50 lines
1.9 KiB
Objective-C
50 lines
1.9 KiB
Objective-C
//
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// RNGestureHandlerButton.m
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// RNGestureHandler
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//
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// Created by Krzysztof Magiera on 12/10/2017.
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// Copyright © 2017 Software Mansion. All rights reserved.
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//
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#import "RNGestureHandlerButton.h"
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#import <UIKit/UIKit.h>
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/**
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* Gesture Handler Button components overrides standard mechanism used by RN
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* to determine touch target, which normally would reurn the UIView that is placed
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* as the deepest element in the view hierarchy.
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* It's done this way as it allows for the actual target determination to run in JS
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* where we can travers up the view ierarchy to find first element that want to became
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* JS responder.
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*
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* Since we want to use native button (or actually a `UIControl`) we need to determine
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* the target in native. This makes it impossible for JS responder based components to
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* function as a subviews of the button component. Here we override `hitTest:withEvent:`
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* method and we only determine the target to be either a subclass of `UIControl` or a
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* view that has gesture recognizers registered.
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*
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* This "default" behaviour of target determinator should be sufficient in most of the
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* cases as in fact it is not that common UI pattern to have many nested buttons (usually
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* there are just two levels e.g. when you have clickable table cells with additional
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* buttons). In cases when the default behaviour is insufficient it is recommended to use
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* `TapGestureHandler` instead of a button which gives much better flexibility as far as
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* controlling the touch flow.
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*/
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@implementation RNGestureHandlerButton
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- (BOOL)shouldHandleTouch:(UIView *)view
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{
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return [view isKindOfClass:[UIControl class]] || [view.gestureRecognizers count] > 0;
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}
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- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
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{
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UIView *inner = [super hitTest:point withEvent:event];
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while (inner && ![self shouldHandleTouch:inner]) inner = inner.superview;
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return inner;
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}
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@end
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