Package com.vaadin.flow.component.spreadsheet

Class SpreadsheetHistoryManager

java.lang.Object
com.vaadin.flow.component.spreadsheet.SpreadsheetHistoryManager
All Implemented Interfaces:
Serializable
public class SpreadsheetHistoryManager extends Object implements Serializable
SpreadsheetHistoryManager is an utility class of the Spreadsheet add-on. This class handles remembering any actions done in the Spreadsheet. The purpose is to allow the user to undo and redo any action.
Author:
Vaadin Ltd.
See Also:

  • Field Details

    • historyIndex

      protected int historyIndex
      Current index within the history

    • commands

      protected final LinkedList<Command> commands
      All executed command in chronological order

    • spreadsheet

      protected final Spreadsheet spreadsheet
      Target Spreadsheet component

  • Constructor Details

    • SpreadsheetHistoryManager

      public SpreadsheetHistoryManager(Spreadsheet spreadsheet)
      Creates a new history manager for the given Spreadsheet.
      Parameters:
      spreadsheet - Target spreadsheet

  • Method Details

    • clear

      public void clear()
      Clears the history.

    • addCommand

      public void addCommand(Command command)
      Adds a command to the end of the command history. Discards commands after the current position (historyIndex) within the history.
      Parameters:
      command - Command to add as the latest command in history

    • getCommand

      public Command getCommand(int historyIndex)
      Gets the Command at the given history index.
      Parameters:
      historyIndex - Index of Command to get, 0-based
      Returns:
      The command at the index or IndexOutOfBoundsException

    • canRedo

      public boolean canRedo()
      Determines if redo is possible at the moment. In practice tells if there is at least one Command available after the current history index.
      Returns:
      true if redo() possible, false otherwise.

    • canUndo

      public boolean canUndo()
      Determines if undo is possible at the moment. In practice tells if there is at least one Command available before the current history index.
      Returns:
      true if undo() possible, false otherwise.

    • redo

      public void redo()
      Does redo if possible. Changes the active sheet to match the one the command belongs to and updates the selection if needed.

    • undo

      public void undo()
      Does undo if possible. Changes the active sheet to match the one that the command belongs to and updates the selection if needed.

    • setHistorySize

      public void setHistorySize(int historySize)
      Changes the history size. Discards possible commands that won't fit the size anymore.
      Parameters:
      historySize - New size for Command history

    • getHistorySize

      public int getHistorySize()
      Gets the current size of the Command history. The default size is 20 commands.
      Returns:
      Current size of history.

    • getHistoryIndex

      public int getHistoryIndex()
      Gets the current index within the Command history.
      Returns:
      Current history index, 0-based

    • makeSureCorrectSheetActive

      protected void makeSureCorrectSheetActive(Command command)
      Ensures that the correct sheet is active, as recorded in the given Command.
      Parameters:
      command - Command to fetch the sheet from

    • changeSelection

      protected void changeSelection(Command command)
      Applies the cell selection from the given Command.
      Parameters:
      command - Command to fetch the cell selection from.

    • discardAllAfter

      protected void discardAllAfter(int index)
      Clears all history after the given history index NOT including the command at the given index.
      Parameters:
      index - History index to start the clearing from.