Equivalent of WM_MOVE - macos

What's is the equivalent of window's WM_MOVE in Mac OS ? I have to capture a mouse event when one moves window using left click. In windows we can capture this event using WM_MOVE but i could not find similar event in Mac OS

In Cocoa, look at the NSWindow and NSNotificationCenter classes (or alternately assign a delegate instance to an NSWindow, which receives notifications implicitly just by implementing appropriate methods).
For instance you can use windowWillMove: or windowDidMove: notifications to notice when a window has been moved by the user. This is not sent continuously; it is sent when the user starts moving a window, or pauses while moving the window. If you need fine-grained control over mouse events you can subclass the window and implement methods from its superclass NSResponder.

Related

How can I make a Mouse Event persist through closing an NSPopover?

I have a NSPopover that opens, and if the user clicks somewhere else in the app, the popover closes.
But the problem is that currently that mouseDown event is consumed during the popover-closing process.
Is it possible to still have that mouseDown event go through to the application, but also close the popover?
I had this same problem, so we changed to using NSPopoverBehaviorSemitransient for the behavior type. It no longer steals the mouseDown: and we just added some extra cases for closing the popover manually.
You can subclass the windows contentViewControllers view object.
I did this in the Storyboard file.
In there, implement the mouseDown() method. In there, you can create a notification which can be received at a point in your project where you need to know about the mouse event.
As the 'root view' captures almost all mouseDown() events, you have to filter them in order to only respond to the notification when the popover is displayed.
Don't forget to call super.mouseDown() at the end of your implementation.

Detecting lost focus for NSTableView in Cocoa

Is there any way to detect and respond when a control on a window loses focus?
I want to run some code when a user leaves NSTableView.
Thanks,
You can do this in 10.6 and later by using KVO to observe the window's firstResponder. It will change when the focused control in the window changes.
Put the code you want to run in the observing object's observeValueForKeyPath:ofObject:change:context: method.

Cocoa: Receiving dock icon click of already-running application

I'm writing an application with a main window that's displayed when the app starts. When the window is closed, I'd like the app to remain running (with a menu-bar menu), and if the user clicks on the dock icon again, I'd like the main window to be presented again.
I'm about 90% of the way there: my app properly keeps running after the main window is closed with Cmd-W, and since "Release When Closed" is unchecked, the window could be [makeKeyAndOrderFront:]-ed to show it again when the dock icon is clicked.
The only missing piece of this puzzle is intercepting the actual dock-icon click.
The other threads about this topic recommend implementing either applicationShouldHandleReopen:hasVisibleWindows: or applicationShouldOpenUntitledFile: in the window controller. I've done both, and neither one ever gets called.
Any other ideas?
The other threads about this topic recommend implementing either applicationShouldHandleReopen:hasVisibleWindows: or applicationShouldOpenUntitledFile: in the window controller.
That's only true if the window controller is the application's delegate. That is the object to which the application sends those messages.
I would not make a window controller the application's delegate, though. I typically make them two separate objects. Make one object specifically to be the application's delegate, and when that object receives the relevant delegate messages, send a message to your window controller telling it to do whatever it needs to do.
Actually, what I usually do in single-window apps is make the application's delegate create and own the window controller. You can respond to window closure by throwing away the WC, and respond to reopen by checking whether you have a WC and creating one (and thereby reopening the window) if you don't.
Use [NSApp setDelegate:self]; in awakeFromNib.

NSWindow: Passing mouse events through window to whatever is underneath

Is it possible to pass mouse events through an NSWindow to whatever is behind it (even if it is a window from another application)?
I am using NSWindow to create a desktop overlay, but would like to still be able to interact with other windows, even if they are behind my overlay window.
IIRC, you can just use [window setIgnoresMouseEvents:YES].

Determine when a NSOpenPanel will close

I'm trying to determine when an NSOpenPanel is closing before it actually closes. I need to do this so I can overlay another window with a screenshot of the open panel on top of it to be animated. Unfortunately, all the notifications that you seem to be able to access seem to fire AFTER the window's already been closed. This leads to a jarring stutter before you start your transition.
I've tried:
- using NSWindow delegate methods on the open panel (apparently, none of the NSWindow delegate methods work)
- monitoring panel:userEnteredFilename:confirmed: (not called)
- showing the dialog with a callback (callback happens AFTER the panel disappears)
You should register your controller as the open panel's delegate and then implement the -panel:isValidFilename: delegate method. This method will be called just before the open dialog closes.
You should return YES from the method if you just want the notification. Returning NO allows you to prevent the open dialog from being closed.
Another way to handle this was to look through NSOpenPanel's subviews for the Cancel button and swap yourself in as the target/action. This is what i ended up doing.

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