tutorial: HelloWorld

Change-Id: Ie19a7749ba028ceda16a2479398645daeb08f277
diff --git a/HelloWorld/CoinCircleVideoSubscriber.h b/HelloWorld/CoinCircleVideoSubscriber.h
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+/**
+ *  Copyright (C) 2020 Savoir-faire Linux Inc.
+ *
+ *  Author: Aline Gondim Santos <aline.gondimsantos@savoirfairelinux.com>
+ *
+ *  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, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA.
+ */
+
+#pragma once
+
+// AvFrame
+extern "C" {
+#include <libavutil/frame.h>
+}
+#include <observer.h>
+
+// Frame Scaler
+#include <framescaler.h>
+
+#include <opencv2/core.hpp>
+
+namespace jami {
+
+class CoinCircleVideoSubscriber : public jami::Observer<AVFrame*>
+{
+public:
+    CoinCircleVideoSubscriber(const std::string& dataPath);
+    ~CoinCircleVideoSubscriber();
+
+    virtual void update(jami::Observable<AVFrame*>*, AVFrame* const&) override;
+    virtual void attached(jami::Observable<AVFrame*>*) override;
+    virtual void detached(jami::Observable<AVFrame*>*) override;
+
+    void detach();
+
+    void setColor(const std::string& color);
+
+private:
+    // Observer pattern
+    Observable<AVFrame*>* observable_ = nullptr;
+
+    // Data
+    std::string path_;
+    FrameScaler scaler;
+
+    // Status variables of the processing
+    bool firstRun {true};
+
+    // define custom variables
+    void copyByLine(const int lineSize);
+    void drawCoinCircle(const int angle);
+    void rotateFrame(const int angle, cv::Mat& frame);
+
+    cv::Point circlePos;
+    cv::Mat processingFrame;
+    cv::Mat resultFrame;
+    int radius;
+    cv::Scalar baseColor;
+};
+} // namespace jami