Chris@1118: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@1118: 
Chris@1118: /*
Chris@1118:     Sonic Visualiser
Chris@1118:     An audio file viewer and annotation editor.
Chris@1118:     Centre for Digital Music, Queen Mary, University of London.
Chris@1118:     
Chris@1118:     This program is free software; you can redistribute it and/or
Chris@1118:     modify it under the terms of the GNU General Public License as
Chris@1118:     published by the Free Software Foundation; either version 2 of the
Chris@1118:     License, or (at your option) any later version.  See the file
Chris@1118:     COPYING included with this distribution for more information.
Chris@1118: */
Chris@1118: 
Chris@1118: #ifndef SCROLLABLE_MAG_RANGE_CACHE_H
Chris@1118: #define SCROLLABLE_MAG_RANGE_CACHE_H
Chris@1118: 
Chris@1118: #include "base/BaseTypes.h"
Chris@1118: #include "base/MagnitudeRange.h"
Chris@1118: 
Chris@1118: #include "LayerGeometryProvider.h"
Chris@1118: 
Chris@1118: /**
Chris@1118:  * A cached set of magnitude range records for a view that scrolls
Chris@1118:  * horizontally, such as a spectrogram. The cache object holds a
Chris@1118:  * magnitude range per column of the view, can report width (likely
Chris@1118:  * the same as the underlying view, but it's the caller's
Chris@1118:  * responsibility to set the size appropriately), can scroll the set
Chris@1118:  * of ranges, and can report and update which columns have had a range
Chris@1118:  * specified.
Chris@1118:  *
Chris@1118:  * The only way to *update* the valid area in a cache is to update the
Chris@1118:  * magnitude range for a column using the sampleColumn call.
Chris@1118:  */
Chris@1118: class ScrollableMagRangeCache
Chris@1118: {
Chris@1118: public:
Chris@1118:     ScrollableMagRangeCache() :
Chris@1325:         m_startFrame(0)
Chris@1118:     {}
Chris@1118: 
Chris@1118:     void invalidate() {
Chris@1266:         m_ranges = std::vector<MagnitudeRange>(m_ranges.size());
Chris@1118:     }
Chris@1118:     
Chris@1118:     int getWidth() const {
Chris@1266:         return int(m_ranges.size());
Chris@1118:     }
Chris@1118: 
Chris@1118:     /**
Chris@1118:      * Set the width of the cache in columns. If the new size differs
Chris@1118:      * from the current size, the cache is invalidated.
Chris@1118:      */
Chris@1118:     void resize(int newWidth) {
Chris@1118:         if (getWidth() != newWidth) {
Chris@1266:             m_ranges = std::vector<MagnitudeRange>(newWidth);
Chris@1118:         }
Chris@1118:     }
Chris@1266:         
Chris@1325:     ZoomLevel getZoomLevel() const {
Chris@1266:         return m_zoomLevel;
Chris@1118:     }
Chris@1118: 
Chris@1118:     /**
Chris@1118:      * Set the zoom level. If the new zoom level differs from the
Chris@1118:      * current one, the cache is invalidated. (Determining whether to
Chris@1118:      * invalidate the cache here is the only thing the zoom level is
Chris@1118:      * used for.)
Chris@1118:      */
Chris@1325:     void setZoomLevel(ZoomLevel zoom) {
Chris@1325:         using namespace std::rel_ops;
Chris@1118:         if (m_zoomLevel != zoom) {
Chris@1118:             m_zoomLevel = zoom;
Chris@1118:             invalidate();
Chris@1118:         }
Chris@1118:     }
Chris@1118: 
Chris@1118:     sv_frame_t getStartFrame() const {
Chris@1266:         return m_startFrame;
Chris@1118:     }
Chris@1118: 
Chris@1118:     /**
Chris@1118:      * Set the start frame. If the new start frame differs from the
Chris@1118:      * current one, the cache is invalidated. To scroll, i.e. to set
Chris@1118:      * the start frame while retaining cache validity where possible,
Chris@1118:      * use scrollTo() instead.
Chris@1118:      */
Chris@1118:     void setStartFrame(sv_frame_t frame) {
Chris@1118:         if (m_startFrame != frame) {
Chris@1118:             m_startFrame = frame;
Chris@1118:             invalidate();
Chris@1118:         }
Chris@1118:     }
Chris@1118: 
Chris@1118:     bool isColumnSet(int column) const {
Chris@1266:         return in_range_for(m_ranges, column) && m_ranges.at(column).isSet();
Chris@1118:     }
Chris@1119: 
Chris@1119:     bool areColumnsSet(int x, int count) const {
Chris@1266:         for (int i = 0; i < count; ++i) {
Chris@1266:             if (!isColumnSet(x + i)) return false;
Chris@1266:         }
Chris@1266:         return true;
Chris@1119:     }
Chris@1118:     
Chris@1119:     /**
Chris@1119:      * Get the magnitude range for a single column.
Chris@1119:      */
Chris@1119:     MagnitudeRange getRange(int column) const {
Chris@1266:         return m_ranges.at(column);
Chris@1118:     }
Chris@1118: 
Chris@1118:     /**
Chris@1119:      * Get the magnitude range for a range of columns.
Chris@1119:      */
Chris@1122:     MagnitudeRange getRange(int x, int count) const;
Chris@1119:     
Chris@1119:     /**
Chris@1118:      * Set the new start frame for the cache, according to the
Chris@1118:      * geometry of the supplied LayerGeometryProvider, if possible
Chris@1118:      * also moving along any existing valid data within the cache so
Chris@1118:      * that it continues to be valid for the new start frame.
Chris@1118:      */
Chris@1118:     void scrollTo(const LayerGeometryProvider *v, sv_frame_t newStartFrame);
Chris@1118:     
Chris@1118:     /**
Chris@1120:      * Update a column in the cache, by column index. (Column zero is
Chris@1120:      * the first column in the cache, it has nothing to do with any
Chris@1120:      * underlying model that the cache may be used with.)
Chris@1118:      */
Chris@1120:     void sampleColumn(int column, const MagnitudeRange &r);
Chris@1118:     
Chris@1118: private:
Chris@1118:     std::vector<MagnitudeRange> m_ranges;
Chris@1118:     sv_frame_t m_startFrame;
Chris@1325:     ZoomLevel m_zoomLevel;
Chris@1118: };
Chris@1118: 
Chris@1118: #endif