Editor prerequisites [part 2] (#889)

lib/LoadProgress.cpp

@@ -0,0 +1,81 @@
+/*
+ * LoadProgress.cpp, part of VCMI engine
+ *
+ * Authors: listed in file AUTHORS in main folder
+ *
+ * License: GNU General Public License v2.0 or later
+ * Full text of license available in license.txt file, in main folder
+ *
+ */
+
+#include "StdInc.h"
+#include "LoadProgress.h"
+
+using namespace Load;
+
+Progress::Progress(): _progress(std::numeric_limits<Type>::min())
+{
+	setupSteps(100);
+}
+
+Type Progress::get() const
+{
+	if(_step >= _maxSteps)
+		return _target;
+	
+	return static_cast<int>(_progress) + _step * static_cast<int>(_target - _progress) / _maxSteps;
+}
+
+void Progress::set(Type p)
+{
+	_progress = p;
+}
+
+bool Progress::finished() const
+{
+	return get() == std::numeric_limits<Type>::max();
+}
+
+void Progress::reset(int s)
+{
+	_progress = std::numeric_limits<Type>::min();
+	setupSteps(s);
+}
+
+void Progress::finish()
+{
+	_progress = _target = std::numeric_limits<Type>::max();
+	_step = std::numeric_limits<Type>::min();
+	_maxSteps = std::numeric_limits<Type>::min();
+}
+
+void Progress::setupSteps(int s)
+{
+	setupStepsTill(s, std::numeric_limits<Type>::max());
+}
+
+void Progress::setupStepsTill(int s, Type p)
+{
+	if(finished())
+		return;
+	
+	if(_step > std::numeric_limits<Type>::min())
+		_progress = get();
+	
+	_step = std::numeric_limits<Type>::min();
+	_maxSteps = s;
+	
+	_target = p;
+}
+
+void Progress::step(int count)
+{
+	if(_step + count > _maxSteps)
+	{
+		_step = _maxSteps.load();
+	}
+	else
+	{
+		_step += count;
+	}
+}