I think this is a very simple question, but I’m new to programming so I may be going about it in a wrong-headed way.
I have a basic understanding of Objective-C writing terminal applications and am teaching myself how to use the Cocoa GUI.
I understand how to use IBOutlet and IBAction to connect a simple button to a method that will repeatedly send random numbers to a textfield.
I understand how to add a NSView file, connect it to a custom view in interface builder and draw a path through random points in the view when the application launches.
(I’ve been putting this code inside the - (void)drawRect:(NSRect)dirtyRect method that is declared when the file is created).
What I can’t seem to figure out is how to connect a button to an action that will then ‘refresh’ the view – in this case repopulate it with another set of random points connected with a path. Looking at the documentation, I think I should somehow be using
– (void) setNeedsDisplay(BOOL)flag
but nothing I have tried so far had worked. Please tell me, what am I missing here?
Something like this:
- (IBAction)refreshButtonAction:(id)sender
{
[theView setNeedsDisplay:YES];
}
Connect your button to that action. "theView" is a reference to your custom NSView.
Related
Hi I've seen this question asked a few times already but with no definite answer yet so I created it for xcode 7 and swift2 (which may have changed things a bit anyway).
I created a project using Xcode 7 and Cocoa OSX Story boards + swift2, so my project started with a NSWindowController that Connects to a NSViewController (as expected!). I added a NSToolbar to my window controller and added a NSButton to the toolbar. I changed my NSViewController to be one of the new NSSplitViewController that links to three NSViewControllers and displays their views horizontally - with vertical dividers - (similar to the layout you see in the photo app or pages in Yosemite +). My final goal will be that the button in My toolbar shows and hides the first split.
It is my understanding is, and I would expect that to achieve this I should create an action in the NSSplitViewController that changes the auto layout constrains more or less in the way they are working it out here: How to do collapse and expand view in mac application?.
And then somehow link this action to the NSButton that is in the Toolbar... which happens to be in the NSWindowController (far up and isolated in the hierarchy)...
I have already gone through other questions about NSToolbar and storyboards and failed to accomplish my goal:
The YouTube video: Cocoa Programming L17 - NSToolbar which is the closest I found to solve the problem, but his method does not work for storyboards, only creating your own xib file.
In this question: How to use NSToolBar in Xcode 6 and Storyboard? One person proposes to make the link using the first reponder and expecting everything to hook up at run-time (which looks a bit dodgy and not the way apple would implement it I think...). A second person suggested to create a view controller variable in the NSWindowController and manipulate its properties from there... but again, a bit dodgy too.
One latest comment I saw in that question which seems the best way to tackle the problem (but still not as good as I guess it could be) is to add a NSObjectController to the dock of each scene and when the scene loads, set the values of the objects to the other secene's controller. Is this really the best way to go ahead? If so, how could I achieve this one?
Apple did mention (again) in WWDC15 that they created storyboards for osx and the split-view controller that owns view-controllers so that you can move your logic and work to the specific view-controller, so I would be expecting to do everything from inside my split-view controller as this is the target that needs to change.
Does anyone know how to achieve this from the view controller itself? I really haven't been able to find a way to connect my ToolBarItem to it.
OK, I've created this question quite a few days ago and no answer so far so I've answer with what I recently did to overcome the problem.
After I created my Xcode project I did this:
Created a subclass MySplitViewController for the NSSplitViewController
Added an IBOutlet for each NSSplitViewItem. For example:
#IBOutlet weak var mySplitViewItem: NSSplitViewItem!
Created a subclass WindowController for the NSWindowController
Added an IBAction in the WindowController class that links to the NSToolbarItem (my button)
Added a property that gets the Window Controller's content as MySplitViewController
var mySplitViewController: MySplitViewController {
return self.window?.contentViewController as! MySplitViewController
}
Now I can access the split view controller's property from the Window Controller in the action I created:
mySplitViewController. mySplitViewItem.collapsed = true
I created some sample code that does this (but using a view controller and changing the text for a label here, just in case someone wants to see a working project with this behaviour. And a blog post about it too :)
One person proposes to make the link using the first reponder and expecting everything to hook up at run-time (which looks a bit dodgy and not the way apple would implement it I think...).
I think this first responder method is actually the proper way.
As an example:
Add something similar to the following, in whichever view controller makes sense.
#IBAction func doSomething(_ sender: AnyObject?) {
print("Do something.")
}
This will magically show up in the first responder:
In your storyboard, right-click the orange "first responder" icon above your window controller, and you should see doSomething in the very long list. You just need to connect that up to your toolbar button.
In the following screen capture, you can see my "Toggle Sidebar" button is connected to the toggleSidebar action in my first responder.
I didn't even have to write this method — it's provided by NSSplitViewController:
#IBAction open func toggleSidebar(_ sender: Any?)
So, I was working this same issue and finding no solution as you experienced. I read your post and was trying to figure how I would implement your solution when it occurred to me to use a notification. In about 30 seconds, I had a perfectly fine working solution:
In your windowController add an IBAction to post a notification like so
-(IBAction)toggleMasterViewClicked:(id)sender
{
[[NSNotificationCenter defaultCenter] postNotificationName:#"TestNotification" object:nil];
}
Hook up that action to your NSToolbarItem, then in the viewController add self as an observer for that notification like so
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(toggleMasterView:) name:#"TestNotification" object:nil];
In your case, selector would be updateMyLabelText
I don't really see any downside here. No reference to other objects needed, no dependancies. Works flawlessly for me
While connectiong IBActions works by using either the First Responder or by adding an "Object" to the scene, then changing its class to the window's view controller class, this doesn't help with IBOutlets and delegates that you'd like to point to the view controller.
Here's a work-around for that:
Add the Toolbar to the View Controller, not to its Window. That way, you can make all the IBOutlet connections in the View Controller Scene easily. I've done that for years and found no issues with it, even when using Tabs.
You'll have to assign the window's toolbar in code, then. E.g. like this:
#interface ViewController ()
#property (weak) IBOutlet NSToolbar *toolbar; // connect this in your storyboard to the Toolbar that you moved to the View Controller Scene
#end
- (void)viewWillAppear {
[super viewWillAppear];
self.view.window.toolbar = self.toolbar;
}
I'm fairly new to Mac development and am slightly confused by the new "storyboard" feature in Xcode 6. What I'm trying to do is segue from one view controller to another in the same window. As of right now, all the different NSViewControllerSegues present the view controller in a new window, be it a modal or just another window. What I'd like to do is just segue within the same window, much in the same way one would on iOS (though an animated transition is not crucial). How would this be achieved?
If you provide a custom segue (subclass of NSStoryboardSegue) you can get the result you are after. There are a few gotchas with this approach though:
the custom segue will use presentViewController:animator so you will need to provide an animator object
because the presented view is not backed by a separate Window object, you may need to provide it with a custom NSView just to catch out mouse events that you don't want to propagate to the underlying NSViewController's view
there's also a Swift-only glitch regarding the custom segue's identifier property you need to watch out for.
As there doesn't seem to be much documentation about this I have made a small demo project with custom segue examples in Swift and Objective-C.
I also have provided some more detail in answer to this question.
(Reviving this as it comes up as first relevant result on Google and I had the same problem but decided against a custom segue)
While custom segues work (at least, the code given in foundry's answer worked under Swift 3; it needs updating for Swift 4), the sheer amount of work involved in writing a custom animator suggests to me that their main use case is custom animations.
The simple solution to changing the content of a window is to create an NSWindowController for your window, and to set its contentViewController to the desired viewController. This is particularly useful if you are following the typical pattern of storyboards and instantiate a new ViewController instance every time you switch.
However.
The NSStoryboard documentation says, quite clearly in macOS, containment (rather than transition) is the more common notion for storyboards which led me to look again at the available tools.
You could use a container view for this task, which adds a NWViewController layer instead of the NSWindowController outlined above. The solution I've gone with is to use an NSTabViewController. In the attributes inspector, set the style to 'unspecified', then select the TabView and set its style to 'tabless'.
To change tabs programatically, you set the selectedTabViewItemIndexof your TabViewController.
This solution reuses the same instance of the ViewControllers for the tab content, so that any data entered in text fields is preserved when the user switches to the other 'tab'.
Simple way with no segues involved to replace the current view controller in the same window:
if let myViewController = self.storyboard?.instantiateController(withIdentifier: "MyViewController") as? MyViewController {
self.view.window?.contentViewController = myViewController
}
Is there a simple way to add a simple rectangle to a Custom View without using a custom NSView subclass for it? Something along the lines of:
Assign an IBOutlet (let's call it colorWheelView) of NSView type to the CustomView
In my NSViewController's initWithNibName use it to change draw the rectangle:
// pseudocode
self.colorWheelView.addRectangle(myRectangle);
self.redraw()
The only way I've seen it done (on this site, and in my book Cocoa Programming for Mac OSX, pp. 241) is by making a custom class for the Custom View and modifying its drawRect method... Is this really the only way to accomplish this?
Edit: not sure why formatting is not being rendered correctly. I'm trying to fix it.
It really isn't all that hard to roll your own..
Just add an NSArray property to your NSView subclass, then in your drawRect method draw them either manually or using one of the NSRectFillList* methods provided by AppKit already.
(Beware: those take a plain C array, not an NSArray).
You wouldn't want to manually trigger the redraw from outside the view as in your sample code, though. To keep things consistent your addRectangle would trigger a redraw of the view itself e.g. by calling setNeedsDisplay:.
I am pretty new to coding and would like to know how to switch XIB views on a button click. IS there also anyway to add animation when switching?
Thanks,
Kevin
this is totally possible, but there are a few things you'll need to do. I imagine you are already familiar with connecting outlets to objects in your XIB, so the first thing you need to do is create the custom views in your XIB and connect them to outlets in your appDelegate. I suggest that one of the views be dragged into the window and one one be outside the window. That way, when the window loads, it already has one of your custom views as a subview. This just makes it easier to get started.
Then you're going to write an IBAction in the appDelegate and connect it to your button. Assuming that one of the custom views is already being hosted by the window, the IBAction should send a replaceSubviewWith message to the window's contentView animator like this [[window.contentView animator] replaceSubview:firstView with:secondView]; where firstView and secondView are the pointer/outlets that you declared and connected to the views in your XIB.
This is sending the animator proxy of the window's content view a message which tells it to replace the old subview with the new one. The reason for sending the message to the view's animator proxy (and not the view itself) is that the transition will be carried out with the deafult CATransitionAnimation. Because you want it to be animated, right?
The reason why you shouldn't remove one subview and then add another is because animating the removal of a subview is actually quite tricky and requires the implementation of the delegate method animationDidEnd. This is because executing an animation on a view that has been removed from the view heirarchy does not make sense. I don't know why Apple hasn't changed this, but for now it will be one of the enduring quirks of CoreAnimation.
Let me know if that helps. I am happy to clarify! And welcome to Cocoa!
An easy way to do this is to use a tabless NSTabView- you can lay everything out in IB so the pain is minimal.
I just created a new Xcode project. In the AppControl class Header file I have the following objects defined (and some other ones, too):
IBOutlet NSImageView *inputImageView;
IBOutlet NSImageView *outputImageView;
IBOutlet NSTextField *myNoiseLevel;
IBOutlet CGFloat *mySharpness;
After putting the basic code into the .h and .m files, I then went into Interface Builder and created my UI. I was able to bind the two NSImageView controls in IB to the corresponding NSImageView objects listed above. And I was able to bind a couple of other objects/controls, also. But I am NOT able to bind the last two items listed (myNoiseLevel and mySharpness) to the NSSlider controls I have on the application main window. I'm not sure why. I know this kind of thing is probably hard to diagnose, because it is not "strictly code related," but if there is something "tricky" about binding sliders please let me know what the main "suspects" are that I should check.
This is my first attempt to use a slider control through IB. I have a book (Cocoa programming for Mac OS X, 3rd ed., by A. Hillegass) that I am using to learn about the basic way to do this stuff. And he has a slider example in there. But his slider example is "continuous" and it uses key path binding. I think this is overkill for what I want/need to do -- I just want to pull the value from the slider when another button is pushed (no need for "continuous" update). So I am trying to directly bind the "outlets" listed when I right-click on my App Control object (one for each of those items shown above), to the slider controls on my window. But when I cntl-drag from the AppControl outlet up to the corresponding slider, the slider will not "accept" the arrow I'm dragging.
Does this make sense? Any idea what I'm doing wrong and/or what I need to do to make the binding work? I have tried saving / building / closing & reopening IB and Xcode -- all to make sure IB has the latest version of everything. Still no luck, though.
One last thing ... What I really need are CGFloat numbers, from the slider. Can I simply declare the Outlet as CGFloat type ... or do I need to define it as NSTextField (or something else), and then convert it to Float in my program? You can see in the IBOutlets I pasted above, that I was trying different data types for the outlets (trying to see if my defining them as CGFloat was somehow preventing the bindings).
Make the outlet an NSSlider*. You should then be able to connect to it. When you need the value (eg, in response to the button press you mention) call [yourSliderOutletName doubleValue].
More generally: an IBOutlet is an ivar that can be filled in with a pointer to the actual object awoken from a NIB file. As such, it needs to be of an appropriate type to hold that pointer -- the object's actual class, or one of its superclasses or protocols, or (least informatively) id. You can't just arbitrarily connect an object to any old variable, like your CGFloat. There's no implicit conversion -- how is the system supposed to know what you want?