cf::ui::base::device::CanvasUnitHelper¶

Helper for converting between canvas units and device pixels. More...

#include <device_pixel.h>

Public Types¶

	Name
enum class	BreakPoint { Compact, Medium, Expanded} Window width breakpoints for responsive layouts.

Public Functions¶

	Name
	CanvasUnitHelper(const qreal devicePixelRatio) Constructs a CanvasUnitHelper with the specified device pixel ratio.
qreal	dpToPx(qreal dp) const Converts device-independent pixels to physical pixels.
qreal	spToPx(qreal sp) const Converts scalable pixels to physical pixels.
qreal	pxToDp(qreal px) const Converts physical pixels to device-independent pixels.
qreal	dpi() const Returns the device pixel ratio.
BreakPoint	breakPoint(qreal widthDp) Determines the breakpoint category for a given width.

Detailed Description¶

struct cf::ui::base::device::CanvasUnitHelper;

Helper for converting between canvas units and device pixels.

Note: Not thread-safe unless externally synchronized.

Provides conversion functions for device-independent pixels (dp), scalable pixels (sp), and physical pixels based on the device pixel ratio.

CanvasUnitHelper helper(2.0);
qreal pixels = helper.dpToPx(16.0); // Converts 16dp to pixels

Public Types Documentation¶

enum BreakPoint¶

Enumerator	Value	Description
Compact		Compact width: < 600dp.
Medium		Medium width: 600dp - 839dp.
Expanded		Expanded width: >= 840dp.

Window width breakpoints for responsive layouts.

Defines breakpoints for different screen size categories following Material Design guidelines.

Public Functions Documentation¶

function CanvasUnitHelper¶

CanvasUnitHelper(
    constqreal devicePixelRatio
)

Constructs a CanvasUnitHelper with the specified device pixel ratio.

Parameters:

devicePixelRatio The device pixel ratio (e.g., 1.0, 2.0, 3.0).

Exceptions:

None.

Return: None (constructor).

Since: 0.1

Note: None.

Warning: None.

function dpToPx¶

qreal dpToPx(
    qreal dp
) const

Converts device-independent pixels to physical pixels.

Parameters:

dp Value in device-independent pixels.

Exceptions:

None

Return: Value in physical pixels.

Since: 0.1

Note: None

Warning: None

function spToPx¶

qreal spToPx(
    qreal sp
) const

Converts scalable pixels to physical pixels.

Parameters:

sp Value in scalable pixels.

Exceptions:

None

Return: Value in physical pixels.

Since: 0.1

Note: None

Warning: None

function pxToDp¶

qreal pxToDp(
    qreal px
) const

Converts physical pixels to device-independent pixels.

Parameters:

px Value in physical pixels.

Exceptions:

None

Return: Value in device-independent pixels.

Since: 0.1

Note: None

Warning: None

function dpi¶

qreal dpi() const

Returns the device pixel ratio.

Exceptions:

None

Return: The device pixel ratio.

Since: 0.1

Note: None

Warning: None

function breakPoint¶

BreakPoint breakPoint(
    qreal widthDp
)

Determines the breakpoint category for a given width.

Parameters:

widthDp Width in device-independent pixels.

Exceptions:

None

Return: The breakpoint category for the specified width.

Since: 0.1

Note: None

Warning: None

Updated on 2026-03-09 at 10:14:00 +0000