//
// ASControlNode.mm
// AsyncDisplayKit
//
// Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
//
#import "ASControlNode.h"
#import "ASControlNode+Subclasses.h"
#import "ASImageNode.h"
#import "AsyncDisplayKit+Debug.h"
#import "ASInternalHelpers.h"
// UIControl allows dragging some distance outside of the control itself during
// tracking. This value depends on the device idiom (25 or 70 points), so
// so replicate that effect with the same values here for our own controls.
#define kASControlNodeExpandedInset (([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) ? -25.0f : -70.0f)
// Initial capacities for dispatch tables.
#define kASControlNodeEventDispatchTableInitialCapacity 4
#define kASControlNodeActionDispatchTableInitialCapacity 4
@interface ASControlNode ()
{
@private
ASDN::RecursiveMutex _controlLock;
// Control Attributes
BOOL _enabled;
BOOL _highlighted;
// Tracking
BOOL _tracking;
BOOL _touchInside;
// Target Messages.
/*
The table structure is as follows:
{
AnEvent -> {
target1 -> (action1, ...)
target2 -> (action1, ...)
...
}
...
}
*/
NSMutableDictionary *_controlEventDispatchTable;
}
// Read-write overrides.
@property (nonatomic, readwrite, assign, getter=isTracking) BOOL tracking;
@property (nonatomic, readwrite, assign, getter=isTouchInside) BOOL touchInside;
/**
@abstract Returns a key to be used in _controlEventDispatchTable that identifies the control event.
@param controlEvent A control event.
@result A key for use in _controlEventDispatchTable.
*/
id _ASControlNodeEventKeyForControlEvent(ASControlNodeEvent controlEvent);
/**
@abstract Enumerates the ASControlNode events included mask, invoking the block for each event.
@param mask An ASControlNodeEvent mask.
@param block The block to be invoked for each ASControlNodeEvent included in mask.
@param anEvent An even that is included in mask.
*/
void _ASEnumerateControlEventsIncludedInMaskWithBlock(ASControlNodeEvent mask, void (^block)(ASControlNodeEvent anEvent));
@end
@implementation ASControlNode
{
ASImageNode *_debugHighlightOverlay;
}
#pragma mark - Lifecycle
- (instancetype)init
{
if (!(self = [super init]))
return nil;
_enabled = YES;
// As we have no targets yet, we start off with user interaction off. When a target is added, it'll get turned back on.
self.userInteractionEnabled = NO;
return self;
}
#if TARGET_OS_TV
- (void)didLoad
{
// On tvOS all controls, such as buttons, interact with the focus system even if they don't have a target set on them.
// Here we add our own internal tap gesture to handle this behaviour.
self.userInteractionEnabled = YES;
UITapGestureRecognizer *tapGestureRec = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(pressDown)];
tapGestureRec.allowedPressTypes = @[@(UIPressTypeSelect)];
[self.view addGestureRecognizer:tapGestureRec];
}
#endif
- (void)setUserInteractionEnabled:(BOOL)userInteractionEnabled
{
[super setUserInteractionEnabled:userInteractionEnabled];
self.isAccessibilityElement = userInteractionEnabled;
}
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wobjc-missing-super-calls"
#pragma mark - ASDisplayNode Overrides
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
// If we're not interested in touches, we have nothing to do.
if (!self.enabled)
return;
ASControlNodeEvent controlEventMask = 0;
// If we get more than one touch down on us, cancel.
// Additionally, if we're already tracking a touch, a second touch beginning is cause for cancellation.
if ([touches count] > 1 || self.tracking)
{
self.tracking = NO;
self.touchInside = NO;
[self cancelTrackingWithEvent:event];
controlEventMask |= ASControlNodeEventTouchCancel;
}
else
{
// Otherwise, begin tracking.
self.tracking = YES;
// No need to check bounds on touchesBegan as we wouldn't get the call if it wasn't in our bounds.
self.touchInside = YES;
self.highlighted = YES;
UITouch *theTouch = [touches anyObject];
[self beginTrackingWithTouch:theTouch withEvent:event];
// Send the appropriate touch-down control event depending on how many times we've been tapped.
controlEventMask |= (theTouch.tapCount == 1) ? ASControlNodeEventTouchDown : ASControlNodeEventTouchDownRepeat;
}
[self sendActionsForControlEvents:controlEventMask withEvent:event];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
// If we're not interested in touches, we have nothing to do.
if (!self.enabled)
return;
NSParameterAssert([touches count] == 1);
UITouch *theTouch = [touches anyObject];
CGPoint touchLocation = [theTouch locationInView:self.view];
// Update our touchInside state.
BOOL dragIsInsideBounds = [self pointInside:touchLocation withEvent:nil];
// Update our highlighted state.
CGRect expandedBounds = CGRectInset(self.view.bounds, kASControlNodeExpandedInset, kASControlNodeExpandedInset);
BOOL dragIsInsideExpandedBounds = CGRectContainsPoint(expandedBounds, touchLocation);
self.touchInside = dragIsInsideExpandedBounds;
self.highlighted = dragIsInsideExpandedBounds;
// Note we are continuing to track the touch.
[self continueTrackingWithTouch:theTouch withEvent:event];
[self sendActionsForControlEvents:(dragIsInsideBounds ? ASControlNodeEventTouchDragInside : ASControlNodeEventTouchDragOutside)
withEvent:event];
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
// If we're not interested in touches, we have nothing to do.
if (!self.enabled)
return;
// We're no longer tracking and there is no touch to be inside.
self.tracking = NO;
self.touchInside = NO;
self.highlighted = NO;
// Note that we've cancelled tracking.
[self cancelTrackingWithEvent:event];
// Send the cancel event.
[self sendActionsForControlEvents:ASControlNodeEventTouchCancel
withEvent:event];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
// If we're not interested in touches, we have nothing to do.
if (!self.enabled)
return;
// On iPhone 6s, iOS 9.2 (and maybe other versions) sometimes calls -touchesEnded:withEvent:
// twice on the view for one call to -touchesBegan:withEvent:. On ASControlNode, it used to
// trigger an action twice unintentionally. Now, we ignore that event if we're not in a tracking
// state in order to have a correct behavior.
// It might be related to that issue: http://www.openradar.me/22910171
if (!self.tracking)
return;
NSParameterAssert([touches count] == 1);
UITouch *theTouch = [touches anyObject];
CGPoint touchLocation = [theTouch locationInView:self.view];
// Update state.
self.tracking = NO;
self.touchInside = NO;
self.highlighted = NO;
// Note that we've ended tracking.
[self endTrackingWithTouch:theTouch withEvent:event];
// Send the appropriate touch-up control event.
CGRect expandedBounds = CGRectInset(self.view.bounds, kASControlNodeExpandedInset, kASControlNodeExpandedInset);
BOOL touchUpIsInsideExpandedBounds = CGRectContainsPoint(expandedBounds, touchLocation);
[self sendActionsForControlEvents:(touchUpIsInsideExpandedBounds ? ASControlNodeEventTouchUpInside : ASControlNodeEventTouchUpOutside)
withEvent:event];
}
#pragma clang diagnostic pop
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
// If we're interested in touches, this is a tap (the only gesture we care about) and passed -hitTest for us, then no, you may not begin. Sir.
if (self.enabled && [gestureRecognizer isKindOfClass:[UITapGestureRecognizer class]] && gestureRecognizer.view != self.view) {
UITapGestureRecognizer *tapRecognizer = (UITapGestureRecognizer *)gestureRecognizer;
// Allow double-tap gestures
return tapRecognizer.numberOfTapsRequired != 1;
}
// Otherwise, go ahead. :]
return YES;
}
#pragma mark - Action Messages
- (void)addTarget:(id)target action:(SEL)action forControlEvents:(ASControlNodeEvent)controlEventMask
{
NSParameterAssert(action);
NSParameterAssert(controlEventMask != 0);
ASDN::MutexLocker l(_controlLock);
// Convert nil to [NSNull null] so that it can be used as a key for NSMapTable.
if (!target)
target = [NSNull null];
if (!_controlEventDispatchTable) {
_controlEventDispatchTable = [[NSMutableDictionary alloc] initWithCapacity:kASControlNodeEventDispatchTableInitialCapacity]; // enough to handle common types without re-hashing the dictionary when adding entries.
// only show tap-able areas for views with 1 or more addTarget:action: pairs
if ([ASControlNode enableHitTestDebug] && _debugHighlightOverlay == nil) {
ASPerformBlockOnMainThread(^{
// add a highlight overlay node with area of ASControlNode + UIEdgeInsets
self.clipsToBounds = NO;
_debugHighlightOverlay = [[ASImageNode alloc] init];
_debugHighlightOverlay.zPosition = 1000; // ensure we're over the top of any siblings
_debugHighlightOverlay.layerBacked = YES;
[self addSubnode:_debugHighlightOverlay];
});
}
}
// Enumerate the events in the mask, adding the target-action pair for each control event included in controlEventMask
_ASEnumerateControlEventsIncludedInMaskWithBlock(controlEventMask, ^
(ASControlNodeEvent controlEvent)
{
// Do we already have an event table for this control event?
id eventKey = _ASControlNodeEventKeyForControlEvent(controlEvent);
NSMapTable *eventDispatchTable = _controlEventDispatchTable[eventKey];
// Create it if necessary.
if (!eventDispatchTable)
{
// Create the dispatch table for this event.
eventDispatchTable = [NSMapTable weakToStrongObjectsMapTable];
_controlEventDispatchTable[eventKey] = eventDispatchTable;
}
// Have we seen this target before for this event?
NSMutableSet *targetActions = [eventDispatchTable objectForKey:target];
if (!targetActions)
{
// Nope. Create an action set for it.
targetActions = [[NSMutableSet alloc] initWithCapacity:kASControlNodeActionDispatchTableInitialCapacity]; // enough to handle common types without re-hashing the dictionary when adding entries.
[eventDispatchTable setObject:targetActions forKey:target];
}
// Add the action message.
// UIControl does not support duplicate target-action-events entries, so we replicate that behavior.
// See: https://github.com/facebook/AsyncDisplayKit/files/205466/DuplicateActionsTest.playground.zip
[targetActions addObject:NSStringFromSelector(action)];
});
self.userInteractionEnabled = YES;
}
- (NSArray *)actionsForTarget:(id)target forControlEvent:(ASControlNodeEvent)controlEvent
{
NSParameterAssert(target);
NSParameterAssert(controlEvent != 0 && controlEvent != ASControlNodeEventAllEvents);
ASDN::MutexLocker l(_controlLock);
// Grab the event dispatch table for this event.
NSMapTable *eventDispatchTable = _controlEventDispatchTable[_ASControlNodeEventKeyForControlEvent(controlEvent)];
if (!eventDispatchTable)
return nil;
// Return the actions for this target.
return [eventDispatchTable objectForKey:target];
}
- (NSSet *)allTargets
{
ASDN::MutexLocker l(_controlLock);
NSMutableSet *targets = [[NSMutableSet alloc] init];
// Look at each event...
for (NSMapTable *eventDispatchTable in [_controlEventDispatchTable allValues])
{
// and each event's targets...
for (id target in eventDispatchTable)
[targets addObject:target];
}
return targets;
}
- (void)removeTarget:(id)target action:(SEL)action forControlEvents:(ASControlNodeEvent)controlEventMask
{
NSParameterAssert(controlEventMask != 0);
ASDN::MutexLocker l(_controlLock);
// Enumerate the events in the mask, removing the target-action pair for each control event included in controlEventMask.
_ASEnumerateControlEventsIncludedInMaskWithBlock(controlEventMask, ^
(ASControlNodeEvent controlEvent)
{
// Grab the dispatch table for this event (if we have it).
id eventKey = _ASControlNodeEventKeyForControlEvent(controlEvent);
NSMapTable *eventDispatchTable = _controlEventDispatchTable[eventKey];
if (!eventDispatchTable)
return;
void (^removeActionFromTarget)(id targetKey, SEL action) = ^
(id aTarget, SEL theAction)
{
// Grab the targetActions for this target.
NSMutableArray *targetActions = [eventDispatchTable objectForKey:aTarget];
// Remove action if we have it.
if (theAction)
[targetActions removeObject:NSStringFromSelector(theAction)];
// Or all actions if not.
else
[targetActions removeAllObjects];
// If there are no actions left, remove this target entry.
if ([targetActions count] == 0)
{
[eventDispatchTable removeObjectForKey:aTarget];
// If there are no targets for this event anymore, remove it.
if ([eventDispatchTable count] == 0)
[_controlEventDispatchTable removeObjectForKey:eventKey];
}
};
// Unlike addTarget:, if target is nil here we remove all targets with action.
if (!target)
{
// Look at every target, removing target-pairs that have action (or all of its actions).
for (id aTarget in [eventDispatchTable copy])
removeActionFromTarget(aTarget, action);
}
else
removeActionFromTarget(target, action);
});
}
#pragma mark -
- (void)sendActionsForControlEvents:(ASControlNodeEvent)controlEvents withEvent:(UIEvent *)event
{
NSParameterAssert(controlEvents != 0);
ASDN::MutexLocker l(_controlLock);
// Enumerate the events in the mask, invoking the target-action pairs for each.
_ASEnumerateControlEventsIncludedInMaskWithBlock(controlEvents, ^
(ASControlNodeEvent controlEvent)
{
// Use a copy to itereate, the action perform could call remove causing a mutation crash.
NSMapTable *eventDispatchTable = [_controlEventDispatchTable[_ASControlNodeEventKeyForControlEvent(controlEvent)] copy];
// For each target interested in this event...
for (id target in eventDispatchTable)
{
NSArray *targetActions = [eventDispatchTable objectForKey:target];
// Invoke each of the actions on target.
for (NSString *actionMessage in targetActions)
{
SEL action = NSSelectorFromString(actionMessage);
id responder = target;
// NSNull means that a nil target was set, so start at self and travel the responder chain
if (responder == [NSNull null]) {
// if the target cannot perform the action, travel the responder chain to try to find something that does
responder = [self.view targetForAction:action withSender:self];
}
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
[responder performSelector:action withObject:self withObject:event];
#pragma clang diagnostic pop
}
}
});
}
#pragma mark - Convenience
id _ASControlNodeEventKeyForControlEvent(ASControlNodeEvent controlEvent)
{
return @(controlEvent);
}
void _ASEnumerateControlEventsIncludedInMaskWithBlock(ASControlNodeEvent mask, void (^block)(ASControlNodeEvent anEvent))
{
// Start with our first event (touch down) and work our way up to the last event (touch cancel)
for (ASControlNodeEvent thisEvent = ASControlNodeEventTouchDown; thisEvent