components/TextFields/src/MDCTextInputControllerLegacyDefault.m

/*
 Copyright 2016-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 "MDCTextInputControllerLegacyDefault.h"

#import "MDCMultilineTextField.h"
#import "MDCTextInputUnderlineView.h"
#import "private/MDCTextInputArt.h"

#import "MaterialTypography.h"

#pragma mark - Constants

static const CGFloat MDCTextInputControllerLegacyDefaultClearButtonImageSquareWidthHeight = 24.f;
static const CGFloat MDCTextInputControllerLegacyDefaultUnderlineActiveHeight = 2.f;
static const CGFloat MDCTextInputControllerLegacyDefaultUnderlineNormalHeight = 1.f;
static const CGFloat MDCTextInputControllerLegacyDefaultVerticalHalfPadding = 8.f;
static const CGFloat MDCTextInputControllerLegacyDefaultVerticalPadding = 16.f;

static inline UIBezierPath *MDCTextInputControllerLegacyDefaultEmptyPath() {
  return [UIBezierPath bezierPath];
}

#pragma mark - Class Properties

static CGFloat _underlineHeightActiveLegacyDefault =
    MDCTextInputControllerLegacyDefaultUnderlineActiveHeight;
static CGFloat _underlineHeightNormalLegacyDefault =
    MDCTextInputControllerLegacyDefaultUnderlineNormalHeight;

@interface MDCTextInputControllerBase ()
- (void)setupInput;
@end

@implementation MDCTextInputControllerLegacyDefault

- (void)setupInput {
  [super setupInput];
  if (!self.textInput) {
    return;
  }
  [self setupClearButton];
}

- (MDCTextInputTextInsetsMode)textInsetModeDefault {
  return MDCTextInputTextInsetsModeIfContent;
}

- (void)setupClearButton {
  UIImage *image = [self
      drawnClearButtonImage:[UIColor colorWithWhite:0 alpha:[MDCTypography captionFontOpacity]]];
  [self.textInput.clearButton setImage:image forState:UIControlStateNormal];
}

#pragma mark - Border Customization

- (void)updateBorder {
  self.textInput.borderPath = MDCTextInputControllerLegacyDefaultEmptyPath();
}

#pragma mark - Clear Button Customization

- (UIImage *)drawnClearButtonImage:(UIColor *)color {
  CGSize clearButtonSize =
      CGSizeMake(MDCTextInputControllerLegacyDefaultClearButtonImageSquareWidthHeight,
                 MDCTextInputControllerLegacyDefaultClearButtonImageSquareWidthHeight);

  CGFloat scale = [UIScreen mainScreen].scale;
  CGRect bounds = CGRectMake(0, 0, clearButtonSize.width * scale, clearButtonSize.height * scale);
  UIGraphicsBeginImageContextWithOptions(bounds.size, false, scale);
  [color setFill];

  [MDCPathForClearButtonLegacyImageFrame(bounds) fill];
  UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();

  image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
  return image;
}

#pragma mark - Properties Implementation

+ (CGFloat)underlineHeightActiveDefault {
  return _underlineHeightActiveLegacyDefault;
}

+ (void)setUnderlineHeightActiveDefault:(CGFloat)underlineHeightActiveDefault {
  _underlineHeightActiveLegacyDefault = underlineHeightActiveDefault;
}

+ (CGFloat)underlineHeightNormalDefault {
  return _underlineHeightNormalLegacyDefault;
}

+ (void)setUnderlineHeightNormalDefault:(CGFloat)underlineHeightNormalDefault {
  _underlineHeightNormalLegacyDefault = underlineHeightNormalDefault;
}

- (UIRectCorner)roundedCorners {
  return 0;
}

- (void)setRoundedCorners:(__unused UIRectCorner)roundedCorners {
  // Not implemented. Corners are not rounded.
}

+ (UIRectCorner)roundedCornersDefault {
  return 0;
}

+ (void)setRoundedCornersDefault:(__unused UIRectCorner)roundedCornersDefault {
  // Not implemented. Corners are not rounded.
}

- (UIEdgeInsets)textInsets:(UIEdgeInsets)defaultInsets {
  // NOTE: UITextFields have a centerY based layout. But you can change EITHER the height or the Y.
  // Not both. Don't know why. So, we have to leave the text rect as big as the bounds and move it
  // to a Y that works. In other words, no bottom inset will make a difference here for UITextFields
  UIEdgeInsets textInsets = defaultInsets;

  if (!self.isFloatingEnabled) {
    return defaultInsets;
  }

  textInsets.top = MDCTextInputControllerLegacyDefaultVerticalPadding +
  MDCRint(self.textInput.placeholderLabel.font.lineHeight *
          (CGFloat)self.floatingPlaceholderScale.floatValue) +
  MDCTextInputControllerLegacyDefaultVerticalHalfPadding;
  return textInsets;
}

- (UIOffset)floatingPlaceholderOffset {
  CGFloat vertical = MDCTextInputControllerLegacyDefaultVerticalPadding;

  // Offsets needed due to transform working on normal (0.5,0.5) anchor point.
  // Why no anchor point of (0,0)? Because autolayout doesn't play well with anchor points.
  vertical -= self.textInput.placeholderLabel.font.lineHeight *
              (1 - (CGFloat)self.floatingPlaceholderScale.floatValue) * .5f;

  // Remember, the insets are always in LTR. It's automatically flipped when used in RTL.
  // See MDCTextInputController.h.
  UIEdgeInsets insets = self.textInput.textInsets;

  CGFloat placeholderMaxWidth =
      CGRectGetWidth(self.textInput.bounds) / self.floatingPlaceholderScale.floatValue -
      insets.left - insets.right;

  CGFloat placeholderWidth =
      [self.textInput.placeholderLabel systemLayoutSizeFittingSize:UILayoutFittingCompressedSize]
      .width;
  if (placeholderWidth > placeholderMaxWidth) {
    placeholderWidth = placeholderMaxWidth;
  }

  CGFloat horizontal =
      placeholderWidth * (1 - (CGFloat)self.floatingPlaceholderScale.floatValue) * .5f;

  return UIOffsetMake(horizontal, vertical);
}

#pragma mark - NSSecureCoding

+ (BOOL)supportsSecureCoding {
  return YES;
}

@end