I have a tabview in which i have added 3 tabview Items.In each tab i have fields into which i want to populate data automatically. Which methods are invoked automatically when a tab is clicked.Please help me in this...
NSTabView allows you to specify an object as its delegate. This delegate object should be an instance of a class that conforms to the NSTabViewDelegate protocol. This protocol declares, amongst others methods,
-tabView:willSelectTabViewItem: to inform the delegate that a tab item is about to be selected;
-tabView:didSelectTabViewItem: to inform the delegate that a tab item has been selected.
You probably want to implement -tabView:willSelectTabViewItem: so that the fields are populated right before that tab item is selected.
Related
The latest update to NSCollectionView allows the delegate to detect the selection of items with
- (NSSet<NSIndexPath *>*)collectionView:(NSCollectionView*)collectionView shouldSelectItemsAtIndexPaths:(NSSet<NSIndexPath*>*)indexPaths
and
- (void)collectionView:(NSCollectionView*)collectionView didSelectItemsAtIndexPaths:(NSSet<NSIndexPath*>*)indexPaths
, among others.
However, insofar as I can tell, these methods only detect the selection of NSCollectionViewItem objects, and not any present header or footer views.
Are there any delegate methods to detect the selection of the header and/or footer views? If not, what is the best way to implement this detection?
Indeed these delegate methods are only for selecting items. If you want to do something when the header of footer view is clicked, you can add a gesture recognizer to those views yourself and hook it up to an IBAction on your controller.
I'm trying to build a To-do list application. I have 2 tablesviews and one textfield. In the first tableview are the different projects, and when you click on one of them the associated todos appear in the second tableview. It's a pretty basic Master-detail I guess.
I set it all up with bindings.
Right now the way you add a task, is you click on an add button and it adds a row with a placeholder text that's editable.
But what I want, is the user to enter the task in the textfield, press add, and then it adds the todo with the name already set.
So basically I have TodoItem Class with a name property, and my question would be, how do I get the content of the nstextfield and assign it to the name property ?
I tried creating an outlet from the Todoitem class to the textfield, but xcode won't let me connect it....
Tell me if you need to see any code, but since I used bindings, there's almost nothing to show. Thanks!
… how do I get the content of the nstextfield and assign it to the name property ?
Translate that directly into Objective-C:
NSString *contentOfTheNSTextField = [myTextField stringValue];
myNewTask.name = contentOfTheNSTextField;
You'd do that in the action method that you've set both the button and the field to call.
I tried creating an outlet from the Todoitem class to the textfield, but xcode won't let me connect it....
To do this, the Todoitem would need to reside in the nib.
But, even if you could do that, why should the model object know about the text field? Carrying values between model and view is a controller's job.
I have a document-based application.
In my document class,
I have a BOOL property : isActionPossible.
I also have an IBAction : - (IBAction) doTheAction:(id)sender.
Now, in MainMenu.xib, I want to connect a menu item to the action.
This is easy, when you know that the First Responder in Interface Builder "stands for" the active document of your application.
But how shall I do to bind the availability (the "enable property") of this item menu with the BOOL property isActionPossible of the active document ?
Indeed, in the list proposed, there isn't "First Responder".
Two choices:
You can implement menu validation, see Apple's docs. In short before a menu is displayed the system sends a validation request to the same object that handles the action, which includes the first responder. You simply add a method to your document class which returns a BOOL; in your case your isActionPossible property.
Use the currentDocument property of NSDocumentController which returns the document associated with the main window. You can then use bindings to bind <Document Controller>.currentDocument.isActionPossible. This approach is more general as you can bind label contents to values etc. as well as use it for menu bindings.
After I drag a controller object to the document window, how do I give it a Boolean property?
Assuming you want the ability to expose and edit the property values of your custom controller as attributes showing up in IB's inspector, you'll need to write your own plugin which tells IB what the inspector should look like. This really can't be answered briefly.
Here's Apple's reference on IB Plugins:
http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/IBPlugInGuide/Introduction/Introduction.html#//apple_ref/doc/uid/TP40004323-CH1-SW1
And here's the inspector portion:
http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/IBPlugInGuide/CreatingInspectors/CreatingInspectors.html#//apple_ref/doc/uid/TP40004323-CH6-SW1
If you truly just want to add a property to the controller's interface, you do this in Xcode (modifying the interface and implementation accordingly) and IB will pick up the changes automagically.
In the case of a checkbox, the checkbox itself is either checked or not. That state stores the boolean value instead of the controller (unless you wish it.)
To have the app undertake an action upon clicking it, think of it as a button instead of a data display and link it to an action method in the view controller. That's the simplest and old school way of doing it.
To use binding, you need to bind the checkbox's value attribute to a controller. Usually for binary values its an object controller. So, in IB, drag an Object controller to your nib window and bind it to your data source. Then, drag a checkmark button to the interface. In the checkmarks binding inspector. Set "value" binding to the name of the object controller, controller key to selection, keypath to the name of the data source attribute and provide a value transformer if needed.
I'm just getting started with Cocoa Bindings and while I've read through much of the documentation, I'm still struggling to implement a basic feature, making me question wether I'm doing it wrong or perhaps it's just not possible via IB.
Goal: Have a menu item called "Toggle visibility" toggle the state of a Boolean property in my application controller (AppController) called "visibility." I think this should be possible completely through IB.
(Note: CoreData is not in use here)
What I think needs to happen is I need to have an NSObjectController who's content outlet is set to my AppController class. Then I think I need to use an Action Innvocation binding. But here's where I run into trouble.
Should the Controller Key be selection? Should the Model Key Path be the name of my Boolean Property? What should Selector Name be?
Or do I need to setup a separate action method called "toggleVisibility" that I can bind to? If I did, why wouldn't I just use standard target/action associations, rather than bindings?
Any input / direction appreciated.
Goal: Have a menu item called "Toggle visibility" toggle the state of a Boolean property in my application controller (AppController) called "visibility."
Your goal tells you why you are failing.
In your description of your goal, you say that you want to set this menu item up as a command, a verb, an imperative sentence—“toggle the visibility”. But that's not the right title for the menu item.
Moreover, implementing a verb menu item with Bindings is inherently difficult because Bindings is the wrong tool for the job. Bindings is for exposing properties in your UI. It isn't for performing commands.
The correct title is supported by the correct Bindings-based solution.
The correct title of the menu item is, simply, “Visible”.
This alone should give you a hint as to how to proceed. Here's another: When the selection is visible, the menu item should have a check mark; when it is not visible, the menu item should have no mark.
You want to bind a property of the menu item to, ultimately, a Boolean property of your controller. Normally, this property of the menu item would be state, but for whatever reason, the binding for it is named value.
So, bind the value binding of the menu item to the Boolean property of your controller.