The QTextBlock class provides a container for text fragments in a QTextDocument . 更多...
The QTextBlock class provides a container for text fragments in a QTextDocument .
A text block encapsulates a block or paragraph of text in a QTextDocument . QTextBlock provides read-only access to the block/paragraph structure of QTextDocuments. It is mainly of use if you want to implement your own layouts for the visual representation of a QTextDocument , or if you want to iterate over a document and write out the contents in your own custom format.
Text blocks are created by their parent documents. If you need to create a new text block, or modify the contents of a document while examining its contents, use the cursor-based interface provided by QTextCursor 代替。
Each text block is located at a specific position () in a document (). The contents of the block can be obtained by using the text () 函数。 length () function determines the block's size within the document (including formatting characters). The visual properties of the block are determined by its text layout (), its charFormat (), and its blockFormat ().
next () 和 上一 () functions enable iteration over consecutive valid blocks in a document under the condition that the document is not modified by other means during the iteration process. Note that, although blocks are returned in sequence, adjacent blocks may come from different places in the document structure. The validity of a block can be determined by calling isValid ().
QTextBlock provides comparison operators to make it easier to work with blocks: operator== () compares two block for equality, operator!= () compares two blocks for inequality, and operator< () determines whether a block precedes another in the same document.
Copies the other text block's attributes to this text 块。
Returns a text block iterator pointing to the beginning of the text block.
另请参阅 end ().
返回 QTextBlockFormat that describes block-specific properties.
另请参阅 charFormat ().
Returns an index into the document's internal list of block formats for the text block's format.
另请参阅 QTextDocument.allFormats ().
Returns the number of this block, or -1 if the block is 无效的。
该函数在 Qt 4.4 引入。
另请参阅 QTextCursor.blockNumber ().
返回 QTextCharFormat that describes the block's character format. The block's character format is used when inserting text into an empty block.
另请参阅 blockFormat ().
Returns an index into the document's internal list of character formats for the text block's character format.
另请参阅 QTextDocument.allFormats ().
清零 QTextLayout that is used to lay out and display the block's contents.
该函数在 Qt 4.4 引入。
另请参阅 layout ().
Returns true if the given position is located within the text block; otherwise returns false.
Returns the text document this text block belongs to, or 0 if the text block does not belong to any document.
Returns a text block iterator pointing to the end of the text 块。
另请参阅 begin (), next ()，和 上一 ().
Returns the first line number of this block, or -1 if the block is invalid. Unless the layout supports it, the line number is identical to the block number.
该函数在 Qt 4.5 引入。
另请参阅 QTextBlock.blockNumber ().
Returns true if this text block is valid; otherwise returns false.
Returns true if the block is visible; otherwise returns false.
该函数在 Qt 4.4 引入。
另请参阅 setVisible ().
返回 QTextLayout that is used to lay out and display the block's contents.
注意：返回的 QTextLayout object can only be modified from the documentChanged implementation of a QAbstractTextDocumentLayout subclass. Any changes applied from the outside cause undefined behavior.
另请参阅 clearLayout ().
Returns the length of the block in characters.
注意： The length returned includes all formatting characters, for example, newline.
另请参阅 text (), charFormat ()，和 blockFormat ().
Returns the line count. Not all document layouts support this feature.
该函数在 Qt 4.5 引入。
另请参阅 setLineCount ().
Returns the text block in the document after this block, or an empty text block if this is the last one.
Note that the next block may be in a different frame or table to this block.
另请参阅 上一 (), begin ()，和 end ().
Returns the index of the block's first character within the 文档。
Returns the text block in the document before this block, or an empty text block if this is the first one.
Note that the next block may be in a different frame or table to this block.
另请参阅 next (), begin ()，和 end ().
返回块修订。
该函数在 Qt 4.4 引入。
另请参阅 setRevision () 和 QTextDocument.revision ().
把行数设为 count .
该函数在 Qt 4.5 引入。
另请参阅 lineCount ().
把块修订设为 rev .
该函数在 Qt 4.4 引入。
另请参阅 revision () 和 QTextDocument.revision ().
Attaches the given data object to the text block.
QTextBlockUserData 可以是 used to store custom settings. The ownership is passed to the underlying text document, i.e. the provided QTextBlockUserData object will be deleted if the corresponding text block gets deleted. The user data object is not stored in the undo history, so it will not be available after undoing the deletion of a text block.
For example, if you write a programming editor in an IDE, you may want to let your user set breakpoints visually in your code for an integrated debugger. In a programming editor a line of text usually corresponds to one QTextBlock 。 QTextBlockUserData interface allows the developer to store data for each QTextBlock , like for example in which lines of the source code the user has a breakpoint set. Of course this could also be stored externally, but by storing it inside the QTextDocument , it will for example be automatically deleted when the user deletes the associated line. It's really just a way to store custom information in the QTextDocument without using custom properties in QTextFormat which would affect the undo/redo stack.
该函数在 Qt 4.1 引入。
另请参阅 userData ().
Stores the specified state integer value in the text block. This may be useful for example in a syntax highlighter to store a text parsing state.
该函数在 Qt 4.1 引入。
另请参阅 userState ().
把块的可见性设为 visible .
该函数在 Qt 4.4 引入。
另请参阅 isVisible ().
以纯文本形式返回块内容。
另请参阅 length (), charFormat ()，和 blockFormat ().
返回解析文本方向。
If the block has no explicit direction set, it will resolve the direction from the blocks content. Returns either Qt.LeftToRight or Qt.RightToLeft .
该函数在 Qt 4.7 引入。
另请参阅 QTextFormat.layoutDirection (), QString.isRightToLeft (), and Qt.LayoutDirection .
If the block represents a list item, returns the list that the item belongs to; otherwise returns 0.
返回指针指向 QTextBlockUserData object if previously set with setUserData () or a null pointer.
该函数在 Qt 4.1 引入。
另请参阅 setUserData ().
Returns the integer value previously set with setUserState () 或 -1。
该函数在 Qt 4.1 引入。
另请参阅 setUserState ().
