// 获取屏幕的宽度
#define screenW [UIScreen mainScreen].bounds.size.width
#import "ViewController.h"
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
// 添加子控件
[self setUpChildView];
// 添加Pan手势
UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];
[self.view addGestureRecognizer:pan];
// 添加点按手势
// UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap)];
//
// [self.view addGestureRecognizer:tap];
}
#pragma mark - 点按手势
//- (void)tap
//{
// // 还原
// if (_mainV.frame.origin.x != 0) {
// [UIView animateWithDuration:0.25 animations:^{
//
// _mainV.frame = self.view.bounds;
// }];
// }
//}
// 只要监听的属性一改变，就会调用观察者的这个方法，通知你有新值
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
NSLog(@"%@",NSStringFromCGRect(_mainV.frame));
if (_mainV.frame.origin.x > 0) { // 往右边移动，隐藏蓝色的view
_rightV.hidden = YES;
}else if (_mainV.frame.origin.x < 0){ // 往左边移动，显示蓝色的view
_rightV.hidden = NO;
}
}
#define kTargetR 275
#define kTargetL -250
#pragma mark - pan的方法
- (void)pan:(UIPanGestureRecognizer *)pan
{
// 获取手势的移动的位置
CGPoint transP = [pan translationInView:self.view];
// 获取X轴的偏移量
CGFloat offsetX = transP.x;
// 修改mainV的Frame
_mainV.frame = [self frameWithOffsetX:offsetX];
// 判断下mainV的x是否大于0
[self observeValueForKeyPath:nil ofObject:nil change:nil context:nil];
// 复位
[pan setTranslation:CGPointZero inView:self.view];
// 判断下当手势结束的时候，定位
if (pan.state == UIGestureRecognizerStateEnded) {
// 定位
CGFloat target = 0;
// 1.判断下main.x > screenW * 0.5,定位到右边 x=275
if (_mainV.frame.origin.x > screenW * 0.5) {
// 定位到右边
target = kTargetR;
}else if (CGRectGetMaxX(_mainV.frame) < screenW * 0.5){
// 2.判断下max(main.x) < screenW * 0.5
target = kTargetL;
}
// 获取x轴偏移量
CGFloat offsetX = target - _mainV.frame.origin.x;
[UIView animateWithDuration:0.25 animations:^{
_mainV.frame = target == 0?self.view.bounds:[self frameWithOffsetX:offsetX];
}];
}
}
// 手指往右移动，视图X轴也要往右移动（x++），y轴往下移动（y增加），尺寸缩放（按比例）。
#define kMaxY 80
#pragma mark - 根据offsetX计算mainV的Frame
- (CGRect)frameWithOffsetX:(CGFloat)offsetX
{
// 获取上一次的frame
CGRect frame = _mainV.frame;
// 获取屏幕的高度
CGFloat screenH = [UIScreen mainScreen].bounds.size.height;
// // 获取屏幕的宽度
// CGFloat screenW = [UIScreen mainScreen].bounds.size.width;
// X轴每平移一点，Y轴需要移动
CGFloat offsetY = offsetX * kMaxY / screenW;
// 获取上一次的高度
CGFloat preH = frame.size.height;
// 获取上一次的宽度
CGFloat preW = frame.size.width;
// 获取当前的高度
CGFloat curH = preH - 2 * offsetY;
if (frame.origin.x < 0) { // 往左移动
curH = preH + 2 * offsetY;
}
// 获取尺寸的缩放比例
CGFloat scale = curH / preH;
// 获取当前的宽度
CGFloat curW = preW * scale;
// 更改frame
// 获取当前X
frame.origin.x += offsetX;
// 获取当前Y
CGFloat y = (screenH - curH) / 2;
frame.origin.y = y;
frame.size.height = curH;
frame.size.width = curW;
return frame;
}
#pragma mark - 添加子控件
- (void)setUpChildView
{
// left
UIView *leftV = [[UIView alloc] initWithFrame:self.view.bounds];
leftV.backgroundColor = [UIColor greenColor];
[self.view addSubview:leftV];
_leftV = leftV;
// right
UIView *rightV = [[UIView alloc] initWithFrame:self.view.bounds];
rightV.backgroundColor = [UIColor blueColor];
[self.view addSubview:rightV];
_rightV = rightV;
// main
UIView *mainV = [[UIView alloc] initWithFrame:self.view.bounds];
mainV.backgroundColor = [UIColor redColor];
[self.view addSubview:mainV];
_mainV = mainV;
}