| andybons | 6eaa0c0d | 2015-08-26 20:12:52 | [diff] [blame] | 1 | # Cocoa Tips and Tricks |
| andybons | 3322f76 | 2015-08-24 21:37:09 | [diff] [blame] | 2 | |
| andybons | 6eaa0c0d | 2015-08-26 20:12:52 | [diff] [blame] | 3 | A collection of idioms that weusewhen writing theCocoa viewsand controllers |
| 4 | forChromium. |
| 5 | |
| 6 | [TOC] |
| andybons | 3322f76 | 2015-08-24 21:37:09 | [diff] [blame] | 7 | |
| 8 | ## NSWindowController Initialization |
| 9 | |
| andybons | 6eaa0c0d | 2015-08-26 20:12:52 | [diff] [blame] | 10 | To make sure that|window|and|delegate| are wired up correctlyin your xib, |
| 11 | it's useful to add this to your window controller: |
| andybons | 3322f76 | 2015-08-24 21:37:09 | [diff] [blame] | 12 | |
| andybons | 6eaa0c0d | 2015-08-26 20:12:52 | [diff] [blame] | 13 | ```objective-c |
| andybons | 3322f76 | 2015-08-24 21:37:09 | [diff] [blame] | 14 | - (void)awakeFromNib { |
| 15 | DCHECK([self window]); |
| 16 | DCHECK_EQ(self, [[self window] delegate]); |
| 17 | } |
| 18 | ``` |
| 19 | |
| 20 | ## NSWindowController Cleanup |
| 21 | |
| andybons | 6eaa0c0d | 2015-08-26 20:12:52 | [diff] [blame] | 22 | "You want the window controller to release itself it |-windowDidClose:|, because |
| 23 | else it could die while its views are still around. if it (auto)releases itself |
| 24 | in the callback, the window and its views are already gone and they won't send |
| 25 | messages to the released controller." |
| andybons | 3322f76 | 2015-08-24 21:37:09 | [diff] [blame] | 26 | - Nico Weber (thakis@) |
| 27 | |
| andybons | 6eaa0c0d | 2015-08-26 20:12:52 | [diff] [blame] | 28 | See |
| 29 | [Window Closing Behavior, ADC Reference](http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/Documents/Concepts/WindowClosingBehav.html#//apple_ref/doc/uid/20000027) |
| 30 | for the full story. |
| andybons | 3322f76 | 2015-08-24 21:37:09 | [diff] [blame] | 31 | |
| 32 | What this means in practice is: |
| 33 | |
| andybons | 6eaa0c0d | 2015-08-26 20:12:52 | [diff] [blame] | 34 | ```objective-c |
| andybons | 3322f76 | 2015-08-24 21:37:09 | [diff] [blame] | 35 | @interface MyWindowController : NSWindowController<NSWindowDelegate> { |
| 36 | IBOutlet NSButton* closeButton_; |
| 37 | } |
| 38 | - (IBAction)closeButton:(id)sender; |
| 39 | @end |
| 40 | |
| 41 | @implementation MyWindowController |
| 42 | - (id)init { |
| 43 | if ((self = [super initWithWindowNibName:@"MyWindow" ofType:@"nib"])) { |
| 44 | } |
| 45 | return self; |
| 46 | } |
| 47 | |
| 48 | - (void)awakeFromNib { |
| 49 | // Check that we set the window and its delegate in the XIB. |
| 50 | DCHECK([self window]); |
| 51 | DCHECK_EQ(self, [[self window] delegate]); |
| 52 | } |
| 53 | |
| 54 | // NSWindowDelegate notification. |
| 55 | - (void)windowWillClose:(NSNotification*)notif { |
| 56 | [self autorelease]; |
| 57 | } |
| 58 | |
| 59 | // Action for a button that lets the user close the window. |
| 60 | - (IBAction)closeButton:(id)sender { |
| 61 | // We clean ourselves up after the window has closed. |
| 62 | [self close]; |
| 63 | } |
| 64 | @end |
| 65 | ``` |
| 66 | |
| 67 | ## Unit Tests |
| 68 | |
| andybons | 6eaa0c0d | 2015-08-26 20:12:52 | [diff] [blame] | 69 | There are four Chromium-specific GTest macros for writing ObjC++ test cases. |
| 70 | These macros are `EXPECT_NSEQ`, `EXPECT_NSNE`, and `ASSERT` variants by the same |
| 71 | names. These test `-[id<NSObject> isEqual:]` and will print the object's |
| 72 | `-description` in GTest-style if the assertion fails. These macros are defined |
| 73 | in `//testing/gtest_mac.h`. Just include that file and you can start using them. |
| andybons | 3322f76 | 2015-08-24 21:37:09 | [diff] [blame] | 74 | |
| 75 | This allows you to write this: |
| andybons | 6eaa0c0d | 2015-08-26 20:12:52 | [diff] [blame] | 76 | |
| 77 | ```objective-c |
| 78 | EXPECT_NSEQ(@"foo", aString); |
| andybons | 3322f76 | 2015-08-24 21:37:09 | [diff] [blame] | 79 | ``` |
| andybons | 6eaa0c0d | 2015-08-26 20:12:52 | [diff] [blame] | 80 | |
| andybons | 3322f76 | 2015-08-24 21:37:09 | [diff] [blame] | 81 | Instead of this: |
| andybons | 6eaa0c0d | 2015-08-26 20:12:52 | [diff] [blame] | 82 | |
| 83 | ```objective-c |
| 84 | EXPECT_TRUE([aString isEqualToString:@"foo"]); |
| andybons | 3322f76 | 2015-08-24 21:37:09 | [diff] [blame] | 85 | ``` |
