grodtron · November 14, 2012 00:20 · Nov 14, 2012 · Nov 14, 2012 · Nov 14, 2012 · Nov 14, 2012
diff --git a/.gitignore b/.gitignore
@@ -1,4 +1,5 @@
 *.o
 *.swp
 *.swo
+*.zip
 test
diff --git a/command_pattern.zip b/command_pattern.zip
diff --git a/deleteme.txt b/deleteme.txt
@@ -1 +0,0 @@
-s

diff --git a/deleteme.txt b/deleteme.txt
@@ -0,0 +1 @@
+s
diff --git a/deleteme.txt b/deleteme.txt
@@ -0,0 +1 @@
+s
diff --git a/.gitignore b/.gitignore
@@ -1,3 +1,4 @@
 *.o
 *.swp
 *.swo
+test
diff --git a/Command.h b/Command.h
@@ -0,0 +1,11 @@
+#ifndef COMMAND_H_
+#define COMMAND_H_
+
+class Command {
+	public:
+	virtual void doit() = 0;
+	virtual void undo() = 0;	
+	virtual ~Command(){}
+};
+
+#endif
diff --git a/CommandStack.cpp b/CommandStack.cpp
@@ -0,0 +1,44 @@
+/*
+ * CommandStack.cpp
+ *
+ *  Created on: 05.11.2012
+ *      Author: dsinnig
+ */
+
+#include "CommandStack.h"
+#include <iostream>
+
+
+CommandStack::CommandStack (int size) : size(size), currentNumberOfCommands(0) {
+		commands = new Command*[size];
+}
+
+CommandStack::~CommandStack() {
+	clear(); // delete all of the commands
+	delete [] commands; // delete the array itself
+}
+
+Command* CommandStack::pop() {
+	return (currentNumberOfCommands > 0) ? commands[--currentNumberOfCommands] : NULL;
+}
+
+void CommandStack::push(Command* aCommand) {
+	if (currentNumberOfCommands < size)
+		commands[currentNumberOfCommands++] = aCommand;
+}
+
+bool CommandStack::empty() {
+	return currentNumberOfCommands == 0;
+}
+
+// Clear the entire stack, deleting all the commands that it held
+void CommandStack::clear(){
+	// Loop over all of the commands in the stack	
+	while(currentNumberOfCommands > 0){
+		--currentNumberOfCommands;
+		// delete the current command, and set the pointer
+		// to NULL (because it's a good habit to do so)
+		delete commands[currentNumberOfCommands];
+		commands[currentNumberOfCommands] = NULL;
+	}
+}
diff --git a/CommandStack.h b/CommandStack.h
@@ -0,0 +1,33 @@
+/*
+ * CommandStack.h
+ *
+ *  Created on: 05.11.2012
+ *      Author: dsinnig
+ */
+
+#ifndef COMMANDSTACK_H_
+#define COMMANDSTACK_H_
+
+#include "Command.h"
+
+class CommandStack {
+public:
+
+	CommandStack (int size);
+	virtual ~CommandStack();
+
+	Command* pop();
+
+	void push(Command* aCommand);
+
+	bool empty();
+
+	void clear();
+
+private:
+	int size;
+	int currentNumberOfCommands;
+	Command** commands;
+};
+
+#endif /* COMMANDSTACK_H_ */
diff --git a/Commands.cpp b/Commands.cpp
@@ -0,0 +1,29 @@
+#include "Commands.h"
+
+AddCommand::AddCommand(int * target, int x)
+	: target(target), x(x)
+{
+
+}
+
+void AddCommand::doit(){
+	*target += x;
+}
+
+void AddCommand::undo(){
+	*target -= x;
+}
+
+MultCommand::MultCommand(int * target, int x)
+	: target(target), x(x)
+{
+
+}
+
+void MultCommand::doit(){
+	*target *= x;
+}
+
+void MultCommand::undo(){
+	*target /= x;
+}
diff --git a/Commands.h b/Commands.h
@@ -0,0 +1,29 @@
+#ifndef COMMANDS_H_
+#define COMMANDS_H_
+
+#include "Command.h"
+
+class AddCommand : public Command {
+	private:
+		int * target;
+		int x;
+
+	public:
+		AddCommand(int * target, int x);
+		void doit();
+		void undo();
+};
+
+class MultCommand : public Command {
+	private:
+		int * target;
+		int x;
+
+	public:
+		MultCommand(int * target, int x);
+		void doit();
+		void undo();
+};
+
+
+#endif
diff --git a/Invoker.cpp b/Invoker.cpp
@@ -0,0 +1,30 @@
+#include "Invoker.h"
+
+Invoker::Invoker()
+	: undoStack(16),
+	  redoStack(16)
+{
+
+}
+
+void Invoker::execute(Command * command){
+	command->doit();
+	undoStack.push(command);
+	redoStack.clear();
+}
+
+void Invoker::undo(){
+	if(!undoStack.empty()){
+		Command * command = undoStack.pop();
+		command->undo();
+		redoStack.push(command);
+	}
+}
+
+void Invoker::redo(){
+	if(!redoStack.empty()){
+		Command * command = redoStack.pop();
+		command->doit();
+		undoStack.push(command);
+	}
+}
diff --git a/Invoker.h b/Invoker.h
@@ -0,0 +1,22 @@
+#ifndef INVOKER_H_
+#define INVOKER_H_
+
+#include "CommandStack.h"
+#include "Command.h"
+
+class Invoker {
+
+	private:
+		CommandStack undoStack;
+		CommandStack redoStack;
+
+	public:
+		Invoker();
+
+		void execute(Command *);
+		void undo();
+		void redo();
+
+};
+
+#endif
diff --git a/Makefile b/Makefile
@@ -3,10 +3,10 @@
 all: test
 
 %.o: %.cpp
-	g++ -c $< -o $@
+	g++ -ggdb -c $< -o $@
 
 test: $(shell ls -1 *.cpp | sed 's/\.cpp/\.o/')
-	g++ $^ -o $@
+	g++ -ggdb $^ -o $@
 
 clean:
 	rm -f *.o

diff --git a/command_pattern.zip b/command_pattern.zip
diff --git a/main.cpp b/main.cpp
@@ -0,0 +1,63 @@
+#include <iostream>
+using std::cout;
+using std::cin;
+using std::endl;
+
+#include "Commands.h"
+#include "Invoker.h"
+
+// This function will ask the user for input in a loop
+// and execute commands, or redo/undo them based on that
+// input
+void commandLoop(){
+
+	// The invoker of the commands
+	Invoker invoker;
+
+	// the receiver of the commands
+	int receiver;
+
+	// initialize the receiver
+	cout << "Set initial value to: ";
+	cin >> receiver;
+
+	while(1){
+
+		char in;
+		int val;
+
+		cout << "Enter command [ '+' (add) | '*' (multiply) | 'u' (undo) | 'r' (redo) ]: ";
+		cin >> in;
+
+		switch (in){
+			case '+':
+				cout << "Enter value: ";
+				cin >> val;
+				invoker.execute(new AddCommand(&receiver, val));
+				break;
+			case '*':
+				cout << "Enter value: ";
+				cin >> val;
+				invoker.execute(new MultCommand(&receiver, val));
+				break;
+			case 'u':
+				invoker.undo();
+				break;
+			case 'r':
+				invoker.redo();
+				break;
+			default:
+				// end the loop
+				return;
+		}
+
+		cout << "== Value is now: " << receiver << endl;
+	}
+}
+
+int main(){
+
+	commandLoop();
+
+	return 0;
+}
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,3 @@
+*.o
+*.swp
+*.swo
diff --git a/Makefile b/Makefile
@@ -0,0 +1,13 @@
+.PHONY: clean all
+
+all: test
+
+%.o: %.cpp
+	g++ -c $< -o $@
+
+test: $(shell ls -1 *.cpp | sed 's/\.cpp/\.o/')
+	g++ $^ -o $@
+
+clean:
+	rm -f *.o
+	rm -f test
-Original file line number
+Diff line change
@@ -1,4 +1,5 @@
     *.o
     *.swp
     *.swo
+    *.zip
     test