LUMIERA.clone/src/gui/widgets/timeline/timeline-view-window.hpp

129 lines
3.6 KiB
C++

/*
timeline-view-window.hpp - Declaration of the timeline window object
Copyright (C) Lumiera.org
2008, Joel Holdsworth <joel@airwebreathe.org.uk>
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 2 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/** @file widgets/timeline/timeline-view-window.hpp
** This file contains the definition of timeline view window helper
* object
*/
#ifndef TIMELINE_VIEW_WINDOW_HPP
#define TIMELINE_VIEW_WINDOW_HPP
#include "../../gtk-lumiera.hpp"
namespace gui {
namespace widgets {
class TimelineWidget;
namespace timeline {
/**
* TimelineViewWindow is a helper class for TimelineWidget which manages
* the view window of the timeline: the zoom and shift. The class also
* provides utility functions for handling time in the timeline.
**/
class TimelineViewWindow
{
public:
/**
* Constructor
* @param offset The initial view offset.
* @param scale The initial scale.
**/
TimelineViewWindow(lumiera::Time offset, int64_t scale);
/**
* Gets the time offset. This is the time value displaid at the
* left-hand edge of the timeline body area.
*/
lumiera::Time get_time_offset() const;
/**
* Sets the time offset. This is the time value displaid at the
* left-hand edge of the timeline body area.
*/
void set_time_offset(lumiera::Time time_offset);
/**
* Gets the time scale value.
* @return The scale factor, which is the number of microseconds per
* screen pixel.
*/
int64_t get_time_scale() const;
/**
* Sets the time scale value.
* @param time_scale The scale factor, which is the number of
* microseconds per screen pixel. This value must be greater than
* zero
*/
void set_time_scale(int64_t time_scale);
/**
* Zooms the view in or out as by a number of steps while keeping a
* given point on the timeline still.
* @param zoom_size The number of steps to zoom by. The scale factor
* is 1.25^(-zoom_size).
**/
void zoom_view(int point, int zoom_size);
/**
* Scrolls the view horizontally as a proportion of the view area.
* @param shift_size The size of the shift in 1/256ths of the view
* width.
**/
void shift_view(int view_width, int shift_size);
/**
* Converts time values to x coordinates in pixels.
* @param time The time value to convert.
* @return Returns the x-value as pixels from the left hand edge of
* the timeline body.
**/
int time_to_x(int64_t time) const;
/**
* Converts x coordinates in pixels to time values.
* @param x The x coordinte (as pixels from the left hand edge of
* the timeline body) to convert.
* @return Returns the time at the coordinate.
**/
lumiera::Time x_to_time(int x) const;
/**
* A signal to indicate that the scale or offset have been changed.
**/
sigc::signal<void> changed_signal() const;
private:
lumiera::Time timeOffset;
int64_t timeScale;
sigc::signal<void> changedSignal;
};
} // namespace timeline
} // namespace widgets
} // namespace gui
#endif // TIMELINE_VIEW_WINDOW_HPP