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plasma-framework/widgets/signalplotter.cpp
Aaron J. Seigo df73771a1b ++compile 
svn path=/trunk/KDE/kdelibs/; revision=879801
2008-11-04 02:55:37 +00:00

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/*
* KSysGuard, the KDE System Guard
*
* Copyright 1999 - 2002 Chris Schlaeger <cs@kde.org>
* Copyright 2006 John Tapsell <tapsell@kde.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "signalplotter.h"
#include <math.h>
#include <string.h>
#include <QList>
#include <QPalette>
#include <QtGui/QPainter>
#include <QtGui/QPixmap>
#include <QtGui/QPainterPath>
#include <QtGui/QPolygon>
#include <kdebug.h>
#include <kglobal.h>
#include <klocale.h>
#include <kapplication.h>
#include <kstandarddirs.h>
#include <plasma/svg.h>
namespace Plasma
{
class SignalPlotterPrivate
{
public:
SignalPlotterPrivate()
: svgBackground(0)
{ }
~SignalPlotterPrivate()
{
}
int precision;
uint samples;
uint bezierCurveOffset;
double scaledBy;
double verticalMin;
double verticalMax;
double niceVertMin;
double niceVertMax;
double niceVertRange;
bool fillPlots;
bool showLabels;
bool showTopBar;
bool stackPlots;
bool useAutoRange;
bool showThinFrame;
bool showVerticalLines;
bool verticalLinesScroll;
uint verticalLinesOffset;
uint verticalLinesDistance;
QColor verticalLinesColor;
bool showHorizontalLines;
uint horizontalScale;
uint horizontalLinesCount;
QColor horizontalLinesColor;
Svg *svgBackground;
QString svgFilename;
QColor fontColor;
QColor backgroundColor;
QPixmap backgroundPixmap;
QFont font;
QString title;
QString unit;
QList<PlotColor> plotColors;
QList<QList<double> > plotData;
};
SignalPlotter::SignalPlotter(QGraphicsItem *parent)
: QGraphicsWidget(parent),
d(new SignalPlotterPrivate)
{
d->precision = 0;
d->bezierCurveOffset = 0;
d->samples = 0;
d->verticalMin = d->verticalMax = 0.0;
d->niceVertMin = d->niceVertMax = 0.0;
d->niceVertRange = 0;
d->useAutoRange = true;
d->scaledBy = 1;
d->showThinFrame = true;
// Anything smaller than this does not make sense.
setMinimumSize(QSizeF(16, 16));
d->showVerticalLines = true;
d->verticalLinesColor = QColor("black");
d->verticalLinesDistance = 30;
d->verticalLinesScroll = true;
d->verticalLinesOffset = 0;
d->horizontalScale = 1;
d->showHorizontalLines = true;
d->horizontalLinesColor = QColor("black");
d->horizontalLinesCount = 5;
d->showLabels = true;
d->showTopBar = true;
d->stackPlots = true;
d->fillPlots = true;
d->svgBackground = 0;
d->backgroundColor = QColor(0, 0, 0);
setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
}
SignalPlotter::~SignalPlotter()
{
delete d;
}
QString SignalPlotter::unit() const
{
return d->unit;
}
void SignalPlotter::setUnit(const QString &unit)
{
d->unit= unit;
}
void SignalPlotter::addPlot(const QColor &color)
{
// When we add a new plot, go back and set the data for this plot to 0 for
// all the other times. This is because it makes it easier for moveSensors.
foreach (QList<double> data, d->plotData) {
data.append(0);
}
PlotColor newColor;
newColor.color = color;
newColor.darkColor = color.dark(150);
d->plotColors.append(newColor);
}
void SignalPlotter::addSample(const QList<double>& sampleBuf)
{
if (d->samples < 4) {
// It might be possible, under some race conditions, for addSample
// to be called before d->samples is set. This is just to be safe.
kDebug() << "Error - d->samples is only " << d->samples;
updateDataBuffers();
kDebug() << "d->samples is now " << d->samples;
if (d->samples < 4) {
return;
}
}
d->plotData.prepend(sampleBuf);
Q_ASSERT(sampleBuf.count() == d->plotColors.count());
if ((uint)d->plotData.size() > d->samples) {
d->plotData.removeLast(); // we have too many. Remove the last item
if ((uint)d->plotData.size() > d->samples) {
// If we still have too many, then we have resized the widget.
// Remove one more. That way we will slowly resize to the new size
d->plotData.removeLast();
}
}
if (d->bezierCurveOffset >= 2) {
d->bezierCurveOffset = 0;
} else {
d->bezierCurveOffset++;
}
Q_ASSERT((uint)d->plotData.size() >= d->bezierCurveOffset);
// If the vertical lines are scrolling, increment the offset
// so they move with the data.
if (d->verticalLinesScroll) {
d->verticalLinesOffset =
(d->verticalLinesOffset + d->horizontalScale) % d->verticalLinesDistance;
}
update();
}
void SignalPlotter::reorderPlots(const QList<uint>& newOrder)
{
if (newOrder.count() != d->plotColors.count()) {
kDebug() << "neworder has " << newOrder.count()
<< " and plot colors is " << d->plotColors.count();
return;
}
foreach (QList<double> data, d->plotData) {
if (newOrder.count() != data.count()) {
kDebug() << "Serious problem in move sample. plotdata[i] has "
<< data.count() << " and neworder has " << newOrder.count();
} else {
QList<double> newPlot;
for (int i = 0; i < newOrder.count(); i++) {
int newIndex = newOrder[i];
newPlot.append(data.at(newIndex));
}
data = newPlot;
}
}
QList<PlotColor> newPlotColors;
for (int i = 0; i < newOrder.count(); i++) {
int newIndex = newOrder[i];
PlotColor newColor = d->plotColors.at(newIndex);
newPlotColors.append(newColor);
}
d->plotColors = newPlotColors;
}
void SignalPlotter::setVerticalRange(double min, double max)
{
d->verticalMin = min;
d->verticalMax = max;
calculateNiceRange();
}
QList<PlotColor> &SignalPlotter::plotColors()
{
return d->plotColors;
}
void SignalPlotter::removePlot(uint pos)
{
if (pos >= (uint)d->plotColors.size()) {
return;
}
d->plotColors.removeAt(pos);
foreach (QList<double> data, d->plotData) {
if ((uint)data.size() >= pos) {
data.removeAt(pos);
}
}
}
void SignalPlotter::scale(qreal delta)
{
if (d->scaledBy == delta) {
return;
}
d->scaledBy = delta;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
calculateNiceRange();
}
qreal SignalPlotter::scaledBy() const
{
return d->scaledBy;
}
void SignalPlotter::setTitle(const QString &title)
{
if (d->title == title) {
return;
}
d->title = title;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
}
QString SignalPlotter::title() const
{
return d->title;
}
void SignalPlotter::setUseAutoRange(bool value)
{
d->useAutoRange = value;
calculateNiceRange();
// this change will be detected in paint and the image cache regenerated
}
bool SignalPlotter::useAutoRange() const
{
return d->useAutoRange;
}
double SignalPlotter::verticalMinValue() const
{
return d->verticalMin;
}
double SignalPlotter::verticalMaxValue() const
{
return d->verticalMax;
}
void SignalPlotter::setHorizontalScale(uint scale)
{
if (scale == d->horizontalScale) {
return;
}
d->horizontalScale = scale;
updateDataBuffers();
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
}
uint SignalPlotter::horizontalScale() const
{
return d->horizontalScale;
}
void SignalPlotter::setShowVerticalLines(bool value)
{
if (d->showVerticalLines == value) {
return;
}
d->showVerticalLines = value;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
}
bool SignalPlotter::showVerticalLines() const
{
return d->showVerticalLines;
}
void SignalPlotter::setVerticalLinesColor(const QColor &color)
{
if (d->verticalLinesColor == color) {
return;
}
d->verticalLinesColor = color;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
}
QColor SignalPlotter::verticalLinesColor() const
{
return d->verticalLinesColor;
}
void SignalPlotter::setVerticalLinesDistance(uint distance)
{
if (distance == d->verticalLinesDistance) {
return;
}
d->verticalLinesDistance = distance;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
}
uint SignalPlotter::verticalLinesDistance() const
{
return d->verticalLinesDistance;
}
void SignalPlotter::setVerticalLinesScroll(bool value)
{
if (value == d->verticalLinesScroll) {
return;
}
d->verticalLinesScroll = value;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
}
bool SignalPlotter::verticalLinesScroll() const
{
return d->verticalLinesScroll;
}
void SignalPlotter::setShowHorizontalLines(bool value)
{
if (value == d->showHorizontalLines) {
return;
}
d->showHorizontalLines = value;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
}
bool SignalPlotter::showHorizontalLines() const
{
return d->showHorizontalLines;
}
void SignalPlotter::setFontColor(const QColor &color)
{
d->fontColor = color;
}
QColor SignalPlotter::fontColor() const
{
return d->fontColor;
}
void SignalPlotter::setHorizontalLinesColor(const QColor &color)
{
if (color == d->horizontalLinesColor) {
return;
}
d->horizontalLinesColor = color;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
}
QColor SignalPlotter::horizontalLinesColor() const
{
return d->horizontalLinesColor;
}
void SignalPlotter::setHorizontalLinesCount(uint count)
{
if (count == d->horizontalLinesCount) {
return;
}
d->horizontalLinesCount = count;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
calculateNiceRange();
}
uint SignalPlotter::horizontalLinesCount() const
{
return d->horizontalLinesCount;
}
void SignalPlotter::setShowLabels(bool value)
{
if (value == d->showLabels) {
return;
}
d->showLabels = value;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
}
bool SignalPlotter::showLabels() const
{
return d->showLabels;
}
void SignalPlotter::setShowTopBar(bool value)
{
if (d->showTopBar == value) {
return;
}
d->showTopBar = value;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
}
bool SignalPlotter::showTopBar() const
{
return d->showTopBar;
}
void SignalPlotter::setFont(const QFont &font)
{
d->font = font;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
}
QFont SignalPlotter::font() const
{
return d->font;
}
QString SignalPlotter::svgBackground()
{
return d->svgFilename;
}
void SignalPlotter::setSvgBackground(const QString &filename)
{
if (d->svgFilename == filename) {
return;
}
if (!filename.isEmpty() && filename[0] == '/') {
KStandardDirs *kstd = KGlobal::dirs();
d->svgFilename = kstd->findResource("data", "ksysguard/" + filename);
} else {
d->svgFilename = filename;
}
if (!d->svgFilename.isEmpty()) {
if (d->svgBackground) {
delete d->svgBackground;
}
d->svgBackground = new Svg(this);
d->svgBackground->setImagePath(d->svgFilename);
}
}
void SignalPlotter::setBackgroundColor(const QColor &color)
{
if (color == d->backgroundColor) {
return;
}
d->backgroundColor = color;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
}
QColor SignalPlotter::backgroundColor() const
{
return d->backgroundColor;
}
void SignalPlotter::setThinFrame(bool set)
{
if (d->showThinFrame == set) {
return;
}
d->showThinFrame = set;
d->backgroundPixmap = QPixmap(); // we changed a paint setting, so reset the cache
}
void SignalPlotter::setStackPlots(bool stack)
{
d->stackPlots = stack;
d->fillPlots = stack;
}
bool SignalPlotter::stackPlots() const
{
return d->stackPlots;
}
void SignalPlotter::updateDataBuffers()
{
// This is called when the widget has resized
//
// Determine new number of samples first.
// +0.5 to ensure rounding up
// +4 for extra data points so there is
// 1) no wasted space and
// 2) no loss of precision when drawing the first data point.
d->samples = static_cast<uint>(((size().width() - 2) /
d->horizontalScale) + 4.5);
}
QPixmap SignalPlotter::getSnapshotImage(uint w, uint height)
{
uint horizontalStep = (uint)((1.0 * w / size().width()) + 0.5); // get the closest integer horizontal step
uint newWidth = (uint) (horizontalStep * size().width());
QPixmap image = QPixmap(newWidth, height);
QPainter p(&image);
drawWidget(&p, newWidth, height, newWidth);
p.end();
return image;
}
void SignalPlotter::setGeometry(const QRectF &geometry)
{
// First update our size, then update the data buffers accordingly.
QGraphicsWidget::setGeometry(geometry);
updateDataBuffers();
}
void SignalPlotter::paint(QPainter *painter,
const QStyleOptionGraphicsItem *option, QWidget *widget)
{
Q_UNUSED(option);
Q_UNUSED(widget);
uint w = (uint) size().width();
uint h = (uint) size().height();
// Do not do repaints when the widget is not yet setup properly.
if (w <= 2) {
return;
}
drawWidget(painter, w, h, d->horizontalScale);
}
void SignalPlotter::drawWidget(QPainter *p, uint w, uint height, int horizontalScale)
{
uint h = height; // h will become the height of just the bit we draw the plots in
p->setFont(d->font);
uint fontheight = p->fontMetrics().height();
if (d->verticalMin < d->niceVertMin ||
d->verticalMax > d->niceVertMax ||
d->verticalMax < (d->niceVertRange * 0.75 + d->niceVertMin) ||
d->niceVertRange == 0) {
calculateNiceRange();
}
QPen pen;
pen.setWidth(1);
pen.setCapStyle(Qt::RoundCap);
p->setPen(pen);
uint top = p->pen().width() / 2; // The y position of the top of the graph. Basically this is one more than the height of the top bar
h-= top;
// Check if there's enough room to actually show a top bar.
// Must be enough room for a bar at the top, plus horizontal
// lines each of a size with room for a scale.
bool showTopBar = d->showTopBar && h > (fontheight/*top bar size*/ +5/*smallest reasonable size for a graph*/);
if (showTopBar) {
top += fontheight; // The top bar has the same height as fontheight. Thus the top of the graph is at fontheight
h -= fontheight;
}
if (d->backgroundPixmap.isNull() ||
(uint)d->backgroundPixmap.size().height() != height ||
(uint)d->backgroundPixmap.size().width() != w) {
// recreate on resize etc
d->backgroundPixmap = QPixmap(w, height);
QPainter pCache(&d->backgroundPixmap);
pCache.setRenderHint(QPainter::Antialiasing, false);
pCache.setFont(d->font);
drawBackground(&pCache, w, height);
if (d->showThinFrame) {
drawThinFrame(&pCache, w, height);
// We have a 'frame' in the bottom and right - so subtract them from the view
h--;
w--;
pCache.setClipRect(0, 0, w, height-1);
}
if (showTopBar) {
int separatorX = w / 2;
drawTopBarFrame(&pCache, separatorX, top);
}
// Draw scope-like grid vertical lines if it doesn't move.
// If it does move, draw it in the dynamic part of the code.
if (!d->verticalLinesScroll && d->showVerticalLines && w > 60) {
drawVerticalLines(&pCache, top, w, h);
}
if (d->showHorizontalLines) {
drawHorizontalLines(&pCache, top, w, h);
}
} else {
if (d->showThinFrame) {
// We have a 'frame' in the bottom and right - so subtract them from the view
h--;
w--;
}
}
p->drawPixmap(0, 0, d->backgroundPixmap);
p->setRenderHint(QPainter::Antialiasing, true);
if (showTopBar) {
int separatorX = w / 2;
int topBarWidth = w - separatorX -2;
drawTopBarContents(p, separatorX, topBarWidth, top -1);
}
p->setClipRect(0, top, w, h);
// Draw scope-like grid vertical lines
if (d->verticalLinesScroll && d->showVerticalLines && w > 60) {
drawVerticalLines(p, top, w, h);
}
drawPlots(p, top, w, h, horizontalScale);
if (d->showLabels && w > 60 && h > (fontheight + 1)) {
// if there's room to draw the labels, then draw them!
drawAxisText(p, top, h);
}
}
void SignalPlotter::drawBackground(QPainter *p, int w, int h)
{
p->fillRect(0, 0, w, h, d->backgroundColor);
if (d->svgBackground) {
d->svgBackground->resize(w, h);
d->svgBackground->paint(p, 0, 0);
}
}
void SignalPlotter::drawThinFrame(QPainter *p, int w, int h)
{
// Draw white line along the bottom and the right side of the
// widget to create a 3D like look.
p->setPen(kapp->palette().color(QPalette::Light));
p->drawLine(0, h - 1, w - 1, h - 1);
p->drawLine(w - 1, 0, w - 1, h - 1);
}
void SignalPlotter::calculateNiceRange()
{
d->niceVertRange = d->verticalMax - d->verticalMin;
// If the range is too small we will force it to 1.0 since it
// looks a lot nicer.
if (d->niceVertRange < 0.000001) {
d->niceVertRange = 1.0;
}
d->niceVertMin = d->verticalMin;
if (d->verticalMin != 0.0) {
double dim = pow(10, floor(log10(fabs(d->verticalMin)))) / 2;
if (d->verticalMin < 0.0) {
d->niceVertMin = dim * floor(d->verticalMin / dim);
} else {
d->niceVertMin = dim * ceil(d->verticalMin / dim);
}
d->niceVertRange = d->verticalMax - d->niceVertMin;
if (d->niceVertRange < 0.000001) {
d->niceVertRange = 1.0;
}
}
// Massage the range so that the grid shows some nice values.
double step = d->niceVertRange / (d->scaledBy * (d->horizontalLinesCount + 1));
int logdim = (int)floor(log10(step));
double dim = pow((double)10.0, logdim) / 2;
int a = (int)ceil(step / dim);
if (logdim >= 0) {
d->precision = 0;
} else if (a % 2 == 0) {
d->precision = -logdim;
} else {
d->precision = 1 - logdim;
}
d->niceVertRange = d->scaledBy * dim * a * (d->horizontalLinesCount + 1);
d->niceVertMax = d->niceVertMin + d->niceVertRange;
}
void SignalPlotter::drawTopBarFrame(QPainter *p, int separatorX, int height)
{
// Draw horizontal bar with current sensor values at top of display.
// Remember that it has a height of 'height'. Thus the lowest pixel
// it can draw on is height-1 since we count from 0.
p->setPen(Qt::NoPen);
p->setPen(d->fontColor);
p->drawText(0, 1, separatorX, height, Qt::AlignCenter, d->title);
p->setPen(d->horizontalLinesColor);
p->drawLine(separatorX - 1, 1, separatorX - 1, height - 1);
}
void SignalPlotter::drawTopBarContents(QPainter *p, int x, int width, int height)
{
// The height is the height of the contents, so this will be
// one pixel less than the height of the topbar
double bias = -d->niceVertMin;
double scaleFac = width / d->niceVertRange;
// The top bar shows the current values of all the plot data.
// This iterates through each different plot and plots the newest data for each.
if (!d->plotData.isEmpty()) {
QList<double> newestData = d->plotData.first();
for (int i = newestData.count()-1; i >= 0; --i) {
double newest_datapoint = newestData.at(i);
int start = x + (int)(bias * scaleFac);
int end = x + (int)((bias += newest_datapoint) * scaleFac);
int start2 = qMin(start, end);
end = qMax(start, end);
start = start2;
// If the rect is wider than 2 pixels we draw only the last
// pixels with the bright color. The rest is painted with
// a 50% darker color.
p->setPen(Qt::NoPen);
QLinearGradient linearGrad(QPointF(start, 1), QPointF(end, 1));
linearGrad.setColorAt(0, d->plotColors[i].darkColor);
linearGrad.setColorAt(1, d->plotColors[i].color);
p->fillRect(start, 1, end - start, height-1, QBrush(linearGrad));
}
}
}
void SignalPlotter::drawVerticalLines(QPainter *p, int top, int w, int h)
{
p->setPen(d->verticalLinesColor);
for (int x = d->verticalLinesOffset; x < (w - 2); x += d->verticalLinesDistance) {
p->drawLine(w - x, top, w - x, h + top -1);
}
}
void SignalPlotter::drawPlots(QPainter *p, int top, int w, int h, int horizontalScale)
{
Q_ASSERT(d->niceVertRange != 0);
if (d->niceVertRange == 0) {
d->niceVertRange = 1;
}
double scaleFac = (h - 1) / d->niceVertRange;
int xPos = 0;
QList< QList<double> >::Iterator it = d->plotData.begin();
p->setPen(Qt::NoPen);
// In autoRange mode we determine the range and plot the values in
// one go. This is more efficiently than running through the
// buffers twice but we do react on recently discarded samples as
// well as new samples one plot too late. So the range is not
// correct if the recently discarded samples are larger or smaller
// than the current extreme values. But we can probably live with
// this.
// These values aren't used directly anywhere. Instead we call
// calculateNiceRange() which massages these values into a nicer
// values. Rounding etc. This means it's safe to change these values
// without affecting any other drawings.
if (d->useAutoRange) {
d->verticalMin = d->verticalMax = 0.0;
}
// d->bezierCurveOffset is how many points we have at the start.
// All the bezier curves are in groups of 3, with the first of the
// next group being the last point of the previous group
// Example, when d->bezierCurveOffset == 0, and we have data, then just
// plot a normal bezier curve. (we will have at least 3 points in this case)
// When d->bezierCurveOffset == 1, then we want a bezier curve that uses
// the first data point and the second data point. Then the next group
// starts from the second data point.
//
// When d->bezierCurveOffset == 2, then we want a bezier curve that
// uses the first, second and third data.
for (uint i = 0; it != d->plotData.end() && i < d->samples; ++i) {
QPen pen;
pen.setWidth(1);
pen.setCapStyle(Qt::FlatCap);
// We will plot 1 bezier curve for every 3 points, with the 4th point
// being the end of one bezier curve and the start of the second.
// This does means the bezier curves will not join nicely, but it
// should be better than nothing.
QList<double> datapoints = *it;
QList<double> prev_datapoints = datapoints;
QList<double> prev_prev_datapoints = datapoints;
QList<double> prev_prev_prev_datapoints = datapoints;
if (i == 0 && d->bezierCurveOffset > 0) {
// We are plotting an incomplete bezier curve - we don't have
// all the data we want. Try to cope.
xPos += horizontalScale * d->bezierCurveOffset;
if (d->bezierCurveOffset == 1) {
prev_datapoints = *it;
++it; // Now we are on the first element of the next group, if it exists
if (it != d->plotData.end()) {
prev_prev_prev_datapoints = prev_prev_datapoints = *it;
} else {
prev_prev_prev_datapoints = prev_prev_datapoints = prev_datapoints;
}
} else {
// d->bezierCurveOffset must be 2 now
prev_datapoints = *it;
Q_ASSERT(it != d->plotData.end());
++it;
prev_prev_datapoints = *it;
Q_ASSERT(it != d->plotData.end());
++it; // Now we are on the first element of the next group, if it exists
if (it != d->plotData.end()) {
prev_prev_prev_datapoints = *it;
} else {
prev_prev_prev_datapoints = prev_prev_datapoints;
}
}
} else {
// We have a group of 3 points at least. That's 1 start point and 2 control points.
xPos += horizontalScale * 3;
it++;
if (it != d->plotData.end()) {
prev_datapoints = *it;
it++;
if (it != d->plotData.end()) {
prev_prev_datapoints = *it;
it++; // We are now on the next set of data points
if (it != d->plotData.end()) {
// We have this datapoint, so use it for our finish point
prev_prev_prev_datapoints = *it;
} else {
// We don't have the next set, so use our last control
// point as our finish point
prev_prev_prev_datapoints = prev_prev_datapoints;
}
} else {
prev_prev_prev_datapoints = prev_prev_datapoints = prev_datapoints;
}
} else {
prev_prev_prev_datapoints = prev_prev_datapoints = prev_datapoints = datapoints;
}
}
float x0 = w - xPos + 3.0 * horizontalScale;
float x1 = w - xPos + 2.0 * horizontalScale;
float x2 = w - xPos + 1.0 * horizontalScale;
float x3 = w - xPos;
float y0 = h - 1 + top;
float y1 = y0;
float y2 = y0;
float y3 = y0;
int offset = 0; // Our line is 2 pixels thick. This means that when we draw the area, we need to offset
double max_y = 0;
double min_y = 0;
for (int j = qMin(datapoints.size(), d->plotColors.size()) - 1; j >=0; --j) {
if (d->useAutoRange) {
// If we use autorange, then we need to prepare the min and max values for _next_ time we paint.
// If we are stacking the plots, then we need to add the maximums together.
double current_maxvalue =
qMax(datapoints[j],
qMax(prev_datapoints[j],
qMax(prev_prev_datapoints[j],
prev_prev_prev_datapoints[j])));
double current_minvalue =
qMin(datapoints[j],
qMin(prev_datapoints[j],
qMin(prev_prev_datapoints[j],
prev_prev_prev_datapoints[j])));
d->verticalMax = qMax(d->verticalMax, current_maxvalue);
d->verticalMin = qMin(d->verticalMin, current_maxvalue);
if (d->stackPlots) {
max_y += current_maxvalue;
min_y += current_minvalue;
}
}
// Draw polygon only if enough data points are available.
if (j < prev_prev_prev_datapoints.count() &&
j < prev_prev_datapoints.count() &&
j < prev_datapoints.count()) {
// The height of the whole widget is h+top-> The height of
// the area we are plotting in is just h.
// The y coordinate system starts from the top, so at the
// bottom the y coordinate is h+top.
// So to draw a point at value y', we need to put this at h+top-y'
float delta_y0;
delta_y0 = (datapoints[j] - d->niceVertMin) * scaleFac;
float delta_y1;
delta_y1 = (prev_datapoints[j] - d->niceVertMin) * scaleFac;
float delta_y2;
delta_y2 = (prev_prev_datapoints[j] - d->niceVertMin) * scaleFac;
float delta_y3;
delta_y3 = (prev_prev_prev_datapoints[j] - d->niceVertMin) * scaleFac;
QPainterPath path;
if (d->stackPlots && offset) {
// we don't want the lines to overdraw each other.
// This isn't a great solution though :(
if (delta_y0 < 3) {
delta_y0=3;
}
if (delta_y1 < 3) {
delta_y1=3;
}
if (delta_y2 < 3) {
delta_y2=3;
}
if (delta_y3 < 3) {
delta_y3=3;
}
}
path.moveTo(x0, y0 - delta_y0);
path.cubicTo(x1, y1 - delta_y1, x2, y2 - delta_y2, x3, y3 - delta_y3);
if (d->fillPlots) {
QPainterPath path2(path);
QLinearGradient myGradient(0,(h - 1 + top), 0, (h - 1 + top) / 5);
Q_ASSERT(d->plotColors.size() >= j);
QColor c0(d->plotColors[j].darkColor);
QColor c1(d->plotColors[j].color);
c0.setAlpha(150);
c1.setAlpha(150);
myGradient.setColorAt(0, c0);
myGradient.setColorAt(1, c1);
path2.lineTo(x3, y3 - offset);
if (d->stackPlots) {
// offset is set to 1 after the first plot is drawn,
// so we don't trample on top of the 2pt thick line
path2.cubicTo(x2, y2 - offset, x1, y1 - offset, x0, y0 - offset);
} else {
path2.lineTo(x0, y0 - 1);
}
p->setBrush(myGradient);
p->setPen(Qt::NoPen);
p->drawPath(path2);
}
p->setBrush(Qt::NoBrush);
Q_ASSERT(d->plotColors.size() >= j);
pen.setColor(d->plotColors[j].color);
p->setPen(pen);
p->drawPath(path);
if (d->stackPlots) {
// We can draw the plots stacked on top of each other.
// This means that say plot 0 has the value 2 and plot
// 1 has the value 3, then we plot plot 0 at 2 and plot 1 at 2+3 = 5.
y0 -= delta_y0;
y1 -= delta_y1;
y2 -= delta_y2;
y3 -= delta_y3;
offset = 1; // see the comment further up for int offset;
}
}
if (d->useAutoRange && d->stackPlots) {
d->verticalMax = qMax(max_y, d->verticalMax);
d->verticalMin = qMin(min_y, d->verticalMin);
}
}
}
}
void SignalPlotter::drawAxisText(QPainter *p, int top, int h)
{
// Draw horizontal lines and values. Lines are always drawn.
// Values are only draw when width is greater than 60.
QString val;
// top = 0 or font.height depending on whether there's a topbar or not
// h = graphing area.height - i.e. the actual space we have to draw inside
// Note we are drawing from 0,0 as the top left corner. So we have to add on top
// to get to the top of where we are drawing so top+h is the height of the widget.
p->setPen(d->fontColor);
double stepsize = d->niceVertRange / (d->scaledBy * (d->horizontalLinesCount + 1));
int step =
(int)ceil((d->horizontalLinesCount+1) *
(p->fontMetrics().height() + p->fontMetrics().leading() / 2.0) / h);
if (step == 0) {
step = 1;
}
for (int y = d->horizontalLinesCount + 1; y >= 1; y-= step) {
int y_coord =
top + (y * (h - 1)) / (d->horizontalLinesCount + 1); // Make sure it's y*h first to avoid rounding bugs
if (y_coord - p->fontMetrics().ascent() < top) {
// at most, only allow 4 pixels of the text to be covered up
// by the top bar. Otherwise just don't bother to draw it
continue;
}
double value;
if ((uint)y == d->horizontalLinesCount + 1) {
value = d->niceVertMin; // sometimes using the formulas gives us a value very slightly off
} else {
value = d->niceVertMax / d->scaledBy - y * stepsize;
}
QString number = KGlobal::locale()->formatNumber(value, d->precision);
val = QString("%1 %2").arg(number, d->unit);
p->drawText(6, y_coord - 3, val);
}
}
void SignalPlotter::drawHorizontalLines(QPainter *p, int top, int w, int h)
{
p->setPen(d->horizontalLinesColor);
for (uint y = 0; y <= d->horizontalLinesCount + 1; y++) {
// note that the y_coord starts from 0. so we draw from pixel number 0 to h-1. Thus the -1 in the y_coord
int y_coord = top + (y * (h - 1)) / (d->horizontalLinesCount + 1); // Make sure it's y*h first to avoid rounding bugs
p->drawLine(0, y_coord, w - 2, y_coord);
}
}
double SignalPlotter::lastValue(uint i) const
{
if (d->plotData.isEmpty() || d->plotData.first().size() <= (int)i) {
return 0;
}
return d->plotData.first()[i];
}
QString SignalPlotter::lastValueAsString(uint i) const
{
if (d->plotData.isEmpty()) {
return QString();
}
double value = d->plotData.first()[i] / d->scaledBy; // retrieve the newest value for this plot then scale it correct
QString number = KGlobal::locale()->formatNumber(value, (value >= 100)?0:2);
return QString("%1 %2").arg(number, d->unit);
}
} // Plasma namespace
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