/**
* Reverts the input for the tree back to the state when the adapter was created.
*
* <p>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.
*/
public void goHome() {
Object currentInput = fChildTree.getInput();
DrillFrame oFrame = fDrillStack.goHome();
Object input = oFrame.getElement();
fChildTree.setInput(input);
expand(oFrame.getExpansion());
// if there was a selection, it should have been preserved,
// but if not, select the element that was last drilled into
if (fChildTree.getSelection().isEmpty()) {
fChildTree.setSelection(new StructuredSelection(currentInput), true);
}
updateNavigationButtons();
}
/**
* Sets the input for the tree to a particular item in the tree.
*
* <p>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 <code>newInput</code>. The expansion state for the
* tree is maintained during the operation.
*
* <p>On return the client may revert back to the previous state by invoking <code>goBack</code>
* or <code>goHome</code>.
*
* @param newInput the new input element
*/
public void goInto(Object newInput) {
// If we can drill ..
if (canExpand(newInput)) {
// Save the old state.
Object oldInput = fChildTree.getInput();
List expandedList = getExpanded();
fDrillStack.add(new DrillFrame(oldInput, "null", expandedList)); // $NON-NLS-1$
// Install the new state.
fChildTree.setInput(newInput);
expand(expandedList);
updateNavigationButtons();
}
}
/**
* Resets the drill down adapter.
*
* <p>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.
*/
public void reset() {
fDrillStack.reset();
updateNavigationButtons();
}
/**
* Returns whether "go home" is possible for child tree. This is only possible if the client has
* performed one or more drilling operations.
*
* @return <code>true</code> if "go home" is possible; <code>false</code> otherwise
*/
public boolean canGoHome() {
return fDrillStack.canGoHome();
}
/**
* Returns whether "go back" is possible for child tree. This is only possible if the client has
* performed one or more drilling operations.
*
* @return <code>true</code> if "go back" is possible; <code>false</code> otherwise
*/
public boolean canGoBack() {
return fDrillStack.canGoBack();
}
