org.csstudio.ui.util.helpers
Class ComboHistoryHelper

java.lang.Object
  org.csstudio.ui.util.helpers.ComboHistoryHelper

public abstract class ComboHistoryHelper
extends java.lang.Object

Decorates a Combo box to maintain the history.

Newly entered items are added to the top of the combo list, dropping last items off the list when reaching a configurable maximum list size. If an item is selected/entered again, it will pop at the beginning of the list (so that continuously used items are not lost).

You must

• implement newSelection() to handle entered/selected values
• decide if you want to call loadSettings() to restore the saved values
• save values via saveSettings, or use the save_on_dispose option of the constructor.

Author:

Kay Kasemir, Gabriele Carcassi

See Also:

newSelection(String)

ComboHistoryHelper

public ComboHistoryHelper(IDialogSettings settings,
                          java.lang.String tag,
                          Combo combo)

Attach helper to given combo box, using max list length.

Parameters:

settings - where to persist the combo box list

tag - tag used for persistence

combo - the combo box

ComboHistoryHelper

public ComboHistoryHelper(IDialogSettings settings,
                          java.lang.String tag,
                          Combo combo,
                          int max,
                          boolean saveOnDispose)

Attach helper to given combo box, using max list length.

Parameters:

settings - where to persist the combo box list

tag - tag used for persistence

combo - the combo box

max - number of elements to keep in history

saveOnDispose - whether current values should be saved at widget disposal

changeSelection

public void changeSelection(java.lang.String entry)

addEntry

public void addEntry(java.lang.String newEntry)

Adds a new entry to the list. If entry already there, do nothing.

Parameters:

newEntry - the new value

newSelection

public abstract void newSelection(java.lang.String entry)

Invoked whenever a new entry was entered or selected.

loadSettings

public void loadSettings()

Load persisted list values.

saveSettings

public void saveSettings()

Save list values to persistent storage.