TextSelection

A range of text that represents a selection.

属性

名称	类型	默认值	说明
base_offset	int	required	The offset at which the selection originates.
extent_offset	int	required	The offset at which the selection terminates.
affinity	'TextAffinity'	TextAffinity.DOWNSTREAM	If the text range is collapsed and has more than one visual location (e.g., occurs at a line break), which of the two locations to use when painting the caret.
directional	bool	False	Whether this selection has disambiguated its base and extent.

只读属性

名称	类型	默认值	说明
start	int	—	The index of the first character in the range. Note: This property is read-only.
end	int	—	The next index after the characters in this range. Note: This property is read-only.
is_valid	bool	—	Whether this range represents a valid position in the text. Note: This property is read-only.
is_collapsed	bool	—	Whether this range is empty (but still potentially placed inside the text). Note: This property is read-only.
is_normalized	bool	—	Whether the start of this range precedes the end. Note: This property is read-only.

方法

名称	类型	默认值	说明
get_selected_text	str	—	Returns the selected text from the given full text. Args: source_text: The full text to get the selection from. Raises: AssertionError: If the selection is not valid, i.e. is_valid is False.