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engines/zvision/common/scroller.h

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef ZVISION_SCROLLER_H
+#define ZVISION_SCROLLER_H
+
+#include "common/rect.h"
+#include "zvision/zvision.h"
+
+namespace ZVision {
+
+/**
+ * Automatically scroll a GUI menu or similar graphical element between an active and an idle position
+ * Movement in one dimension; idle & active positions specified as int16.
+ * Movement is at constant speed determined by period, specified in ms.
+ * If active/idle status is changed mid-transition, will scroll from current position to the appropriate position.
+ * LinearScroller also be used to reversibly scroll animation frames.
+ */
+
+class LinearScroller {
+public:
+	LinearScroller(const int16 activePos, const int16 idlePos, const int16 period = 500);
+	~LinearScroller();
+	void reset();  ///< Set idle and immediately jump to idle position
+	bool update(uint32 deltatime);  ///< Calculate updated position of scrolled graphics; return true if redraw is necessary.
+	void setActive(bool active);	  ///< Set active or idle & scroll at set speed from current position to that position.
+	bool isMoving();
+	int16 getPos();
+
+	int16 _pos;
+	int16 _prevPos;
+
+private:
+	bool _active = false;
+	bool _moving = false;
+	const int16 _activePos;
+	const int16 _idlePos;
+	const int16 _deltaPos;
+	const int16 _period;
+};
+
+/**
+ * Automatically scroll a GUI menu or similar graphical element between an active and an idle position
+ * Movement in two dimensions; idle & active positions specified as Common::Point
+ * Movement is at constant speed determined by period, specified in ms.
+ * If active/idle status is changed mid-transition, will scroll from current position to the appropriate position.
+ */
+
+class Scroller {
+public:
+	Scroller(const Common::Point &activePos, const Common::Point &idlePos, const int16 period = 500);
+	~Scroller();
+	void reset();  ///< Set idle and immediately jump to idle position
+	bool update(uint32 deltatime);  ///< Calculate updated position of scrolled graphics; return true if redraw is necessary.
+	void setActive(bool active);  ///< Set active or idle & scroll at set speed from current position to that position.
+	bool isMoving();
+	
+	Common::Point _pos;
+
+private:
+	LinearScroller _xScroller, _yScroller;
+};
+
+} // End of namespace ZVision
+
+#endif