diff widgets/Thumbwheel.cpp @ 132:5d3a483856ff

* Add Thumbwheel widget for all our zooming needs
* Use QSettings to save/restore window size and position -- precursor to
  switching our preferences to QSettings as well -- wish I'd noticed it sooner
* Only suspend writes (not reads from the underlying cache objects) from the
  fft caches when repainting the spectrogram -- performance should now be
  significantly better

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/widgets/Thumbwheel.cpp	Thu Aug 03 15:40:11 2006 +0000
@@ -0,0 +1,246 @@
+/* -*- 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 "Thumbwheel.h"
+
+#include <QMouseEvent>
+#include <QPaintEvent>
+#include <QWheelEvent>
+#include <QPainter>
+
+#include <cmath>
+#include <iostream>
+
+Thumbwheel::Thumbwheel(int min, int max, int defaultValue,
+                       Qt::Orientation orientation,
+		       QWidget *parent) :
+    QWidget(parent),
+    m_min(min),
+    m_max(max),
+    m_default(defaultValue),
+    m_value((min + max) / 2),
+    m_orientation(orientation),
+    m_tracking(true),
+    m_showScale(true),
+    m_clicked(false),
+    m_clickValue(m_value)
+{
+    if (max <= min) max = min + 1;
+    m_speed = float(max - min) / 300.f;
+}
+
+Thumbwheel::~Thumbwheel()
+{
+}
+
+void
+Thumbwheel::setValue(int value)
+{
+    if (value < m_min) value = m_min;
+    if (value > m_max) value = m_max;
+    m_value = value;
+    update();
+}
+
+int
+Thumbwheel::getValue() const
+{
+    return m_value;
+}
+
+void
+Thumbwheel::setSpeed(float speed)
+{
+    m_speed = speed;
+}
+
+float
+Thumbwheel::getSpeed() const
+{
+    return m_speed;
+}
+
+void
+Thumbwheel::setTracking(bool tracking)
+{
+    m_tracking = tracking;
+}
+
+bool
+Thumbwheel::getTracking() const
+{
+    return m_tracking;
+}
+
+void
+Thumbwheel::setShowScale(bool showScale)
+{
+    m_showScale = showScale;
+}
+
+bool
+Thumbwheel::getShowScale() const
+{
+    return m_showScale;
+}
+
+void
+Thumbwheel::mousePressEvent(QMouseEvent *e)
+{
+    m_clicked = true;
+    m_clickPos = e->pos();
+    m_clickValue = m_value;
+}
+
+void
+Thumbwheel::mouseDoubleClickEvent(QMouseEvent *)
+{
+    setValue(m_default);
+    emit valueChanged(getValue());
+}
+
+void
+Thumbwheel::mouseMoveEvent(QMouseEvent *e)
+{
+    int dist = 0;
+    if (m_orientation == Qt::Horizontal) {
+        dist = e->x() - m_clickPos.x();
+    } else {
+        dist = e->y() - m_clickPos.y();
+    }
+    int value = m_clickValue + lrintf(m_speed * dist);
+    if (value < m_min) value = m_min;
+    if (value > m_max) value = m_max;
+    if (value != m_value) {
+        setValue(value);
+        if (m_tracking) emit valueChanged(getValue());
+    }        
+}
+
+void
+Thumbwheel::mouseReleaseEvent(QMouseEvent *e)
+{
+    bool reallyTracking = m_tracking;
+    m_tracking = true;
+    mouseMoveEvent(e);
+    m_tracking = reallyTracking;
+}
+
+void
+Thumbwheel::wheelEvent(QWheelEvent *e)
+{
+    int step = lrintf(m_speed);
+    if (step == 0) step = 1;
+
+    if (e->delta() > 0) {
+	setValue(m_value + step);
+    } else {
+	setValue(m_value - step);
+    }
+    
+    emit valueChanged(getValue());
+}
+
+void
+Thumbwheel::paintEvent(QPaintEvent *)
+{
+    float distance = float(m_value - m_min) / float(m_max - m_min);
+    float rotation = distance * 1.5f * M_PI;
+
+//    std::cerr << "value = " << m_value << ", min = " << m_min << ", max = " << m_max << ", rotation = " << rotation << std::endl;
+
+    int w = (m_orientation == Qt::Horizontal ? width() : height());
+
+    // total number of notches on the entire wheel
+    int notches = 25;
+    
+    // radius of the wheel including invisible part
+    int radius = w / 2 + 2;
+
+    QPainter paint(this);
+    paint.fillRect(rect(), palette().background().color());
+    paint.setRenderHint(QPainter::Antialiasing, true);
+
+    for (int i = 0; i < notches; ++i) {
+
+        float a0 = (2.f * M_PI * i) / notches + rotation;
+        float a1 = a0 + M_PI / (notches * 2);
+        float a2 = (2.f * M_PI * (i + 1)) / notches + rotation;
+
+        float depth = cosf((a0 + a2) / 2);
+        if (depth < 0) continue;
+
+        float x0 = radius * sinf(a0) + w/2;
+        float x1 = radius * sinf(a1) + w/2;
+        float x2 = radius * sinf(a2) + w/2;
+        if (x2 < 0 || x0 > w) continue;
+
+        if (x0 < 0) x0 = 0;
+        if (x2 > w) x2 = w;
+
+        int grey = lrintf(255 * depth);
+        QColor fc = QColor(grey, grey, grey);
+        QColor oc = palette().dark().color();
+
+        paint.setPen(oc);
+        paint.setBrush(fc);
+
+        if (m_orientation == Qt::Horizontal) {
+            paint.drawRect(QRectF(x1, 0, x2 - x1, height()));
+        } else {
+            paint.drawRect(QRectF(0, x1, width(), x2 - x1));
+        }
+
+        if (m_showScale) {
+
+            paint.setBrush(oc);
+
+            float prop;
+            if (i >= notches / 4) {
+                prop = float(notches - (((i - float(notches) / 4.f) * 4.f) / 3.f))
+                    / notches;
+            } else {
+                prop = 0.f;
+            }
+            
+            if (m_orientation == Qt::Horizontal) {
+                paint.drawRect(QRectF(x1, height() - height() * prop,
+                                      x2 - x1, height() * prop));
+            } else {
+                paint.drawRect(QRectF(0, x1, width() * prop, x2 - x1));
+            }
+        }
+
+        paint.setPen(oc);
+        paint.setBrush(palette().background().color());
+
+        if (m_orientation == Qt::Horizontal) {
+            paint.drawRect(QRectF(x0, 0, x1 - x0, height()));
+        } else {
+            paint.drawRect(QRectF(0, x0, width(), x1 - x0));
+        }
+    }
+}
+
+QSize
+Thumbwheel::sizeHint() const
+{
+    if (m_orientation == Qt::Horizontal) {
+        return QSize(80, 12);
+    } else {
+        return QSize(12, 80);
+    }
+}
+