Package 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:

  • Method Details

    • 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

      @Deprecated 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