Files
PiliPlus/lib/common/widgets/text/rich_text.dart
bggRGjQaUbCoE cc00b2cc39 feat: dyn show more
Closes #1629

Signed-off-by: bggRGjQaUbCoE <githubaccount56556@proton.me>
2025-10-19 20:27:42 +08:00

345 lines
12 KiB
Dart

import 'dart:ui' as ui;
import 'package:PiliPlus/common/widgets/text/paragraph.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart' hide RenderParagraph;
/// A paragraph of rich text.
///
/// {@youtube 560 315 https://www.youtube.com/watch?v=rykDVh-QFfw}
///
/// The [RichText] widget displays text that uses multiple different styles. The
/// text to display is described using a tree of [TextSpan] objects, each of
/// which has an associated style that is used for that subtree. The text might
/// break across multiple lines or might all be displayed on the same line
/// depending on the layout constraints.
///
/// Text displayed in a [RichText] widget must be explicitly styled. When
/// picking which style to use, consider using [DefaultTextStyle.of] the current
/// [BuildContext] to provide defaults. For more details on how to style text in
/// a [RichText] widget, see the documentation for [TextStyle].
///
/// Consider using the [Text] widget to integrate with the [DefaultTextStyle]
/// automatically. When all the text uses the same style, the default constructor
/// is less verbose. The [Text.rich] constructor allows you to style multiple
/// spans with the default text style while still allowing specified styles per
/// span.
///
/// {@tool snippet}
///
/// This sample demonstrates how to mix and match text with different text
/// styles using the [RichText] Widget. It displays the text "Hello bold world,"
/// emphasizing the word "bold" using a bold font weight.
///
/// ![](https://flutter.github.io/assets-for-api-docs/assets/widgets/rich_text.png)
///
/// ```dart
/// RichText(
/// text: TextSpan(
/// text: 'Hello ',
/// style: DefaultTextStyle.of(context).style,
/// children: const <TextSpan>[
/// TextSpan(text: 'bold', style: TextStyle(fontWeight: FontWeight.bold)),
/// TextSpan(text: ' world!'),
/// ],
/// ),
/// )
/// ```
/// {@end-tool}
///
/// ## Selections
///
/// To make this [RichText] Selectable, the [RichText] needs to be in the
/// subtree of a [SelectionArea] or [SelectableRegion] and a
/// [SelectionRegistrar] needs to be assigned to the
/// [RichText.selectionRegistrar]. One can use
/// [SelectionContainer.maybeOf] to get the [SelectionRegistrar] from a
/// context. This enables users to select the text in [RichText]s with mice or
/// touch events.
///
/// The [selectionColor] also needs to be set if the selection is enabled to
/// draw the selection highlights.
///
/// {@tool snippet}
///
/// This sample demonstrates how to assign a [SelectionRegistrar] for RichTexts
/// in the SelectionArea subtree.
///
/// ![](https://flutter.github.io/assets-for-api-docs/assets/widgets/rich_text.png)
///
/// ```dart
/// RichText(
/// text: const TextSpan(text: 'Hello'),
/// selectionRegistrar: SelectionContainer.maybeOf(context),
/// selectionColor: const Color(0xAF6694e8),
/// )
/// ```
/// {@end-tool}
///
/// See also:
///
/// * [TextStyle], which discusses how to style text.
/// * [TextSpan], which is used to describe the text in a paragraph.
/// * [Text], which automatically applies the ambient styles described by a
/// [DefaultTextStyle] to a single string.
/// * [Text.rich], a const text widget that provides similar functionality
/// as [RichText]. [Text.rich] will inherit [TextStyle] from [DefaultTextStyle].
/// * [SelectableRegion], which provides an overview of the selection system.
class RichText extends MultiChildRenderObjectWidget {
/// Creates a paragraph of rich text.
///
/// The [maxLines] property may be null (and indeed defaults to null), but if
/// it is not null, it must be greater than zero.
///
/// The [textDirection], if null, defaults to the ambient [Directionality],
/// which in that case must not be null.
RichText({
super.key,
required this.text,
this.textAlign = TextAlign.start,
this.textDirection,
this.softWrap = true,
this.overflow = TextOverflow.clip,
@Deprecated(
'Use textScaler instead. '
'Use of textScaleFactor was deprecated in preparation for the upcoming nonlinear text scaling support. '
'This feature was deprecated after v3.12.0-2.0.pre.',
)
double textScaleFactor = 1.0,
TextScaler textScaler = TextScaler.noScaling,
this.maxLines,
this.locale,
this.strutStyle,
this.textWidthBasis = TextWidthBasis.parent,
this.textHeightBehavior,
this.selectionRegistrar,
this.selectionColor,
this.onShowMore,
}) : assert(maxLines == null || maxLines > 0),
assert(selectionRegistrar == null || selectionColor != null),
assert(
textScaleFactor == 1.0 || identical(textScaler, TextScaler.noScaling),
'Use textScaler instead.',
),
textScaler = _effectiveTextScalerFrom(textScaler, textScaleFactor),
super(
children: WidgetSpan.extractFromInlineSpan(
text,
_effectiveTextScalerFrom(textScaler, textScaleFactor),
),
);
static TextScaler _effectiveTextScalerFrom(
TextScaler textScaler,
double textScaleFactor,
) {
return switch ((textScaler, textScaleFactor)) {
(final TextScaler scaler, 1.0) => scaler,
(TextScaler.noScaling, final double textScaleFactor) => TextScaler.linear(
textScaleFactor,
),
(final TextScaler scaler, _) => scaler,
};
}
/// The text to display in this widget.
final InlineSpan text;
/// How the text should be aligned horizontally.
final TextAlign textAlign;
/// The directionality of the text.
///
/// This decides how [textAlign] values like [TextAlign.start] and
/// [TextAlign.end] are interpreted.
///
/// This is also used to disambiguate how to render bidirectional text. For
/// example, if the [text] is an English phrase followed by a Hebrew phrase,
/// in a [TextDirection.ltr] context the English phrase will be on the left
/// and the Hebrew phrase to its right, while in a [TextDirection.rtl]
/// context, the English phrase will be on the right and the Hebrew phrase on
/// its left.
///
/// Defaults to the ambient [Directionality], if any. If there is no ambient
/// [Directionality], then this must not be null.
final TextDirection? textDirection;
/// Whether the text should break at soft line breaks.
///
/// If false, the glyphs in the text will be positioned as if there was unlimited horizontal space.
final bool softWrap;
/// How visual overflow should be handled.
final TextOverflow overflow;
/// Deprecated. Will be removed in a future version of Flutter. Use
/// [textScaler] instead.
///
/// The number of font pixels for each logical pixel.
///
/// For example, if the text scale factor is 1.5, text will be 50% larger than
/// the specified font size.
@Deprecated(
'Use textScaler instead. '
'Use of textScaleFactor was deprecated in preparation for the upcoming nonlinear text scaling support. '
'This feature was deprecated after v3.12.0-2.0.pre.',
)
double get textScaleFactor => textScaler.textScaleFactor;
/// {@macro flutter.painting.textPainter.textScaler}
final TextScaler textScaler;
/// An optional maximum number of lines for the text to span, wrapping if necessary.
/// If the text exceeds the given number of lines, it will be truncated according
/// to [overflow].
///
/// If this is 1, text will not wrap. Otherwise, text will be wrapped at the
/// edge of the box.
final int? maxLines;
/// Used to select a font when the same Unicode character can
/// be rendered differently, depending on the locale.
///
/// It's rarely necessary to set this property. By default its value
/// is inherited from the enclosing app with `Localizations.localeOf(context)`.
///
/// See [RenderParagraph.locale] for more information.
final Locale? locale;
/// {@macro flutter.painting.textPainter.strutStyle}
final StrutStyle? strutStyle;
/// {@macro flutter.painting.textPainter.textWidthBasis}
final TextWidthBasis textWidthBasis;
/// {@macro dart.ui.textHeightBehavior}
final ui.TextHeightBehavior? textHeightBehavior;
/// The [SelectionRegistrar] this rich text is subscribed to.
///
/// If this is set, [selectionColor] must be non-null.
final SelectionRegistrar? selectionRegistrar;
/// The color to use when painting the selection.
///
/// This is ignored if [selectionRegistrar] is null.
///
/// See the section on selections in the [RichText] top-level API
/// documentation for more details on enabling selection in [RichText]
/// widgets.
final Color? selectionColor;
final VoidCallback? onShowMore;
@override
RenderParagraph createRenderObject(BuildContext context) {
assert(textDirection != null || debugCheckHasDirectionality(context));
return RenderParagraph(
text,
textAlign: textAlign,
textDirection: textDirection ?? Directionality.of(context),
softWrap: softWrap,
overflow: overflow,
textScaler: textScaler,
maxLines: maxLines,
strutStyle: strutStyle,
textWidthBasis: textWidthBasis,
textHeightBehavior: textHeightBehavior,
locale: locale ?? Localizations.maybeLocaleOf(context),
registrar: selectionRegistrar,
selectionColor: selectionColor,
primary: Theme.of(context).colorScheme.primary,
onShowMore: onShowMore,
);
}
@override
void updateRenderObject(BuildContext context, RenderParagraph renderObject) {
assert(textDirection != null || debugCheckHasDirectionality(context));
renderObject
..text = text
..textAlign = textAlign
..textDirection = textDirection ?? Directionality.of(context)
..softWrap = softWrap
..overflow = overflow
..textScaler = textScaler
..maxLines = maxLines
..strutStyle = strutStyle
..textWidthBasis = textWidthBasis
..textHeightBehavior = textHeightBehavior
..locale = locale ?? Localizations.maybeLocaleOf(context)
..registrar = selectionRegistrar
..selectionColor = selectionColor
..primary = Theme.of(context).colorScheme.primary
..onShowMore = onShowMore;
}
@override
void debugFillProperties(DiagnosticPropertiesBuilder properties) {
super.debugFillProperties(properties);
properties.add(
EnumProperty<TextAlign>(
'textAlign',
textAlign,
defaultValue: TextAlign.start,
),
);
properties.add(
EnumProperty<TextDirection>(
'textDirection',
textDirection,
defaultValue: null,
),
);
properties.add(
FlagProperty(
'softWrap',
value: softWrap,
ifTrue: 'wrapping at box width',
ifFalse: 'no wrapping except at line break characters',
showName: true,
),
);
properties.add(
EnumProperty<TextOverflow>(
'overflow',
overflow,
defaultValue: TextOverflow.clip,
),
);
properties.add(
DiagnosticsProperty<TextScaler>(
'textScaler',
textScaler,
defaultValue: TextScaler.noScaling,
),
);
properties.add(IntProperty('maxLines', maxLines, ifNull: 'unlimited'));
properties.add(
EnumProperty<TextWidthBasis>(
'textWidthBasis',
textWidthBasis,
defaultValue: TextWidthBasis.parent,
),
);
properties.add(StringProperty('text', text.toPlainText()));
properties.add(
DiagnosticsProperty<Locale>('locale', locale, defaultValue: null),
);
properties.add(
DiagnosticsProperty<StrutStyle>(
'strutStyle',
strutStyle,
defaultValue: null,
),
);
properties.add(
DiagnosticsProperty<TextHeightBehavior>(
'textHeightBehavior',
textHeightBehavior,
defaultValue: null,
),
);
}
}