[Catalog] Add BottomSheetPresentationControllerDelegateExample to dem…

…onstrate usage of MDCBottomSheetPresentationControllerDelegate.

PiperOrigin-RevId: 314784259

components/BottomSheet/examples/BottomSheetPresentationControllerDelegateExample.m

@@ -0,0 +1,92 @@
+#import "BottomSheetPresenterViewController.h"
+#import "MaterialBottomSheet.h"
+
+/**
+ Demonstrates the use of MDCBottomSheetTransitionController.
+ */
+@interface BottomSheetPresentationControllerDelegateExamplePresentedSheetController
+    : UIViewController
+@end
+
+@implementation BottomSheetPresentationControllerDelegateExamplePresentedSheetController {
+  id<UIViewControllerAnimatedTransitioning, UIViewControllerTransitioningDelegate>
+      _transitionController;
+}
+
+- (instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
+  self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
+  if (self) {
+    MDCBottomSheetTransitionController *transitionController =
+        [[MDCBottomSheetTransitionController alloc] init];
+    transitionController.dismissOnBackgroundTap = YES;
+    _transitionController = transitionController;
+    self.transitioningDelegate = _transitionController;
+    self.modalPresentationStyle = UIModalPresentationCustom;
+
+    self.view.backgroundColor = UIColor.purpleColor;
+    self.view.isAccessibilityElement = YES;
+    self.view.accessibilityLabel = @"Example content";
+  }
+  return self;
+}
+
+@end
+
+/**
+ Demonstrates use of MDCBottomSheetPresentationController functionality.
+*/
+@interface BottomSheetPresentationControllerDelegateExample
+    : BottomSheetPresenterViewController <MDCBottomSheetPresentationControllerDelegate>
+@end
+
+@implementation BottomSheetPresentationControllerDelegateExample
+
+- (void)viewDidLoad {
+  [super viewDidLoad];
+  [self.button setTitle:@"Present Custom Controller" forState:UIControlStateNormal];
+}
+
+- (void)presentBottomSheet {
+  BottomSheetPresentationControllerDelegateExamplePresentedSheetController *sheetController =
+      [[BottomSheetPresentationControllerDelegateExamplePresentedSheetController alloc] init];
+  MDCBottomSheetPresentationController *presentationController =
+      (MDCBottomSheetPresentationController *)sheetController.presentationController;
+  presentationController.delegate = self;
+
+  [self presentViewController:sheetController animated:YES completion:nil];
+}
+
+- (void)exit {
+  [self dismissViewControllerAnimated:YES completion:nil];
+}
+
+#pragma mark - MDCBottomSheetPresentationControllerDelegate
+
+- (void)bottomSheetDidChangeYOffset:(MDCBottomSheetPresentationController *)bottomSheet
+                            yOffset:(CGFloat)yOffset {
+  NSLog(@"%@", NSStringFromSelector(_cmd));
+}
+
+- (void)bottomSheetPresentationControllerDidDismissBottomSheet:
+    (MDCBottomSheetPresentationController *)bottomSheet {
+  NSLog(@"%@", NSStringFromSelector(_cmd));
+}
+
+- (void)bottomSheetWillChangeState:(MDCBottomSheetPresentationController *)bottomSheet
+                        sheetState:(MDCSheetState)sheetState {
+  NSLog(@"%@", NSStringFromSelector(_cmd));
+}
+
+@end
+
+@implementation BottomSheetPresentationControllerDelegateExample (CatalogByConvention)
+
++ (NSDictionary *)catalogMetadata {
+  return @{
+    @"breadcrumbs" : @[ @"Bottom Sheet", @"Presentation Controller with Custom View Controller" ],
+    @"primaryDemo" : @NO,
+    @"presentable" : @NO,
+  };
+}
+
+@end