/*

File: MyViewController.m

Abstract: Main view controller for displaying the image, reflection and slider table.

Version: 1.6

Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple

Inc. ("Apple") in consideration of your agreement to the following

terms, and your use, installation, modification or redistribution of

this Apple software constitutes acceptance of these terms. If you do

not agree with these terms, please do not use, install, modify or

redistribute this Apple software.

In consideration of your agreement to abide by the following terms, and

subject to these terms, Apple grants you a personal, non-exclusive

license, under Apple's copyrights in this original Apple software (the

"Apple Software"), to use, reproduce, modify and redistribute the Apple

Software, with or without modifications, in source and/or binary forms;

provided that if you redistribute the Apple Software in its entirety and

without modifications, you must retain this notice and the following

text and disclaimers in all such redistributions of the Apple Software.

Neither the name, trademarks, service marks or logos of Apple Inc. may

be used to endorse or promote products derived from the Apple Software

without specific prior written permission from Apple. Except as

expressly stated in this notice, no other rights or licenses, express or

implied, are granted by Apple herein, including but not limited to any

patent rights that may be infringed by your derivative works or by other

works in which the Apple Software may be incorporated.

The Apple Software is provided by Apple on an "AS IS" basis. APPLE

MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION

THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS

FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND

OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.

IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL

OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION,

MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED

AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE),

STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE

POSSIBILITY OF SUCH DAMAGE.

Copyright (C) 2012 Apple Inc. All Rights Reserved.

*/

#import "MyViewController.h"

@interface MyViewController ()

@property (nonatomic, strong) UIImageView *imageView;

@property (nonatomic, strong) UIImageView *reflectionView;

@property (nonatomic, strong) UITableView *slidersTableView;

- (UIImage *)reflectedImage:(UIImageView *)fromImage withHeight:(NSUInteger)height;

- (IBAction)sizeSlideAction:(id)sender;

- (IBAction)alphaSlideAction:(id)sender;

@end

@implementation MyViewController

// image reflection

static const CGFloat kDefaultReflectionFraction = 0.65;

static const CGFloat kDefaultReflectionOpacity = 0.40;

static const NSInteger kSliderTag = 1337;

- (void)viewDidLoad

{

[super viewDidLoad];

self.slidersTableView.backgroundColor = [UIColor clearColor];

self.view.autoresizesSubviews = YES;

self.view.userInteractionEnabled = YES;

// determine the size of the reflection to create

NSUInteger reflectionHeight = self.imageView.bounds.size.height * kDefaultReflectionFraction;

// create the reflection image and assign it to the UIImageView

self.reflectionView.image = [self reflectedImage:self.imageView withHeight:reflectionHeight];

self.reflectionView.alpha = kDefaultReflectionOpacity;

}

- (void)viewDidUnload

{

[super viewDidUnload];

self.reflectionView = nil;

}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation

{

return (toInterfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);

}

#pragma mark - slider action methods

- (IBAction)sizeSlideAction:(id)sender

{

UISlider* slider = (UISlider *)sender;

CGFloat val = [slider value];

NSUInteger reflectionHeight = self.imageView.bounds.size.height * val;

// create the reflection image, assign it to the UIImageView and add the image view to the containerView

self.reflectionView.image = [self reflectedImage:self.imageView withHeight:reflectionHeight];

// get the alpha slider value, keep it set on the reflection

UISlider *alphaSlider = (UISlider *)[[self.slidersTableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:1 inSection:0]].contentView viewWithTag:kSliderTag];

self.reflectionView.alpha = alphaSlider.value;

[self.slidersTableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0]].detailTextLabel.text = [NSString stringWithFormat:@"%0.2f", val];

}

- (IBAction)alphaSlideAction:(id)sender

{

UISlider* slider = (UISlider *)sender;

CGFloat val = [slider value];

self.reflectionView.alpha = val;

[self.slidersTableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:1 inSection:0]].detailTextLabel.text = [NSString stringWithFormat:@"%0.2f", val];

}

#pragma mark - Image Reflection

CGImageRef CreateGradientImage(int pixelsWide, int pixelsHigh)

{

CGImageRef theCGImage = NULL;

// gradient is always black-white and the mask must be in the gray colorspace

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();

// create the bitmap context

CGContextRef gradientBitmapContext = CGBitmapContextCreate(NULL, pixelsWide, pixelsHigh,

8, 0, colorSpace, kCGImageAlphaNone);

// define the start and end grayscale values (with the alpha, even though

// our bitmap context doesn't support alpha the gradient requires it)

CGFloat colors[] = {0.0, 1.0, 1.0, 1.0};

// create the CGGradient and then release the gray color space

CGGradientRef grayScaleGradient = CGGradientCreateWithColorComponents(colorSpace, colors, NULL, 2);

CGColorSpaceRelease(colorSpace);

// create the start and end points for the gradient vector (straight down)

CGPoint gradientStartPoint = CGPointZero;

CGPoint gradientEndPoint = CGPointMake(0, pixelsHigh);

// draw the gradient into the gray bitmap context

CGContextDrawLinearGradient(gradientBitmapContext, grayScaleGradient, gradientStartPoint,

gradientEndPoint, kCGGradientDrawsAfterEndLocation);

CGGradientRelease(grayScaleGradient);

// convert the context into a CGImageRef and release the context

theCGImage = CGBitmapContextCreateImage(gradientBitmapContext);

CGContextRelease(gradientBitmapContext);

// return the imageref containing the gradient

return theCGImage;

}

CGContextRef MyCreateBitmapContext(int pixelsWide, int pixelsHigh)

{

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

// create the bitmap context

CGContextRef bitmapContext = CGBitmapContextCreate (NULL, pixelsWide, pixelsHigh, 8,

0, colorSpace,

// this will give us an optimal BGRA format for the device:

(kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst));

CGColorSpaceRelease(colorSpace);

return bitmapContext;

}

- (UIImage *)reflectedImage:(UIImageView *)fromImage withHeight:(NSUInteger)height

{

if(height == 0)

return nil;

// create a bitmap graphics context the size of the image

CGContextRef mainViewContentContext = MyCreateBitmapContext(fromImage.bounds.size.width, height);

// create a 2 bit CGImage containing a gradient that will be used for masking the

// main view content to create the 'fade' of the reflection. The CGImageCreateWithMask

// function will stretch the bitmap image as required, so we can create a 1 pixel wide gradient

CGImageRef gradientMaskImage = CreateGradientImage(1, height);

// create an image by masking the bitmap of the mainView content with the gradient view

// then release the pre-masked content bitmap and the gradient bitmap

CGContextClipToMask(mainViewContentContext, CGRectMake(0.0, 0.0, fromImage.bounds.size.width, height), gradientMaskImage);

CGImageRelease(gradientMaskImage);

// In order to grab the part of the image that we want to render, we move the context origin to the

// height of the image that we want to capture, then we flip the context so that the image draws upside down.

CGContextTranslateCTM(mainViewContentContext, 0.0, height);

CGContextScaleCTM(mainViewContentContext, 1.0, -1.0);

// draw the image into the bitmap context

CGContextDrawImage(mainViewContentContext, fromImage.bounds, fromImage.image.CGImage);

// create CGImageRef of the main view bitmap content, and then release that bitmap context

CGImageRef reflectionImage = CGBitmapContextCreateImage(mainViewContentContext);

CGContextRelease(mainViewContentContext);

// convert the finished reflection image to a UIImage

UIImage *theImage = [UIImage imageWithCGImage:reflectionImage];

// image is retained by the property setting above, so we can release the original

CGImageRelease(reflectionImage);

return theImage;

}

#pragma mark - UITableViewDelegate

- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section

{

return 0.0;

}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath

{

return 40.0;

}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

{

return 2;

}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{

static NSString *kCellID = @"CellID";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:kCellID];

if (cell == nil)

{

cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:kCellID];

cell.textLabel.backgroundColor = [UIColor clearColor];

cell.textLabel.font = [UIFont boldSystemFontOfSize:14.0];

cell.textLabel.textColor = [UIColor blackColor];

cell.selectionStyle = UITableViewCellSelectionStyleNone;

UISlider *slider = [[UISlider alloc] initWithFrame:CGRectMake(cell.contentView.bounds.origin.x + 55.0, 0.0,

cell.contentView.bounds.size.width - 110.0, 40.0)];

slider.tag = kSliderTag;

[cell.contentView addSubview:slider];

cell.detailTextLabel.backgroundColor = [UIColor clearColor];

cell.detailTextLabel.font = [UIFont boldSystemFontOfSize:12.0];

cell.detailTextLabel.textColor = [UIColor blackColor];

}

UISlider *slider = (UISlider *)[cell.contentView viewWithTag:kSliderTag];

if (indexPath.row == 0)

{

cell.textLabel.text = @"Size";

slider.value = kDefaultReflectionFraction;

[slider addTarget:self action:@selector(sizeSlideAction:) forControlEvents:UIControlEventTouchUpInside];

cell.detailTextLabel.text = [NSString stringWithFormat:@"%0.2f", slider.value];

}

else

{

cell.textLabel.text = @"Alpha";

slider.value = kDefaultReflectionOpacity;

[slider addTarget:self action:@selector(alphaSlideAction:) forControlEvents:UIControlEventValueChanged];

cell.detailTextLabel.text = [NSString stringWithFormat:@"%0.2f", slider.value];

}

return cell;

}

@end