Package org.eclipse.ui.part

Class DrillDownAdapter

java.lang.Object

org.eclipse.ui.part.DrillDownAdapter

All Implemented Interfaces:

ISelectionChangedListener

public class DrillDownAdapter
extends Object
implements ISelectionChangedListener

Implements a simple web style navigation metaphor for a TreeViewer. Home, back, and "drill into" functions are supported for the viewer,

To use the DrillDownAdapter:

1. Create an instance of TreeViewer.
2. Create a DrillDownAdapter for the viewer.
3. Create a container for your viewer with a toolbar or a popup menu. Add actions for "goBack", "goHome", and "goInto" to either one by calling addNavigationActions with the popup menu or toolbar.

If the input for the underlying viewer is changed by something other than the adapter the reset method should be called. This will clear the drill stack and update the navigation buttons to reflect the new state of the underlying viewer.

Constructor Summary

Constructors

Constructor	Description
DrillDownAdapter(TreeViewer tree)	Allocates a new DrillDownTreePart.

Method Summary

Modifier and Type	Method	Description
void	addNavigationActions(IMenuManager manager)	Adds actions for "go back", "go home", and "go into" to a menu manager.
void	addNavigationActions(IToolBarManager toolBar)	Adds actions for "go back", "go home", and "go into" to a tool bar manager.
boolean	canExpand(Object element)	Returns whether expansion is possible for the current selection.
boolean	canGoBack()	Returns whether "go back" is possible for child tree.
boolean	canGoHome()	Returns whether "go home" is possible for child tree.
boolean	canGoInto()	Returns whether "go into" is possible for child tree.
void	goBack()	Reverts the input for the tree back to the state when goInto was last called.
void	goHome()	Reverts the input for the tree back to the state when the adapter was created.
void	goInto()	Sets the input for the tree to the current selection.
void	goInto(Object newInput)	Sets the input for the tree to a particular item in the tree.
void	reset()	Resets the drill down adapter.
void	selectionChanged(SelectionChangedEvent event)	Updates the navigation buttons when a selection change occurs in the tree.
protected void	updateNavigationButtons()	Updates the enabled state for each navigation button.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

DrillDownAdapter

public DrillDownAdapter(TreeViewer tree)

Allocates a new DrillDownTreePart.

Parameters:

tree - the target tree for refocusing

Method Details

addNavigationActions

public void addNavigationActions(IMenuManager manager)

Adds actions for "go back", "go home", and "go into" to a menu manager.

Parameters:

manager - is the target manager to update

addNavigationActions

public void addNavigationActions(IToolBarManager toolBar)

Adds actions for "go back", "go home", and "go into" to a tool bar manager.

Parameters:

toolBar - is the target manager to update

canExpand

public boolean canExpand(Object element)

Returns whether expansion is possible for the current selection. This will only be true if it has children.

Parameters:

element - the object to test for expansion

Returns:

true if expansion is possible; otherwise return false

canGoBack

public boolean canGoBack()

Returns whether "go back" is possible for child tree. This is only possible if the client has performed one or more drilling operations.

Returns:

true if "go back" is possible; false otherwise

canGoHome

public boolean canGoHome()

Returns whether "go home" is possible for child tree. This is only possible if the client has performed one or more drilling operations.

Returns:

true if "go home" is possible; false otherwise

canGoInto

public boolean canGoInto()

Returns whether "go into" is possible for child tree. This is only possible if the current selection in the client has one item and it has children.

Returns:

true if "go into" is possible; false otherwise

goBack

public void goBack()

Reverts the input for the tree back to the state when goInto was last called.

A frame is removed from the drill stack. Then that frame is used to reset the input and expansion state for the child tree.

goHome

public void goHome()

Reverts the input for the tree back to the state when the adapter was created.

All of the frames are removed from the drill stack. Then the oldest frame is used to reset the input and expansion state for the child tree.

goInto

public void goInto()

Sets the input for the tree to the current selection.

The current input and expansion state are saved in a frame and added to the drill stack. Then the input for the tree is changed to be the current selection. The expansion state for the tree is maintained during the operation.

On return the client may revert back to the previous state by invoking goBack or goHome.

goInto

public void goInto(Object newInput)

Sets the input for the tree to a particular item in the tree.

The current input and expansion state are saved in a frame and added to the drill stack. Then the input for the tree is changed to be newInput. The expansion state for the tree is maintained during the operation.

On return the client may revert back to the previous state by invoking goBack or goHome.

Parameters:

newInput - the new input element

reset

public void reset()

Resets the drill down adapter.

This method is typically called when the input for the underlying view is reset by something other than the adapter. On return the drill stack has been cleared and the navigation buttons reflect the new state of the underlying viewer.

selectionChanged

public void selectionChanged(SelectionChangedEvent event)

Updates the navigation buttons when a selection change occurs in the tree.

Specified by:

selectionChanged in interface ISelectionChangedListener

Parameters:

event - event object describing the change

updateNavigationButtons

protected void updateNavigationButtons()

Updates the enabled state for each navigation button.