view widgets/Panner.cpp @ 94:c7ade7ea3cfe

* It turns out we can be more efficient in the spectrogram repaints by
  marking the spectrogram layer as non-scrollable, and using the spectrogram
  cache alone instead of both spectrogram and view caches.

/* -*- 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 "Panner.h"
#include "base/Layer.h"
#include "base/Model.h"
#include "base/ZoomConstraint.h"

#include <QPaintEvent>
#include <QPainter>
#include <iostream>

using std::cerr;
using std::endl;

Panner::Panner(QWidget *w) :
    View(w, false),
    m_clickedInRange(false)
{
    setObjectName(tr("Panner"));
    m_followPan = false;
    m_followZoom = false;
}

void
Panner::modelChanged(size_t startFrame, size_t endFrame)
{
    View::modelChanged(startFrame, endFrame);
}

void
Panner::modelReplaced()
{
    View::modelReplaced();
}

void
Panner::registerView(View *widget)
{
    m_widgets.insert(widget);
    update(); 
}

void
Panner::unregisterView(View *widget)
{
    m_widgets.erase(widget);
    update();
}

void
Panner::viewManagerCentreFrameChanged(void *p, unsigned long f, bool)
{
//    std::cerr << "Panner[" << this << "]::viewManagerCentreFrameChanged(" 
//	      << p << ", " << f << ")" << std::endl;

    if (p == this) return;
    if (m_widgets.find(p) != m_widgets.end()) {
	update();
    }
}

void
Panner::viewManagerZoomLevelChanged(void *p, unsigned long z, bool)
{
    if (p == this) return;
    if (m_widgets.find(p) != m_widgets.end()) {
	update();
    }
}

void
Panner::viewManagerPlaybackFrameChanged(unsigned long f)
{
    bool changed = false;

    if (getXForFrame(m_playPointerFrame) != getXForFrame(f)) changed = true;
    m_playPointerFrame = f;

    if (changed) update();
}

void
Panner::paintEvent(QPaintEvent *e)
{
    // Recalculate zoom in case the size of the widget has changed.

    size_t startFrame = getModelsStartFrame();
    size_t frameCount = getModelsEndFrame() - getModelsStartFrame();
    int zoomLevel = frameCount / width();
    if (zoomLevel < 1) zoomLevel = 1;
    zoomLevel = getZoomConstraintBlockSize(zoomLevel,
					   ZoomConstraint::RoundUp);
    if (zoomLevel != m_zoomLevel) {
	m_zoomLevel = zoomLevel;
	emit zoomLevelChanged(this, m_zoomLevel, m_followZoom);
    }
    size_t centreFrame = startFrame + m_zoomLevel * (width() / 2);
    if (centreFrame > (startFrame + getModelsEndFrame())/2) {
	centreFrame = (startFrame + getModelsEndFrame())/2;
    }
    if (centreFrame != m_centreFrame) {
	m_centreFrame = centreFrame;
	emit centreFrameChanged(this, m_centreFrame, false);
    }

    View::paintEvent(e);

    QPainter paint;
    paint.begin(this);

    QRect r(rect());

    if (e) {
	r = e->rect();
	paint.setClipRect(r);
    }

    paint.setPen(Qt::black);

    int y = 0;

    int prevx0 = -10;
    int prevx1 = -10;

    for (WidgetSet::iterator i = m_widgets.begin(); i != m_widgets.end(); ++i) {
	if (!*i) continue;

	View *w = (View *)*i;

	long f0 = w->getFrameForX(0);
	long f1 = w->getFrameForX(w->width());

	int x0 = getXForFrame(f0);
	int x1 = getXForFrame(f1);

	if (x0 != prevx0 || x1 != prevx1) {
	    y += height() / 10 + 1;
	    prevx0 = x0;
	    prevx1 = x1;
	}

	if (x1 <= x0) x1 = x0 + 1;
	
	paint.drawRect(x0, y, x1 - x0, height() - 2 * y);
    }

    paint.end();
}

void
Panner::mousePressEvent(QMouseEvent *e)
{
    m_clickPos = e->pos();
    for (WidgetSet::iterator i = m_widgets.begin(); i != m_widgets.end(); ++i) {
	if (*i) {
	    m_clickedInRange = true;
	    m_dragCentreFrame = ((View *)*i)->getCentreFrame();
	    break;
	}
    }
}

void
Panner::mouseReleaseEvent(QMouseEvent *e)
{
    if (m_clickedInRange) {
	mouseMoveEvent(e);
    }
    m_clickedInRange = false;
}

void
Panner::mouseMoveEvent(QMouseEvent *e)
{
    if (!m_clickedInRange) return;

    long xoff = int(e->x()) - int(m_clickPos.x());
    long frameOff = xoff * m_zoomLevel;
    
    size_t newCentreFrame = m_dragCentreFrame;
    if (frameOff > 0) {
	newCentreFrame += frameOff;
    } else if (newCentreFrame >= size_t(-frameOff)) {
	newCentreFrame += frameOff;
    } else {
	newCentreFrame = 0;
    }

    if (newCentreFrame >= getModelsEndFrame()) {
	newCentreFrame = getModelsEndFrame();
	if (newCentreFrame > 0) --newCentreFrame;
    }
    
    if (std::max(m_centreFrame, newCentreFrame) -
	std::min(m_centreFrame, newCentreFrame) > size_t(m_zoomLevel)) {
	emit centreFrameChanged(this, newCentreFrame, true);
    }
}

#ifdef INCLUDE_MOCFILES
#include "Panner.moc.cpp"
#endif