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Eclipse Platform
Release 3.5

org.eclipse.jface.text
Interface ITextViewer

All Known Subinterfaces:
ISourceViewer
All Known Implementing Classes:
ProjectionViewer, SourceViewer, TextConsoleViewer, TextViewer

public interface ITextViewer

A text viewer connects a text widget with an IDocument. The document is used as the widget's text model.

It supports the following kinds of listeners:

  • view port listeners to inform about changes of the viewer's view port
  • text listeners to inform about changes of the document and the subsequent viewer change
  • text input listeners to inform about changes of the viewer's input document.
A text viewer supports a set of configuration options and plug-ins defining its behavior:
  • undo manager
  • double click behavior
  • auto indentation
  • text hover
Installed plug-ins are not automatically activated. Plug-ins must be activated with the activatePlugins call. Most plug-ins can be defined per content type. Content types are derived from a partitioning of the text viewer's input document. In case of documents that support multiple partitionings, the implementer is responsible for determining the partitioning to use.

A text viewer also provides the concept of event consumption. Events handled by the viewer can be filtered and processed by a dynamic event consumer. With ITextViewerExtension, this mechanism has been replaced with the support for VerifyKeyListener.

A text viewer provides several text editing functions, some of them are configurable, through a text operation target interface. It also supports a presentation mode in which it only shows a specified section of its document. By calling setVisibleRegion clients define which section is visible. Clients can get access to this section by calling getVisibleRegion. The viewer's presentation mode does not affect any client of the viewer other than text listeners. With ITextViewerExtension5 the visible region support has been reworked. With that extension interface, text viewers are allowed to show fractions of their input document. I.e. a widget selection of two visually neighboring characters is no longer guaranteed to be two neighboring characters in the viewer's input document. Thus, viewers implementing ITextViewerExtension5 are potentially forced to change the fractions of the input document that are shown when clients ask for the visible region.

In order to provide backward compatibility for clients of ITextViewer, extension interfaces are used as a means of evolution. The following extension interfaces exist:

  • ITextViewerExtension since version 2.0 replacing the event consumer mechanism and introducing the concept of rewrite targets and means to manage the viewer's redraw behavior
  • ITextViewerExtension2since version 2.1 adding a way to invalidate a viewer's presentation and setters for hovers.
  • ITextViewerExtension3 since version 2.1 which itself was replaced by ITextViewerExtension5 in version 3.0
  • ITextViewerExtension4 since version 3.0 introducing focus handling for widget token keepers and the concept of text presentation listeners.
  • ITextViewerExtension5 since version 3.0 extending the visible region concept with explicit handling and conversion of widget and model coordinates.
  • ITextViewerExtension6 since version 3.1 extending the text viewer with the ability to detect hyperlinks and access the undo manager.
  • ITextViewerExtension7 since version 3.3 extending the text viewer with the ability to install tabs to spaces conversion.
  • ITextViewerExtension8 since version 3.4 extending the text viewer with the ability to print and rich hover support.

Clients may implement this interface and its extension interfaces or use the standard implementation TextViewer.

See Also:
ITextViewerExtension, ITextViewerExtension2, ITextViewerExtension3, ITextViewerExtension4, ITextViewerExtension5, ITextViewerExtension6, ITextViewerExtension7, ITextViewerExtension8, IDocument, ITextInputListener, IViewportListener, ITextListener, IEventConsumer

Method Summary
 void activatePlugins ()
          Activates the installed plug-ins.
 void addTextInputListener ( ITextInputListener listener)
          Adds a text input listener to this viewer.
 void addTextListener ( ITextListener listener)
          Adds a text listener to this viewer.
 void addViewportListener ( IViewportListener listener)
          Adds the given view port listener to this viewer.
 void changeTextPresentation ( TextPresentation presentation, boolean controlRedraw)
          Applies the color information encoded in the given text presentation.
 int getBottomIndex ()
          Returns the visible line with the highest line number.
 int getBottomIndexEndOffset ()
          Returns the document offset of the lower right corner of this viewer's view port.
  IDocument getDocument ()
          Returns the text viewer's input document.
  IFindReplaceTarget getFindReplaceTarget ()
          Returns the find/replace operation target of this viewer.
  Point getSelectedRange ()
          Returns the range of the current selection in coordinates of this viewer's document.
  ISelectionProvider getSelectionProvider ()
          Returns a selection provider dedicated to this viewer.
  ITextOperationTarget getTextOperationTarget ()
          Returns the text operation target of this viewer.
  StyledText getTextWidget ()
          Returns this viewer's SWT control, null if the control is disposed.
 int getTopIndex ()
          Returns the visible line with the smallest line number.
 int getTopIndexStartOffset ()
          Returns the document offset of the upper left corner of this viewer's view port.
 int getTopInset ()
          Returns the vertical offset of the first visible line.
  IRegion getVisibleRegion ()
          Returns the current visible region of this viewer's document.
 void invalidateTextPresentation ()
          Marks the currently applied text presentation as invalid.
 boolean isEditable ()
          Returns whether the shown text can be manipulated.
 boolean overlapsWithVisibleRegion (int offset, int length)
          Returns whether a given range overlaps with the visible region of this viewer's document.
 void removeTextInputListener ( ITextInputListener listener)
          Removes the given listener from this viewer's set of text input listeners.
 void removeTextListener ( ITextListener listener)
          Removes the given listener from this viewer's set of text listeners.
 void removeViewportListener ( IViewportListener listener)
          Removes the given listener from this viewer's set of view port listeners.
 void resetPlugins ()
          Resets the installed plug-ins.
 void resetVisibleRegion ()
          Resets the region of this viewer's document which is visible in the presentation.
 void revealRange (int offset, int length)
          Ensures that the given range is visible.
 void setAutoIndentStrategy ( IAutoIndentStrategy strategy, String contentType)
          Deprecated. since 3.1, use ITextViewerExtension2.prependAutoEditStrategy(IAutoEditStrategy, String) and ITextViewerExtension2.removeAutoEditStrategy(IAutoEditStrategy, String) instead
 void setDefaultPrefixes ( String[] defaultPrefixes, String contentType)
          Sets the strings that are used as prefixes when lines of the given content type are prefixed using the prefix text operation.
 void setDocument ( IDocument document)
          Sets the given document as the text viewer's model and updates the presentation accordingly.
 void setDocument ( IDocument document, int modelRangeOffset, int modelRangeLength)
          Sets the given document as this viewer's model and exposes the specified region.
 void setEditable (boolean editable)
          Sets the editable state.
 void setEventConsumer ( IEventConsumer consumer)
          Registers an event consumer with this viewer.
 void setIndentPrefixes ( String[] indentPrefixes, String contentType)
          Sets the strings that are used as prefixes when lines of the given content type are shifted using the shift text operation.
 void setSelectedRange (int offset, int length)
          Sets the selection to the specified range.
 void setTextColor ( Color color)
          Applies the given color as text foreground color to this viewer's selection.
 void setTextColor ( Color color, int offset, int length, boolean controlRedraw)
          Applies the given color as text foreground color to the specified section of this viewer.
 void setTextDoubleClickStrategy ( ITextDoubleClickStrategy strategy, String contentType)
          Sets this viewer's text double click strategy for the given content type.
 void setTextHover ( ITextHover textViewerHover, String contentType)
          Sets this viewer's text hover for the given content type.
 void setTopIndex (int index)
          Scrolls the widget so that the given index is the line with the smallest line number of all visible lines.
 void setUndoManager ( IUndoManager undoManager)
          Sets this viewer's undo manager.
 void setVisibleRegion (int offset, int length)
          Defines and sets the region of this viewer's document which will be visible in the presentation.
 

Method Detail

getTextWidget

StyledText getTextWidget()
Returns this viewer's SWT control, null if the control is disposed.

Calling API directly on the widget can interfere with features provided by a text viewer. Clients who call API directly on the widget are responsible to resolve such conflicts on their side.

Returns:
the SWT control or null

setUndoManager

void setUndoManager(
IUndoManager undoManager)
Sets this viewer's undo manager.

Parameters:
undoManager - the new undo manager. null is a valid argument.

setTextDoubleClickStrategy

void setTextDoubleClickStrategy(
ITextDoubleClickStrategy strategy,
                                
String contentType)
Sets this viewer's text double click strategy for the given content type.

Parameters:
strategy - the new double click strategy. null is a valid argument.
contentType - the type for which the strategy is registered

setAutoIndentStrategy

void setAutoIndentStrategy(
IAutoIndentStrategy strategy,
                           
String contentType)
Deprecated. since 3.1, use ITextViewerExtension2.prependAutoEditStrategy(IAutoEditStrategy, String) and ITextViewerExtension2.removeAutoEditStrategy(IAutoEditStrategy, String) instead

Sets this viewer's auto indent strategy for the given content type. If the given strategy is null any installed strategy for the content type is removed. This method has been replaced by ITextViewerExtension2.prependAutoEditStrategy(IAutoEditStrategy, String) and ITextViewerExtension2.removeAutoEditStrategy(IAutoEditStrategy, String). It is now equivalent to
                ITextViewerExtension2 extension= (ITextViewerExtension2) viewer;
                extension.removeAutoEditStrategy(oldStrategy, contentType);
                extension.prependAutoEditStrategy(strategy, contentType);
 

Parameters:
strategy - the new auto indent strategy. null is a valid argument.
contentType - the type for which the strategy is registered

setTextHover

void setTextHover(
ITextHover textViewerHover,
                  
String contentType)
Sets this viewer's text hover for the given content type.

This method has been replaced by ITextViewerExtension2.setTextHover(ITextHover, String, int). It is now equivalent to

    ITextViewerExtension2 extension= (ITextViewerExtension2) document;
    extension.setTextHover(textViewerHover, contentType, ITextViewerExtension2#DEFAULT_HOVER_STATE_MASK);
 

Parameters:
textViewerHover - the new hover. null is a valid argument.
contentType - the type for which the hover is registered

activatePlugins

void activatePlugins()
Activates the installed plug-ins. If the plug-ins are already activated this call has no effect.


resetPlugins

void resetPlugins()
Resets the installed plug-ins. If plug-ins change their state or behavior over the course of time, this method causes them to be set back to their initial state and behavior. E.g., if an IUndoManager has been installed on this text viewer, the manager's list of remembered text editing operations is removed.


addViewportListener

void addViewportListener(
IViewportListener listener)
Adds the given view port listener to this viewer. If the listener is already registered with this viewer, this call has no effect.

Parameters:
listener - the listener to be added

removeViewportListener

void removeViewportListener(
IViewportListener listener)
Removes the given listener from this viewer's set of view port listeners. If the listener is not registered with this viewer, this call has no effect.

Parameters:
listener - the listener to be removed

addTextListener

void addTextListener(
ITextListener listener)
Adds a text listener to this viewer. If the listener is already registered with this viewer, this call has no effect.

Parameters:
listener - the listener to be added

removeTextListener

void removeTextListener(
ITextListener listener)
Removes the given listener from this viewer's set of text listeners. If the listener is not registered with this viewer, this call has no effect.

Parameters:
listener - the listener to be removed

addTextInputListener

void addTextInputListener(
ITextInputListener listener)
Adds a text input listener to this viewer. If the listener is already registered with this viewer, this call has no effect.

Parameters:
listener - the listener to be added

removeTextInputListener

void removeTextInputListener(
ITextInputListener listener)
Removes the given listener from this viewer's set of text input listeners. If the listener is not registered with this viewer, this call has no effect.

Parameters:
listener - the listener to be removed

setDocument

void setDocument(
IDocument document)
Sets the given document as the text viewer's model and updates the presentation accordingly. An appropriate TextEvent is issued. This text event does not carry a related document event.

Parameters:
document - the viewer's new input document null if none

getDocument

IDocument getDocument()
Returns the text viewer's input document.

Returns:
the viewer's input document or null if none

setEventConsumer

void setEventConsumer(
IEventConsumer consumer)
Registers an event consumer with this viewer. This method has been replaces with the VerifyKeyListener management methods in ITextViewerExtension.

Parameters:
consumer - the viewer's event consumer. null is a valid argument.

setEditable

void setEditable(boolean editable)
Sets the editable state.

Parameters:
editable - the editable state

isEditable

boolean isEditable()
Returns whether the shown text can be manipulated.

Returns:
the viewer's editable state

setDocument

void setDocument(
IDocument document,
                 int modelRangeOffset,
                 int modelRangeLength)
Sets the given document as this viewer's model and exposes the specified region. An appropriate TextEvent is issued. The text event does not carry a related document event. This method is a convenience method for setDocument(document);setVisibleRegion(offset, length).

Parameters:
document - the new input document or null if none
modelRangeOffset - the offset of the model range
modelRangeLength - the length of the model range

setVisibleRegion

void setVisibleRegion(int offset,
                      int length)
Defines and sets the region of this viewer's document which will be visible in the presentation. Every character inside the specified region is supposed to be visible in the viewer's widget after that call.

Parameters:
offset - the offset of the visible region
length - the length of the visible region

resetVisibleRegion

void resetVisibleRegion()
Resets the region of this viewer's document which is visible in the presentation. Afterwards, the whole input document is visible.


getVisibleRegion

IRegion getVisibleRegion()
Returns the current visible region of this viewer's document. The result may differ from the argument passed to setVisibleRegion if the document has been modified since then. The visible region is supposed to be a consecutive region in viewer's input document and every character inside that region is supposed to visible in the viewer's widget.

Viewers implementing ITextViewerExtension5 may be forced to change the fractions of the input document that are shown, in order to fulfill this contract.

Returns:
this viewer's current visible region

overlapsWithVisibleRegion

boolean overlapsWithVisibleRegion(int offset,
                                  int length)
Returns whether a given range overlaps with the visible region of this viewer's document.

Viewers implementing ITextViewerExtension5may be forced to change the fractions of the input document that are shown in order to fulfill this request. This is because the overlap is supposed to be without gaps.

Parameters:
offset - the offset
length - the length
Returns:
true if the specified range overlaps with the visible region

changeTextPresentation

void changeTextPresentation(
TextPresentation presentation,
                            boolean controlRedraw)
Applies the color information encoded in the given text presentation. controlRedraw tells this viewer whether it should take care of redraw management or not. If, e.g., this call is one in a sequence of multiple presentation calls, it is more appropriate to explicitly control redrawing at the beginning and the end of the sequence.

Parameters:
presentation - the presentation to be applied to this viewer
controlRedraw - indicates whether this viewer should manage redraws

invalidateTextPresentation

void invalidateTextPresentation()
Marks the currently applied text presentation as invalid. It is the viewer's responsibility to take any action it can to repair the text presentation.

See ITextViewerExtension2.invalidateTextPresentation(int, int) for a way to invalidate specific regions rather than the presentation as a whole.

Since:
2.0

setTextColor

void setTextColor(
Color color)
Applies the given color as text foreground color to this viewer's selection.

Parameters:
color - the color to be applied

setTextColor

void setTextColor(
Color color,
                  int offset,
                  int length,
                  boolean controlRedraw)
Applies the given color as text foreground color to the specified section of this viewer. controlRedraw tells this viewer whether it should take care of redraw management or not.

Parameters:
color - the color to be applied
offset - the offset of the range to be changed
length - the length of the range to be changed
controlRedraw - indicates whether this viewer should manage redraws

getTextOperationTarget

ITextOperationTarget getTextOperationTarget()
Returns the text operation target of this viewer.

Returns:
the text operation target of this viewer

getFindReplaceTarget

IFindReplaceTarget getFindReplaceTarget()
Returns the find/replace operation target of this viewer.

Returns:
the find/replace operation target of this viewer

setDefaultPrefixes

void setDefaultPrefixes(
String[] defaultPrefixes,
                        
String contentType)
Sets the strings that are used as prefixes when lines of the given content type are prefixed using the prefix text operation. The prefixes are considered equivalent. Inserting a prefix always inserts the defaultPrefixes[0]. Removing a prefix removes all of the specified prefixes.

Parameters:
defaultPrefixes - the prefixes to be used
contentType - the content type for which the prefixes are specified
Since:
2.0

setIndentPrefixes

void setIndentPrefixes(
String[] indentPrefixes,
                       
String contentType)
Sets the strings that are used as prefixes when lines of the given content type are shifted using the shift text operation. The prefixes are considered equivalent. Thus "\t" and " " can both be used as prefix characters. Shift right always inserts the indentPrefixes[0]. Shift left removes all of the specified prefixes.

Parameters:
indentPrefixes - the prefixes to be used
contentType - the content type for which the prefixes are specified

setSelectedRange

void setSelectedRange(int offset,
                      int length)
Sets the selection to the specified range.

Parameters:
offset - the offset of the selection range
length - the length of the selection range. A negative length places the caret at the visual start of the selection.

getSelectedRange

Point getSelectedRange()
Returns the range of the current selection in coordinates of this viewer's document.

Returns:
a Point with x as the offset and y as the length of the current selection

getSelectionProvider

ISelectionProvider getSelectionProvider()
Returns a selection provider dedicated to this viewer. Subsequent calls to this method return always the same selection provider.

Returns:
this viewer's selection provider

revealRange

void revealRange(int offset,
                 int length)
Ensures that the given range is visible.

Parameters:
offset - the offset of the range to be revealed
length - the length of the range to be revealed

setTopIndex

void setTopIndex(int index)
Scrolls the widget so that the given index is the line with the smallest line number of all visible lines.

Parameters:
index - the line which should become the top most line

getTopIndex

int getTopIndex()
Returns the visible line with the smallest line number.

Returns:
the number of the top most visible line

getTopIndexStartOffset

int getTopIndexStartOffset()
Returns the document offset of the upper left corner of this viewer's view port.

Returns:
the upper left corner offset

getBottomIndex

int getBottomIndex()
Returns the visible line with the highest line number.

Returns:
the number of the bottom most line

getBottomIndexEndOffset

int getBottomIndexEndOffset()
Returns the document offset of the lower right corner of this viewer's view port. This is the visible character with the highest character position. If the content of this viewer is shorter, the position of the last character of the content is returned.

Returns:
the lower right corner offset

getTopInset

int getTopInset()
Returns the vertical offset of the first visible line.

Returns:
the vertical offset of the first visible line

Eclipse Platform
Release 3.5

Guidelines for using Eclipse APIs.

Copyright (c) Eclipse contributors and others 2000, 2008. All rights reserved.


 
 
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