A wrapper widget that automatically scales its content (e.g., image, GIF) to fit within the maximum allowed size, while preserving an aspect ratio. More...

#include <auto_scaling_attachment.h>

Inheritance diagram for AutoScalingAttachment:

Collaboration diagram for AutoScalingAttachment:

Signals
void	clicked ()
	Emitted when the user clicks on the attachment container. Typically used to trigger showing the full-size attachment.

Public Member Functions
	AutoScalingAttachment (QWidget content, QWidget parent=nullptr)
	Constructs an AutoScalingAttachment widget. Sets up the layout, installs event filters, connects signals for content loading, and triggers initial scaling check.

QWidget *	Content () const
	Gets a pointer to the original content widget.

QSize	ContentOriginalSize () const
	Gets the original, unscaled size of the content widget. Primarily uses the content's sizeHint().

bool	IsScaled () const
	Checks if the content is currently scaled down.

void	SetMaxAllowedSize (const QSize &max_size)
	Sets the maximum allowed size for the content. If the content's original size exceeds this, it will be scaled down. Triggers a re-evaluation of the scaling.

QSize	sizeHint () const override
	Provides a size hint for the AutoScalingAttachment widget. Returns the current (potentially scaled) size of the content container.

Protected Member Functions
void	enterEvent (QEvent *event) override
	Handles mouse enter events. Shows the "Click to enlarge" label if the content is scaled.

bool	eventFilter (QObject watched, QEvent event) override
	Filters events for the content container, specifically capturing mouse clicks. Emits the clicked() signal when the content container is left-clicked.

void	leaveEvent (QEvent *event) override
	Handles mouse leave events. Hides the "Click to enlarge" label.

void	resizeEvent (QResizeEvent *event) override
	Handles resize events for the widget. Updates the position of the "Click to enlarge" label if it's visible.

Private Slots
void	CheckAndScaleContent ()
	Checks the content's original size against the maximum allowed size and applies scaling if necessary. Calculates the target scaled size, sets the fixed size of the content container, updates the is_scaled_ flag, and adjusts the UI accordingly (e.g., info label visibility). Triggers layout updates.

Private Member Functions
void	UpdateInfoLabelPosition () const
	Updates the position of the info_label_ ("Click to enlarge") to be centered at the bottom of the content container.

Private Attributes
QWidget *	content_
	Pointer to the original widget displaying the attachment content.

QWidget *	content_container_
	Container widget that holds the content_ and whose size is adjusted during scaling.

QLabel *	info_label_
	Label displayed over scaled content on hover ("Click to enlarge").

bool	is_scaled_
	Flag indicating whether the content is currently scaled down.

QSize	max_allowed_size_
	The maximum size allowed for the content before scaling is applied.

QSize	scaled_size_
	The current scaled size of the content_container_.

Detailed Description

A wrapper widget that automatically scales its content (e.g., image, GIF) to fit within the maximum allowed size, while preserving an aspect ratio.

This widget takes another widget (content) and displays it. If the content's original size exceeds the specified maximum size, the content is scaled down proportionally. A label indicating "Click to enlarge" is shown over the scaled content when the mouse hovers over it. Clicking the widget emits the clicked() signal, typically used to show the content in its original size in a separate viewer.

Constructor & Destructor Documentation

◆ AutoScalingAttachment()

AutoScalingAttachment::AutoScalingAttachment	(	QWidget *	content,
		QWidget *	parent = nullptr )

explicit

Constructs an AutoScalingAttachment widget. Sets up the layout, installs event filters, connects signals for content loading, and triggers initial scaling check.

Parameters

content	The widget containing the attachment content to be scaled.
parent	Optional parent widget.

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Member Function Documentation

◆ CheckAndScaleContent

void AutoScalingAttachment::CheckAndScaleContent ( )

privateslot

Checks the content's original size against the maximum allowed size and applies scaling if necessary. Calculates the target scaled size, sets the fixed size of the content container, updates the is_scaled_ flag, and adjusts the UI accordingly (e.g., info label visibility). Triggers layout updates.

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◆ clicked

void AutoScalingAttachment::clicked ( )

signal

Emitted when the user clicks on the attachment container. Typically used to trigger showing the full-size attachment.

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◆ Content()

QWidget * AutoScalingAttachment::Content ( ) const

inline

Gets a pointer to the original content widget.

Returns: Pointer to the content QWidget.

◆ ContentOriginalSize()

QSize AutoScalingAttachment::ContentOriginalSize ( ) const

Gets the original, unscaled size of the content widget. Primarily uses the content's sizeHint().

Returns: The original QSize of the content, or an invalid QSize if undetermined.

◆ enterEvent()

void AutoScalingAttachment::enterEvent ( QEvent * event )

overrideprotected

Handles mouse enter events. Shows the "Click to enlarge" label if the content is scaled.

Parameters

event The entered event.

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◆ eventFilter()

bool AutoScalingAttachment::eventFilter	(	QObject *	watched,
		QEvent *	event )

overrideprotected

Filters events for the content container, specifically capturing mouse clicks. Emits the clicked() signal when the content container is left-clicked.

Parameters

watched	The object being watched (should be content_container_).
event	The event being processed.

Returns: True if the event was a left-click on the container (event handled), false otherwise.

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◆ IsScaled()

bool AutoScalingAttachment::IsScaled ( ) const

inline

Checks if the content is currently scaled down.

Returns: True if the content is scaled, false otherwise.

◆ leaveEvent()

void AutoScalingAttachment::leaveEvent ( QEvent * event )

overrideprotected

Handles mouse leave events. Hides the "Click to enlarge" label.

Parameters

event The leave event.

◆ resizeEvent()

void AutoScalingAttachment::resizeEvent ( QResizeEvent * event )

overrideprotected

Handles resize events for the widget. Updates the position of the "Click to enlarge" label if it's visible.

Parameters

event The resize event.

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◆ SetMaxAllowedSize()

void AutoScalingAttachment::SetMaxAllowedSize ( const QSize & max_size )

Sets the maximum allowed size for the content. If the content's original size exceeds this, it will be scaled down. Triggers a re-evaluation of the scaling.

Parameters

max_size The maximum QSize allowed for the content.

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◆ sizeHint()

QSize AutoScalingAttachment::sizeHint ( ) const

override

Provides a size hint for the AutoScalingAttachment widget. Returns the current (potentially scaled) size of the content container.

Returns: The recommended QSize for the widget.

◆ UpdateInfoLabelPosition()

void AutoScalingAttachment::UpdateInfoLabelPosition ( ) const

private

Updates the position of the info_label_ ("Click to enlarge") to be centered at the bottom of the content container.

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Member Data Documentation

◆ content_

QWidget* AutoScalingAttachment::content_

private

Pointer to the original widget displaying the attachment content.

◆ content_container_

QWidget* AutoScalingAttachment::content_container_

private

Container widget that holds the content_ and whose size is adjusted during scaling.

◆ info_label_

QLabel* AutoScalingAttachment::info_label_

private

Label displayed over scaled content on hover ("Click to enlarge").

◆ is_scaled_

bool AutoScalingAttachment::is_scaled_

private

Flag indicating whether the content is currently scaled down.

◆ max_allowed_size_

QSize AutoScalingAttachment::max_allowed_size_

private

The maximum size allowed for the content before scaling is applied.

◆ scaled_size_

QSize AutoScalingAttachment::scaled_size_

private

The current scaled size of the content_container_.

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

src/chat/files/attachments/auto_scaling_attachment.h
src/chat/files/attachments/auto_scaling_attachment.cpp

Signals

Public Member Functions

Protected Member Functions

Private Slots

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ AutoScalingAttachment()

Member Function Documentation

◆ CheckAndScaleContent

◆ clicked

◆ Content()

◆ ContentOriginalSize()

◆ enterEvent()

◆ eventFilter()

◆ IsScaled()

◆ leaveEvent()

◆ resizeEvent()

◆ SetMaxAllowedSize()

◆ sizeHint()

◆ UpdateInfoLabelPosition()

Member Data Documentation

◆ content_

◆ content_container_

◆ info_label_

◆ is_scaled_

◆ max_allowed_size_

◆ scaled_size_