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java.lang.Objectcom.trolltech.qt.internal.QSignalEmitterInternal
com.trolltech.qt.QSignalEmitter
com.trolltech.qt.QtJambiObject
com.trolltech.qt.gui.QTextBlock
public class QTextBlock
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
instead.
Each text block is located at a specific position()
in a document()
. The contents of the block can be obtained by using the text()
function. The 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()
.
The next()
and previous()
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.
QTextBlockFormat
, QTextCharFormat
, and QTextFragment
.
Nested Class Summary |
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Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter |
---|
QSignalEmitter.AbstractSignal, QSignalEmitter.Signal0, QSignalEmitter.Signal1, QSignalEmitter.Signal2, QSignalEmitter.Signal3, QSignalEmitter.Signal4, QSignalEmitter.Signal5, QSignalEmitter.Signal6, QSignalEmitter.Signal7, QSignalEmitter.Signal8, QSignalEmitter.Signal9 |
Nested classes/interfaces inherited from class com.trolltech.qt.internal.QSignalEmitterInternal |
---|
com.trolltech.qt.internal.QSignalEmitterInternal.AbstractSignalInternal |
Field Summary |
---|
Fields inherited from class com.trolltech.qt.internal.QSignalEmitterInternal |
---|
currentSender |
Constructor Summary | |
---|---|
QTextBlock(QTextBlock o)
Copies the other text block's attributes to this text block. |
Method Summary | |
---|---|
QTextBlock_iterator |
begin()
Returns a text block iterator pointing to the beginning of the text block. |
QTextBlockFormat |
blockFormat()
Returns the QTextBlockFormat that describes block-specific properties. |
int |
blockFormatIndex()
Returns an index into the document's internal list of block formats for the text block's format. |
int |
blockNumber()
Returns the number of this block, or -1 if the block is invalid. |
QTextCharFormat |
charFormat()
Returns the QTextCharFormat that describes the block's character format. |
int |
charFormatIndex()
Returns an index into the document's internal list of character formats for the text block's character format. |
void |
clearLayout()
Clears the QTextLayout that is used to lay out and display the block's contents. |
QTextBlock |
clone()
This method is reimplemented for internal reasons |
boolean |
contains(int position)
Returns true if the given position is located within the text block; otherwise returns false. |
QTextDocument |
document()
Returns the text document this text block belongs to, or 0 if the text block does not belong to any document. |
QTextBlock_iterator |
end()
Returns a text block iterator pointing to the end of the text block. |
boolean |
isValid()
Returns true if this text block is valid; otherwise returns false. |
boolean |
isVisible()
Returns true if the block is visible; otherwise returns false. |
QTextLayout |
layout()
Returns the QTextLayout that is used to lay out and display the block's contents. |
int |
length()
Returns the length of the block in characters. |
QTextBlock |
next()
Returns the text block in the document after this block, or an empty text block if this is the last one. |
int |
position()
Returns the index of the block's first character within the document. |
QTextBlock |
previous()
Returns the text block in the document before this block, or an empty text block if this is the first one. |
int |
revision()
Returns the blocks revision. |
void |
setRevision(int rev)
Sets a blocks revision to rev. |
void |
setUserData(QTextBlockUserData data)
Attaches the given data object to the text block. |
void |
setUserState(int state)
Stores the specified state integer value in the text block. |
void |
setVisible(boolean visible)
Sets the block's visibility to visible. |
java.lang.String |
text()
Returns the block's contents as plain text. |
QTextList |
textList()
If the block represents a list item, returns the list that the item belongs to; otherwise returns 0. |
QTextBlockUserData |
userData()
Returns a pointer to a QTextBlockUserData object if previously set with setUserData() or a null pointer. |
int |
userState()
Returns the integer value previously set with setUserState() or -1. |
Methods inherited from class com.trolltech.qt.QtJambiObject |
---|
dispose, disposed, equals, finalize, reassignNativeResources, tr, tr, tr |
Methods inherited from class com.trolltech.qt.QSignalEmitter |
---|
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread |
Methods inherited from class com.trolltech.qt.internal.QSignalEmitterInternal |
---|
__qt_signalInitialization |
Methods inherited from class java.lang.Object |
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getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Methods inherited from interface java.lang.Comparable |
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compareTo |
Methods inherited from interface com.trolltech.qt.QtJambiInterface |
---|
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership |
Constructor Detail |
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public QTextBlock(QTextBlock o)
Method Detail |
---|
public final QTextBlock_iterator begin()
end()
.
public final QTextBlockFormat blockFormat()
QTextBlockFormat
that describes block-specific properties. charFormat()
.
public final int blockFormatIndex()
QTextDocument::object()
.
public final int blockNumber()
QTextCursor::blockNumber()
.
public final QTextCharFormat charFormat()
QTextCharFormat
that describes the block's character format. The block's character format is used when inserting text into an empty block. blockFormat()
.
public final int charFormatIndex()
QTextDocument::object()
.
public final void clearLayout()
QTextLayout
that is used to lay out and display the block's contents. layout()
.
public final boolean contains(int position)
public final QTextDocument document()
public final QTextBlock_iterator end()
begin()
, next()
, and previous()
.
public final boolean isValid()
public final boolean isVisible()
setVisible()
.
public final QTextLayout layout()
QTextLayout
that is used to lay out and display the block's contents. Note that the returned QTextLayout
object can only be modified from the documentChanged implementation of a QAbstractTextDocumentLayout
subclass. Any changes applied from the outside cause undefined behavior.
clearLayout()
.
public final int length()
Note: The length returned includes all formatting characters, for example, newline.
text()
, charFormat()
, and blockFormat()
.
public final QTextBlock next()
Note that the next block may be in a different frame or table to this block.
previous()
, begin()
, and end()
.
public final int position()
public final QTextBlock previous()
Note that the next block may be in a different frame or table to this block.
next()
, begin()
, and end()
.
public final int revision()
setRevision()
, and QTextDocument::revision()
.
public final void setRevision(int rev)
revision()
, and QTextDocument::revision()
.
public final void setUserData(QTextBlockUserData data)
QTextBlockUserData
can be 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. The 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.
userData()
.
public final void setUserState(int state)
userState()
.
public final void setVisible(boolean visible)
isVisible()
.
public final java.lang.String text()
length()
, charFormat()
, and blockFormat()
.
public final QTextList textList()
public final QTextBlockUserData userData()
QTextBlockUserData
object if previously set with setUserData()
or a null pointer. setUserData()
.
public final int userState()
setUserState()
or -1. setUserState()
.
public QTextBlock clone()
clone
in class java.lang.Object
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