1 // ========================================================================== 2 // Project: SproutCore - JavaScript Application Framework 3 // Copyright: ©2006-2011 Strobe Inc. and contributors. 4 // Portions ©2008-2011 Apple Inc. All rights reserved. 5 // License: Licensed under MIT license (see license.js) 6 // ========================================================================== 7 8 sc_require('system/drag') ; 9 10 /** @namespace 11 The `SC.DragSourceProtocol` protocol defines the properties and methods that you may implement in 12 your drag source objects in order to access additional functionality of SproutCore's drag support. 13 14 If you implement the `SC.DragSourceProtocol` protocol on your drag's source, it will receive a 15 series of callbacks throughout the course of the drag, and be consulted about what operations to 16 allow on a particular candidate drop target. Note that when you initiate a drag you must also 17 provide an object implementing `SC.DragDataSourceProtocol`, which includes some *required* 18 methods. A single object may serve as both the drag's source and its data source. 19 20 *Note: Do not mix `SC.DragSourceProtocol` into your classes. As a protocol, it exists only for 21 reference sake. You only need define any of the properties or methods listed below in order to use 22 this protocol.* 23 */ 24 SC.DragSourceProtocol = { 25 26 /** 27 Return a bitwise OR'd mask of the drag operations allowed on the 28 specified target. If you don't care about the target, just return a 29 constant value. If a drag's source does not implement this method, 30 it will assume that any drag operation (SC.DRAG_ANY) is allowed. 31 32 @param {SC.Drag} drag The SC.Drag instance managing this drag. 33 @param {SC.View} dropTarget The proposed target of the drop. 34 */ 35 dragSourceOperationMaskFor: function(drag, dropTarget) { 36 return SC.DRAG_ANY; 37 }, 38 39 /** 40 If this property is set to `NO` or is not implemented, then the user may 41 modify the drag operation by changing the modifier keys they have 42 pressed. 43 44 @type Boolean 45 @default NO 46 */ 47 ignoreModifierKeysWhileDragging: NO, 48 49 /** 50 This method is called when the drag begins. You can use this to do any 51 visual highlighting to indicate that the receiver is the source of the 52 drag. 53 54 @param {SC.Drag} drag The Drag instance managing this drag. 55 @param {Point} loc The point in *window* coordinates where the drag 56 began. You can use convertOffsetFromView() to convert this to local 57 coordinates. 58 */ 59 dragDidBegin: function(drag, loc) {}, 60 61 /** 62 This method is called whenever the drag image is moved. This is 63 similar to the `dragUpdated()` method called on drop targets. 64 65 @param {SC.Drag} drag The Drag instance managing this drag. 66 @param {Point} loc The point in *window* coordinates where the drag 67 mouse is. You can use convertOffsetFromView() to convert this to local 68 coordinates. 69 */ 70 dragDidMove: function(drag, loc) {}, 71 72 /** 73 This method is called if the drag ends and is successfully handled by a 74 drop target (i.e. the drop target returns any operation other than 75 SC.DRAG_NONE). 76 77 @param {SC.Drag} drag The drag instance managing the drag. 78 @param {Point} loc The point in WINDOW coordinates where the drag 79 ended. 80 @param {DragOp} op The drag operation that was performed. One of 81 SC.DRAG_COPY, SC.DRAG_MOVE, or SC.DRAG_LINK. 82 */ 83 dragDidSucceed: function(drag, loc, op) {}, 84 85 /** 86 This method is called if the drag ends without being handled, or if a drop 87 target handles it but returns SC.DRAG_NONE. 88 89 @param {SC.Drag} drag The drag instance managing the drag. 90 @param {Point} loc The point in WINDOW coordinates where the drag 91 ended. 92 @param {DragOp} op Provided for consistency. Always SC.DRAG_NONE. 93 */ 94 dragDidCancel: function(drag, loc, op) {}, 95 96 /** 97 This method is called when the drag ended, regardless of whether it succeeded 98 or not. You can use this to do any cleanup. 99 100 @param {SC.Drag} drag The drag instance managing the drag. 101 @param {Point} loc The point in WINDOW coordinates where the drag 102 ended. 103 @param {DragOp} op The drag operation that was performed. One of 104 SC.DRAG_COPY, SC.DRAG_MOVE, SC.DRAG_LINK, or SC.DRAG_NONE. 105 */ 106 dragDidEnd: function(drag, loc, op) {}, 107 108 /** 109 If a drag is canceled or not handled, and has its slideBack property set 110 to YES, then the drag's ghost view will slide back to its initial location. 111 dragDidEnd is called immediately upon mouseUp; dragSlideBackDidEnd is called 112 after the slide-back animation completes. 113 114 @param {SC.Drag} drag The drag instance managing the drag. 115 */ 116 dragSlideBackDidEnd: function(drag) {} 117 118 }; 119