view widgets/Panner.cpp @ 349:369a197737c7

* Various fixes to object lifetime management, particularly in the spectrum
  layer and for notification of main model deletion.
  The main purpose of this is to improve the behaviour of the spectrum, but I
  think it may also help with #1840922 Various crashes in Layer Summary window.

/* -*- 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 QMUL.
    
    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 <QMouseEvent>
#include <QPaintEvent>
#include <QWheelEvent>
#include <QPainter>

#include <iostream>
#include <cmath>

Panner::Panner(QWidget *parent) :
    QWidget(parent),
    m_rectX(0),
    m_rectY(0),
    m_rectWidth(1),
    m_rectHeight(1),
    m_scrollUnit(0),
    m_defaultCentreX(0),
    m_defaultCentreY(0),
    m_defaultsSet(false),
    m_thumbColour(palette().highlightedText().color()),
    m_backgroundAlpha(255),
    m_thumbAlpha(255),
    m_clicked(false)
{
}

Panner::~Panner()
{
}

void
Panner::setAlpha(int backgroundAlpha, int thumbAlpha)
{
    m_backgroundAlpha = backgroundAlpha;
    m_thumbAlpha = thumbAlpha;
}

void
Panner::setScrollUnit(float unit)
{
    m_scrollUnit = unit;
}

void
Panner::scroll(bool up)
{
    float unit = m_scrollUnit;
    if (unit == 0.f) {
        unit = float(m_rectHeight) / (6 * float(height()));
        if (unit < 0.01) unit = 0.01;
    }

    if (!up) {
        m_rectY += unit;
    } else {
        m_rectY -= unit;
    }

    normalise();
    emitAndUpdate();
}

void
Panner::mousePressEvent(QMouseEvent *e)
{
    if (e->button() == Qt::MidButton ||
        ((e->button() == Qt::LeftButton) &&
         (e->modifiers() & Qt::ControlModifier))) {
        resetToDefault();
    } else if (e->button() == Qt::LeftButton) {
        m_clicked = true;
        m_clickPos = e->pos();
        m_dragStartX = m_rectX;
        m_dragStartY = m_rectY;
    }
}

void
Panner::mouseDoubleClickEvent(QMouseEvent *e)
{
    if (e->button() != Qt::LeftButton) {
        return;
    }

    emit doubleClicked();
}

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

    float dx = float(e->pos().x() - m_clickPos.x()) / float(width());
    float dy = float(e->pos().y() - m_clickPos.y()) / float(height());
    
    m_rectX = m_dragStartX + dx;
    m_rectY = m_dragStartY + dy;
    
    normalise();
    repaint();
    emit rectExtentsChanged(m_rectX, m_rectY, m_rectWidth, m_rectHeight);
    emit rectCentreMoved(centreX(), centreY());
}

void
Panner::mouseReleaseEvent(QMouseEvent *e)
{
    if (!m_clicked) return;

    mouseMoveEvent(e);
    m_clicked = false;
}

void
Panner::wheelEvent(QWheelEvent *e)
{
    scroll(e->delta() > 0);
}

void
Panner::enterEvent(QEvent *)
{
    emit mouseEntered();
}

void
Panner::leaveEvent(QEvent *)
{
    emit mouseLeft();
}

void
Panner::paintEvent(QPaintEvent *)
{
    QPainter paint(this);
    paint.setRenderHint(QPainter::Antialiasing, false);

    QColor bg(palette().background().color());
    bg.setAlpha(m_backgroundAlpha);

    paint.setPen(palette().dark().color());
    paint.setBrush(bg);
    paint.drawRect(0, 0, width(), height());

    QColor hl(m_thumbColour);
    hl.setAlpha(m_thumbAlpha);

    paint.setBrush(hl);

    paint.drawRect(lrintf(width() * m_rectX),
                   lrintf(height() * m_rectY),
                   lrintf(width() * m_rectWidth),
                   lrintf(height() * m_rectHeight));
}

void
Panner::normalise()
{
    if (m_rectWidth > 1.0) m_rectWidth = 1.0;
    if (m_rectHeight > 1.0) m_rectHeight = 1.0;
    if (m_rectX + m_rectWidth > 1.0) m_rectX = 1.0 - m_rectWidth;
    if (m_rectX < 0) m_rectX = 0;
    if (m_rectY + m_rectHeight > 1.0) m_rectY = 1.0 - m_rectHeight;
    if (m_rectY < 0) m_rectY = 0;

    if (!m_defaultsSet) {
        m_defaultCentreX = centreX();
        m_defaultCentreY = centreY();
        m_defaultsSet = true;
    }
}

void
Panner::emitAndUpdate()
{
    emit rectExtentsChanged(m_rectX, m_rectY, m_rectWidth, m_rectHeight);
    emit rectCentreMoved(centreX(), centreY());
    update();
}  

void
Panner::getRectExtents(float &x0, float &y0, float &width, float &height)
{
    x0 = m_rectX;
    y0 = m_rectY;
    width = m_rectWidth;
    height = m_rectHeight;
}

void
Panner::setRectExtents(float x0, float y0, float width, float height)
{
//    std::cerr << "Panner::setRectExtents(" << x0 << ", " << y0 << ", "
//              << width << ", " << height << ")" << std::endl;

    if (m_rectX == x0 &&
        m_rectY == y0 &&
        m_rectWidth == width &&
        m_rectHeight == height) {
        return;
    }

    m_rectX = x0;
    m_rectY = y0;
    m_rectWidth = width;
    m_rectHeight = height;

    normalise();
    emitAndUpdate();
}

void
Panner::setRectWidth(float width)
{
    if (m_rectWidth == width) return;
    m_rectWidth = width;
    normalise();
    emitAndUpdate();
}

void
Panner::setRectHeight(float height)
{
    if (m_rectHeight == height) return;
    m_rectHeight = height;
    normalise();
    emitAndUpdate();
}

void
Panner::setRectCentreX(float x)
{
    float x0 = x - m_rectWidth/2;
    if (x0 == m_rectX) return;
    m_rectX = x0;
    normalise();
    emitAndUpdate();
}

void
Panner::setRectCentreY(float y)
{
    float y0 = y - m_rectHeight/2;
    if (y0 == m_rectY) return;
    m_rectY = y0;
    normalise();
    emitAndUpdate();
}

QSize
Panner::sizeHint() const
{
    return QSize(30, 30);
}

void
Panner::setDefaultRectCentre(float cx, float cy)
{
    m_defaultCentreX = cx;
    m_defaultCentreY = cy;
    m_defaultsSet = true;
}

void
Panner::resetToDefault()
{
    float x0 = m_defaultCentreX - m_rectWidth/2;
    float y0 = m_defaultCentreY - m_rectHeight/2;
    if (x0 == m_rectX && y0 == m_rectY) return;
    m_rectX = x0;
    m_rectY = y0;
    normalise();
    emitAndUpdate();
}