comparison base/Selection.cpp @ 0:fc9323a41f5a

start base : Sonic Visualiser sv1-1.0rc1

+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Sonic Visualiser
+    An audio file viewer and annotation editor.
+    Centre for Digital Music, Queen Mary, University of London.
+    This file copyright 2006 Chris Cannam.
+    
+    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.
+*/
+
+#include "Selection.h"
+
+Selection::Selection() :
+    m_startFrame(0),
+    m_endFrame(0)
+{
+}
+
+Selection::Selection(size_t startFrame, size_t endFrame) :
+    m_startFrame(startFrame),
+    m_endFrame(endFrame)
+{
+    if (m_startFrame > m_endFrame) {
+	size_t tmp = m_endFrame;
+	m_endFrame = m_startFrame;
+	m_startFrame = tmp;
+    }
+}
+
+Selection::Selection(const Selection &s) :
+    m_startFrame(s.m_startFrame),
+    m_endFrame(s.m_endFrame)
+{
+}
+
+Selection &
+Selection::operator=(const Selection &s)
+{
+    if (this != &s) {
+	m_startFrame = s.m_startFrame;
+	m_endFrame = s.m_endFrame;
+    } 
+    return *this;
+}
+
+Selection::~Selection()
+{
+}
+
+bool
+Selection::isEmpty() const
+{
+    return m_startFrame == m_endFrame;
+}
+
+size_t
+Selection::getStartFrame() const
+{
+    return m_startFrame;
+}
+
+size_t
+Selection::getEndFrame() const
+{
+    return m_endFrame;
+}
+
+bool
+Selection::contains(size_t frame) const
+{
+    return (frame >= m_startFrame) && (frame < m_endFrame);
+}
+
+bool
+Selection::operator<(const Selection &s) const
+{
+    if (isEmpty()) {
+	if (s.isEmpty()) return false;
+	else return true;
+    } else {
+	if (s.isEmpty()) return false;
+	else return (m_startFrame < s.m_startFrame);
+    }
+}
+
+bool
+Selection::operator==(const Selection &s) const
+{
+    if (isEmpty()) return s.isEmpty();
+
+    return (m_startFrame == s.m_startFrame &&
+	    m_endFrame == s.m_endFrame);
+}
+
+
+MultiSelection::MultiSelection()
+{
+}
+
+MultiSelection::~MultiSelection()
+{
+}
+
+const MultiSelection::SelectionList &
+MultiSelection::getSelections() const
+{
+    return m_selections;
+}
+
+void
+MultiSelection::setSelection(const Selection &selection)
+{
+    clearSelections();
+    addSelection(selection);
+}
+
+void
+MultiSelection::addSelection(const Selection &selection)
+{
+    m_selections.insert(selection);
+
+    // Cope with a sitation where the new selection overlaps one or
+    // more existing ones.  This is a terribly inefficient way to do
+    // this, but that probably isn't significant in real life.
+
+    // It's essential for the correct operation of
+    // getContainingSelection that the selections do not overlap, so
+    // this is not just a frill.
+
+    for (SelectionList::iterator i = m_selections.begin();
+	 i != m_selections.end(); ) {
+	
+	SelectionList::iterator j = i;
+	if (++j == m_selections.end()) break;
+
+	if (i->getEndFrame() >= j->getStartFrame()) {
+	    Selection merged(i->getStartFrame(),
+			     std::max(i->getEndFrame(), j->getEndFrame()));
+	    m_selections.erase(i);
+	    m_selections.erase(j);
+	    m_selections.insert(merged);
+	    i = m_selections.begin();
+	} else {
+	    ++i;
+	}
+    }
+}
+
+void
+MultiSelection::removeSelection(const Selection &selection)
+{
+    //!!! Likewise this needs to cope correctly with the situation
+    //where selection is not one of the original selection set but
+    //simply overlaps one of them (cutting down the original selection
+    //appropriately)
+
+    if (m_selections.find(selection) != m_selections.end()) {
+	m_selections.erase(selection);
+    }
+}
+
+void
+MultiSelection::clearSelections()
+{
+    if (!m_selections.empty()) {
+	m_selections.clear();
+    }
+}
+
+Selection
+MultiSelection::getContainingSelection(size_t frame, bool defaultToFollowing) const
+{
+    // This scales very badly with the number of selections, but it's
+    // more efficient for very small numbers of selections than a more
+    // scalable method, and I think that may be what we need
+
+    for (SelectionList::const_iterator i = m_selections.begin();
+	 i != m_selections.end(); ++i) {
+
+	if (i->contains(frame)) return *i;
+
+	if (i->getStartFrame() > frame) {
+	    if (defaultToFollowing) return *i;
+	    else return Selection();
+	}
+    }
+
+    return Selection();
+}
+
+QString
+MultiSelection::toXmlString(QString indent,
+			    QString extraAttributes) const
+{
+    QString s;
+    s += indent + QString("<selections %1>\n").arg(extraAttributes);
+	for (SelectionList::const_iterator i = m_selections.begin();
+	 i != m_selections.end(); ++i) {
+	s += indent + QString("  <selection start=\"%1\" end=\"%2\"/>\n")
+	    .arg(i->getStartFrame()).arg(i->getEndFrame());
+    }
+    s += indent + "</selections>\n";
+    return s;
+}
+