react-native/Libraries/Text/RCTUITextView.m

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/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
#import "RCTUITextView.h"
@implementation RCTUITextView
{
BOOL _jsRequestingFirstResponder;
UILabel *_placeholderView;
UITextView *_detachedTextView;
}
static UIFont *defaultPlaceholderFont()
{
return [UIFont systemFontOfSize:17];
}
static UIColor *defaultPlaceholderTextColor()
{
// Default placeholder color from UITextField.
return [UIColor colorWithRed:0 green:0 blue:0.0980392 alpha:0.22];
}
- (instancetype)initWithFrame:(CGRect)frame
{
if (self = [super initWithFrame:frame]) {
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(textDidChange)
name:UITextViewTextDidChangeNotification
object:self];
_placeholderView = [[UILabel alloc] initWithFrame:self.bounds];
_placeholderView.isAccessibilityElement = NO;
_placeholderView.numberOfLines = 0;
[self addSubview:_placeholderView];
}
return self;
}
- (void)dealloc
{
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
#pragma mark - Properties
- (void)setPlaceholderText:(NSString *)placeholderText
{
_placeholderText = placeholderText;
_placeholderView.text = _placeholderText;
}
- (void)setPlaceholderTextColor:(UIColor *)placeholderTextColor
{
_placeholderTextColor = placeholderTextColor;
_placeholderView.textColor = _placeholderTextColor ?: defaultPlaceholderTextColor();
}
- (void)textDidChange
{
_textWasPasted = NO;
[self invalidatePlaceholderVisibility];
}
#pragma mark - UIResponder
- (void)reactWillMakeFirstResponder
{
_jsRequestingFirstResponder = YES;
}
- (BOOL)canBecomeFirstResponder
{
return _jsRequestingFirstResponder;
}
- (void)reactDidMakeFirstResponder
{
_jsRequestingFirstResponder = NO;
}
- (void)didMoveToWindow
{
if (_jsRequestingFirstResponder) {
[self becomeFirstResponder];
[self reactDidMakeFirstResponder];
}
}
#pragma mark - Overrides
- (void)setFont:(UIFont *)font
{
[super setFont:font];
_placeholderView.font = font ?: defaultPlaceholderFont();
}
- (void)setTextAlignment:(NSTextAlignment)textAlignment
{
[super setTextAlignment:textAlignment];
_placeholderView.textAlignment = textAlignment;
}
- (void)setText:(NSString *)text
{
[super setText:text];
[self textDidChange];
}
- (void)setAttributedText:(NSAttributedString *)attributedText
{
[super setAttributedText:attributedText];
[self textDidChange];
}
- (void)paste:(id)sender
{
[super paste:sender];
_textWasPasted = YES;
}
- (void)setContentOffset:(CGPoint)contentOffset animated:(__unused BOOL)animated
{
// Turning off scroll animation.
// This fixes the problem also known as "flaky scrolling".
[super setContentOffset:contentOffset animated:NO];
}
#pragma mark - Layout
- (void)layoutSubviews
{
[super layoutSubviews];
CGRect textFrame = UIEdgeInsetsInsetRect(self.bounds, self.textContainerInset);
CGFloat placeholderHeight = [_placeholderView sizeThatFits:textFrame.size].height;
textFrame.size.height = MIN(placeholderHeight, textFrame.size.height);
_placeholderView.frame = textFrame;
}
- (CGSize)sizeThatFits:(CGSize)size
{
// UITextView on iOS 8 has a bug that automatically scrolls to the top
// when calling `sizeThatFits:`. Use a copy so that self is not screwed up.
static BOOL useCustomImplementation = NO;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
useCustomImplementation = ![[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion:(NSOperatingSystemVersion){9,0,0}];
});
if (!useCustomImplementation) {
return [super sizeThatFits:size];
}
if (!_detachedTextView) {
_detachedTextView = [UITextView new];
}
_detachedTextView.attributedText = self.attributedText;
_detachedTextView.font = self.font;
_detachedTextView.textContainerInset = self.textContainerInset;
return [_detachedTextView sizeThatFits:size];
}
#pragma mark - Placeholder
- (void)invalidatePlaceholderVisibility
{
BOOL isVisible = _placeholderText.length != 0 && self.text.length == 0;
_placeholderView.hidden = !isVisible;
}
@end