material-components_material-components-ios/components/ShadowLayer/examples/ShadowCornerRadiusExample.m

// Copyright 2018-present the Material Components for iOS authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#import <UIKit/UIKit.h>

#import "MaterialSlider.h"
#import "ShadowRadiusLabel.h"

static const CGFloat kShadowElevationsDefault = 8;
static const CGFloat kShadowElevationsMax = 24;
static const CGFloat kShadowElevationsSliderFrameHeight = 27;

@interface ShadowCornerRadiusView : UIView <MDCSliderDelegate>

@property(nonatomic) ShadowRadiusLabel *paper;
@property(nonatomic) UILabel *elevationLabel;

@end

@implementation ShadowCornerRadiusView

- (id)initWithFrame:(CGRect)frame {
  self = [super initWithFrame:frame];
  if (self) {
    self.backgroundColor = [UIColor whiteColor];

    _elevationLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 20, frame.size.width, 100)];
    _elevationLabel.textAlignment = NSTextAlignmentCenter;
    _elevationLabel.text = @"8 pt";
    _elevationLabel.textColor = UIColor.blackColor;
    [self addSubview:_elevationLabel];

    CGFloat paperDim = 200;
    CGRect paperFrame = CGRectMake((CGRectGetWidth(frame) - paperDim) / 2, 200, paperDim, paperDim);
    _paper = [[ShadowRadiusLabel alloc] initWithFrame:paperFrame];
    _paper.cornerRadius = 8.0;
    _paper.elevation = 12.0;
    _paper.backgroundColor = UIColor.grayColor;
    [self addSubview:_paper];

    CGFloat margin = 20;
    CGRect sliderRect =
        CGRectMake(margin, 140, frame.size.width - margin * 2, kShadowElevationsSliderFrameHeight);
    MDCSlider *sliderControl = [[MDCSlider alloc] initWithFrame:sliderRect];
    sliderControl.numberOfDiscreteValues = (NSUInteger)kShadowElevationsMax + 1;
    sliderControl.maximumValue = kShadowElevationsMax;
    sliderControl.minimumValue = 0;
    sliderControl.value = kShadowElevationsDefault;
    sliderControl.delegate = self;
    sliderControl.autoresizingMask =
        (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleLeftMargin |
         UIViewAutoresizingFlexibleRightMargin);
    [sliderControl addTarget:self
                      action:@selector(sliderValueChanged:)
            forControlEvents:UIControlEventValueChanged];
    sliderControl.accessibilityLabel = @"Change corner radius";
    sliderControl.accessibilityHint = @"Updates the corner radius of the example view";
    sliderControl.accessibilityValue = [NSString stringWithFormat:@"%f", sliderControl.value];
    [self addSubview:sliderControl];
  }
  return self;
}

- (NSString *)slider:(MDCSlider *)slider displayedStringForValue:(CGFloat)value {
  NSInteger points = (NSInteger)round(value);
  return [NSString stringWithFormat:@"%ld pt", (long)points];
}

// TODO: (#4848) [ShadowLayer] cornerRadius changes don't render
- (void)sliderValueChanged:(MDCSlider *)slider {
  NSInteger points = (NSInteger)round(slider.value);
  _paper.cornerRadius = (CGFloat)points;
  _elevationLabel.text = [NSString stringWithFormat:@"%ld pt", (long)points];
}

- (NSString *)slider:(MDCSlider *)slider accessibilityLabelForValue:(CGFloat)value {
  NSInteger points = (NSInteger)round(slider.value);
  return [NSString stringWithFormat:@"%ld points", (long)points];
}

@end

@interface ShadowCornerRadiusViewController : UIViewController
@property(nonatomic) ShadowCornerRadiusView *shadowsView;
@end

@implementation ShadowCornerRadiusViewController

- (void)viewDidLoad {
  [super viewDidLoad];

  self.view.backgroundColor = [UIColor whiteColor];
  self.title = @"Shadow Corner Radius";
  _shadowsView = [[ShadowCornerRadiusView alloc] initWithFrame:self.view.bounds];
  _shadowsView.autoresizingMask =
      UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
  [self.view addSubview:_shadowsView];
}

- (void)viewDidLayoutSubviews {
  [super viewDidLayoutSubviews];

  if (@available(iOS 11.0, *)) {
    _shadowsView.frame = UIEdgeInsetsInsetRect(self.view.bounds, self.view.safeAreaInsets);
  } else {
    CGRect frame = self.view.bounds;
    frame.origin.y += self.topLayoutGuide.length;
    frame.size.height -= self.topLayoutGuide.length;
    _shadowsView.frame = frame;
  }
}

#pragma mark catalog by convention

+ (NSDictionary *)catalogMetadata {
  return @{
    @"breadcrumbs" : @[ @"Shadow", @"Shadow Corner Radius" ],
    @"primaryDemo" : @NO,
    @"presentable" : @NO,
  };
}

@end