// -*- c-basic-offset: 4 -*- /* Rosegarden A sequencer and musical notation editor. Copyright 2000-2008 the Rosegarden development team. See the AUTHORS file for more details. 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. See the file COPYING included with this distribution for more information. */ #ifndef _SNAP_GRID_H_ #define _SNAP_GRID_H_ #include "RulerScale.h" #include <map> namespace Rosegarden { /** * SnapGrid is a class that maps x-coordinate onto time, using a * RulerScale to get the mapping but constraining the results to a * discrete set of suitable times. * * (It also snaps y-coordinates, but that bit isn't very interesting.) */ 00033 class SnapGrid { public: /** * Construct a SnapGrid that uses the given RulerScale for * x-coordinate mappings and the given ysnap for y-coords. * If ysnap is zero, y-coords are not snapped at all. */ SnapGrid(RulerScale *rulerScale, int ysnap = 0); static const timeT NoSnap; static const timeT SnapToBar; static const timeT SnapToBeat; static const timeT SnapToUnit; enum SnapDirection { SnapEither, SnapLeft, SnapRight }; /** * Set the snap size of the grid to the given time. * The snap time must be positive, or else one of the * special constants NoSnap, SnapToBar, SnapToBeat or * SnapToUnit. * The default is SnapToBeat. */ void setSnapTime(timeT snap); /** * Return the snap size of the grid, at the given x-coordinate. * (The x-coordinate is required in case the built-in snap size is * SnapToBar, SnapToBeat or SnapToUnit, in which case we need to * know the current time signature.) Returns zero for NoSnap. */ timeT getSnapTime(double x) const; /** * Return the snap setting -- the argument that was passed to * setSnapTime. This differs from getSnapTime, which interprets * the NoSnap, SnapToBar, SnapToBeat and SnapToUnit settings to * return actual timeT values; instead this function returns those * actual constants if set. */ timeT getSnapSetting() const; /** * Return the snap size of the grid, at the given time. (The time * is required in case the built-in snap size is SnapToBar, * SnapToBeat or SnapToUnit, in which case we need to know the * current time signature.) Returns zero for NoSnap. */ timeT getSnapTime(timeT t) const; /** * Snap a given x-coordinate to the nearest time on the grid. Of * course this also does x-to-time conversion, so it's useful even * in NoSnap mode. If the snap time is greater than the bar * duration at this point, the bar duration will be used instead. * * If d is SnapLeft or SnapRight, a time to the left or right * respectively of the given coordinate will be returned; * otherwise the nearest time on either side will be returned. */ timeT snapX(double x, SnapDirection d = SnapEither) const; /** * Snap a given time to the nearest time on the grid. Unlike * snapX, this is not useful in NoSnap mode. If the snap time is * greater than the bar duration at this point, the bar duration * will be used instead. * * If d is SnapLeft or SnapRight, a time to the left or right * respectively of the given coordinate will be returned; * otherwise the nearest time on either side will be returned. */ timeT snapTime(timeT t, SnapDirection d = SnapEither) const; /** * Snap a given y-coordinate to the nearest lower bin coordinate. */ 00111 int snapY(int y) const { if (m_ysnap == 0) return y; return getYBinCoordinate(getYBin(y)); } /** * Return the bin number for the given y-coordinate. */ int getYBin(int y) const; /** * Return the y-coordinate of the grid line at the start of the * given bin. */ int getYBinCoordinate(int bin) const; /** * Set the default vertical step. This is used as the height for * bins that have no specific height multiple set, and the base * height for bins that have a multiple. Setting the Y snap here * is equivalent to specifying it in the constructor. */ 00133 void setYSnap(int ysnap) { m_ysnap = ysnap; } /** * Retrieve the default vertical step. */ 00140 int getYSnap() const { return m_ysnap; } /** * Set the height multiple for a specific bin. The bin will be * multiple * ysnap high. The default is 1 for all bins. */ 00148 void setBinHeightMultiple(int bin, int multiple) { m_ymultiple[bin] = multiple; } /** * Retrieve the height multiple for a bin. */ 00155 int getBinHeightMultiple(int bin) { if (m_ymultiple.find(bin) == m_ymultiple.end()) return 1; return m_ymultiple[bin]; } RulerScale *getRulerScale() { return m_rulerScale; } const RulerScale *getRulerScale() const { return m_rulerScale; } protected: RulerScale *m_rulerScale; // I don't own this timeT m_snapTime; int m_ysnap; std::map<int, int> m_ymultiple; }; } #endif

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