Merge pull request #243 from krris/customizable-center-point-of-overlay-component

Customizable center point of overlay component

Author: JohnSundell

demo/sources/NavigationController.swift

@@ -66,4 +66,8 @@ class NavigationController: UINavigationController, HUBViewControllerDelegate {
     func viewControllerShouldAutomaticallyManageTopContentInset(_ viewController: HUBViewController) -> Bool {
         return true
     }
+
+    func centerPointForOverlayComponent(in viewController: HUBViewController, proposedCenter proposedCenterPoint: CGPoint) -> CGPoint {
+        return proposedCenterPoint
+    }
 }

include/HubFramework/HUBViewController.h

@@ -147,6 +147,18 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (BOOL)viewControllerShouldAutomaticallyManageTopContentInset:(HUBViewController *)viewController;
 
+/**
+ *  Return the center point of overlay coponents used in a view controller.
+ *
+ *  @param viewController The view controller in question
+ *  @param proposedCenterPoint The center point that the Hub Framework is proposing
+ *
+ *  The Hub Framework will call this method every time a view controller is being laid out, which is usually in
+ *  response to that its view model has been changed. The returned value will be set as a center point of the overlay.
+ */
+- (CGPoint)centerPointForOverlayComponentInViewController:(HUBViewController *)viewController
+                                      proposedCenterPoint:(CGPoint)proposedCenterPoint;
+
 @end
 
 /**

sources/HUBViewController.m

@@ -1054,7 +1054,16 @@ - (CGPoint)overlayComponentCenterPoint
     CGRect frame = self.view.bounds;
     frame.origin.y = self.collectionView.contentInset.top;
     frame.size.height -= self.visibleKeyboardHeight + CGRectGetMinY(frame);
-    return CGPointMake(CGRectGetMidX(frame), CGRectGetMidY(frame));
+
+    CGPoint proposedCenterPoint = CGPointMake(CGRectGetMidX(frame), CGRectGetMidY(frame));
+
+    id<HUBViewControllerDelegate> delegate = self.delegate;
+    if (delegate == nil) {
+        return proposedCenterPoint;
+    }
+
+    return [delegate centerPointForOverlayComponentInViewController:self
+                                                proposedCenterPoint:proposedCenterPoint];
 }
 
 - (void)updateOverlayComponentCenterPointsWithKeyboardNotification:(NSNotification *)notification

sources/HUBViewControllerDefaultScrollHandler.m

@@ -52,6 +52,12 @@ - (UIEdgeInsets)contentInsetsForViewController:(HUBViewController *)viewControll
     return proposedContentInsets;
 }
 
+- (CGPoint)centerPointForOverlayComponentInViewController:(HUBViewController *)viewController
+                                      proposedCenterPoint:(CGPoint)proposedCenterPoint
+{
+    return proposedCenterPoint;
+}
+
 - (void)scrollingWillStartInViewController:(HUBViewController *)viewController
                         currentContentRect:(CGRect)currentContentRect
 {

tests/HUBViewControllerTests.m

@@ -97,6 +97,7 @@ @interface HUBViewControllerTests : XCTestCase <HUBViewControllerDelegate>
 @property (nonatomic, copy) void (^viewControllerDidFinishRenderingBlock)(void);
 @property (nonatomic, copy) BOOL (^viewControllerShouldStartScrollingBlock)(void);
 @property (nonatomic, copy) BOOL (^viewControllerShouldAutomaticallyManageTopContentInset)(void);
+@property (nonatomic, strong, nullable) NSValue *centerPointForOverlayComponents;
 
 @end
 
@@ -2818,7 +2819,7 @@ - (void)testAdaptingOverlayComponentCenterPointToKeyboard
     NSNotification * const keyboardNotification = [NSNotification notificationWithName:UIKeyboardWillShowNotification
                                                                                 object:nil
                                                                               userInfo:notificationUserInfo];
-    
+
     // Show keyboard, which should push the overlay component
     NSNotificationCenter * const notificationCenter = [NSNotificationCenter defaultCenter];
     [notificationCenter postNotification:keyboardNotification];
@@ -2831,6 +2832,17 @@ - (void)testAdaptingOverlayComponentCenterPointToKeyboard
 
     HUBAssertEqualFloatValues(self.component.view.center.x, 160);
     HUBAssertEqualFloatValues(self.component.view.center.y, 200);
+
+    self.centerPointForOverlayComponents = [NSValue valueWithCGPoint:CGPointMake(80, 100)];
+    [notificationCenter postNotification:keyboardNotification];
+    HUBAssertEqualFloatValues(self.component.view.center.x, 80);
+    HUBAssertEqualFloatValues(self.component.view.center.y, 100);
+
+    self.viewController.delegate = nil;
+    self.centerPointForOverlayComponents = nil;
+    [notificationCenter postNotificationName:UIKeyboardWillHideNotification object:nil];
+    HUBAssertEqualFloatValues(self.component.view.center.x, 160);
+    HUBAssertEqualFloatValues(self.component.view.center.y, 200);
 }
 
 - (void)testScrollingToComponentAfterViewModelFinishesRendering
@@ -3173,6 +3185,17 @@ - (BOOL)viewControllerShouldAutomaticallyManageTopContentInset:(HUBViewControlle
     return NO;
 }
 
+- (CGPoint)centerPointForOverlayComponentInViewController:(HUBViewController *)viewController
+                                      proposedCenterPoint:(CGPoint)proposedCenterPoint
+{
+    XCTAssertEqual(viewController, self.viewController);
+    if (self.centerPointForOverlayComponents == nil) {
+        return proposedCenterPoint;
+    } else {
+        return [self.centerPointForOverlayComponents CGPointValue];
+    }
+}
+
 #pragma mark - Utilities
 
 - (void)simulateViewControllerLayoutCycle