----- Description

We have video timeline control which represents list of video frames.
Timeline consists of 3 moving parts:
- slider
- left part
- right part



----- Init

Call this method to init control:
- (id)initWithFrame:(CGRect)frame fileURL:(NSURL *)fileUrl;
fileUrl - url to the local storage video file



----- Supported Orientations

Portrait and Landscape orientations are supported.

Call this method inside didRotateFromInterfaceOrientation method of ViewController
- (void)reloadTimelineInCurrentInterfaceOrientation;



----- Manipulation
We have ability to manipulate behavior of control via 3 properties:

1)
@property (nonatomic, assign) BOOL editing;
Set left and right parts moved or unmoved.

When you moving left or right part of control and part go to the next thumbnail on timeline this methods will be called:
- (void) timelineControl:(TimelineControl *)control startThumbnailChanged:(CMTime)time;		// for left part
- (void) timelineControl:(TimelineControl *)control endThumbnailChanged:(CMTime)time;		// for right part

When you stop moving left or right part of the control and hold on finger on the timeline, this methods will be called.
- (void) timelineControl:(TimelineControl *)control startHovered:(CMTime)time;
- (void) timelineControl:(TimelineControl *)control endHovered:(CMTime)time;

2)
@property (nonatomic, assign) BOOL sliderHidden;
This set slider hidden.

If NO: this methods will be called:
- (void) timelineControl:(TimelineControl *)control sliderThumbnailChanged:(CMTime)time;
- (void) timelineControl:(TimelineControl *)control sliderHovered:(CMTime)time;

3)
@property (nonatomic, assign) NSTimeInterval touchedDelayToGenerateNewFrame;
Value of this property influent on time when this methods will be called:
- (void) timelineControl:(TimelineControl *)control sliderHovered:(CMTime)time;
- (void) timelineControl:(TimelineControl *)control startHovered:(CMTime)time;
- (void) timelineControl:(TimelineControl *)control endHovered:(CMTime)time;



----- Delegate

To receive information about interaction with control need set delegate value and realize it methods:

@property (nonatomic, assign) id<TimelineControlDelegate> delegate;

// moving through thumbnails
- (void) timelineControl:(TimelineControl *)control sliderThumbnailChanged:(CMTime)time;
- (void) timelineControl:(TimelineControl *)control startThumbnailChanged:(CMTime)time;
- (void) timelineControl:(TimelineControl *)control endThumbnailChanged:(CMTime)time;

// end of moving
- (void) timelineControl:(TimelineControl *)control sliderMovingEnded:(CMTime)time;
- (void) timelineControl:(TimelineControl *)control startMovingEnded:(CMTime)time;
- (void) timelineControl:(TimelineControl *)control endMovingEnded:(CMTime)time;

// hovering
- (void) timelineControl:(TimelineControl *)control sliderHovered:(CMTime)time;
- (void) timelineControl:(TimelineControl *)control startHovered:(CMTime)time;
- (void) timelineControl:(TimelineControl *)control endHovered:(CMTime)time;



----- Gettin times of moved parts

- (CMTime)timelineSliderTime;     // slider time
- (CMTime)timelineStartTime;    // start time
- (CMTime)timelineEndTime;      // end time



----- Getting images

Recommended use synchronous methods, when you need get only one image.
Not recommended use in real time image extraction synchronous methods.
// synchronously
- (UIImage *)imageForTime:(CMTime)time;
- (UIImage *)imageForTime:(CMTime)time size:(CGSize)size;
- (UIImage *)imageForTime:(CMTime)time width:(NSInteger)width;
- (UIImage *)imageForTime:(CMTime)time height:(NSInteger)height;

// If you need request images very often and need only last result use asynchronous methods.
// asynchronously
- (void)imageForTime:(CMTime)time completionHandler:(void(^)(UIImage *image))completionHandler;
- (void)imageForTime:(CMTime)time size:(CGSize)size completionHandler:(void(^)(UIImage *image))completionHandler;
- (void)imageForTime:(CMTime)time width:(NSInteger)width completionHandler:(void(^)(UIImage *image))completionHandler;
- (void)imageForTime:(CMTime)time height:(NSInteger)height completionHandler:(void(^)(UIImage *image))completionHandler;

Every asynchronous method call stops previously asynchronous calls.


----- Examples

1) 
- (id)init {
    self = [super init];
    if (self) {
        NSString *filepath = [[NSBundle mainBundle] pathForResource:@"aaa" ofType:@"MOV"];
        NSURL *fileURL = [NSURL fileURLWithPath:filepath];
        _timelineControl = [[TimelineControl alloc] initWithFrame:CGRectMake(0, 0, 320, 60) fileURL:fileURL];
        [_timelineControl setDelegate:self];
    }
    return self;
}

- (void) didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
    [super didRotateFromInterfaceOrientation:fromInterfaceOrientation];
    [_timelineControl reloadTimelineInCurrentInterfaceOrientation];
}



// delegate methods

- (void) timelineControl:(TimelineControl *)control sliderThumbnailChanged:(CMTime)time {
    int width = CGRectGetWidth(_imageView.frame) * 2;
    [_timelineControl imageForTime:time width:width completionHandler:^(UIImage *image) {
        [_imageView performSelectorOnMainThread:@selector(setImage:) withObject:image waitUntilDone:NO];
    }];
}

- (void) timelineControl:(TimelineControl *)control startThumbnailChanged:(CMTime)time {

}

- (void) timelineControl:(TimelineControl *)control endThumbnailChanged:(CMTime)time {

}

- (void) timelineControl:(TimelineControl *)control sliderMovingEnded:(CMTime)time {
    int width = CGRectGetWidth(_imageView.frame);
    [_timelineControl imageForTime:time width:width completionHandler:^(UIImage *image) {
        [_imageView performSelectorOnMainThread:@selector(setImage:) withObject:image waitUntilDone:NO];
    }];
}

- (void) timelineControl:(TimelineControl *)control startMovingEnded:(CMTime)time {
    int width = CGRectGetWidth(_imageView.frame);
    [_timelineControl imageForTime:[_timelineControl timelineSliderTime] width:width completionHandler:^(UIImage *image) {
        [_imageView performSelectorOnMainThread:@selector(setImage:) withObject:image waitUntilDone:NO];
    }];
}

- (void) timelineControl:(TimelineControl *)control endMovingEnded:(CMTime)time {
    int width = CGRectGetWidth(_imageView.frame);
    [_timelineControl imageForTime:[_timelineControl timelineSliderTime] width:width completionHandler:^(UIImage *image) {
        [_imageView performSelectorOnMainThread:@selector(setImage:) withObject:image waitUntilDone:NO];
    }];    
}


- (void) timelineControl:(TimelineControl *)control sliderHovered:(CMTime)time {
    int width = CGRectGetWidth(_imageView.frame);
    [_timelineControl imageForTime:time width:width completionHandler:^(UIImage *image) {
        [_imageView performSelectorOnMainThread:@selector(setImage:) withObject:image waitUntilDone:NO];
    }];
}

- (void) timelineControl:(TimelineControl *)control startHovered:(CMTime)time {
    int width = CGRectGetWidth(_imageView.frame);
    [_timelineControl imageForTime:time width:width completionHandler:^(UIImage *image) {
        [_imageView performSelectorOnMainThread:@selector(setImage:) withObject:image waitUntilDone:NO];
    }];
}

- (void) timelineControl:(TimelineControl *)control endHovered:(CMTime)time {
    int width = CGRectGetWidth(_imageView.frame);
    [_timelineControl imageForTime:time width:width completionHandler:^(UIImage *image) {
        [_imageView performSelectorOnMainThread:@selector(setImage:) withObject:image waitUntilDone:NO];
    }];
}