//
//  YMKeyboardLayoutHelperView.m
//  ios-chat
//
//  Created by Steven Hepting on 7/17/13.
//  Copyright (c) 2013 Yammer. All rights reserved.
//

#import "YMKeyboardLayoutHelperView.h"
#import "UIView+LayoutAdditions.h"

@interface YMKeyboardLayoutHelperView ()
@property (nonatomic) CGFloat desiredHeight;
@property (nonatomic) CGFloat duration;
@end

@implementation YMKeyboardLayoutHelperView

- (id)init
{
    self = [super init];
    if (self) {
        self.translatesAutoresizingMaskIntoConstraints = NO;
        
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
    }
    return self;
}

- (void)keyboardWillShow:(NSNotification *)notification
{
    // Save the height of keyboard and animation duration
    NSDictionary *userInfo = [notification userInfo];
    CGRect keyboardRect = [userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    self.desiredHeight = CGRectGetHeight(keyboardRect);
    self.duration = [userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
    
    [self animateSizeChange];
}

- (void)keyboardWillHide:(NSNotification *)notification
{
    self.desiredHeight = 0.0f;
    
    [self animateSizeChange];
}

- (CGSize)intrinsicContentSize
{
    return CGSizeMake(UIViewNoIntrinsicMetric, self.desiredHeight);
}

- (void)animateSizeChange
{
    [self invalidateIntrinsicContentSize];
    
    // Animate transition
    [UIView animateWithDuration:self.duration animations:^{
        [self.superview layoutIfNeeded];
    }];
}

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

@end