class QTextCursor

The QTextCursor class offers an API to access and modify QTextDocuments. More…

Synopsis

Methods

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description

Text cursors are objects that are used to access and modify the contents and underlying structure of text documents via a programming interface that mimics the behavior of a cursor in a text editor. QTextCursor contains information about both the cursor’s position within a QTextDocument and any selection that it has made.

QTextCursor is modeled on the way a text cursor behaves in a text editor, providing a programmatic means of performing standard actions through the user interface. A document can be thought of as a single string of characters. The cursor’s current position() then is always either between two consecutive characters in the string, or else before the very first character or after the very last character in the string. Documents can also contain tables, lists, images, and other objects in addition to text but, from the developer’s point of view, the document can be treated as one long string. Some portions of that string can be considered to lie within particular blocks (e.g. paragraphs), or within a table’s cell, or a list’s item, or other structural elements. When we refer to “current character” we mean the character immediately before the cursor position() in the document. Similarly, the “current block” is the block that contains the cursor position() .

A QTextCursor also has an anchor() position. The text that is between the anchor() and the position() is the selection. If anchor() == position() there is no selection.

The cursor position can be changed programmatically using setPosition() and movePosition() ; the latter can also be used to select text. For selections see selectionStart() , selectionEnd() , hasSelection() , clearSelection() , and removeSelectedText() .

If the position() is at the start of a block, atBlockStart() returns true; and if it is at the end of a block, atBlockEnd() returns true. The format of the current character is returned by charFormat() , and the format of the current block is returned by blockFormat() .

Formatting can be applied to the current text document using the setCharFormat() , mergeCharFormat() , setBlockFormat() and mergeBlockFormat() functions. The ‘set’ functions will replace the cursor’s current character or block format, while the ‘merge’ functions add the given format properties to the cursor’s current format. If the cursor has a selection, the given format is applied to the current selection. Note that when only a part of a block is selected, the block format is applied to the entire block. The text at the current character position can be turned into a list using createList() .

Deletions can be achieved using deleteChar() , deletePreviousChar() , and removeSelectedText() .

Text strings can be inserted into the document with the insertText() function, blocks (representing new paragraphs) can be inserted with insertBlock() .

Existing fragments of text can be inserted with insertFragment() but, if you want to insert pieces of text in various formats, it is usually still easier to use insertText() and supply a character format.

Various types of higher-level structure can also be inserted into the document with the cursor:

  • Lists are ordered sequences of block elements that are decorated with bullet points or symbols. These are inserted in a specified format with insertList() .

  • Tables are inserted with the insertTable() function, and can be given an optional format. These contain an array of cells that can be traversed using the cursor.

  • Inline images are inserted with insertImage() . The image to be used can be specified in an image format, or by name.

  • Frames are inserted by calling insertFrame() with a specified format.

Actions can be grouped (i.e. treated as a single action for undo/redo) using beginEditBlock() and endEditBlock() .

Cursor movements are limited to valid cursor positions. In Latin writing this is between any two consecutive characters in the text, before the first character, or after the last character. In some other writing systems cursor movements are limited to “clusters” (e.g. a syllable in Devanagari, or a base letter plus diacritics). Functions such as movePosition() and deleteChar() limit cursor movement to these valid positions.

class MoveMode

Constant

Description

QTextCursor.MoveAnchor

Moves the anchor to the same position as the cursor itself.

QTextCursor.KeepAnchor

Keeps the anchor where it is.

If the anchor() is kept where it is and the position() is moved, the text in between will be selected.

class MoveOperation

Constant

Description

QTextCursor.NoMove

Keep the cursor where it is

QTextCursor.Start

Move to the start of the document.

QTextCursor.StartOfLine

Move to the start of the current line.

QTextCursor.StartOfBlock

Move to the start of the current block.

QTextCursor.StartOfWord

Move to the start of the current word.

QTextCursor.PreviousBlock

Move to the start of the previous block.

QTextCursor.PreviousCharacter

Move to the previous character.

QTextCursor.PreviousWord

Move to the beginning of the previous word.

QTextCursor.Up

Move up one line.

QTextCursor.Left

Move left one character.

QTextCursor.WordLeft

Move left one word.

QTextCursor.End

Move to the end of the document.

QTextCursor.EndOfLine

Move to the end of the current line.

QTextCursor.EndOfWord

Move to the end of the current word.

QTextCursor.EndOfBlock

Move to the end of the current block.

QTextCursor.NextBlock

Move to the beginning of the next block.

QTextCursor.NextCharacter

Move to the next character.

QTextCursor.NextWord

Move to the next word.

QTextCursor.Down

Move down one line.

QTextCursor.Right

Move right one character.

QTextCursor.WordRight

Move right one word.

QTextCursor.NextCell

Move to the beginning of the next table cell inside the current table. If the current cell is the last cell in the row, the cursor will move to the first cell in the next row.

QTextCursor.PreviousCell

Move to the beginning of the previous table cell inside the current table. If the current cell is the first cell in the row, the cursor will move to the last cell in the previous row.

QTextCursor.NextRow

Move to the first new cell of the next row in the current table.

QTextCursor.PreviousRow

Move to the last cell of the previous row in the current table.

See also

movePosition()

class SelectionType

This enum describes the types of selection that can be applied with the select() function.

Constant

Description

QTextCursor.Document

Selects the entire document.

QTextCursor.BlockUnderCursor

Selects the block of text under the cursor.

QTextCursor.LineUnderCursor

Selects the line of text under the cursor.

QTextCursor.WordUnderCursor

Selects the word under the cursor. If the cursor is not positioned within a string of selectable characters, no text is selected.
__init__()

Constructs a null cursor.

__init__(document)
Parameters:

document – QTextDocument

Constructs a cursor pointing to the beginning of the document.

__init__(frame)
Parameters:

frame – QTextFrame

Constructs a cursor pointing to the beginning of the frame.

__init__(block)
Parameters:

block – QTextBlock

Constructs a cursor pointing to the beginning of the block.

__init__(cursor)
Parameters:

cursor – QTextCursor

Constructs a new cursor that is a copy of cursor.

anchor()
Return type:

int

Returns the anchor position; this is the same as position() unless there is a selection in which case position() marks one end of the selection and anchor() marks the other end. Just like the cursor position, the anchor position is between characters.

atBlockEnd()
Return type:

bool

Returns true if the cursor is at the end of a block; otherwise returns false.

atBlockStart()
Return type:

bool

Returns true if the cursor is at the start of a block; otherwise returns false.

atEnd()
Return type:

bool

Returns true if the cursor is at the end of the document; otherwise returns false.

atStart()
Return type:

bool

Returns true if the cursor is at the start of the document; otherwise returns false.

beginEditBlock()

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

Indicates the start of a block of editing operations on the document that should appear as a single operation from an undo/redo point of view.

For example:

cursor = QTextCursor(textDocument)
cursor.beginEditBlock()
cursor.insertText("Hello")
cursor.insertText("World")
cursor.endEditBlock()
textDocument.undo()

The call to undo() will cause both insertions to be undone, causing both “World” and “Hello” to be removed.

It is possible to nest calls to beginEditBlock and endEditBlock . The top-most pair will determine the scope of the undo/redo operation.

See also

endEditBlock()

block()
Return type:

QTextBlock

Returns the block that contains the cursor.

blockCharFormat()
Return type:

QTextCharFormat

Returns the block character format of the block the cursor is in.

The block char format is the format used when inserting text at the beginning of an empty block.

blockFormat()
Return type:

QTextBlockFormat

Returns the block format of the block the cursor is in.

blockNumber()
Return type:

int

Returns the number of the block the cursor is in, or 0 if the cursor is invalid.

Note that this function only makes sense in documents without complex objects such as tables or frames.

charFormat()
Return type:

QTextCharFormat

Returns the format of the character immediately before the cursor position() . If the cursor is positioned at the beginning of a text block that is not empty then the format of the character immediately after the cursor is returned.

clearSelection()

Clears the current selection by setting the anchor to the cursor position.

Note that it does not delete the text of the selection.

columnNumber()
Return type:

int

Returns the position of the cursor within its containing line.

Note that this is the column number relative to a wrapped line, not relative to the block (i.e. the paragraph).

You probably want to call positionInBlock() instead.

createList(style)
Parameters:

style – Style

Return type:

QTextList

This is an overloaded function.

Creates and returns a new list with the given style, making the cursor’s current paragraph the first list item.

The style to be used is defined by the Style enum.

createList(format)
Parameters:

format – QTextListFormat

Return type:

QTextList

Creates and returns a new list with the given format, and makes the current paragraph the cursor is in the first list item.

currentFrame()
Return type:

QTextFrame

Returns a pointer to the current frame. Returns None if the cursor is invalid.

See also

insertFrame()

currentList()
Return type:

QTextList

Returns the current list if the cursor position() is inside a block that is part of a list; otherwise returns None.

currentTable()
Return type:

QTextTable

Returns a pointer to the current table if the cursor position() is inside a block that is part of a table; otherwise returns None.

See also

insertTable()

deleteChar()

If there is no selected text, deletes the character at the current cursor position; otherwise deletes the selected text.

deletePreviousChar()

If there is no selected text, deletes the character before the current cursor position; otherwise deletes the selected text.

document()
Return type:

QTextDocument

Returns the document this cursor is associated with.

endEditBlock()

Indicates the end of a block of editing operations on the document that should appear as a single operation from an undo/redo point of view.

See also

beginEditBlock()

hasComplexSelection()
Return type:

bool

Returns true if the cursor contains a selection that is not simply a range from selectionStart() to selectionEnd() ; otherwise returns false.

Complex selections are ones that span at least two cells in a table; their extent is specified by selectedTableCells() .

hasSelection()
Return type:

bool

Returns true if the cursor contains a selection; otherwise returns false.

insertBlock()

Inserts a new empty block at the cursor position() with the current blockFormat() and charFormat() .

See also

setBlockFormat()

insertBlock(format)
Parameters:

format – QTextBlockFormat

This is an overloaded function.

Inserts a new empty block at the cursor position() with block format format and the current charFormat() as block char format.

See also

setBlockFormat()

insertBlock(format, charFormat)
Parameters:

This is an overloaded function.

Inserts a new empty block at the cursor position() with block format format and charFormat as block char format.

See also

setBlockFormat()

insertFragment(fragment)
Parameters:

fragment – QTextDocumentFragment

Inserts the text fragment at the current position() .

insertFrame(format)
Parameters:

format – QTextFrameFormat

Return type:

QTextFrame

Inserts a frame with the given format at the current cursor position() , moves the cursor position() inside the frame, and returns the frame.

If the cursor holds a selection, the whole selection is moved inside the frame.

See also

hasSelection()

insertHtml(html)
Parameters:

html – str

Inserts the text html at the current position() . The text is interpreted as HTML.

Note

When using this function with a style sheet, the style sheet will only apply to the current block in the document. In order to apply a style sheet throughout a document, use setDefaultStyleSheet() instead.

insertImage(name)
Parameters:

name – str

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

This is an overloaded function.

Convenience method for inserting the image with the given name at the current position() .

img = QImage()
textDocument.addResource(QTextDocument.ImageResource, QUrl("myimage"), img)
cursor.insertImage("myimage")
insertImage(format)
Parameters:

format – QTextImageFormat

Inserts the image defined by format at the current position() .

insertImage(image[, name=""])
Parameters:

  • image – QImage

  • name – str

This is an overloaded function.

Convenience function for inserting the given image with an optional name at the current position() .

insertImage(format, alignment)
Parameters:

This is an overloaded function.

Inserts the image defined by the given format at the cursor’s current position with the specified alignment.

See also

position()

insertList(style)
Parameters:

style – Style

Return type:

QTextList

This is an overloaded function.

Inserts a new block at the current position and makes it the first list item of a newly created list with the given style. Returns the created list.

insertList(format)
Parameters:

format – QTextListFormat

Return type:

QTextList

Inserts a new block at the current position and makes it the first list item of a newly created list with the given format. Returns the created list.

insertMarkdown(markdown[, features=QTextDocument.MarkdownDialectGitHub])
Parameters:

Inserts the markdown text at the current position() , with the specified Markdown features. The default is GitHub dialect.

insertTable(rows, cols)
Parameters:

  • rows – int

  • cols – int

Return type:

QTextTable

This is an overloaded function.

Creates a new table with the given number of rows and columns, inserts it at the current cursor position() in the document, and returns the table object. The cursor is moved to the beginning of the first cell.

There must be at least one row and one column in the table.

See also

currentTable()

insertTable(rows, cols, format)
Parameters:
Return type:

QTextTable

Creates a new table with the given number of rows and columns in the specified format, inserts it at the current cursor position() in the document, and returns the table object. The cursor is moved to the beginning of the first cell.

There must be at least one row and one column in the table.

See also

currentTable()

insertText(text)
Parameters:

text – str

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

Inserts text at the current position, using the current character format.

If there is a selection, the selection is deleted and replaced by text, for example:

cursor.clearSelection()
cursor.movePosition(QTextCursor.NextWord, QTextCursor.KeepAnchor)
cursor.insertText("Hello World")

This clears any existing selection, selects the word at the cursor (i.e. from position() forward), and replaces the selection with the phrase “Hello World”.

Any ASCII linefeed characters (\n) in the inserted text are transformed into unicode block separators, corresponding to insertBlock() calls.

insertText(text, format)
Parameters:

This is an overloaded function.

Inserts text at the current position with the given format.

isCopyOf(other)
Parameters:

other – QTextCursor

Return type:

bool

Returns true if this cursor and other are copies of each other, i.e. one of them was created as a copy of the other and neither has moved since. This is much stricter than equality.

See also

operator=() operator==()

isNull()
Return type:

bool

Returns true if the cursor is null; otherwise returns false. A null cursor is created by the default constructor.

joinPreviousEditBlock()

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

Like beginEditBlock() indicates the start of a block of editing operations that should appear as a single operation for undo/redo. However unlike beginEditBlock() it does not start a new block but reverses the previous call to endEditBlock() and therefore makes following operations part of the previous edit block created.

For example:

cursor = QTextCursor(textDocument)
cursor.beginEditBlock()
cursor.insertText("Hello")
cursor.insertText("World")
cursor.endEditBlock()
# ...
cursor.joinPreviousEditBlock()
cursor.insertText("Hey")
cursor.endEditBlock()
textDocument.undo()

The call to undo() will cause all three insertions to be undone.

keepPositionOnInsert()
Return type:

bool

Returns whether the cursor should keep its current position when text gets inserted at the position of the cursor.

The default is false;

mergeBlockCharFormat(modifier)
Parameters:

modifier – QTextCharFormat

Modifies the block char format of the current block (or all blocks that are contained in the selection) with the block format specified by modifier.

mergeBlockFormat(modifier)
Parameters:

modifier – QTextBlockFormat

Modifies the block format of the current block (or all blocks that are contained in the selection) with the block format specified by modifier.

mergeCharFormat(modifier)
Parameters:

modifier – QTextCharFormat

Merges the cursor’s current character format with the properties described by format modifier. If the cursor has a selection, this function applies all the properties set in modifier to all the character formats that are part of the selection.

movePosition(op[, arg__2=QTextCursor.MoveMode.MoveAnchor[, n=1]])
Parameters:
Return type:

bool

Moves the cursor by performing the given operation n times, using the specified mode, and returns true if all operations were completed successfully; otherwise returns false.

For example, if this function is repeatedly used to seek to the end of the next word, it will eventually fail when the end of the document is reached.

By default, the move operation is performed once (n = 1).

If mode is KeepAnchor, the cursor selects the text it moves over. This is the same effect that the user achieves when they hold down the Shift key and move the cursor with the cursor keys.

__ne__(rhs)
Parameters:

rhs – QTextCursor

Return type:

bool

Returns true if the other cursor is at a different position in the document as this cursor; otherwise returns false.

__lt__(rhs)
Parameters:

rhs – QTextCursor

Return type:

bool

Returns true if the other cursor is positioned later in the document than this cursor; otherwise returns false.

__le__(rhs)
Parameters:

rhs – QTextCursor

Return type:

bool

Returns true if the other cursor is positioned later or at the same position in the document as this cursor; otherwise returns false.

__eq__(rhs)
Parameters:

rhs – QTextCursor

Return type:

bool

Returns true if the other cursor is at the same position in the document as this cursor; otherwise returns false.

__gt__(rhs)
Parameters:

rhs – QTextCursor

Return type:

bool

Returns true if the other cursor is positioned earlier in the document than this cursor; otherwise returns false.

__ge__(rhs)
Parameters:

rhs – QTextCursor

Return type:

bool

Returns true if the other cursor is positioned earlier or at the same position in the document as this cursor; otherwise returns false.

position()
Return type:

int

Returns the absolute position of the cursor within the document. The cursor is positioned between characters.

Note

The “characters” in this case refer to the string of QChar objects, i.e. 16-bit Unicode characters, and the position is considered an index into this string. This does not necessarily correspond to individual graphemes in the writing system, as a single grapheme may be represented by multiple Unicode characters, such as in the case of surrogate pairs, linguistic ligatures or diacritics.

See also

setPosition() movePosition() anchor() positionInBlock()

positionInBlock()
Return type:

int

Returns the relative position of the cursor within the block. The cursor is positioned between characters.

This is equivalent to position() - block().position().

Note

The “characters” in this case refer to the string of QChar objects, i.e. 16-bit Unicode characters, and the position is considered an index into this string. This does not necessarily correspond to individual graphemes in the writing system, as a single grapheme may be represented by multiple Unicode characters, such as in the case of surrogate pairs, linguistic ligatures or diacritics.

See also

position()

removeSelectedText()

If there is a selection, its content is deleted; otherwise does nothing.

See also

hasSelection()

select(selection)
Parameters:

selection – SelectionType

Selects text in the document according to the given selection.

selectedTableCells()
Return type:

PyObject

If the selection spans over table cells, firstRow is populated with the number of the first row in the selection, firstColumn with the number of the first column in the selection, and numRows and numColumns with the number of rows and columns in the selection. If the selection does not span any table cells the results are harmless but undefined.

selectedText()
Return type:

str

Returns the current selection’s text (which may be empty). This only returns the text, with no rich text formatting information. If you want a document fragment (i.e. formatted rich text) use selection() instead.

Note

If the selection obtained from an editor spans a line break, the text will contain a Unicode U+2029 paragraph separator character instead of a newline \n character. Use QString::replace() to replace these characters with newlines.

selection()
Return type:

QTextDocumentFragment

Returns the current selection (which may be empty) with all its formatting information. If you just want the selected text (i.e. plain text) use selectedText() instead.

Note

Unlike toPlainText() , selectedText() may include special unicode characters such as QChar::ParagraphSeparator.

See also

toPlainText()

selectionEnd()
Return type:

int

Returns the end of the selection or position() if the cursor doesn’t have a selection.

selectionStart()
Return type:

int

Returns the start of the selection or position() if the cursor doesn’t have a selection.

setBlockCharFormat(format)
Parameters:

format – QTextCharFormat

Sets the block char format of the current block (or all blocks that are contained in the selection) to format.

setBlockFormat(format)
Parameters:

format – QTextBlockFormat

Sets the block format of the current block (or all blocks that are contained in the selection) to format.

setCharFormat(format)
Parameters:

format – QTextCharFormat

Sets the cursor’s current character format to the given format. If the cursor has a selection, the given format is applied to the current selection.

setKeepPositionOnInsert(b)
Parameters:

b – bool

Defines whether the cursor should keep its current position when text gets inserted at the current position of the cursor.

If b is true, the cursor keeps its current position when text gets inserted at the positing of the cursor. If b is false, the cursor moves along with the inserted text.

The default is false.

Note that a cursor always moves when text is inserted before the current position of the cursor, and it always keeps its position when text is inserted after the current position of the cursor.

setPosition(pos[, mode=QTextCursor.MoveMode.MoveAnchor])
Parameters:

Moves the cursor to the absolute position in the document specified by pos using a MoveMode specified by m. The cursor is positioned between characters.

Note

The “characters” in this case refer to the string of QChar objects, i.e. 16-bit Unicode characters, and pos is considered an index into this string. This does not necessarily correspond to individual graphemes in the writing system, as a single grapheme may be represented by multiple Unicode characters, such as in the case of surrogate pairs, linguistic ligatures or diacritics. For a more generic approach to navigating the document, use movePosition() , which will respect the actual grapheme boundaries in the text.

See also

position() movePosition() anchor()

setVerticalMovementX(x)
Parameters:

x – int

Sets the visual x position for vertical cursor movements to x.

The vertical movement x position is cleared automatically when the cursor moves horizontally, and kept unchanged when the cursor moves vertically. The mechanism allows the cursor to move up and down on a visually straight line with proportional fonts, and to gently “jump” over short lines.

A value of -1 indicates no predefined x position. It will then be set automatically the next time the cursor moves up or down.

setVisualNavigation(b)
Parameters:

b – bool

Sets visual navigation to b.

Visual navigation means skipping over hidden text paragraphs. The default is false.

swap(other)
Parameters:

other – QTextCursor

Swaps this text cursor instance with other. This function is very fast and never fails.

verticalMovementX()
Return type:

int

Returns the visual x position for vertical cursor movements.

A value of -1 indicates no predefined x position. It will then be set automatically the next time the cursor moves up or down.

visualNavigation()
Return type:

bool

Returns true if the cursor does visual navigation; otherwise returns false.

Visual navigation means skipping over hidden text paragraphs. The default is false.