickSize` : int optional parameter for specifying that the element should move iTickSize pixels at a time. Returns: void | DragDrop
| startDrag( int X, int Y ) : void Abstract method called after a drag/drop object is clicked and the drag or mousedown time thresholds have beeen met. Abstract method called after a drag/drop object is clicked and the drag or mousedown time thresholds have beeen met. Parameters: `X` : int click location `Y` : int click location Returns: void | DragDrop
| toString() : string toString method toString method Parameters: None. Returns: `string` string representation of the dd obj | DragDrop
| unlock() : void Unlock this instace Unlock this instace Parameters: None. Returns: void | DragDrop
| unreg() : void Remove all drag and drop hooks for this element Remove all drag and drop hooks for this element Parameters: None. Returns: void | DragDrop

## Public Events

This class has no public events.