Paragraph
A paragraph of text that is laid out.
Paragraphs can be displayed on a Canvas using the paint method.
Summary
Public functions |
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Unit |
fillBoundingBoxes(Fills the bounding boxes for characters provided in the |
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ResolvedTextDirection |
getBidiRunDirection(offset: Int)Get the text direction of the character at the given offset. |
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Rect |
getBoundingBox(offset: Int)Returns the bounding box as Rect of the character for given character offset. |
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Rect |
getCursorRect(offset: Int)Returns rectangle of the cursor area. |
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Float |
getHorizontalPosition(offset: Int, usePrimaryDirection: Boolean)Compute the horizontal position where a newly inserted character at |
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Float |
getLineBaseline(lineIndex: Int)Returns the distance from the top of the paragraph to the alphabetic baseline of the given line. |
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Float |
getLineBottom(lineIndex: Int)Returns the bottom y coordinate of the given line. |
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Int |
getLineEnd(lineIndex: Int, visibleEnd: Boolean)Returns the end offset of the given line |
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Int |
getLineForOffset(offset: Int)Returns the line number on which the specified text offset appears. |
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Int |
getLineForVerticalPosition(vertical: Float)Returns line number closest to the given graphical vertical position. |
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Float |
getLineHeight(lineIndex: Int)Returns the height of the given line. |
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Float |
getLineLeft(lineIndex: Int)Returns the left x Coordinate of the given line. |
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Float |
getLineRight(lineIndex: Int)Returns the right x Coordinate of the given line. |
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Int |
getLineStart(lineIndex: Int)Returns the start offset of the given line, inclusive. |
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Float |
getLineTop(lineIndex: Int)Returns the bottom y coordinate of the given line. |
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Float |
getLineWidth(lineIndex: Int)Returns the width of the given line. |
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Int |
getOffsetForPosition(position: Offset)Returns the character offset closest to the given graphical position. |
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ResolvedTextDirection |
getParagraphDirection(offset: Int)Get the text direction of the paragraph containing the given offset. |
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Path |
getPathForRange(start: Int, end: Int)Returns path that enclose the given text range. |
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TextRange |
getRangeForRect(Find the range of text which is inside the specified |
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TextRange |
getWordBoundary(offset: Int)Returns the TextRange of the word at the given character offset. |
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Boolean |
isLineEllipsized(lineIndex: Int)Returns true if the given line is ellipsized, otherwise returns false. |
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Unit |
paint( |
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Unit |
paint(Draws this paragraph onto given |
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Unit |
paint(Draws this paragraph onto given |
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Public properties |
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Boolean |
True if there is more vertical content, but the text was truncated, either because we reached |
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Float |
The distance from the top of the paragraph to the alphabetic baseline of the first line, in logical pixels. |
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Float |
The amount of vertical space this paragraph occupies. |
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Float |
The distance from the top of the paragraph to the alphabetic baseline of the last line, in logical pixels. |
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Int |
The total number of lines in the text. |
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Float |
Returns the smallest width beyond which increasing the width never decreases the height. |
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Float |
The width for text if all soft wrap opportunities were taken. |
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List<Rect?> |
The bounding boxes reserved for the input placeholders in this Paragraphs. |
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Float |
The amount of horizontal space this paragraph occupies. |
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Public functions
fillBoundingBoxes
fun fillBoundingBoxes(
range: TextRange,
array: FloatArray,
arrayStart: @IntRange(from = 0) Int
): Unit
Fills the bounding boxes for characters provided in the range into array. The array is filled starting from arrayStart (inclusive). The coordinates are in local text layout coordinates.
The returned information consists of left/right of a character; line top and bottom for the same character.
For the grapheme consists of multiple code points, e.g. ligatures, combining marks, the first character has the total width and the remaining are returned as zero-width.
The array divided into segments of four where each index in that segment represents left, top, right, bottom of the character.
The size of the provided array should be greater or equal than the four times * TextRange length.
The final order of characters in the array is from TextRange.min to TextRange.max.
| Parameters | |
|---|---|
range: TextRange |
the |
array: FloatArray |
the array to fill in the values. The array divided into segments of four where each index in that segment represents left, top, right, bottom of the character. |
arrayStart: @IntRange(from = 0) Int |
the inclusive start index in the array where the function will start filling in the values from |
getBidiRunDirection
fun getBidiRunDirection(offset: Int): ResolvedTextDirection
Get the text direction of the character at the given offset.
getBoundingBox
fun getBoundingBox(offset: Int): Rect
Returns the bounding box as Rect of the character for given character offset. Rect includes the top, bottom, left and right of a character.
getHorizontalPosition
fun getHorizontalPosition(offset: Int, usePrimaryDirection: Boolean): Float
Compute the horizontal position where a newly inserted character at offset would be.
If the inserted character at offset is within a LTR/RTL run, the returned position will be the left(right) edge of the character.
For example:
Paragraph's direction is LTR.
Text in logic order: L0 L1 L2 R3 R4 R5
Text in visual order: L0 L1 L2 R5 R4 R3
position of the offset(2): |
position of the offset(4): |
However, when the offset is at the BiDi transition offset, there will be two possible visual positions, which depends on the direction of the inserted character.
For example:
Paragraph's direction is LTR.
Text in logic order: L0 L1 L2 R3 R4 R5
Text in visual order: L0 L1 L2 R5 R4 R3
position of the offset(3): | (The inserted character is LTR)
| (The inserted character is RTL)
In this case, usePrimaryDirection will be used to resolve the ambiguity. If true, the inserted character's direction is assumed to be the same as Paragraph's direction. Otherwise, the inserted character's direction is assumed to be the opposite of the Paragraph's direction.
For example:
Paragraph's direction is LTR.
Text in logic order: L0 L1 L2 R3 R4 R5
Text in visual order: L0 L1 L2 R5 R4 R3
position of the offset(3): | (usePrimaryDirection is true)
| (usePrimaryDirection is false)
This method is useful to compute cursor position.
| Parameters | |
|---|---|
offset: Int |
the offset of the character, in the range of 0, length. |
usePrimaryDirection: Boolean |
whether the paragraph direction is respected when |
| Returns | |
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Float |
a float number representing the horizontal position in the unit of pixel. |
getLineBaseline
fun getLineBaseline(lineIndex: Int): Float
Returns the distance from the top of the paragraph to the alphabetic baseline of the given line.
getLineBottom
fun getLineBottom(lineIndex: Int): Float
Returns the bottom y coordinate of the given line.
getLineEnd
fun getLineEnd(lineIndex: Int, visibleEnd: Boolean = false): Int
Returns the end offset of the given line
Characters being ellipsized are treated as invisible characters. So that if visibleEnd is false, it will return line end including the ellipsized characters and vice verse.
| Parameters | |
|---|---|
lineIndex: Int |
the line number |
visibleEnd: Boolean = false |
if true, the returned line end will not count trailing whitespaces or linefeed characters. Otherwise, this function will return the logical line end. By default it's false. |
| Returns | |
|---|---|
Int |
an exclusive end offset of the line. |
getLineForOffset
fun getLineForOffset(offset: Int): Int
Returns the line number on which the specified text offset appears. If you ask for a position before 0, you get 0; if you ask for a position beyond the end of the text, you get the last line.
getLineForVerticalPosition
fun getLineForVerticalPosition(vertical: Float): Int
Returns line number closest to the given graphical vertical position. If you ask for a vertical position before 0, you get 0; if you ask for a vertical position beyond the last line, you get the last line.
getLineRight
fun getLineRight(lineIndex: Int): Float
Returns the right x Coordinate of the given line.
getLineStart
fun getLineStart(lineIndex: Int): Int
Returns the start offset of the given line, inclusive.
getOffsetForPosition
fun getOffsetForPosition(position: Offset): Int
Returns the character offset closest to the given graphical position.
getParagraphDirection
fun getParagraphDirection(offset: Int): ResolvedTextDirection
Get the text direction of the paragraph containing the given offset.
getPathForRange
fun getPathForRange(start: Int, end: Int): Path
Returns path that enclose the given text range.
getRangeForRect
fun getRangeForRect(
rect: Rect,
granularity: TextGranularity,
inclusionStrategy: TextInclusionStrategy
): TextRange
Find the range of text which is inside the specified rect. This method will break text into small text segments based on the given granularity such as character or word. It also support different inclusionStrategy, which determines when a small text segments is considered as inside the rect. Note that the word/character breaking is both operating system and language dependent. In the certain cases, the text may be break into smaller segments than the specified the granularity. If a text segment spans multiple lines or multiple directional runs (e.g. a hyphenated word), the text segment is divided into pieces at the line and run breaks, then the text segment is considered to be inside the area if any of its pieces are inside the area.
| Parameters | |
|---|---|
rect: Rect |
the rectangle area in which the text range will be found. |
granularity: TextGranularity |
the granularity of the text, it controls how text is segmented. |
inclusionStrategy: TextInclusionStrategy |
the strategy that determines whether a range of text's bounds is inside the given |
| Returns | |
|---|---|
TextRange |
the |
getWordBoundary
fun getWordBoundary(offset: Int): TextRange
Returns the TextRange of the word at the given character offset. Characters not part of a word, such as spaces, symbols, and punctuation, have word breaks on both sides. In such cases, this method will return TextRange(offset, offset). Word boundaries are defined more precisely in Unicode Standard Annex #29 http://www.unicode.org/reports/tr29/#Word_Boundaries
isLineEllipsized
fun isLineEllipsized(lineIndex: Int): Boolean
Returns true if the given line is ellipsized, otherwise returns false.
| Parameters | |
|---|---|
lineIndex: Int |
a 0 based line index |
| Returns | |
|---|---|
Boolean |
true if the given line is ellipsized, otherwise false |
paint
fun paint(
canvas: Canvas,
color: Color,
shadow: Shadow?,
textDecoration: TextDecoration?
): Unit
paint
fun paint(
canvas: Canvas,
color: Color = Color.Unspecified,
shadow: Shadow? = null,
textDecoration: TextDecoration? = null,
drawStyle: DrawStyle? = null,
blendMode: BlendMode = DrawScope.DefaultBlendMode
): Unit
Draws this paragraph onto given canvas while modifying supported draw properties. Any change caused by overriding parameters are permanent, meaning that they affect the subsequent paint calls.
| Parameters | |
|---|---|
canvas: Canvas |
Canvas to draw this paragraph on. |
color: Color = Color.Unspecified |
Applies to the default text paint color that's used by this paragraph. Text color spans are not affected. |
shadow: Shadow? = null |
Applies to the default text paint shadow that's used by this paragraph. Text shadow spans are not affected. |
textDecoration: TextDecoration? = null |
Applies to the default text paint that's used by this paragraph. Spans that specify a TextDecoration are not affected. |
drawStyle: DrawStyle? = null |
Applies to the default text paint style that's used by this paragraph. Spans that specify a DrawStyle are not affected. Passing this value as |
blendMode: BlendMode = DrawScope.DefaultBlendMode |
Blending algorithm to be applied to the Paragraph while painting. |
paint
fun paint(
canvas: Canvas,
brush: Brush,
alpha: Float = Float.NaN,
shadow: Shadow? = null,
textDecoration: TextDecoration? = null,
drawStyle: DrawStyle? = null,
blendMode: BlendMode = DrawScope.DefaultBlendMode
): Unit
Draws this paragraph onto given canvas while modifying supported draw properties. Any change caused by overriding parameters are permanent, meaning that they affect the subsequent paint calls.
| Parameters | |
|---|---|
canvas: Canvas |
Canvas to draw this paragraph on. |
brush: Brush |
Applies to the default text paint shader that's used by this paragraph. Text brush spans are not affected. If brush is type of |
alpha: Float = Float.NaN |
Applies to the default text paint alpha that's used by this paragraph. Text alpha spans are not affected. |
shadow: Shadow? = null |
Applies to the default text paint shadow that's used by this paragraph. Text shadow spans are not affected. |
textDecoration: TextDecoration? = null |
Applies to the default text paint that's used by this paragraph. Spans that specify a TextDecoration are not affected. |
drawStyle: DrawStyle? = null |
Applies to the default text paint style that's used by this paragraph. Spans that specify a DrawStyle are not affected. Passing this value as |
blendMode: BlendMode = DrawScope.DefaultBlendMode |
Blending algorithm to be applied to the Paragraph while painting. |
Public properties
didExceedMaxLines
val didExceedMaxLines: Boolean
True if there is more vertical content, but the text was truncated, either because we reached maxLines lines of text or because the maxLines was null, ellipsis was not null, and one of the lines exceeded the width constraint.
See the discussion of the maxLines and ellipsis arguments at ParagraphStyle.
firstBaseline
val firstBaseline: Float
The distance from the top of the paragraph to the alphabetic baseline of the first line, in logical pixels.
lastBaseline
val lastBaseline: Float
The distance from the top of the paragraph to the alphabetic baseline of the last line, in logical pixels.
maxIntrinsicWidth
val maxIntrinsicWidth: Float
Returns the smallest width beyond which increasing the width never decreases the height.
minIntrinsicWidth
val minIntrinsicWidth: Float
The width for text if all soft wrap opportunities were taken.
placeholderRects
val placeholderRects: List<Rect?>
The bounding boxes reserved for the input placeholders in this Paragraphs. Their locations are relative to this Paragraph's coordinate. The order of this list corresponds to that of input placeholders. Notice that Rect in placeholderRects is nullable. When Rect is null, it indicates that the corresponding Placeholder is ellipsized.