react-native/Libraries/Text/RCTTextView.m

412 lines
14 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 <React/RCTConvert.h>
#import <React/RCTEventDispatcher.h>
#import <React/RCTFont.h>
#import <React/RCTUIManager.h>
#import <React/RCTUtils.h>
#import <React/UIView+React.h>
#import "RCTShadowText.h"
#import "RCTText.h"
#import "RCTTextSelection.h"
#import "RCTUITextView.h"
@interface RCTTextView () <RCTBackedTextInputDelegate>
@end
@implementation RCTTextView
{
RCTUITextView *_backedTextInput;
RCTText *_richTextView;
NSAttributedString *_pendingAttributedText;
NSString *_predictedText;
BOOL _blockTextShouldChange;
BOOL _nativeUpdatesInFlight;
}
- (instancetype)initWithBridge:(RCTBridge *)bridge
{
RCTAssertParam(bridge);
if (self = [super initWithBridge:bridge]) {
// `blurOnSubmit` defaults to `false` for <TextInput multiline={true}> by design.
_blurOnSubmit = NO;
_backedTextInput = [[RCTUITextView alloc] initWithFrame:self.bounds];
_backedTextInput.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
_backedTextInput.backgroundColor = [UIColor clearColor];
_backedTextInput.textColor = [UIColor blackColor];
// This line actually removes 5pt (default value) left and right padding in UITextView.
_backedTextInput.textContainer.lineFragmentPadding = 0;
#if !TARGET_OS_TV
_backedTextInput.scrollsToTop = NO;
#endif
_backedTextInput.scrollEnabled = YES;
_backedTextInput.textInputDelegate = self;
_backedTextInput.font = self.fontAttributes.font;
[self addSubview:_backedTextInput];
}
return self;
}
RCT_NOT_IMPLEMENTED(- (instancetype)initWithFrame:(CGRect)frame)
RCT_NOT_IMPLEMENTED(- (instancetype)initWithCoder:(NSCoder *)aDecoder)
- (id<RCTBackedTextInputViewProtocol>)backedTextInputView
{
return _backedTextInput;
}
#pragma mark - RCTComponent
- (void)insertReactSubview:(UIView *)subview atIndex:(NSInteger)index
{
[super insertReactSubview:subview atIndex: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;
// If this <TextInput> is in rich text editing mode, and the child <Text> node providing rich text
// styling has a backgroundColor, then the attributedText produced by the child <Text> node will have an
// NSBackgroundColor attribute. We need to forward this attribute to the text view manually because the text view
// always has a clear background color in `initWithBridge:`.
//
// TODO: This should be removed when the related hack in -performPendingTextUpdate is removed.
if (subview.backgroundColor) {
NSMutableDictionary<NSString *, id> *attrs = [_backedTextInput.typingAttributes mutableCopy];
attrs[NSBackgroundColorAttributeName] = subview.backgroundColor;
_backedTextInput.typingAttributes = attrs;
}
[self performTextUpdate];
}
}
- (void)removeReactSubview:(UIView *)subview
{
[super removeReactSubview:subview];
if (_richTextView == subview) {
_richTextView = nil;
[self performTextUpdate];
}
}
- (void)didUpdateReactSubviews
{
// Do nothing, as we don't allow non-text subviews.
}
#pragma mark - Routine
- (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) {
_backedTextInput.attributedText = nil;
}
}
static NSAttributedString *removeReactTagFromString(NSAttributedString *string)
{
if (string.length == 0) {
return string;
} else {
NSMutableAttributedString *mutableString = [[NSMutableAttributedString alloc] initWithAttributedString:string];
[mutableString removeAttribute:RCTReactTagAttributeName range:NSMakeRange(0, mutableString.length)];
return mutableString;
}
}
- (void)performPendingTextUpdate
{
if (!_pendingAttributedText || _mostRecentEventCount < _nativeEventCount || _nativeUpdatesInFlight) {
return;
}
// The underlying <Text> node that produces _pendingAttributedText has a react tag attribute on it that causes the
// -isEqualToAttributedString: comparison below to spuriously fail. We don't want that comparison to fail unless it
// needs to because when the comparison fails, we end up setting attributedText on the text view, which clears
// autocomplete state for CKJ text input.
//
// TODO: Kill this after we finish passing all style/attribute info into JS.
_pendingAttributedText = removeReactTagFromString(_pendingAttributedText);
if ([_backedTextInput.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 = _backedTextInput.selectedTextRange;
NSInteger oldTextLength = _backedTextInput.attributedText.length;
_backedTextInput.attributedText = _pendingAttributedText;
_predictedText = _pendingAttributedText.string;
_pendingAttributedText = nil;
if (selection.empty) {
// maintain cursor position relative to the end of the old text
NSInteger start = [_backedTextInput offsetFromPosition:_backedTextInput.beginningOfDocument toPosition:selection.start];
NSInteger offsetFromEnd = oldTextLength - start;
NSInteger newOffset = _backedTextInput.attributedText.length - offsetFromEnd;
UITextPosition *position = [_backedTextInput positionFromPosition:_backedTextInput.beginningOfDocument offset:newOffset];
[_backedTextInput setSelectedTextRange:[_backedTextInput textRangeFromPosition:position toPosition:position]
notifyDelegate:YES];
}
[_backedTextInput layoutIfNeeded];
[self invalidateContentSize];
_blockTextShouldChange = NO;
}
#pragma mark - Properties
- (UIFont *)font
{
return _backedTextInput.font;
}
- (void)setFont:(UIFont *)font
{
_backedTextInput.font = font;
[self setNeedsLayout];
}
- (NSString *)text
{
return _backedTextInput.text;
}
- (void)setText:(NSString *)text
{
NSInteger eventLag = _nativeEventCount - _mostRecentEventCount;
if (eventLag == 0 && ![text isEqualToString:_backedTextInput.text]) {
UITextRange *selection = _backedTextInput.selectedTextRange;
NSInteger oldTextLength = _backedTextInput.text.length;
_predictedText = text;
_backedTextInput.text = text;
if (selection.empty) {
// maintain cursor position relative to the end of the old text
NSInteger start = [_backedTextInput offsetFromPosition:_backedTextInput.beginningOfDocument toPosition:selection.start];
NSInteger offsetFromEnd = oldTextLength - start;
NSInteger newOffset = text.length - offsetFromEnd;
UITextPosition *position = [_backedTextInput positionFromPosition:_backedTextInput.beginningOfDocument offset:newOffset];
[_backedTextInput setSelectedTextRange:[_backedTextInput textRangeFromPosition:position toPosition:position]
notifyDelegate:YES];
}
[self invalidateContentSize];
} else if (eventLag > RCTTextUpdateLagWarningThreshold) {
RCTLogWarn(@"Native TextInput(%@) is %lld events ahead of JS - try to make your JS faster.", self.text, (long long)eventLag);
}
}
#pragma mark - RCTBackedTextInputDelegate
- (BOOL)textInputShouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
if (!_backedTextInput.textWasPasted) {
[_eventDispatcher sendTextEventWithType:RCTTextEventTypeKeyPress
reactTag:self.reactTag
text:nil
key:text
eventCount:_nativeEventCount];
}
// So we need to track that there is a native update in flight just in case JS manages to come back around and update
// things /before/ UITextView can update itself asynchronously. If there is a native update in flight, we defer the
// JS update when it comes in and apply the deferred update once textViewDidChange fires with the native update applied.
if (_blockTextShouldChange) {
return NO;
}
if (_maxLength) {
NSUInteger allowedLength = _maxLength.integerValue - _backedTextInput.text.length + range.length;
if (text.length > allowedLength) {
// If we typed/pasted more than one character, limit the text inputted
if (text.length > 1) {
// Truncate the input string so the result is exactly maxLength
NSString *limitedString = [text substringToIndex:allowedLength];
NSMutableString *newString = _backedTextInput.text.mutableCopy;
[newString replaceCharactersInRange:range withString:limitedString];
_backedTextInput.text = newString;
_predictedText = newString;
// Collapse selection at end of insert to match normal paste behavior
UITextPosition *insertEnd = [_backedTextInput positionFromPosition:_backedTextInput.beginningOfDocument
offset:(range.location + allowedLength)];
[_backedTextInput setSelectedTextRange:[_backedTextInput textRangeFromPosition:insertEnd toPosition:insertEnd]
notifyDelegate:YES];
[self textInputDidChange];
}
return NO;
}
}
_nativeUpdatesInFlight = YES;
if (range.location + range.length > _predictedText.length) {
// _predictedText got out of sync in a bad way, so let's just force sync it. Haven't been able to repro this, but
// it's causing a real crash here: #6523822
_predictedText = _backedTextInput.text;
}
NSString *previousText = [_predictedText substringWithRange:range];
if (_predictedText) {
_predictedText = [_predictedText stringByReplacingCharactersInRange:range withString:text];
} else {
_predictedText = text;
}
if (_onTextInput) {
_onTextInput(@{
@"text": text,
@"previousText": previousText ?: @"",
@"range": @{
@"start": @(range.location),
@"end": @(range.location + range.length)
},
@"eventCount": @(_nativeEventCount),
});
}
return YES;
}
static BOOL findMismatch(NSString *first, NSString *second, NSRange *firstRange, NSRange *secondRange)
{
NSInteger firstMismatch = -1;
for (NSUInteger ii = 0; ii < MAX(first.length, second.length); ii++) {
if (ii >= first.length || ii >= second.length || [first characterAtIndex:ii] != [second characterAtIndex:ii]) {
firstMismatch = ii;
break;
}
}
if (firstMismatch == -1) {
return NO;
}
NSUInteger ii = second.length;
NSUInteger lastMismatch = first.length;
while (ii > firstMismatch && lastMismatch > firstMismatch) {
if ([first characterAtIndex:(lastMismatch - 1)] != [second characterAtIndex:(ii - 1)]) {
break;
}
ii--;
lastMismatch--;
}
*firstRange = NSMakeRange(firstMismatch, lastMismatch - firstMismatch);
*secondRange = NSMakeRange(firstMismatch, ii - firstMismatch);
return YES;
}
- (void)textInputDidChange
{
[self invalidateContentSize];
// Detect when _backedTextInput updates happend that didn't invoke `shouldChangeTextInRange`
// (e.g. typing simplified chinese in pinyin will insert and remove spaces without
// calling shouldChangeTextInRange). This will cause JS to get out of sync so we
// update the mismatched range.
NSRange currentRange;
NSRange predictionRange;
if (findMismatch(_backedTextInput.text, _predictedText, &currentRange, &predictionRange)) {
NSString *replacement = [_backedTextInput.text substringWithRange:currentRange];
[self textInputShouldChangeTextInRange:predictionRange replacementText:replacement];
// JS will assume the selection changed based on the location of our shouldChangeTextInRange, so reset it.
[self textInputDidChangeSelection];
_predictedText = _backedTextInput.text;
}
_nativeUpdatesInFlight = NO;
_nativeEventCount++;
if (!self.reactTag || !_onChange) {
return;
}
_onChange(@{
@"text": self.text,
@"target": self.reactTag,
@"eventCount": @(_nativeEventCount),
});
}
#pragma mark - UIScrollViewDelegate
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
if (_onScroll) {
CGPoint contentOffset = scrollView.contentOffset;
CGSize contentSize = scrollView.contentSize;
CGSize size = scrollView.bounds.size;
UIEdgeInsets contentInset = scrollView.contentInset;
_onScroll(@{
@"contentOffset": @{
@"x": @(contentOffset.x),
@"y": @(contentOffset.y)
},
@"contentInset": @{
@"top": @(contentInset.top),
@"left": @(contentInset.left),
@"bottom": @(contentInset.bottom),
@"right": @(contentInset.right)
},
@"contentSize": @{
@"width": @(contentSize.width),
@"height": @(contentSize.height)
},
@"layoutMeasurement": @{
@"width": @(size.width),
@"height": @(size.height)
},
@"zoomScale": @(scrollView.zoomScale ?: 1),
});
}
}
@end