Class TreeCursor

All Implemented Interfaces:
Drawable

public class TreeCursor extends Canvas
A TreeCursor provides a way for the user to navigate around a Tree with columns using the keyboard. It also provides a mechanism for selecting an individual cell in a tree.

For a detailed example of using a TreeCursor to navigate to a cell and then edit it see https://github.com/eclipse-platform/eclipse.platform.swt/tree/master/examples/org.eclipse.swt.snippets/src/org/eclipse/swt/snippets/Snippet360.java .

Styles:
BORDER
Events:
Selection, DefaultSelection
Since:
3.8
  • Constructor Details

    • TreeCursor

      public TreeCursor(Tree parent, int style)
      Constructs a new instance of this class given its parent tree and a style value describing its behavior and appearance.

      The style value is either one of the style constants defined in class SWT which is applicable to instances of this class, or must be built by bitwise OR'ing together (that is, using the int "|" operator) two or more of those SWT style constants. The class description lists the style constants that are applicable to the class. Style bits are also inherited from superclasses.

      Parameters:
      parent - a Tree control which will be the parent of the new instance (cannot be null)
      style - the style of control to construct
      Throws:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the parent is null
      SWTException -
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
      • ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
      See Also:
  • Method Details

    • addSelectionListener

      public void addSelectionListener(SelectionListener listener)
      Adds the listener to the collection of listeners who will be notified when the receiver's selection changes, by sending it one of the messages defined in the SelectionListener interface.

      When widgetSelected is called, the item field of the event object is valid. If the receiver has SWT.CHECK style set and the check selection changes, the event object detail field contains the value SWT.CHECK. widgetDefaultSelected is typically called when an item is double-clicked.

      Parameters:
      listener - the listener which should be notified
      Throws:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the listener is null
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      See Also:
    • getBackground

      public Color getBackground()
      Returns the background color that the receiver will use to draw.
      Overrides:
      getBackground in class Control
      Returns:
      the receiver's background color
    • getColumn

      public int getColumn()
      Returns the index of the column over which the TreeCursor is positioned.
      Returns:
      the column index for the current position
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
    • getForeground

      public Color getForeground()
      Returns the foreground color that the receiver will use to draw.
      Overrides:
      getForeground in class Control
      Returns:
      the receiver's foreground color
    • getRow

      public TreeItem getRow()
      Returns the row over which the TreeCursor is positioned.
      Returns:
      the item for the current position, or null if none
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
    • removeSelectionListener

      public void removeSelectionListener(SelectionListener listener)
      Removes the listener from the collection of listeners who will be notified when the receiver's selection changes.
      Parameters:
      listener - the listener which should no longer be notified
      Throws:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the listener is null
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      See Also:
    • setBackground

      public void setBackground(Color color)
      Sets the receiver's background color to the color specified by the argument, or to the default system color for the control if the argument is null.

      Note: This operation is a hint and may be overridden by the platform. For example, on Windows the background of a Button cannot be changed.

      Overrides:
      setBackground in class Control
      Parameters:
      color - the new color (or null)
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the argument has been disposed
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
    • setForeground

      public void setForeground(Color color)
      Sets the receiver's foreground color to the color specified by the argument, or to the default system color for the control if the argument is null.

      Note: This operation is a hint and may be overridden by the platform.

      Overrides:
      setForeground in class Control
      Parameters:
      color - the new color (or null)
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the argument has been disposed
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
    • setSelection

      public void setSelection(int row, int column)
      Positions the TreeCursor over the root-level cell at the given row and column in the parent tree.
      Parameters:
      row - the index of the root-level row for the cell to select
      column - the index of column for the cell to select
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
    • setSelection

      public void setSelection(TreeItem row, int column)
      Positions the TreeCursor over the cell at the given row and column in the parent tree.
      Parameters:
      row - the TreeItem of the row for the cell to select
      column - the index of column for the cell to select
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
    • setVisible

      public void setVisible(boolean visible)
      Description copied from class: Control
      Marks the receiver as visible if the argument is true, and marks it invisible otherwise.

      If one of the receiver's ancestors is not visible or some other condition makes the receiver not visible, marking it visible may not actually cause it to be displayed.

      Overrides:
      setVisible in class Control
      Parameters:
      visible - the new visibility state