update,

_resources/it114105/itp4507/Assignment/19-20/src/CommandHandler.java

@@ -0,0 +1,59 @@
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Scanner;
+
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+/**
+ *
+ * @author jerrykwok
+ */
+public class CommandHandler {
+
+    private LinkedHashMap<String, CommandFactory> mapCmds;
+    private StateManager state;
+
+    public CommandHandler(StateManager state) {
+        this.mapCmds = new LinkedHashMap<String, CommandFactory>();
+        this.state = state;
+    }
+
+    public void regCommand(String key, CommandFactory cmdFactory) {
+        mapCmds.put(key, cmdFactory);
+    }
+
+    public void printCommandList() {
+        System.out.print("Please enter command: [");
+        System.out.print(String.join(" | ", mapCmds.keySet()));
+        System.out.println("]");
+        for (Map.Entry<String, CommandFactory> mapCmd : mapCmds.entrySet()) {
+            System.out.print(mapCmd.getKey() + " = " + mapCmd.getValue().getCommandName());
+        }
+        System.out.println("\n");
+    }
+
+    public boolean run(String cmd) {
+        CommandFactory commandFactory = mapCmds.get(cmd);
+        if (commandFactory != null) {
+            Command command = commandFactory.createCommand();
+            boolean result = command.execute();
+            if (result) {
+                switch (cmd) {
+                    case "a":
+                    case "c":
+                    case "s":
+                        state.getUndoList().add(command);
+                        state.getRedoList().clear();
+                }
+            }
+            return true;
+        }
+
+        return false;
+    }
+
+}