// ========================================================================== // Project: SproutCore - JavaScript Application Framework // Copyright: ©2006-2011 Strobe Inc. and contributors. // Portions ©2008-2010 Apple Inc. All rights reserved. // License: Licensed under MIT license (see license.js) // ========================================================================== /** @namespace The Editable mixin is a standard protocol used to activate keyboard editing on views that are editable such as text fields, label views and item views. You should apply this mixin, or implement the methods, if you are designing an item view for a collection and you want to automatically trigger editing. h2. Using Editable Views To use a view that includes the Editable mixin, you simply call three methods on the view: - To begin editing, call beginEditing(). This will make the view first responder and allow the user to make changes to it. If the view cannot begin editing for some reason, it will return NO. - If you want to cancel editing, you should try calling discardEditing(). This will cause the editor to discard its changed value and resign first responder. Some editors do not support cancelling editing and will return NO. If this is the case, you may optionally try calling commitEditing() instead to force the view to resign first responder, even though this will commit the changes. - If you want to end editing, while saving any changes that were made, try calling commitEditing(). This will cause the editor to validate and apply its changed value and resign first responder. If the editor cannot validate its contents for some reason, it will return NO. In this case you may optionally try calling discardEditing() instead to force the view to resign first responder, even though this will discard the changes. h2. Implementing an Editable View To implement a new view that is editable, you should implement the three methods defined below: beginEditing(), discardEditing(), and commitEditing(). If you already allow editing when your view becomes first responder and commit your changes when the view loses first responder status then you can simply apply this mixin and not override any methods. @since SproutCore 1.0 */ SC.Editable = { editorDelegate: null, /** Indicates whether a view is editable or not. You can optionally implement the methods in this mixin to disallow editing is isEditable is NO. @property {Boolean} */ isEditable: NO, /** Indicates whether editing is currently in progress. The methods you implement should generally up this property as appropriate when you begin and end editing. @property {Boolean} */ isEditing: NO, /** Begins editing on the view. This method is called by other views when they want you to begin editing. You should write this method to become first responder, perform any additional setup needed to begin editing and then return YES. If for some reason you do not want to allow editing right now, you can also return NO. If your view is already editing, then you should not restart editing again but just return YES. The default implementation checks to see if editing is allowed, then becomes first responder and updates the isEditing property if appropriate. Generally you will want to replace this method with your own implementation and not call the default. @returns {Boolean} YES if editing began or is in progress, NO otherwise */ beginEditing: function() { if (!this.get('isEditable')) return NO ; if (this.get('isEditing')) return YES ; // begin editing this.beginPropertyChanges(); this.set('isEditing', YES) ; this.becomeFirstResponder() ; this.endPropertyChanges(); return YES ; }, /** Ends editing on the view, discarding any changes that were made to the view value in the meantime. This method is called by other views when they want to cancel editing that began earlier. When this method is called you should resign first responder, restore the original value of the view and return YES. If your view cannot revert back to its original state before editing began then you can implement this method to simply return NO. A properly implemented client may try to call commitEditing() instead to force your view to end editing anyway. If this method is called on a view that is not currently editing, you should always just return YES. The default implementation does not support discarding changes and always returns NO. @returns {Boolean} YES if changes were discarded and editing ended. */ discardEditing: function() { // if we are not editing, return YES, otherwise NO. return !this.get('isEditing') ; }, /** Ends editing on the view, committing any changes that were made to the view value in the meantime. This method is called by other views when they want to end editing, saving any changes that were made to the view in the meantime. When this method is called you should resign first responder, save the latest value of the view and return YES. If your view cannot save the current state of the view for some reason (for example if validation fails), then you should return NO. Properly implemented clients may then try to call discardEditing() to force your view to resign first responder anyway. Some views apply changes to their value immediately during an edit instead of waiting for the view to end editing. If this is the case, you should still implement commitEditing but you simply may not save any value changes. If this method is called on a view that is not currently editing, you should always just reutrn YES. The default implementation sets isEditing to NO, resigns first responder and returns YES. @returns {Boolean} YES if changes were discarded and editing ended. */ commitEditing: function() { if (!this.get('isEditing')) return YES; this.set('isEditing', NO) ; this.resignFirstResponder() ; this.invokeDelegateMethod(this.get('editorDelegate'), 'inlineEditorShouldCommitEditing', this, this.get('value')); return YES ; } } ;