react-native/Libraries/Text/RCTTextView.m

537 lines
16 KiB
Objective-C

/**
* 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 "RCTTextView.h"
#import "RCTConvert.h"
#import "RCTEventDispatcher.h"
#import "RCTText.h"
#import "RCTUtils.h"
#import "UIView+React.h"
@interface RCTUITextView : UITextView
@property (nonatomic, assign) BOOL textWasPasted;
@end
@implementation RCTUITextView
{
BOOL _jsRequestingFirstResponder;
}
- (void)paste:(id)sender
{
_textWasPasted = YES;
[super paste:sender];
}
- (void)reactWillMakeFirstResponder
{
_jsRequestingFirstResponder = YES;
}
- (BOOL)canBecomeFirstResponder
{
return _jsRequestingFirstResponder;
}
- (void)reactDidMakeFirstResponder
{
_jsRequestingFirstResponder = NO;
}
@end
@implementation RCTTextView
{
RCTEventDispatcher *_eventDispatcher;
NSString *_placeholder;
UITextView *_placeholderView;
UITextView *_textView;
NSInteger _nativeEventCount;
RCTText *_richTextView;
NSAttributedString *_pendingAttributedText;
NSMutableArray<UIView *> *_subviews;
BOOL _blockTextShouldChange;
UITextRange *_previousSelectionRange;
NSUInteger _previousTextLength;
CGFloat _previousContentHeight;
UIScrollView *_scrollView;
}
- (instancetype)initWithEventDispatcher:(RCTEventDispatcher *)eventDispatcher
{
RCTAssertParam(eventDispatcher);
if ((self = [super initWithFrame:CGRectZero])) {
_contentInset = UIEdgeInsetsZero;
_eventDispatcher = eventDispatcher;
_placeholderTextColor = [self defaultPlaceholderTextColor];
_blurOnSubmit = NO;
_textView = [[RCTUITextView alloc] initWithFrame:CGRectZero];
_textView.backgroundColor = [UIColor clearColor];
_textView.scrollsToTop = NO;
_textView.scrollEnabled = NO;
_textView.delegate = self;
_scrollView = [[UIScrollView alloc] initWithFrame:CGRectZero];
_scrollView.scrollsToTop = NO;
[_scrollView addSubview:_textView];
_previousSelectionRange = _textView.selectedTextRange;
_subviews = [NSMutableArray new];
[self addSubview:_scrollView];
}
return self;
}
RCT_NOT_IMPLEMENTED(- (instancetype)initWithFrame:(CGRect)frame)
RCT_NOT_IMPLEMENTED(- (instancetype)initWithCoder:(NSCoder *)aDecoder)
- (NSArray<UIView *> *)reactSubviews
{
return _subviews;
}
- (void)insertReactSubview:(UIView *)subview atIndex:(NSInteger)index
{
if ([subview isKindOfClass:[RCTText class]]) {
if (_richTextView) {
RCTLogError(@"Tried to insert a second <Text> into <TextInput> - there can only be one.");
}
_richTextView = (RCTText *)subview;
[_subviews insertObject:_richTextView atIndex:index];
} else {
[_subviews insertObject:subview atIndex:index];
[self insertSubview:subview atIndex:index];
}
}
- (void)removeReactSubview:(UIView *)subview
{
if (_richTextView == subview) {
[_subviews removeObject:_richTextView];
_richTextView = nil;
} else {
[_subviews removeObject:subview];
[subview removeFromSuperview];
}
}
- (void)setMostRecentEventCount:(NSInteger)mostRecentEventCount
{
_mostRecentEventCount = mostRecentEventCount;
// Props are set after uiBlockToAmendWithShadowViewRegistry, which means that
// at the time performTextUpdate is called, _mostRecentEventCount will be
// behind _eventCount, with the result that performPendingTextUpdate will do
// nothing. For that reason we call it again here after mostRecentEventCount
// has been set.
[self performPendingTextUpdate];
}
- (void)performTextUpdate
{
if (_richTextView) {
_pendingAttributedText = _richTextView.textStorage;
[self performPendingTextUpdate];
} else if (!self.text) {
_textView.attributedText = nil;
}
}
- (void)performPendingTextUpdate
{
if (!_pendingAttributedText || _mostRecentEventCount < _nativeEventCount) {
return;
}
if ([_textView.attributedText isEqualToAttributedString:_pendingAttributedText]) {
_pendingAttributedText = nil; // Don't try again.
return;
}
// When we update the attributed text, there might be pending autocorrections
// that will get accepted by default. In order for this to not garble our text,
// we temporarily block all textShouldChange events so they are not applied.
_blockTextShouldChange = YES;
UITextRange *selection = _textView.selectedTextRange;
NSInteger oldTextLength = _textView.attributedText.length;
_textView.attributedText = _pendingAttributedText;
_pendingAttributedText = nil;
if (selection.empty) {
// maintain cursor position relative to the end of the old text
NSInteger start = [_textView offsetFromPosition:_textView.beginningOfDocument toPosition:selection.start];
NSInteger offsetFromEnd = oldTextLength - start;
NSInteger newOffset = _textView.attributedText.length - offsetFromEnd;
UITextPosition *position = [_textView positionFromPosition:_textView.beginningOfDocument offset:newOffset];
_textView.selectedTextRange = [_textView textRangeFromPosition:position toPosition:position];
}
[_textView layoutIfNeeded];
[self _setPlaceholderVisibility];
_blockTextShouldChange = NO;
}
- (void)updateFrames
{
// Adjust the insets so that they are as close as possible to single-line
// RCTTextField defaults, using the system defaults of font size 17 and a
// height of 31 points.
//
// We apply the left inset to the frame since a negative left text-container
// inset mysteriously causes the text to be hidden until the text view is
// first focused.
UIEdgeInsets adjustedFrameInset = UIEdgeInsetsZero;
adjustedFrameInset.left = _contentInset.left - 5;
UIEdgeInsets adjustedTextContainerInset = _contentInset;
adjustedTextContainerInset.top += 5;
adjustedTextContainerInset.left = 0;
CGRect frame = UIEdgeInsetsInsetRect(self.bounds, adjustedFrameInset);
_textView.frame = frame;
_placeholderView.frame = frame;
_scrollView.frame = frame;
[self updateContentSize];
_textView.textContainerInset = adjustedTextContainerInset;
_placeholderView.textContainerInset = adjustedTextContainerInset;
}
- (void)updateContentSize
{
CGSize size = (CGSize){_scrollView.frame.size.width, INFINITY};
size.height = [_textView sizeThatFits:size].height;
_scrollView.contentSize = size;
_textView.frame = (CGRect){CGPointZero, size};
}
- (void)updatePlaceholder
{
[_placeholderView removeFromSuperview];
_placeholderView = nil;
if (_placeholder) {
_placeholderView = [[UITextView alloc] initWithFrame:self.bounds];
_placeholderView.editable = NO;
_placeholderView.userInteractionEnabled = NO;
_placeholderView.backgroundColor = [UIColor clearColor];
_placeholderView.scrollEnabled = false;
_placeholderView.scrollsToTop = NO;
_placeholderView.attributedText =
[[NSAttributedString alloc] initWithString:_placeholder attributes:@{
NSFontAttributeName : (_textView.font ? _textView.font : [self defaultPlaceholderFont]),
NSForegroundColorAttributeName : _placeholderTextColor
}];
[self insertSubview:_placeholderView belowSubview:_textView];
[self _setPlaceholderVisibility];
}
}
- (UIFont *)font
{
return _textView.font;
}
- (void)setFont:(UIFont *)font
{
_textView.font = font;
[self updatePlaceholder];
}
- (void)setPlaceholder:(NSString *)placeholder
{
_placeholder = placeholder;
[self updatePlaceholder];
}
- (void)setPlaceholderTextColor:(UIColor *)placeholderTextColor
{
if (placeholderTextColor) {
_placeholderTextColor = placeholderTextColor;
} else {
_placeholderTextColor = [self defaultPlaceholderTextColor];
}
[self updatePlaceholder];
}
- (void)setContentInset:(UIEdgeInsets)contentInset
{
_contentInset = contentInset;
[self updateFrames];
}
- (NSString *)text
{
return _textView.text;
}
- (BOOL)textView:(RCTUITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
if (_blockTextShouldChange) {
return NO;
}
if (textView.textWasPasted) {
textView.textWasPasted = NO;
} else {
[_eventDispatcher sendTextEventWithType:RCTTextEventTypeKeyPress
reactTag:self.reactTag
text:nil
key:text
eventCount:_nativeEventCount];
if (_blurOnSubmit && [text isEqualToString:@"\n"]) {
// TODO: the purpose of blurOnSubmit on RCTextField is to decide if the
// field should lose focus when return is pressed or not. We're cheating a
// bit here by using it on RCTextView to decide if return character should
// submit the form, or be entered into the field.
//
// The reason this is cheating is because there's no way to specify that
// you want the return key to be swallowed *and* have the field retain
// focus (which was what blurOnSubmit was originally for). For the case
// where _blurOnSubmit = YES, this is still the correct and expected
// behavior though, so we'll leave the don't-blur-or-add-newline problem
// to be solved another day.
[_eventDispatcher sendTextEventWithType:RCTTextEventTypeSubmit
reactTag:self.reactTag
text:self.text
key:nil
eventCount:_nativeEventCount];
[self resignFirstResponder];
return NO;
}
}
if (_maxLength == nil) {
return YES;
}
NSUInteger allowedLength = _maxLength.integerValue - textView.text.length + range.length;
if (text.length > allowedLength) {
if (text.length > 1) {
// Truncate the input string so the result is exactly maxLength
NSString *limitedString = [text substringToIndex:allowedLength];
NSMutableString *newString = textView.text.mutableCopy;
[newString replaceCharactersInRange:range withString:limitedString];
textView.text = newString;
// Collapse selection at end of insert to match normal paste behavior
UITextPosition *insertEnd = [textView positionFromPosition:textView.beginningOfDocument
offset:(range.location + allowedLength)];
textView.selectedTextRange = [textView textRangeFromPosition:insertEnd toPosition:insertEnd];
[self textViewDidChange:textView];
}
return NO;
} else {
return YES;
}
}
- (void)textViewDidChangeSelection:(RCTUITextView *)textView
{
if (_onSelectionChange &&
textView.selectedTextRange != _previousSelectionRange &&
![textView.selectedTextRange isEqual:_previousSelectionRange]) {
_previousSelectionRange = textView.selectedTextRange;
UITextRange *selection = textView.selectedTextRange;
NSInteger start = [textView offsetFromPosition:textView.beginningOfDocument toPosition:selection.start];
NSInteger end = [textView offsetFromPosition:textView.beginningOfDocument toPosition:selection.end];
_onSelectionChange(@{
@"selection": @{
@"start": @(start),
@"end": @(end),
},
});
}
}
- (void)setText:(NSString *)text
{
NSInteger eventLag = _nativeEventCount - _mostRecentEventCount;
if (eventLag == 0 && ![text isEqualToString:_textView.text]) {
UITextRange *selection = _textView.selectedTextRange;
NSInteger oldTextLength = _textView.text.length;
_textView.text = text;
if (selection.empty) {
// maintain cursor position relative to the end of the old text
NSInteger start = [_textView offsetFromPosition:_textView.beginningOfDocument toPosition:selection.start];
NSInteger offsetFromEnd = oldTextLength - start;
NSInteger newOffset = text.length - offsetFromEnd;
UITextPosition *position = [_textView positionFromPosition:_textView.beginningOfDocument offset:newOffset];
_textView.selectedTextRange = [_textView textRangeFromPosition:position toPosition:position];
}
[self _setPlaceholderVisibility];
[self updateContentSize]; //keep the text wrapping when the length of
//the textline has been extended longer than the length of textinputView
} else if (eventLag > RCTTextUpdateLagWarningThreshold) {
RCTLogWarn(@"Native TextInput(%@) is %zd events ahead of JS - try to make your JS faster.", self.text, eventLag);
}
}
- (void)_setPlaceholderVisibility
{
if (_textView.text.length > 0) {
[_placeholderView setHidden:YES];
} else {
[_placeholderView setHidden:NO];
}
}
- (void)setAutoCorrect:(BOOL)autoCorrect
{
_textView.autocorrectionType = (autoCorrect ? UITextAutocorrectionTypeYes : UITextAutocorrectionTypeNo);
}
- (BOOL)autoCorrect
{
return _textView.autocorrectionType == UITextAutocorrectionTypeYes;
}
- (BOOL)textViewShouldBeginEditing:(UITextView *)textView
{
if (_selectTextOnFocus) {
dispatch_async(dispatch_get_main_queue(), ^{
[textView selectAll:nil];
});
}
return YES;
}
- (void)textViewDidBeginEditing:(UITextView *)textView
{
if (_clearTextOnFocus) {
_textView.text = @"";
[self _setPlaceholderVisibility];
}
[_eventDispatcher sendTextEventWithType:RCTTextEventTypeFocus
reactTag:self.reactTag
text:nil
key:nil
eventCount:_nativeEventCount];
}
- (void)textViewDidChange:(UITextView *)textView
{
[self updateContentSize];
[self _setPlaceholderVisibility];
_nativeEventCount++;
if (!self.reactTag) {
return;
}
// When the context size increases, iOS updates the contentSize twice; once
// with a lower height, then again with the correct height. To prevent a
// spurious event from being sent, we track the previous, and only send the
// update event if it matches our expectation that greater text length
// should result in increased height. This assumption is, of course, not
// necessarily true because shorter text might include more linebreaks, but
// in practice this works well enough.
NSUInteger textLength = textView.text.length;
CGFloat contentHeight = textView.contentSize.height;
if (textLength >= _previousTextLength) {
contentHeight = MAX(contentHeight, _previousContentHeight);
}
_previousTextLength = textLength;
_previousContentHeight = contentHeight;
NSDictionary *event = @{
@"text": self.text,
@"contentSize": @{
@"height": @(contentHeight),
@"width": @(textView.contentSize.width)
},
@"target": self.reactTag,
@"eventCount": @(_nativeEventCount),
};
[_eventDispatcher sendInputEventWithName:@"change" body:event];
}
- (void)textViewDidEndEditing:(UITextView *)textView
{
[_eventDispatcher sendTextEventWithType:RCTTextEventTypeEnd
reactTag:self.reactTag
text:textView.text
key:nil
eventCount:_nativeEventCount];
[_eventDispatcher sendTextEventWithType:RCTTextEventTypeBlur
reactTag:self.reactTag
text:nil
key:nil
eventCount:_nativeEventCount];
}
- (BOOL)isFirstResponder
{
return [_textView isFirstResponder];
}
- (BOOL)canBecomeFirstResponder
{
return [_textView canBecomeFirstResponder];
}
- (void)reactWillMakeFirstResponder
{
[_textView reactWillMakeFirstResponder];
}
- (BOOL)becomeFirstResponder
{
return [_textView becomeFirstResponder];
}
- (void)reactDidMakeFirstResponder
{
[_textView reactDidMakeFirstResponder];
}
- (BOOL)resignFirstResponder
{
[super resignFirstResponder];
return [_textView resignFirstResponder];
}
- (void)layoutSubviews
{
[super layoutSubviews];
[self updateFrames];
}
- (UIFont *)defaultPlaceholderFont
{
return [UIFont systemFontOfSize:17];
}
- (UIColor *)defaultPlaceholderTextColor
{
return [UIColor colorWithRed:0.0/255.0 green:0.0/255.0 blue:0.098/255.0 alpha:0.22];
}
@end