Finalize command history documentation

docs/DeveloperGuide.md

@@ -397,14 +397,24 @@ The following activity diagram summarizes what happens when a user executes a ne
 The `CommandHistory` class is an abstraction for a command history data structure.
 It stores all command strings that were successfully executed by the user.
 
+When the user executes a command successfully, `LogicManager` calls the `add()` method in `CommandHistory` to store the command string.
+
+<puml src="diagrams/CommandHistoryAddSequenceDiagram.puml" />
+<br><br>
+
+
+`CommandExecutor` is an interface that has the methods `execute()`, `getPreviousCommandText()` and `getNextCommandText()`.
+A private nested class `RecordedCommandExecutor` in `MainWindow` implements this interface.
+
 When the user presses the `UP` key, a `KeyEvent` is generated by JavaFX, which is then handled by the `CommandBox` class through the `handleKeyPressed()` method.
 
 The following sequence diagram shows the interaction between the classes when the user presses the `UP` key.
 Note that `TextField` is a class in JavaFX. `CommandBox` has a `textField` attribute. 
 
-<puml src="diagrams/CommandHistorySequenceDiagram.puml" />
+<puml src="diagrams/CommandHistoryUpSequenceDiagram.puml" />
 <br><br>
 
+A similar interaction occurs when the user presses the `DOWN` key.
 
 --------------------------------------------------------------------------------------------------------------------
 

docs/diagrams/CommandHistoryAddSequenceDiagram.puml

@@ -0,0 +1,22 @@
+@startuml
+!include style.puml
+skinparam ArrowFontStyle plain
+
+box Logic LOGIC_COLOR_T1
+participant ":LogicManager" as LogicManager LOGIC_COLOR
+participant ":CommandHistory" as CommandHistory LOGIC_COLOR
+end box
+
+-> LogicManager : execute(commandText)
+activate LogicManager
+
+LogicManager -> CommandHistory : add(commandText)
+activate CommandHistory
+
+CommandHistory --> LogicManager : commandText
+deactivate CommandHistory
+
+<-- LogicManager : commandResult
+deactivate LogicManager
+
+@enduml

docs/diagrams/CommandHistorySequenceDiagram.puml → docs/diagrams/CommandHistoryUpSequenceDiagram.puml

@@ -4,7 +4,7 @@ skinparam ArrowFontStyle plain
 
 box UI UI_COLOR_T1
 participant ":CommandBox" as CommandBox UI_COLOR
-participant ":CommandExecutor" as CommandExecutor UI_COLOR
+participant ":RecordedCommandExecutor" as RecordedCommandExecutor UI_COLOR
 end box
 
 box Logic LOGIC_COLOR_T1
@@ -19,10 +19,10 @@ participant ":TextField" as TextField JAVAFX_COLOR
 -> CommandBox : handleKeyPressed(event)
 activate CommandBox
 
-CommandBox -> CommandExecutor : getPreviousCommandText()
-activate CommandExecutor
+CommandBox -> RecordedCommandExecutor : getPreviousCommandText()
+activate RecordedCommandExecutor
 
-CommandExecutor -> LogicManager : getPreviousCommandText()
+RecordedCommandExecutor -> LogicManager : getPreviousCommandText()
 activate LogicManager
 
 LogicManager -> CommandHistory : getPrevious()
@@ -31,11 +31,11 @@ activate CommandHistory
 CommandHistory --> LogicManager : commandText
 deactivate CommandHistory
 
-LogicManager --> CommandExecutor : commandText
+LogicManager --> RecordedCommandExecutor : commandText
 deactivate LogicManager
 
-CommandExecutor --> CommandBox : commandText
-deactivate CommandExecutor
+RecordedCommandExecutor --> CommandBox : commandText
+deactivate RecordedCommandExecutor
 
 CommandBox -> TextField : setText(commandText)
 activate TextField