I am learning Objective-C + Cocoa. According to a very outdated book (there are no newer ones like this one), I need to do the following:
Create the application.
Create a new Cocoa application named VideoPlayer.
Once the project has been created, you need to add the required frameworks. Select the VideoPlayer project at the top of the project navigator; the project information will open in the main editor.
Click the + button under the list of frameworks in the Linked Frameworks and Libraries section. Add the AVFoundation, CoreMedia, and QuartzCore frameworks to the projects.
Drag the sample video into the project navigator.
The interface for this project will consist of an NSView, which will host the AVPlayerLayer, as well as buttons that make the video play back at normal speed, play back at one-quarter speed, and rewind. In order to add the AVPlayerLayer into the view, that view must be backed by a CALayer. This requires checking a checkbox in the Interface Builder — once that’s done, the view will have a layer to which we can add the AVPlayerLayer as a sublayer. Create the interface.
Open MainMenu.xib.
Drag a custom view into the main window. Make it fill the window, but leave some space at the bottom. This view will contain the video playback layer.
Drag in three NSButtons and place them underneath the video playback view. Label them Play, Play Slow Motion, and Rewind. To add an AVPlayerLayer to the window, the view that it’s being inserted into must have its own CALayer. To make this happen, you tell either the video playback view or any of its superviews that it should use a CALayer. Once a view has a CALayer, it and all of its subviews use CALayers to display their content. Make the window use a CALayer.
Click inside the window and open the View Effects inspector, which is the last button at the top of the inspector.
The Core Animation Layer section of the inspector will list the selected view. Check the checkbox to give it a layer (Figure 8-1).
Connect the code to the interface.
Now that the interface is laid out correctly, we’ll make the code aware of the view that the video should be displayed in and create the actions that control playback.
Open AppDelegate.h in the Assistant. Control-drag from the video container view into the AppDelegate’s interface. Create an outlet called playerView. Control-drag from each of the buttons under the video container view into the AppDelegate’s interface, and create actions for each of them. Name these actions: play, playSlowMotion, and rewind. Now we’ll write the code that loads and prepares the AVPlayer and AVPlayerLayer. Because we want to control the player, we’ll keep a reference to it around by adding a class extension that contains an instance variable to store the AVPlayer. We don’t need to keep the AVPlayerLayer around in the same way, because once we add it to the layer tree, we can forget about it — it will just display whatever the AVPlayer needs to show. ...
Buttfield-Addison, Paris; Manning, Jonathon; Nugent, Tim. Learning Cocoa with Objective-C: Developing for the Mac and iOS App Stores (pp. 190-191). (Function). Kindle Edition.
So this item is about Control-Drag into AppDelegate.h - simply doesn't work. I've got a recent Xcode - 26 and a target OS is - macOS 15.7. I have no idea. Maybe something has changed in how this is being done?
