ITextLayout3

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Interface ITextLayout3

interface ITextLayout3

Extends ITextLayout2 This interface extends ITextLayout2 with additional functionalities to retrieve ellipsis-related information for lines with text truncation.

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Methods

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getEllipsisStart()

u64 getEllipsisStart(u64 lineNumber)

Gets the UTF-16 character index where truncation begins for a given line:

• Where ellipsis is inserted (for tail, head, and middle modes)
• Where clipping occurs (for clip mode, without ellipsis character)

For multi-line layouts, each line’s indices start from 0. Supports ellipsis modes: tail, head, middle, clip. Use ITextLayout3::getEllipsisCount to check if a line is ellipsized/clipped (non-zero value indicates truncation).

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Parameters

lineNumber

u64 — Required The 0-based line index to query. Use ITextLayout2::getLineMetrics to get the total number of lines laid out.

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Returns

u64 The UTF-16 character index where ellipsis/clipping begins in the full line text. Note: It is recommended to always check ITextLayout3::getEllipsisCount to determine if ellipsis/clipping is present before using this method.

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Throws

• InvalidOperationError — when:
• Ellipsis was not successfully placed for tail, head, or middle modes
• Text fits within constraints without truncation
• Marquee ellipsis mode is used
• InvalidArgumentError — when:
• The line number is greater than the number of lines laid out

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getEllipsisCount()

u64 getEllipsisCount(u64 lineNumber)

Gets the count of UTF-16 characters for a given line:

• Replaced by ellipsis (for tail, head, and middle modes)
• Clipped (for clip mode, without ellipsis character)

This value represents the number of characters from the full line text that are hidden by the ellipsis/clipped. Combined with ITextLayout3::getEllipsisStart, you can determine the exact range of hidden text: [start, start + count).

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Parameters

lineNumber

u64 — Required The 0-based line index to query. Use ITextLayout2::getLineMetrics to get the total number of lines.

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Returns

u64 The count of UTF-16 characters hidden. Returns 0 if:

• Ellipsis was not successfully placed for tail, head, or middle modes
• No clipping occurred for clip mode
• Text fits within constraints without truncation
• The line number is greater than the number of lines laid out
• Marquee ellipsis mode is used

Returns non-zero when ellipsis is successfully applied:

• For tail, head, and middle modes: Ellipsis character was inserted and text was replaced
• For clip mode: Text was clipped even though no ellipsis character is displayed

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