//
// ViewController.m
// 22
//
// Created by xjk on 2018/9/6.
// Copyright ? 2018年 xjk. All rights reserved.
//
import "ViewController.h"
CGFloat const gestureMinimumTranslation =20.0;
typedef enum:NSInteger{
kCameraMoveDirectionNone,
kCameraMoveDirectionUp,
kCameraMoveDirectionDown,
kCameraMoveDirectionRight,
kCameraMoveDirectionLeft
}CameraMoveDirection;
@interface ViewController ()
{
CameraMoveDirection direction;
}
@end
@implementation ViewController
-
(void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UIPanGestureRecognizer*recognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipe:)];[self.view addGestureRecognizer:recognizer];
} (void)handleSwipe:(UIPanGestureRecognizer*)gesture
{
CGPoint translation = [gesture translationInView:self.view];
if(gesture.state ==UIGestureRecognizerStateBegan)
{
direction = kCameraMoveDirectionNone;
}
else if(gesture.state ==UIGestureRecognizerStateChanged&& direction == kCameraMoveDirectionNone)
{
direction = [self determineCameraDirectionIfNeeded:translation];
// ok, now initiate movement in the direction indicated by the user's gesture
switch(direction) {
case kCameraMoveDirectionDown:
NSLog(@"Start moving down");
break;
case kCameraMoveDirectionUp:
NSLog(@"Start moving up");
break;
case kCameraMoveDirectionRight:
NSLog(@"Start moving right");
break;
case kCameraMoveDirectionLeft:
NSLog(@"Start moving left");
break;
default:
break;
}
}
else if(gesture.state ==UIGestureRecognizerStateEnded)
{
// now tell the camera to stop
NSLog(@"Stop");
}
}
// This method will determine whether the direction of the user's swipe
- (CameraMoveDirection)determineCameraDirectionIfNeeded:(CGPoint)translation
{
if(direction != kCameraMoveDirectionNone)
return direction;
// determine if horizontal swipe only if you meet some minimum velocity
if(fabs(translation.x) > gestureMinimumTranslation)
{
BOOL gestureHorizontal = NO;
if(translation.y ==0.0)
gestureHorizontal = YES;
else
gestureHorizontal = (fabs(translation.x / translation.y) >5.0);
if(gestureHorizontal)
{
if(translation.x >0.0)
return kCameraMoveDirectionRight;
else
return kCameraMoveDirectionLeft;
}
}
// determine if vertical swipe only if you meet some minimum velocity
else if(fabs(translation.y) > gestureMinimumTranslation)
{
BOOL gestureVertical = NO;
if(translation.x ==0.0)
gestureVertical = YES;
else
gestureVertical = (fabs(translation.y / translation.x) >5.0);
if(gestureVertical)
{
if(translation.y >0.0)
return kCameraMoveDirectionDown;
else
return kCameraMoveDirectionUp;
}
}
return direction;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
