Merge pull request #69 from joellow88/add-undo-command

Update undo functionality

docs/UserGuide.md

@@ -236,6 +236,23 @@ Examples:
 * `filter t/family t/friends t/classmates` returns `3 contacts listed!`
 * ![filterByTags](images/filter/filterByTagsResult.png)
 
+
+### Undo past commands
+
+Undoes previous commands that modified ModCheck.
+Undo will only undo commands that have successfully modified the data in ModCheck. For example, a successful `add`,
+`edit`, or `delete` command can be undone by the undo command.
+Any commands that does not modify the data in ModCheck will NOT be undone. This includes `view`, `find`, and other
+similar commands. Any command that would have modified the data in ModCheck, but was unsuccessful in doing so (eg:
+`add` duplicate person), will NOT be undone.
+
+Chaining of a few undo commands is supported. Once the undo limit has been reached, the error message `No command to
+undo!` will be shown.
+
+Format: `undo`
+
+Use `redo` to reapply the changes undone by undo.
+
 --------------------------------------------------------------------------------------------------------------------
 
 ## FAQ
@@ -247,14 +264,16 @@ Examples:
 
 ## Command summary
 
-Action | Format, Examples
---------|------------------
-**Add** | `add n/NAME p/PHONE_NUMBER e/EMAIL a/ADDRESS [t/TAG]…​` <br> e.g., `add n/James Ho p/22224444 e/[email protected] a/123, Clementi Rd, 1234665 t/friend t/colleague`
-**View** | `view INDEX`<br> e.g., `view 2`
-**Clear** | `clear`
-**Delete** | `delete INDEX`<br> e.g., `delete 3`
-**Edit** | `edit INDEX [n/NAME] [p/PHONE_NUMBER] [e/EMAIL] [a/ADDRESS] [t/TAG]…​`<br> e.g.,`edit 2 n/James Lee e/[email protected]`
-**Find** | `find KEYWORD [MORE_KEYWORDS]`<br> e.g., `find James Jake`
-**List** | `list`
-**Help** | `help`
-**Filter** | `filter n/NAME` <br> `filter p/PHONE_NUMBER`<br> `filter e/EMAIL_ADDRESS` <br> `filter d/DESCRIPTION` <br> `filter t/TAG` <br> e.g. `filter n/Alex` <br> e.g. `filter p/91031282` <br> e.g. `filter e/[email protected]` <br> e.g. `filter d/helpful` <br> e.g. `filter t/family` <br>
+| Action     | Format, Examples                                                                                                                                                                                                                                                                      |
+|------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| **Add**    | `add n/NAME p/PHONE_NUMBER e/EMAIL a/ADDRESS [t/TAG]…​` <br> e.g., `add n/James Ho p/22224444 e/[email protected] a/123, Clementi Rd, 1234665 t/friend t/colleague`                                                                                                                 |
+| **View**   | `view INDEX`<br> e.g., `view 2`                                                                                                                                                                                                                                                       |
+| **Clear**  | `clear`                                                                                                                                                                                                                                                                               |
+| **Delete** | `delete INDEX`<br> e.g., `delete 3`                                                                                                                                                                                                                                                   |
+| **Edit**   | `edit INDEX [n/NAME] [p/PHONE_NUMBER] [e/EMAIL] [a/ADDRESS] [t/TAG]…​`<br> e.g.,`edit 2 n/James Lee e/[email protected]`                                                                                                                                                           |
+| **Find**   | `find KEYWORD [MORE_KEYWORDS]`<br> e.g., `find James Jake`                                                                                                                                                                                                                            |
+| **List**   | `list`                                                                                                                                                                                                                                                                                |
+| **Help**   | `help`                                                                                                                                                                                                                                                                                |
+| **Filter** | `filter n/NAME` <br> `filter p/PHONE_NUMBER`<br> `filter e/EMAIL_ADDRESS` <br> `filter d/DESCRIPTION` <br> `filter t/TAG` <br> e.g. `filter n/Alex` <br> e.g. `filter p/91031282` <br> e.g. `filter e/[email protected]` <br> e.g. `filter d/helpful` <br> e.g. `filter t/family` <br> |
+| **Undo**   | `undo`                                                                                                                                                                                                                                                                                |
+| **Redo**   | `redo`                                                                                                                                                                                                                                                                                |

src/main/java/seedu/address/logic/commands/RedoCommand.java

@@ -4,6 +4,7 @@
 
 import seedu.address.logic.commands.exceptions.CommandException;
 import seedu.address.model.Model;
+import seedu.address.model.Undoable;
 
 
 /**
@@ -18,11 +19,16 @@ public class RedoCommand extends Command {
     @Override
     public CommandResult execute(Model model) throws CommandException {
         requireNonNull(model);
-        if (!model.hasRedoableCommand()) {
-            throw new CommandException(MESSAGE_NO_REDOABLE_COMMAND);
+        if (model instanceof Undoable) {
+            Undoable undoableModel = (Undoable) model;
+            if (!undoableModel.hasRedoableCommand()) {
+                throw new CommandException(MESSAGE_NO_REDOABLE_COMMAND);
+            }
+            String returnMessage = undoableModel.executeRedo();
+            return new CommandResult(String.format(MESSAGE_SUCCESS, returnMessage));
+        } else {
+            throw new IllegalArgumentException("Model passed does not support undo!");
         }
-        String returnMessage = model.executeRedo();
-        return new CommandResult(String.format(MESSAGE_SUCCESS, returnMessage));
     }
 }
 

src/main/java/seedu/address/logic/commands/UndoCommand.java

@@ -4,6 +4,7 @@
 
 import seedu.address.logic.commands.exceptions.CommandException;
 import seedu.address.model.Model;
+import seedu.address.model.Undoable;
 
 
 /**
@@ -22,11 +23,16 @@ public class UndoCommand extends Command {
     @Override
     public CommandResult execute(Model model) throws CommandException {
         requireNonNull(model);
-        if (!model.hasUndoableCommand()) {
-            throw new CommandException(MESSAGE_NO_UNDOABLE_COMMAND);
+        if (model instanceof Undoable) {
+            Undoable undoableModel = (Undoable) model;
+            if (!undoableModel.hasUndoableCommand()) {
+                throw new CommandException(MESSAGE_NO_UNDOABLE_COMMAND);
+            }
+            String returnMessage = undoableModel.executeUndo();
+            return new CommandResult(String.format(MESSAGE_SUCCESS, returnMessage));
+        } else {
+            throw new IllegalArgumentException("Model passed does not support undo!");
         }
-        String returnMessage = model.executeUndo();
-        return new CommandResult(String.format(MESSAGE_SUCCESS, returnMessage));
     }
 }
 

src/main/java/seedu/address/model/Model.java

@@ -93,27 +93,5 @@ public interface Model {
      */
     void updateFilteredPersonList(Predicate<Person> predicate);
 
-    /**
-     * Returns if there is an undoable command in model.
-     * @return True if there is an undoable command in model, false otherwise.
-     */
-    boolean hasUndoableCommand();
-
-    /**
-     * Undoes the changes made by the last modification command used
-     * @return The string representation of the last modification command used
-     */
-    String executeUndo();
-    /**
-     * Returns if there is a redoable command in model.
-     * @return True if there is a redoable command in model, false otherwise.
-     */
-    boolean hasRedoableCommand();
-
-    /**
-     * Redoes the changes unmade by the last undo command
-     * @return The string representation of the command redone
-     */
-    String executeRedo();
 
 }

src/main/java/seedu/address/model/ModelManager.java

@@ -19,7 +19,7 @@
 /**
  * Represents the in-memory model of the address book data.
  */
-public class ModelManager implements Model {
+public class ModelManager implements Model, Undoable {
     private static final Logger logger = LogsCenter.getLogger(ModelManager.class);
     private final AddressBook addressBook;
     private final UserPrefs userPrefs;

src/main/java/seedu/address/model/Undoable.java

@@ -0,0 +1,29 @@
+package seedu.address.model;
+
+/**
+ * The interface for supporting undo and redo functionality.
+ */
+public interface Undoable {
+    /**
+     * Returns if there is an undoable command in model.
+     * @return True if there is an undoable command in model, false otherwise.
+     */
+    boolean hasUndoableCommand();
+
+    /**
+     * Undoes the changes made by the last modification command used
+     * @return The string representation of the last modification command used
+     */
+    String executeUndo();
+    /**
+     * Returns if there is a redoable command in model.
+     * @return True if there is a redoable command in model, false otherwise.
+     */
+    boolean hasRedoableCommand();
+
+    /**
+     * Redoes the changes unmade by the last undo command
+     * @return The string representation of the command redone
+     */
+    String executeRedo();
+}

src/main/java/seedu/address/model/person/Person.java

@@ -116,7 +116,7 @@ public String toString() {
                 .append(getPhone())
                 .append("; Email: ")
                 .append(getEmail())
-                .append("; Address: ")
+                .append("; Description: ")
                 .append(getAddress());
 
         Set<Tag> tags = getTags();

src/test/java/seedu/address/logic/commands/AddCommandTest.java

@@ -20,6 +20,7 @@
 import seedu.address.model.Model;
 import seedu.address.model.ReadOnlyAddressBook;
 import seedu.address.model.ReadOnlyUserPrefs;
+import seedu.address.model.Undoable;
 import seedu.address.model.person.Person;
 import seedu.address.testutil.PersonBuilder;
 
@@ -77,7 +78,7 @@ public void equals() {
     /**
      * A default model stub that have all of the methods failing.
      */
-    private class ModelStub implements Model {
+    private class ModelStub implements Model, Undoable {
         @Override
         public void setUserPrefs(ReadOnlyUserPrefs userPrefs) {
             throw new AssertionError("This method should not be called.");