Caption.h

/**
 * @file
 * @brief Header file for Caption effect class
 * @author Jonathan Thomas <jonathan@openshot.org>
 *
 * @ref License
 */

/* LICENSE
 *
 * Copyright (c) 2008-2019 OpenShot Studios, LLC
 * <http://www.openshotstudios.com/>. This file is part of
 * OpenShot Library (libopenshot), an open-source project dedicated to
 * delivering high quality video editing and animation solutions to the
 * world. For more information visit <http://www.openshot.org/>.
 *
 * OpenShot Library (libopenshot) is free software: you can redistribute it
 * and/or modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * OpenShot Library (libopenshot) 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef OPENSHOT_CAPTION_EFFECT_H
#define OPENSHOT_CAPTION_EFFECT_H

#include <cmath>
#include <stdio.h>
#include <memory>
#include <QtCore/QRegularExpression>
#include "../Color.h"
#include "../EffectBase.h"
#include "../Fraction.h"
#include "../Json.h"
#include "../KeyFrame.h"



namespace openshot
{

	/**
	 * @brief This class adds captions/text over a video, based on timestamps. You can also animate some limited
	 * aspects, such as words appearing/disappearing.
	 *
	 * Adding captions can be an easy way to generate text overlays through-out a long clip.
	 */
	class Caption : public EffectBase
	{
	private:
		std::vector<QRegularExpressionMatch> matchedCaptions; ///< RegEx to capture cues and text
		std::string caption_text;    ///< Text of caption
		QFontMetrics* metrics;       ///< Font metrics object
		QFont* font; 			     ///< QFont object
		bool is_dirty;

		/// Init effect settings
		void init_effect_details();

		/// Process regex capture
		void process_regex();


	public:
		Color color;		 ///< Color of caption text
		Color stroke;		 ///< Color of text border / stroke
		Color background;	 ///< Color of caption area background
		Keyframe background_alpha;     ///< Background color alpha
		Keyframe background_corner;    ///< Background cornder radius
		Keyframe background_padding;    ///< Background padding
		Keyframe stroke_width;  ///< Width of text border / stroke
		Keyframe font_size;     ///< Font size in points
		Keyframe font_alpha;     ///< Font color alpha
		Keyframe left;		 ///< Size of left bar
		Keyframe top;		 ///< Size of top bar
		Keyframe right;		 ///< Size of right bar
		Keyframe fade_in;		 ///< Fade in per caption (# of seconds)
		Keyframe fade_out;		 ///< Fade in per caption (# of seconds)
		std::string font_name;	///< Font string

		/// Blank constructor, useful when using Json to load the effect properties
		Caption();

		/// Default constructor, which takes a string of VTT/Subrip formatted caption data, and displays them over time.
		///
		/// @param captions A string with VTT/Subrip format text captions
		Caption(std::string captions);

		/// @brief This method is required for all derived classes of ClipBase, and returns a
		/// new openshot::Frame object. All Clip keyframes and effects are resolved into
		/// pixels.
		///
		/// @returns A new openshot::Frame object
		/// @param frame_number The frame number (starting at 1) of the clip or effect on the timeline.
		std::shared_ptr<openshot::Frame> GetFrame(int64_t frame_number) override { return GetFrame(std::make_shared<openshot::Frame>(), frame_number); }

		/// @brief This method is required for all derived classes of ClipBase, and returns a
		/// modified openshot::Frame object
		///
		/// The frame object is passed into this method and used as a starting point (pixels and audio).
		/// All Clip keyframes and effects are resolved into pixels.
		///
		/// @returns The modified openshot::Frame object
		/// @param frame The frame object that needs the clip or effect applied to it
		/// @param frame_number The frame number (starting at 1) of the clip or effect on the timeline.
		std::shared_ptr<openshot::Frame> GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number) override;

		// Get and Set caption data
		std::string CaptionText(); ///< Set the caption string to use (see VTT format)
		void CaptionText(std::string new_caption_text); ///< Get the caption string

		/// Get and Set JSON methods
		std::string Json() const override; ///< Generate JSON string of this object
		void SetJson(const std::string value) override; ///< Load JSON string into this object
		Json::Value JsonValue() const override; ///< Generate Json::Value for this object
		void SetJsonValue(const Json::Value root) override; ///< Load Json::Value into this object

		/// Get all properties for a specific frame (perfect for a UI to display the current state
		/// of all properties at any time)
		std::string PropertiesJSON(int64_t requested_frame) const override;
	};

}

#endif