lib_ui/ui/text/text.h

// This file is part of Desktop App Toolkit,
// a set of libraries for developing nice desktop applications.
//
// For license and copyright information please follow this link:
// https://github.com/desktop-app/legal/blob/master/LEGAL
//
#pragma once

#include "ui/text/text_entity.h"
#include "ui/click_handler.h"
#include "base/flags.h"
#include "ui/style/style_core_types.h"

#include <crl/crl_time.h>

#include <any>

class Painter;

namespace anim {
enum class type : uchar;
} // namespace anim

namespace style {
struct TextStyle;
struct TextPalette;
struct ParagraphStyle;
} // namespace style

namespace Ui {

class SpoilerMessCached;

extern const QString kQEllipsis;

inline constexpr auto kQFixedMax = (INT_MAX / 256);

} // namespace Ui

struct TextParseOptions {
	int32 flags;
	int32 maxw;
	int32 maxh;
	Qt::LayoutDirection dir;
};
extern const TextParseOptions kDefaultTextOptions;
extern const TextParseOptions kMarkupTextOptions;
extern const TextParseOptions kPlainTextOptions;

enum class TextSelectType {
	Letters    = 0x01,
	Words      = 0x02,
	Paragraphs = 0x03,
};

struct TextSelection {
	constexpr TextSelection() = default;
	constexpr TextSelection(uint16 from, uint16 to) : from(from), to(to) {
	}
	constexpr bool empty() const {
		return from == to;
	}
	uint16 from = 0;
	uint16 to = 0;
};

inline bool operator==(TextSelection a, TextSelection b) {
	return a.from == b.from && a.to == b.to;
}

inline bool operator!=(TextSelection a, TextSelection b) {
	return !(a == b);
}

static constexpr TextSelection AllTextSelection = { 0, 0xFFFF };

namespace Ui::Text {

struct Block;
class AbstractBlock;
struct IsolatedEmoji;
struct OnlyCustomEmoji;
struct SpoilerData;
struct ParagraphDetails;
struct ExtendedData;

struct Modification {
	int position = 0;
	uint16 skipped = 0;
	bool added = false;
};

struct StateRequest {
	enum class Flag {
		BreakEverywhere = (1 << 0),
		LookupSymbol = (1 << 1),
		LookupLink = (1 << 2),
		LookupCustomTooltip = (1 << 3),
	};
	using Flags = base::flags<Flag>;
	friend inline constexpr auto is_flag_type(Flag) { return true; };

	StateRequest() {
	}

	style::align align = style::al_left;
	Flags flags = Flag::LookupLink;
};

struct StateResult {
	ClickHandlerPtr link;
	bool uponSymbol = false;
	bool afterSymbol = false;
	uint16 symbol = 0;
};

struct StateRequestElided : StateRequest {
	StateRequestElided() {
	}
	StateRequestElided(const StateRequest &other) : StateRequest(other) {
	}
	int lines = 1;
	int removeFromEnd = 0;
};

class SpoilerMessCache {
public:
	explicit SpoilerMessCache(int capacity);
	~SpoilerMessCache();

	[[nodiscard]] not_null<SpoilerMessCached*> lookup(QColor color);
	void reset();

private:
	struct Entry;

	std::vector<Entry> _cache;
	const int _capacity = 0;

};

struct SpecialColor {
	const QPen *pen = nullptr;
	const QPen *penSelected = nullptr;
};

struct LineGeometry {
	int left = 0;
	int top = 0;
	int width = 0;
	bool elided = false;
};
struct GeometryDescriptor {
	Fn<LineGeometry(LineGeometry line)> layout;
	bool breakEverywhere = false;
};

[[nodiscard]] not_null<SpoilerMessCache*> DefaultSpoilerCache();

[[nodiscard]] GeometryDescriptor SimpleGeometry(
	int availableWidth,
	int fontHeight,
	int elisionHeight,
	int elisionRemoveFromEnd,
	bool elisionOneLine,
	bool elisionBreakEverywhere);

struct BlockPaintCache {
	QImage corners;
	QColor headerCached;
	QColor bgCached;
	QColor outlineCached;
	QColor iconCached;

	QColor header;
	QColor bg;
	QColor outline;
	QColor icon;
};

void ValidateBlockPaintCache(
	BlockPaintCache &cache,
	const style::ParagraphStyle &st);

struct SkipBlockPaintParts {
	bool skipTop : 1 = false;
	bool skipBottom : 1 = false;
};
void FillBlockPaint(
	QPainter &p,
	QRect rect,
	const BlockPaintCache &cache,
	const style::ParagraphStyle &st,
	SkipBlockPaintParts parts = {});

struct PaintContext {
	QPoint position;
	int outerWidth = 0; // For automatic RTL Ui inversion.
	int availableWidth = 0;
	GeometryDescriptor geometry; // By default is SimpleGeometry.
	style::align align = style::al_left;
	QRect clip;

	const style::TextPalette *palette = nullptr;
	BlockPaintCache *pre = nullptr;
	BlockPaintCache *blockquote = nullptr;
	std::span<SpecialColor> colors;
	SpoilerMessCache *spoiler = nullptr;
	crl::time now = 0;
	bool paused = false;
	bool pausedEmoji = false;
	bool pausedSpoiler = false;

	TextSelection selection;
	bool fullWidthSelection = true;

	int elisionHeight = 0;
	int elisionRemoveFromEnd = 0;
	bool elisionOneLine = false;
	bool elisionBreakEverywhere = false;
};

class String {
public:
	String(int minResizeWidth = kQFixedMax);
	String(
		const style::TextStyle &st,
		const QString &text,
		const TextParseOptions &options = kDefaultTextOptions,
		int minResizeWidth = kQFixedMax);
	String(
		const style::TextStyle &st,
		const TextWithEntities &textWithEntities,
		const TextParseOptions &options = kMarkupTextOptions,
		int minResizeWidth = kQFixedMax,
		const std::any &context = {});
	String(String &&other);
	String &operator=(String &&other);
	~String();

	[[nodiscard]] int countWidth(
		int width,
		bool breakEverywhere = false) const;
	[[nodiscard]] int countHeight(
		int width,
		bool breakEverywhere = false) const;

	struct LineWidthsOptions {
		bool breakEverywhere = false;
		int reserve = 0;
	};
	[[nodiscard]] std::vector<int> countLineWidths(int width) const;
	[[nodiscard]] std::vector<int> countLineWidths(
		int width,
		LineWidthsOptions options) const;

	struct DimensionsResult {
		int width = 0;
		int height = 0;
		std::vector<int> lineWidths;
	};
	struct DimensionsRequest {
		bool lineWidths = false;
		int reserve = 0;
	};
	[[nodiscard]] DimensionsResult countDimensions(
		GeometryDescriptor geometry) const;
	[[nodiscard]] DimensionsResult countDimensions(
		GeometryDescriptor geometry,
		DimensionsRequest request) const;

	void setText(const style::TextStyle &st, const QString &text, const TextParseOptions &options = kDefaultTextOptions);
	void setMarkedText(const style::TextStyle &st, const TextWithEntities &textWithEntities, const TextParseOptions &options = kMarkupTextOptions, const std::any &context = {});

	[[nodiscard]] bool hasLinks() const;
	void setLink(uint16 index, const ClickHandlerPtr &lnk);

	[[nodiscard]] bool hasSpoilers() const;
	void setSpoilerRevealed(bool revealed, anim::type animated);
	void setSpoilerLinkFilter(Fn<bool(const ClickContext&)> filter);

	[[nodiscard]] bool hasSkipBlock() const;
	bool updateSkipBlock(int width, int height);
	bool removeSkipBlock();

	[[nodiscard]] int maxWidth() const {
		return _maxWidth;
	}
	[[nodiscard]] int minHeight() const {
		return _minHeight;
	}
	[[nodiscard]] int countMaxMonospaceWidth() const;

	void draw(QPainter &p, const PaintContext &context) const;
	[[nodiscard]] StateResult getState(
		QPoint point,
		GeometryDescriptor geometry,
		StateRequest request = StateRequest()) const;

	void draw(Painter &p, int32 left, int32 top, int32 width, style::align align = style::al_left, int32 yFrom = 0, int32 yTo = -1, TextSelection selection = { 0, 0 }, bool fullWidthSelection = true) const;
	void drawElided(Painter &p, int32 left, int32 top, int32 width, int32 lines = 1, style::align align = style::al_left, int32 yFrom = 0, int32 yTo = -1, int32 removeFromEnd = 0, bool breakEverywhere = false, TextSelection selection = { 0, 0 }) const;
	void drawLeft(Painter &p, int32 left, int32 top, int32 width, int32 outerw, style::align align = style::al_left, int32 yFrom = 0, int32 yTo = -1, TextSelection selection = { 0, 0 }) const;
	void drawLeftElided(Painter &p, int32 left, int32 top, int32 width, int32 outerw, int32 lines = 1, style::align align = style::al_left, int32 yFrom = 0, int32 yTo = -1, int32 removeFromEnd = 0, bool breakEverywhere = false, TextSelection selection = { 0, 0 }) const;
	void drawRight(Painter &p, int32 right, int32 top, int32 width, int32 outerw, style::align align = style::al_left, int32 yFrom = 0, int32 yTo = -1, TextSelection selection = { 0, 0 }) const;
	void drawRightElided(Painter &p, int32 right, int32 top, int32 width, int32 outerw, int32 lines = 1, style::align align = style::al_left, int32 yFrom = 0, int32 yTo = -1, int32 removeFromEnd = 0, bool breakEverywhere = false, TextSelection selection = { 0, 0 }) const;

	[[nodiscard]] StateResult getState(QPoint point, int width, StateRequest request = StateRequest()) const;
	[[nodiscard]] StateResult getStateLeft(QPoint point, int width, int outerw, StateRequest request = StateRequest()) const;
	[[nodiscard]] StateResult getStateElided(QPoint point, int width, StateRequestElided request = StateRequestElided()) const;
	[[nodiscard]] StateResult getStateElidedLeft(QPoint point, int width, int outerw, StateRequestElided request = StateRequestElided()) const;

	[[nodiscard]] TextSelection adjustSelection(TextSelection selection, TextSelectType selectType) const;
	[[nodiscard]] bool isFullSelection(TextSelection selection) const {
		return (selection.from == 0) && (selection.to >= _text.size());
	}

	[[nodiscard]] bool isEmpty() const;
	[[nodiscard]] bool isNull() const {
		return !_st;
	}
	[[nodiscard]] int length() const {
		return _text.size();
	}

	[[nodiscard]] QString toString(
		TextSelection selection = AllTextSelection) const;
	[[nodiscard]] TextWithEntities toTextWithEntities(
		TextSelection selection = AllTextSelection) const;
	[[nodiscard]] TextForMimeData toTextForMimeData(
		TextSelection selection = AllTextSelection) const;

	[[nodiscard]] bool hasPersistentAnimation() const;
	void unloadPersistentAnimation();

	[[nodiscard]] bool isIsolatedEmoji() const;
	[[nodiscard]] IsolatedEmoji toIsolatedEmoji() const;

	[[nodiscard]] bool isOnlyCustomEmoji() const;
	[[nodiscard]] OnlyCustomEmoji toOnlyCustomEmoji() const;

	[[nodiscard]] bool hasNotEmojiAndSpaces() const;
	[[nodiscard]] const std::vector<Modification> &modifications() const;

	[[nodiscard]] const style::TextStyle *style() const {
		return _st;
	}

	void clear();

private:
	using TextBlocks = std::vector<Block>;

	class ExtendedWrap : public std::unique_ptr<ExtendedData> {
	public:
		ExtendedWrap() noexcept;
		ExtendedWrap(ExtendedWrap &&other) noexcept;
		ExtendedWrap &operator=(ExtendedWrap &&other) noexcept;
		~ExtendedWrap();

		ExtendedWrap(
			std::unique_ptr<ExtendedData> &&other) noexcept;
		ExtendedWrap &operator=(
			std::unique_ptr<ExtendedData> &&other) noexcept;

	private:
		void adjustFrom(const ExtendedWrap *other);

	};

	[[nodiscard]] not_null<ExtendedData*> ensureExtended();

	[[nodiscard]] uint16 countBlockEnd(
		const TextBlocks::const_iterator &i,
		const TextBlocks::const_iterator &e) const;
	[[nodiscard]] uint16 countBlockLength(
		const TextBlocks::const_iterator &i,
		const TextBlocks::const_iterator &e) const;
	[[nodiscard]] ParagraphDetails *paragraphByIndex(int index) const;
	[[nodiscard]] const style::ParagraphStyle &paragraphStyle(
		not_null<ParagraphDetails*> info) const;
	[[nodiscard]] QMargins paragraphPadding(ParagraphDetails *info) const;
	[[nodiscard]] int paragraphMinWidth(ParagraphDetails *info) const;
	[[nodiscard]] const QString &paragraphHeaderText(
		ParagraphDetails *info) const;

	// block must be either nullptr or a pointer to a NewlineBlock.
	[[nodiscard]] int paragraphIndex(const AbstractBlock *block) const;

	// Template method for originalText(), originalTextWithEntities().
	template <
		typename AppendPartCallback,
		typename ClickHandlerStartCallback,
		typename ClickHandlerFinishCallback,
		typename FlagsChangeCallback>
	void enumerateText(
		TextSelection selection,
		AppendPartCallback appendPartCallback,
		ClickHandlerStartCallback clickHandlerStartCallback,
		ClickHandlerFinishCallback clickHandlerFinishCallback,
		FlagsChangeCallback flagsChangeCallback) const;

	// Template method for countWidth(), countHeight(), countLineWidths().
	// callback(lineWidth, lineHeight) will be called for all lines with:
	// QFixed lineWidth, int lineHeight
	template <typename Callback>
	void enumerateLines(
		int w,
		bool breakEverywhere,
		Callback callback) const;

	void recountNaturalSize(
		bool initial,
		Qt::LayoutDirection optionsDir = Qt::LayoutDirectionAuto);

	[[nodiscard]] TextForMimeData toText(
		TextSelection selection,
		bool composeExpanded,
		bool composeEntities) const;

	const style::TextStyle *_st = nullptr;
	QString _text;
	TextBlocks _blocks;
	ExtendedWrap _extended;

	int _minResizeWidth = 0;
	int _maxWidth = 0;
	int _minHeight = 0;
	uint16 _startParagraphIndex = 0;
	bool _startParagraphLTR : 1 = false;
	bool _startParagraphRTL : 1 = false;
	bool _hasCustomEmoji : 1 = false;
	bool _isIsolatedEmoji : 1 = false;
	bool _isOnlyCustomEmoji : 1 = false;
	bool _hasNotEmojiAndSpaces : 1 = false;
	bool _skipBlockAddedNewline : 1 = false;
	bool _endsWithParagraphDetails : 1 = false;

	friend class Parser;
	friend class Renderer;

};

[[nodiscard]] bool IsBad(QChar ch);
[[nodiscard]] bool IsWordSeparator(QChar ch);
[[nodiscard]] bool IsAlmostLinkEnd(QChar ch);
[[nodiscard]] bool IsLinkEnd(QChar ch);
[[nodiscard]] bool IsNewline(QChar ch);
[[nodiscard]] bool IsSpace(QChar ch);
[[nodiscard]] bool IsDiacritic(QChar ch);
[[nodiscard]] bool IsReplacedBySpace(QChar ch);
[[nodiscard]] bool IsTrimmed(QChar ch);

} // namespace Ui::Text

inline TextSelection snapSelection(int from, int to) {
	return { static_cast<uint16>(std::clamp(from, 0, 0xFFFF)), static_cast<uint16>(std::clamp(to, 0, 0xFFFF)) };
}
inline TextSelection shiftSelection(TextSelection selection, uint16 byLength) {
	return snapSelection(int(selection.from) + byLength, int(selection.to) + byLength);
}
inline TextSelection unshiftSelection(TextSelection selection, uint16 byLength) {
	return snapSelection(int(selection.from) - int(byLength), int(selection.to) - int(byLength));
}
inline TextSelection shiftSelection(TextSelection selection, const Ui::Text::String &byText) {
	return shiftSelection(selection, byText.length());
}
inline TextSelection unshiftSelection(TextSelection selection, const Ui::Text::String &byText) {
	return unshiftSelection(selection, byText.length());
}