LongTextDisplayEffect Class Reference

A custom widget for displaying potentially long text with cyberpunk aesthetics and efficient rendering. More...

#include <long_text_display_effect.h>

Inheritance diagram for LongTextDisplayEffect:

Collaboration diagram for LongTextDisplayEffect:

Signals
void	contentHeightChanged (int new_height)
	Emitted after ProcessText() finishes, indicating the total calculated height required to display all the processed lines.

Public Member Functions
	LongTextDisplayEffect (QString text, const QColor &text_color, QWidget *parent=nullptr)
	Constructs a CyberLongTextDisplay widget. Initializes the widget with default size policies, font, text color, and sets up a timer for delayed text processing.
QSize	minimumSizeHint () const override
void	SetScrollPosition (int position)
	Sets the vertical scroll position. This determines which part of the processed text is rendered in the paintEvent. Schedules a repaint if the position changes.
void	SetText (const QString &text)
	Sets the text content to be displayed. Updates the internal original text, invalidates the processed text cache, triggers delayed processing, and schedules a repaint.
void	SetTextColor (const QColor &color)
	Sets the color for the displayed text. Updates the internal text color and schedules a repaint.
QSize	sizeHint () const override
	Returns the recommended size for the widget based on the processed text content. The height is calculated based on the number of processed lines and font metrics. The width is calculated based on the longest processed line.

Protected Member Functions
void	paintEvent (QPaintEvent *event) override
	Overridden paint event handler. Draws the widget's appearance. Ensures the text is processed, draws the background gradient, renders the visible lines of the processed text based on the scroll position, and applies a scanline effect.
void	resizeEvent (QResizeEvent *event) override
	Overridden resize event handler. Invalidates the processed text cache and triggers delayed text processing when the widget's size changes.

Private Member Functions
void	ProcessText ()
	Processes the original_text_ into wrapped lines based on the current widget width. Splits the text into paragraphs and words, then reconstructs lines ensuring they fit within the available width. Handles word wrapping and breaking long words. Updates the processed_lines_ cache, calculates the required dimensions (width and height), updates the size_hint_, marks the cache as valid, and emits contentHeightChanged.

Private Attributes
bool	cached_text_valid_
	Flag indicating if the processed_lines_ cache is up to date with the original_text_ and widget width.
QFont	font_
	The font used for rendering text and calculating metrics.
QString	original_text_
	The original, unprocessed text content set via constructor or SetText().
QStringList	processed_lines_
	List of strings representing the text after processing (line wrapping).
int	scroll_position_
	Current vertical scroll position in pixels.
QSize	size_hint_
	Cached size hint calculated based on processed text dimensions.
QColor	text_color_
	The color used to render the text.
QTimer *	update_timer_ {}
	Timer used to delay text processing after resize or text change events.

Detailed Description

A custom widget for displaying potentially long text with cyberpunk aesthetics and efficient rendering.

This widget takes a long string, processes it by wrapping lines based on the widget's width, and renders only the visible portion of the text. It includes a cyberpunk-style background gradient and scanline effect. Text processing is delayed and cached to avoid excessive recalculations during resizing. It supports vertical scrolling via the SetScrollPosition method and emits a signal indicating the total required height for the content.

Constructor & Destructor Documentation

LongTextDisplayEffect()

LongTextDisplayEffect::LongTextDisplayEffect ( QString text, const QColor & text_color, QWidget * parent = nullptr )

explicit

Constructs a CyberLongTextDisplay widget. Initializes the widget with default size policies, font, text color, and sets up a timer for delayed text processing.

Parameters

text	The initial text content to display.
text_color	The color for the displayed text.
parent	Optional parent widget.

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Member Function Documentation

contentHeightChanged

void LongTextDisplayEffect::contentHeightChanged ( int new_height )

signal

Emitted after ProcessText() finishes, indicating the total calculated height required to display all the processed lines.

Parameters

new_height

The total content height in pixels.

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minimumSizeHint()

QSize LongTextDisplayEffect::minimumSizeHint ( ) const

nodiscardoverride

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paintEvent()

void LongTextDisplayEffect::paintEvent ( QPaintEvent * event )

overrideprotected

Overridden paint event handler. Draws the widget's appearance. Ensures the text is processed, draws the background gradient, renders the visible lines of the processed text based on the scroll position, and applies a scanline effect.

Parameters

event

The paint event.

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ProcessText()

void LongTextDisplayEffect::ProcessText ( )

private

Processes the original_text_ into wrapped lines based on the current widget width. Splits the text into paragraphs and words, then reconstructs lines ensuring they fit within the available width. Handles word wrapping and breaking long words. Updates the processed_lines_ cache, calculates the required dimensions (width and height), updates the size_hint_, marks the cache as valid, and emits contentHeightChanged.

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resizeEvent()

void LongTextDisplayEffect::resizeEvent ( QResizeEvent * event )

overrideprotected

Overridden resize event handler. Invalidates the processed text cache and triggers delayed text processing when the widget's size changes.

Parameters

event

The resize event.

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SetScrollPosition()

void LongTextDisplayEffect::SetScrollPosition

(

int

position

)

Sets the vertical scroll position. This determines which part of the processed text is rendered in the paintEvent. Schedules a repaint if the position changes.

Parameters

position

The vertical scroll position in pixels.

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SetText()

void LongTextDisplayEffect::SetText

(

const QString &

text

)

Sets the text content to be displayed. Updates the internal original text, invalidates the processed text cache, triggers delayed processing, and schedules a repaint.

Parameters

text	The new text content.

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SetTextColor()

void LongTextDisplayEffect::SetTextColor

(

const QColor &

color

)

Sets the color for the displayed text. Updates the internal text color and schedules a repaint.

Parameters

color

The new text color.

sizeHint()

QSize LongTextDisplayEffect::sizeHint ( ) const

nodiscardoverride

Returns the recommended size for the widget based on the processed text content. The height is calculated based on the number of processed lines and font metrics. The width is calculated based on the longest processed line.

Returns

The calculated QSize hint.

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Member Data Documentation

cached_text_valid_

bool LongTextDisplayEffect::cached_text_valid_

private

Flag indicating if the processed_lines_ cache is up to date with the original_text_ and widget width.

font_

QFont LongTextDisplayEffect::font_

private

The font used for rendering text and calculating metrics.

original_text_

QString LongTextDisplayEffect::original_text_

private

The original, unprocessed text content set via constructor or SetText().

processed_lines_

QStringList LongTextDisplayEffect::processed_lines_

private

List of strings representing the text after processing (line wrapping).

scroll_position_

int LongTextDisplayEffect::scroll_position_

private

Current vertical scroll position in pixels.

size_hint_

QSize LongTextDisplayEffect::size_hint_

private

Cached size hint calculated based on processed text dimensions.

text_color_

QColor LongTextDisplayEffect::text_color_

private

The color used to render the text.

update_timer_

QTimer* LongTextDisplayEffect::update_timer_ {}

private

Timer used to delay text processing after resize or text change events.

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The documentation for this class was generated from the following files:

• src/ui/chat/effects/long_text_display_effect.h
• src/ui/chat/effects/long_text_display_effect.cpp