harmony 鸿蒙OH_Drawing_LineMetrics

2025-06-12
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OH_Drawing_LineMetrics

Overview

The OH_Drawing_LineMetrics struct describes the measurement information about a line of text.

Since: 12

Related module: Drawing

Header file: drawing_text_typography.h

Summary

Member Variables

Name	Description
double ascender	Part of a lowercase letter that extends beyond the meanline.
double descender	Part of a lowercase letter that extends below the baseline.
double capHeight	Height of an uppercase letter above the baseline.
double xHeight	Height of a lowercase letter, specifically the lowercase x, not including ascenders and descenders.
double width	Horizontal space taken up by a character.
double height	Line height.
double x	Distance from the left edge of the leftmost character to the left edge of the container. For left alignment, the value is 0. For right alignment, the value is the container width minus the text width.
double y	Height from the top edge of the character to the top of the container. The first line is 0, and the second line is the height of the first line.
size_t startIndex	Index of the first character in the line.
size_t endIndex	Index of the last character in the line.
OH_Drawing_Font_Metrics firstCharMetrics	Measurement information of the first character.

Member Variable Description

ascender

double OH_Drawing_LineMetrics::ascender

Description

Part of a lowercase letter that extends beyond the meanline.

capHeight

double OH_Drawing_LineMetrics::capHeight

Description

Height of an uppercase letter above the baseline.

descender

double OH_Drawing_LineMetrics::descender

Description

Part of a lowercase letter that extends below the baseline.

endIndex

size_t OH_Drawing_LineMetrics::endIndex

Description

Index of the last character in the line.

firstCharMetrics

OH_Drawing_Font_Metrics OH_Drawing_LineMetrics::firstCharMetrics

Description

Measurement information of the first character.

height

double OH_Drawing_LineMetrics::height

Description

Line height.

startIndex

size_t OH_Drawing_LineMetrics::startIndex

Description

Index of the first character in the line.

width

double OH_Drawing_LineMetrics::width

Description

Horizontal space taken up by a character.

x

double OH_Drawing_LineMetrics::x

Description

Distance from the left edge of the leftmost character to the left edge of the container. For left alignment, the value is 0. For right alignment, the value is the container width minus the text width.