Path-Style Menu

Path-Style-Menu.m

//
//  ViewController.m
//  PathStyleMenu
//
//  Created by Jason Lee on 12-10-9.
//  Copyright (c) 2012年 Jason Lee. All rights reserved.
//

#import "ViewController.h"

typedef enum _screenStateType {
    kNormalState = 0,
    kLeftState,     // Show the left-view
    kRightState,    // Show the right-view
    kDriftingState  // Drifting
} ScreenStateType;

@interface ViewController ()

@property (nonatomic, strong) UIView    *leftView;
@property (nonatomic, strong) UIView    *rightView;
@property (nonatomic, strong) UIView    *middleView;

@property (nonatomic, strong) UIView    *navBar;
@property (nonatomic, assign) BOOL      isSliding;
@property (nonatomic, assign) ScreenStateType screenState;

@property (nonatomic, assign) BOOL      canDrag;
@property (nonatomic, assign) CGFloat   lastFingerX;

@end

@implementation ViewController

- (void)dealloc
{
    [super dealloc];
    //
    [_leftView release];
    [_rightView release];
    [_middleView release];
    
    [_navBar release];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
	// Do any additional setup after loading the view, typically from a nib.
    
    //
    _leftView = [[UIView alloc] initWithFrame:self.view.bounds];
    _leftView.backgroundColor = [UIColor greenColor];
    [self.view addSubview:self.leftView];
    
    //
    _rightView = [[UIView alloc] initWithFrame:self.view.bounds];
    _rightView.backgroundColor = [UIColor yellowColor];
    [self.view addSubview:self.rightView];
    
    //
    _middleView = [[UIView alloc] initWithFrame:self.view.bounds];
    _middleView.backgroundColor = [UIColor redColor];
    [self.view addSubview:self.middleView];
    
    [self setupNavBar];
    self.screenState = kNormalState;
}

- (void)viewDidUnload
{
    [super viewDidUnload];
    //
    
    self.leftView = nil;
    self.rightView = nil;
    self.middleView = nil;
    
    self.navBar = nil;
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Initialize UI

- (void)setupNavBar
{
    _navBar = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.middleView.frame.size.width, 44)];
    self.navBar.backgroundColor = [UIColor blueColor];
    [self.middleView addSubview:self.navBar];
    
    UIButton *leftNavBtn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    leftNavBtn.frame = CGRectMake(10, 0, 44, 44);
    [self.navBar addSubview:leftNavBtn];
    [leftNavBtn setTitle:@"Left" forState:UIControlStateNormal];
    [leftNavBtn addTarget:self action:@selector(leftNavBtnDidClick:) forControlEvents:UIControlEventTouchUpInside];
    
    UIButton *rightNavBtn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    rightNavBtn.frame = CGRectMake(self.navBar.frame.size.width - 10 - 44, 0, 44, 44);
    [self.navBar addSubview:rightNavBtn];
    [rightNavBtn setTitle:@"Right" forState:UIControlStateNormal];
    [rightNavBtn addTarget:self action:@selector(rightNavBtnDidClick:) forControlEvents:UIControlEventTouchUpInside];
}

#pragma mark - Slide to Left or Right

#define LEFT_SLIDE_OFFSET   260.0f
#define RIGHT_SLIDE_OFFSET  (-260.0f)

- (void)leftNavBtnDidClick:(UIButton *)btn
{
    if (kNormalState == self.screenState) {
        [self slideFromeState:self.screenState toState:kLeftState];
    } else {
        [self slideFromeState:self.screenState toState:kNormalState];
    }
}

- (void)rightNavBtnDidClick:(UIButton *)btn
{
    if (kNormalState == self.screenState) {
        [self slideFromeState:self.screenState toState:kRightState];
    } else {
        [self slideFromeState:self.screenState toState:kNormalState];
    }
}

- (void)slideFromeState:(ScreenStateType)oState toState:(ScreenStateType)dState
{
    if (self.isSliding) return ;
    self.isSliding = YES;
    
    __block CGRect rect = self.middleView.frame;
    rect.origin.x = 0.0f;
    
    id completionBlk = nil;
    
    switch (oState) {
        case kNormalState:
            if (kLeftState == dState) {
                self.rightView.hidden = YES;
                rect.origin.x = LEFT_SLIDE_OFFSET;
            } else if (kRightState == dState) {
                self.leftView.hidden = YES;
                rect.origin.x = RIGHT_SLIDE_OFFSET;
            }
            break;
            
        case kLeftState:
        case kRightState:
            if (kNormalState == dState) {
                completionBlk = ^(BOOL finished) { self.leftView.hidden = NO; self.rightView.hidden = NO; };
            }
            break;
            
        case kDriftingState:
            if (kLeftState == dState) {
                rect.origin.x = LEFT_SLIDE_OFFSET;
            } else if (kRightState == dState) {
                rect.origin.x = RIGHT_SLIDE_OFFSET;
            } else if (kNormalState == dState) {
                completionBlk = ^(BOOL finished) { self.leftView.hidden = NO; self.rightView.hidden = NO; };
            }
            break;
            
        default:
            break;
    }
    
    id animationBlk = ^{ self.middleView.frame = rect; };
    [UIView animateWithDuration:0.3f animations:animationBlk completion:completionBlk];
    
    self.screenState = dState;
    self.isSliding = NO;
}

#pragma mark - Finger Touch

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    CGPoint fingerPoint = [touch locationInView:self.middleView];
    if ([self.middleView pointInside:fingerPoint withEvent:nil]) {
        fingerPoint = [touch locationInView:self.view];
        self.lastFingerX = fingerPoint.x;
    }
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    CGPoint fingerPoint = [touch locationInView:self.view];
    
    // The user really wants to move the screen ?
    if (!self.canDrag && abs(fingerPoint.x - self.lastFingerX) > 30) {
        self.canDrag = YES ;
        self.lastFingerX = fingerPoint.x;
    }
    
    if (!self.canDrag) return ;
    
    CGRect rect = self.middleView.frame;
    rect.origin.x += (fingerPoint.x - self.lastFingerX);
    rect.origin.x = (rect.origin.x > LEFT_SLIDE_OFFSET) ? LEFT_SLIDE_OFFSET : rect.origin.x;
    rect.origin.x = (rect.origin.x < RIGHT_SLIDE_OFFSET) ? RIGHT_SLIDE_OFFSET : rect.origin.x;
    self.middleView.frame = rect;
    
    if (rect.origin.x > 0) {
        self.rightView.hidden = YES;
        self.leftView.hidden = NO;
    } else if (rect.origin.x < 0) {
        self.leftView.hidden = YES;
        self.rightView.hidden = NO;
    } else {
        self.leftView.hidden = self.rightView.hidden = NO;
    }
    
    self.lastFingerX = fingerPoint.x;
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    self.canDrag = NO;
    
    CGFloat boundary = 50.0f;
    CGRect rect = self.middleView.frame;
    
    ScreenStateType lastScreenState = self.screenState;
    self.screenState = kDriftingState;
    
    switch (lastScreenState) {
        case kNormalState:
            if (rect.origin.x < (0 - boundary)) {
                [self slideFromeState:self.screenState toState:kRightState];
            } else if (rect.origin.x > (0 + boundary)) {
                [self slideFromeState:self.screenState toState:kLeftState];
            } else {
                [self slideFromeState:self.screenState toState:kNormalState];
            }
            break;
            
        case kLeftState:
            if (rect.origin.x < LEFT_SLIDE_OFFSET - boundary) {
                [self slideFromeState:self.screenState toState:kNormalState];
            } else {
                [self slideFromeState:self.screenState toState:kLeftState];
            }
            break;
            
        case kRightState:
            if (rect.origin.x > RIGHT_SLIDE_OFFSET + boundary) {
                [self slideFromeState:self.screenState toState:kNormalState];
            } else {
                [self slideFromeState:self.screenState toState:kRightState];
            }
            break;
            
        default:
            [self slideFromeState:self.screenState toState:kNormalState];
            break;
    }
}

@end