ui: color schemes

Put all colors into single xml file. Accessing colors is handled via the singleton class ColorScheme. The default scheme
"bright.xml" holds the original colors. The scheme "dark.xml" is a start, but still a poor alternative. Color schemes
can be switched via the View menu.

src/lib/component/controller/FeatureController.cpp

@@ -88,6 +88,15 @@ void FeatureController::handleMessage(MessageSearch* message)
 	m.dispatchImmediately();
 }
 
+void FeatureController::handleMessage(MessageSwitchColorScheme* message)
+{
+	ApplicationSettings* settings = ApplicationSettings::getInstance().get();
+	settings->setColorSchemePath(message->colorSchemeFilePath);
+	settings->save();
+
+	MessageRefresh(true).dispatch();
+}
+
 void FeatureController::handleMessage(MessageZoom* message)
 {
 	ApplicationSettings* settings = ApplicationSettings::getInstance().get();

src/lib/component/controller/FeatureController.h

@@ -7,6 +7,7 @@
 #include "utility/messaging/type/MessageActivateNode.h"
 #include "utility/messaging/type/MessageActivateTokenLocation.h"
 #include "utility/messaging/type/MessageSearch.h"
+#include "utility/messaging/type/MessageSwitchColorScheme.h"
 #include "utility/messaging/type/MessageZoom.h"
 
 #include "component/controller/Controller.h"
@@ -20,6 +21,7 @@ class FeatureController
 	, public MessageListener<MessageActivateNode>
 	, public MessageListener<MessageActivateTokenLocation>
 	, public MessageListener<MessageSearch>
+	, public MessageListener<MessageSwitchColorScheme>
 	, public MessageListener<MessageZoom>
 {
 public:
@@ -32,6 +34,7 @@ private:
 	virtual void handleMessage(MessageActivateNode* message);
 	virtual void handleMessage(MessageActivateTokenLocation* message);
 	virtual void handleMessage(MessageSearch* message);
+	virtual void handleMessage(MessageSwitchColorScheme* message);
 	virtual void handleMessage(MessageZoom* message);
 
 	StorageAccess* m_storageAccess;

src/lib/component/controller/UndoRedoController.cpp

@@ -213,10 +213,13 @@ void UndoRedoController::processNormalCommand(const Command& command)
 
 void UndoRedoController::processRedoCommand(const Command& command)
 {
-	m_undo.push_back(m_lastCommand);
-	m_lastCommand = command;
+	if (m_lastCommand.message)
+	{
+		m_undo.push_back(m_lastCommand);
+		getView()->setUndoButtonEnabled(true);
+	}
 
-	getView()->setUndoButtonEnabled(true);
+	m_lastCommand = command;
 
 	if (m_redo.empty())
 	{
@@ -226,10 +229,13 @@ void UndoRedoController::processRedoCommand(const Command& command)
 
 void UndoRedoController::processUndoCommand(const Command& command)
 {
-	m_redo.push_back(m_lastCommand);
-	m_lastCommand = command;
+	if (m_lastCommand.message)
+	{
+		m_redo.push_back(m_lastCommand);
+		getView()->setRedoButtonEnabled(true);
+	}
 
-	getView()->setRedoButtonEnabled(true);
+	m_lastCommand = command;
 
 	if (m_undo.empty())
 	{