新增超级曲线图表

third/qcustomplotdemo/frmexample2/axistag.cpp

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+/***************************************************************************
+**                                                                        **
+**  QCustomPlot, an easy to use, modern plotting widget for Qt            **
+**  Copyright (C) 2011-2021 Emanuel Eichhammer                            **
+**                                                                        **
+**  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 3 of the License, 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, see http://www.gnu.org/licenses/.   **
+**                                                                        **
+****************************************************************************
+**           Author: Emanuel Eichhammer                                   **
+**  Website/Contact: http://www.qcustomplot.com/                          **
+**             Date: 29.03.21                                             **
+**          Version: 2.1.0                                                **
+****************************************************************************/
+
+#include "axistag.h"
+
+AxisTag::AxisTag(QCPAxis *parentAxis) :
+    QObject(parentAxis),
+    mAxis(parentAxis)
+{
+    // The dummy tracer serves here as an invisible anchor which always sticks to the right side of
+    // the axis rect
+    mDummyTracer = new QCPItemTracer(mAxis->parentPlot());
+    mDummyTracer->setVisible(false);
+    mDummyTracer->position->setTypeX(QCPItemPosition::ptAxisRectRatio);
+    mDummyTracer->position->setTypeY(QCPItemPosition::ptPlotCoords);
+    mDummyTracer->position->setAxisRect(mAxis->axisRect());
+    mDummyTracer->position->setAxes(0, mAxis);
+    mDummyTracer->position->setCoords(1, 0);
+
+    // the arrow end (head) is set to move along with the dummy tracer by setting it as its parent
+    // anchor. Its coordinate system (setCoords) is thus pixels, and this is how the needed horizontal
+    // offset for the tag of the second y axis is achieved. This horizontal offset gets dynamically
+    // updated in AxisTag::updatePosition. the arrow "start" is simply set to have the "end" as parent
+    // anchor. It is given a horizontal offset to the right, which results in a 15 pixel long arrow.
+    mArrow = new QCPItemLine(mAxis->parentPlot());
+    mArrow->setLayer("overlay");
+    mArrow->setClipToAxisRect(false);
+    mArrow->setHead(QCPLineEnding::esSpikeArrow);
+    mArrow->end->setParentAnchor(mDummyTracer->position);
+    mArrow->start->setParentAnchor(mArrow->end);
+    mArrow->start->setCoords(15, 0);
+
+    // The text label is anchored at the arrow start (tail) and has its "position" aligned at the
+    // left, and vertically centered to the text label box.
+    mLabel = new QCPItemText(mAxis->parentPlot());
+    mLabel->setLayer("overlay");
+    mLabel->setClipToAxisRect(false);
+    mLabel->setPadding(QMargins(3, 0, 3, 0));
+    mLabel->setBrush(QBrush(Qt::white));
+    mLabel->setPen(QPen(Qt::blue));
+    mLabel->setPositionAlignment(Qt::AlignLeft | Qt::AlignVCenter);
+    mLabel->position->setParentAnchor(mArrow->start);
+}
+
+AxisTag::~AxisTag()
+{
+    if (mDummyTracer) {
+        mDummyTracer->parentPlot()->removeItem(mDummyTracer);
+    }
+    if (mArrow) {
+        mArrow->parentPlot()->removeItem(mArrow);
+    }
+    if (mLabel) {
+        mLabel->parentPlot()->removeItem(mLabel);
+    }
+}
+
+void AxisTag::setPen(const QPen &pen)
+{
+    mArrow->setPen(pen);
+    mLabel->setPen(pen);
+}
+
+void AxisTag::setBrush(const QBrush &brush)
+{
+    mLabel->setBrush(brush);
+}
+
+void AxisTag::setText(const QString &text)
+{
+    mLabel->setText(text);
+}
+
+void AxisTag::updatePosition(double value)
+{
+    // since both the arrow and the text label are chained to the dummy tracer (via anchor
+    // parent-child relationships) it is sufficient to update the dummy tracer coordinates. The
+    // Horizontal coordinate type was set to ptAxisRectRatio so to keep it aligned at the right side
+    // of the axis rect, it is always kept at 1. The vertical coordinate type was set to
+    // ptPlotCoordinates of the passed parent axis, so the vertical coordinate is set to the new
+    // value.
+    mDummyTracer->position->setCoords(1, value);
+
+    // We want the arrow head to be at the same horizontal position as the axis backbone, even if
+    // the axis has a certain offset from the axis rect border (like the added second y axis). Thus we
+    // set the horizontal pixel position of the arrow end (head) to the axis offset (the pixel
+    // distance to the axis rect border). This works because the parent anchor of the arrow end is
+    // the dummy tracer, which, as described earlier, is tied to the right axis rect border.
+    mArrow->end->setCoords(mAxis->offset(), 0);
+}

third/qcustomplotdemo/frmexample2/axistag.h

@@ -0,0 +1,60 @@
+/***************************************************************************
+**                                                                        **
+**  QCustomPlot, an easy to use, modern plotting widget for Qt            **
+**  Copyright (C) 2011-2021 Emanuel Eichhammer                            **
+**                                                                        **
+**  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 3 of the License, 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, see http://www.gnu.org/licenses/.   **
+**                                                                        **
+****************************************************************************
+**           Author: Emanuel Eichhammer                                   **
+**  Website/Contact: http://www.qcustomplot.com/                          **
+**             Date: 29.03.21                                             **
+**          Version: 2.1.0                                                **
+****************************************************************************/
+
+#ifndef AXISTAG_H
+#define AXISTAG_H
+
+#include <QObject>
+#include "qcustomplot.h"
+
+class AxisTag : public QObject
+{
+  Q_OBJECT
+public:
+  explicit AxisTag(QCPAxis *parentAxis);
+  virtual ~AxisTag();
+  
+  // setters:
+  void setPen(const QPen &pen);
+  void setBrush(const QBrush &brush);
+  void setText(const QString &text);
+  
+  // getters:
+  QPen pen() const { return mLabel->pen(); }
+  QBrush brush() const { return mLabel->brush(); }
+  QString text() const { return mLabel->text(); }
+  
+  // other methods:
+  void updatePosition(double value);
+  
+protected:
+  QCPAxis *mAxis;
+  QPointer<QCPItemTracer> mDummyTracer;
+  QPointer<QCPItemLine> mArrow;
+  QPointer<QCPItemText> mLabel;
+};
+
+
+#endif // AXISTAG_H

third/qcustomplotdemo/frmexample2/frmaxistag.cpp

@@ -0,0 +1,67 @@
+#include "frmaxistag.h"
+#include "ui_frmaxistag.h"
+#include "qdebug.h"
+
+frmAxisTag::frmAxisTag(QWidget *parent) : QWidget(parent), ui(new Ui::frmAxisTag)
+{
+    ui->setupUi(this);
+    this->initForm();
+}
+
+frmAxisTag::~frmAxisTag()
+{
+    delete ui;
+}
+
+void frmAxisTag::initForm()
+{
+    mPlot = ui->customPlot;
+
+    // configure plot to have two right axes:
+    mPlot->yAxis->setTickLabels(false);
+    connect(mPlot->yAxis2, SIGNAL(rangeChanged(QCPRange)), mPlot->yAxis, SLOT(setRange(QCPRange))); // left axis only mirrors inner right axis
+    mPlot->yAxis2->setVisible(true);
+    mPlot->axisRect()->addAxis(QCPAxis::atRight);
+    mPlot->axisRect()->axis(QCPAxis::atRight, 0)->setPadding(30); // add some padding to have space for tags
+    mPlot->axisRect()->axis(QCPAxis::atRight, 1)->setPadding(30); // add some padding to have space for tags
+
+    // create graphs:
+    mGraph1 = mPlot->addGraph(mPlot->xAxis, mPlot->axisRect()->axis(QCPAxis::atRight, 0));
+    mGraph2 = mPlot->addGraph(mPlot->xAxis, mPlot->axisRect()->axis(QCPAxis::atRight, 1));
+    mGraph1->setPen(QPen(QColor(250, 120, 0)));
+    mGraph2->setPen(QPen(QColor(0, 180, 60)));
+
+    // create tags with newly introduced AxisTag class (see axistag.h/.cpp):
+    mTag1 = new AxisTag(mGraph1->valueAxis());
+    mTag1->setPen(mGraph1->pen());
+    mTag2 = new AxisTag(mGraph2->valueAxis());
+    mTag2->setPen(mGraph2->pen());
+
+    connect(&mDataTimer, SIGNAL(timeout()), this, SLOT(timerSlot()));
+    mDataTimer.start(40);
+}
+
+void frmAxisTag::timerSlot()
+{
+    // calculate and add a new data point to each graph:
+    int count1 = mGraph1->dataCount();
+    mGraph1->addData(count1, qSin(count1 / 50.0) + qSin(count1 / 50.0 / 0.3843) * 0.25);
+    int count2 = mGraph2->dataCount();
+    mGraph2->addData(count2, qCos(count2 / 50.0) + qSin(count2 / 50.0 / 0.4364) * 0.15);
+
+    // make key axis range scroll with the data:
+    mPlot->xAxis->rescale();
+    mGraph1->rescaleValueAxis(false, true);
+    mGraph2->rescaleValueAxis(false, true);
+    mPlot->xAxis->setRange(mPlot->xAxis->range().upper, 100, Qt::AlignRight);
+
+    // update the vertical axis tag positions and texts to match the rightmost data point of the graphs:
+    double graph1Value = mGraph1->dataMainValue(mGraph1->dataCount() - 1);
+    double graph2Value = mGraph2->dataMainValue(mGraph2->dataCount() - 1);
+    mTag1->updatePosition(graph1Value);
+    mTag2->updatePosition(graph2Value);
+    mTag1->setText(QString::number(graph1Value, 'f', 2));
+    mTag2->setText(QString::number(graph2Value, 'f', 2));
+
+    mPlot->replot();
+}

third/qcustomplotdemo/frmexample2/frmaxistag.h

@@ -0,0 +1,34 @@
+#ifndef FRMAXISTAG_H
+#define FRMAXISTAG_H
+
+#include <QWidget>
+#include "qcustomplot.h"
+#include "axistag.h"
+
+namespace Ui {
+class frmAxisTag;
+}
+
+class frmAxisTag : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit frmAxisTag(QWidget *parent = 0);
+    ~frmAxisTag();
+
+private:
+    Ui::frmAxisTag *ui;
+    QCustomPlot *mPlot;
+    QPointer<QCPGraph> mGraph1;
+    QPointer<QCPGraph> mGraph2;
+    AxisTag *mTag1;
+    AxisTag *mTag2;
+    QTimer mDataTimer;
+
+private slots:
+    void initForm();
+    void timerSlot();
+};
+
+#endif // FRMAXISTAG_H

third/qcustomplotdemo/frmexample2/frmaxistag.ui

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>frmAxisTag</class>
+ <widget class="QWidget" name="frmAxisTag">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>400</width>
+    <height>300</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Form</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QCustomPlot" name="customPlot" native="true"/>
+   </item>
+  </layout>
+ </widget>
+ <customwidgets>
+  <customwidget>
+   <class>QCustomPlot</class>
+   <extends>QWidget</extends>
+   <header>qcustomplot.h</header>
+   <container>1</container>
+  </customwidget>
+ </customwidgets>
+ <resources/>
+ <connections/>
+</ui>

third/qcustomplotdemo/frmexample2/frmexample2.pri

@@ -0,0 +1,16 @@
+FORMS += \
+    $$PWD/frmaxistag.ui \
+    $$PWD/frminteraction.ui \
+    $$PWD/frmscrollbar.ui
+
+HEADERS += \
+    $$PWD/axistag.h \
+    $$PWD/frmaxistag.h \
+    $$PWD/frminteraction.h \
+    $$PWD/frmscrollbar.h
+
+SOURCES += \
+    $$PWD/axistag.cpp \
+    $$PWD/frmaxistag.cpp \
+    $$PWD/frminteraction.cpp \
+    $$PWD/frmscrollbar.cpp

third/qcustomplotdemo/frmexample2/frminteraction.cpp

@@ -0,0 +1,266 @@
+#include "frminteraction.h"
+#include "ui_frminteraction.h"
+#include "qmenu.h"
+#include "qdebug.h"
+
+frmInterAction::frmInterAction(QWidget *parent) : QWidget(parent), ui(new Ui::frmInterAction)
+{
+    ui->setupUi(this);
+    this->initForm();
+}
+
+frmInterAction::~frmInterAction()
+{
+    delete ui;
+}
+
+void frmInterAction::initForm()
+{
+    std::srand(QDateTime::currentDateTime().toMSecsSinceEpoch() / 1000.0);
+
+    ui->customPlot->setInteractions(QCP::iRangeDrag | QCP::iRangeZoom | QCP::iSelectAxes | QCP::iSelectLegend | QCP::iSelectPlottables);
+    ui->customPlot->xAxis->setRange(-8, 8);
+    ui->customPlot->yAxis->setRange(-5, 5);
+    ui->customPlot->axisRect()->setupFullAxesBox();
+
+    ui->customPlot->plotLayout()->insertRow(0);
+    QCPTextElement *title = new QCPTextElement(ui->customPlot, "Interaction Example", QFont("sans", 17, QFont::Bold));
+    ui->customPlot->plotLayout()->addElement(0, 0, title);
+
+    ui->customPlot->xAxis->setLabel("x Axis");
+    ui->customPlot->yAxis->setLabel("y Axis");
+    ui->customPlot->legend->setVisible(true);
+    QFont legendFont = font();
+    legendFont.setPointSize(10);
+    ui->customPlot->legend->setFont(legendFont);
+    ui->customPlot->legend->setSelectedFont(legendFont);
+    //ui->customPlot->legend->setSelectableParts(QCPLegend::spItems); // legend box shall not be selectable, only legend items
+
+    addRandomGraph();
+    addRandomGraph();
+    addRandomGraph();
+    addRandomGraph();
+    ui->customPlot->rescaleAxes();
+
+    //  // connect slot that ties some axis selections together (especially opposite axes):
+    connect(ui->customPlot, SIGNAL(selectionChangedByUser()), this, SLOT(selectionChanged()));
+    //  // connect slots that takes care that when an axis is selected, only that direction can be dragged and zoomed:
+    connect(ui->customPlot, SIGNAL(mousePress(QMouseEvent *)), this, SLOT(mousePress()));
+    connect(ui->customPlot, SIGNAL(mouseWheel(QWheelEvent *)), this, SLOT(mouseWheel()));
+
+    // make bottom and left axes transfer their ranges to top and right axes:
+    connect(ui->customPlot->xAxis, SIGNAL(rangeChanged(QCPRange)), ui->customPlot->xAxis2, SLOT(setRange(QCPRange)));
+    connect(ui->customPlot->yAxis, SIGNAL(rangeChanged(QCPRange)), ui->customPlot->yAxis2, SLOT(setRange(QCPRange)));
+
+    // connect some interaction slots:
+    connect(ui->customPlot, SIGNAL(axisDoubleClick(QCPAxis *, QCPAxis::SelectablePart, QMouseEvent *)), this, SLOT(axisLabelDoubleClick(QCPAxis *, QCPAxis::SelectablePart)));
+    connect(ui->customPlot, SIGNAL(legendDoubleClick(QCPLegend *, QCPAbstractLegendItem *, QMouseEvent *)), this, SLOT(legendDoubleClick(QCPLegend *, QCPAbstractLegendItem *)));
+    connect(title, SIGNAL(doubleClicked(QMouseEvent *)), this, SLOT(titleDoubleClick(QMouseEvent *)));
+
+    // connect slot that shows a message in the status bar when a graph is clicked:
+    connect(ui->customPlot, SIGNAL(plottableClick(QCPAbstractPlottable *, int, QMouseEvent *)), this, SLOT(graphClicked(QCPAbstractPlottable *, int)));
+
+    // setup policy and connect slot for context menu popup:
+    ui->customPlot->setContextMenuPolicy(Qt::CustomContextMenu);
+    connect(ui->customPlot, SIGNAL(customContextMenuRequested(QPoint)), this, SLOT(contextMenuRequest(QPoint)));
+}
+
+void frmInterAction::titleDoubleClick(QMouseEvent *event)
+{
+    Q_UNUSED(event)
+    if (QCPTextElement *title = qobject_cast<QCPTextElement *>(sender())) {
+        // Set the plot title by double clicking on it
+        bool ok;
+        QString newTitle = QInputDialog::getText(this, "QCustomPlot example", "New plot title:", QLineEdit::Normal, title->text(), &ok);
+        if (ok) {
+            title->setText(newTitle);
+            ui->customPlot->replot();
+        }
+    }
+}
+
+void frmInterAction::axisLabelDoubleClick(QCPAxis *axis, QCPAxis::SelectablePart part)
+{
+    // Set an axis label by double clicking on it
+    if (part == QCPAxis::spAxisLabel) { // only react when the actual axis label is clicked, not tick label or axis backbone
+        bool ok;
+        QString newLabel = QInputDialog::getText(this, "QCustomPlot example", "New axis label:", QLineEdit::Normal, axis->label(), &ok);
+        if (ok) {
+            axis->setLabel(newLabel);
+            ui->customPlot->replot();
+        }
+    }
+}
+
+void frmInterAction::legendDoubleClick(QCPLegend *legend, QCPAbstractLegendItem *item)
+{
+    // Rename a graph by double clicking on its legend item
+    Q_UNUSED(legend)
+    if (item) { // only react if item was clicked (user could have clicked on border padding of legend where there is no item, then item is 0)
+        QCPPlottableLegendItem *plItem = qobject_cast<QCPPlottableLegendItem *>(item);
+        bool ok;
+        QString newName = QInputDialog::getText(this, "QCustomPlot example", "New graph name:", QLineEdit::Normal, plItem->plottable()->name(), &ok);
+        if (ok) {
+            plItem->plottable()->setName(newName);
+            ui->customPlot->replot();
+        }
+    }
+}
+
+void frmInterAction::selectionChanged()
+{
+    /*
+     normally, axis base line, axis tick labels and axis labels are selectable separately, but we want
+     the user only to be able to select the axis as a whole, so we tie the selected states of the tick labels
+     and the axis base line together. However, the axis label shall be selectable individually.
+
+     The selection state of the left and right axes shall be synchronized as well as the state of the
+     bottom and top axes.
+
+     Further, we want to synchronize the selection of the graphs with the selection state of the respective
+     legend item belonging to that graph. So the user can select a graph by either clicking on the graph itself
+     or on its legend item.
+    */
+
+    // make top and bottom axes be selected synchronously, and handle axis and tick labels as one selectable object:
+    if (ui->customPlot->xAxis->selectedParts().testFlag(QCPAxis::spAxis) || ui->customPlot->xAxis->selectedParts().testFlag(QCPAxis::spTickLabels) ||
+        ui->customPlot->xAxis2->selectedParts().testFlag(QCPAxis::spAxis) || ui->customPlot->xAxis2->selectedParts().testFlag(QCPAxis::spTickLabels)) {
+        ui->customPlot->xAxis2->setSelectedParts(QCPAxis::spAxis | QCPAxis::spTickLabels);
+        ui->customPlot->xAxis->setSelectedParts(QCPAxis::spAxis | QCPAxis::spTickLabels);
+    }
+    // make left and right axes be selected synchronously, and handle axis and tick labels as one selectable object:
+    if (ui->customPlot->yAxis->selectedParts().testFlag(QCPAxis::spAxis) || ui->customPlot->yAxis->selectedParts().testFlag(QCPAxis::spTickLabels) ||
+        ui->customPlot->yAxis2->selectedParts().testFlag(QCPAxis::spAxis) || ui->customPlot->yAxis2->selectedParts().testFlag(QCPAxis::spTickLabels)) {
+        ui->customPlot->yAxis2->setSelectedParts(QCPAxis::spAxis | QCPAxis::spTickLabels);
+        ui->customPlot->yAxis->setSelectedParts(QCPAxis::spAxis | QCPAxis::spTickLabels);
+    }
+
+    // synchronize selection of graphs with selection of corresponding legend items:
+    for (int i = 0; i < ui->customPlot->graphCount(); ++i) {
+        QCPGraph *graph = ui->customPlot->graph(i);
+        QCPPlottableLegendItem *item = ui->customPlot->legend->itemWithPlottable(graph);
+        if (item->selected() || graph->selected()) {
+            item->setSelected(true);
+            graph->setSelection(QCPDataSelection(graph->data()->dataRange()));
+        }
+    }
+}
+
+void frmInterAction::mousePress()
+{
+    // if an axis is selected, only allow the direction of that axis to be dragged
+    // if no axis is selected, both directions may be dragged
+
+    if (ui->customPlot->xAxis->selectedParts().testFlag(QCPAxis::spAxis)) {
+        ui->customPlot->axisRect()->setRangeDrag(ui->customPlot->xAxis->orientation());
+    } else if (ui->customPlot->yAxis->selectedParts().testFlag(QCPAxis::spAxis)) {
+        ui->customPlot->axisRect()->setRangeDrag(ui->customPlot->yAxis->orientation());
+    } else {
+        ui->customPlot->axisRect()->setRangeDrag(Qt::Horizontal | Qt::Vertical);
+    }
+}
+
+void frmInterAction::mouseWheel()
+{
+    // if an axis is selected, only allow the direction of that axis to be zoomed
+    // if no axis is selected, both directions may be zoomed
+
+    if (ui->customPlot->xAxis->selectedParts().testFlag(QCPAxis::spAxis)) {
+        ui->customPlot->axisRect()->setRangeZoom(ui->customPlot->xAxis->orientation());
+    } else if (ui->customPlot->yAxis->selectedParts().testFlag(QCPAxis::spAxis)) {
+        ui->customPlot->axisRect()->setRangeZoom(ui->customPlot->yAxis->orientation());
+    } else {
+        ui->customPlot->axisRect()->setRangeZoom(Qt::Horizontal | Qt::Vertical);
+    }
+}
+
+void frmInterAction::addRandomGraph()
+{
+    int n = 50; // number of points in graph
+    double xScale = (std::rand() / (double)RAND_MAX + 0.5) * 2;
+    double yScale = (std::rand() / (double)RAND_MAX + 0.5) * 2;
+    double xOffset = (std::rand() / (double)RAND_MAX - 0.5) * 4;
+    double yOffset = (std::rand() / (double)RAND_MAX - 0.5) * 10;
+    double r1 = (std::rand() / (double)RAND_MAX - 0.5) * 2;
+    double r2 = (std::rand() / (double)RAND_MAX - 0.5) * 2;
+    double r3 = (std::rand() / (double)RAND_MAX - 0.5) * 2;
+    double r4 = (std::rand() / (double)RAND_MAX - 0.5) * 2;
+    QVector<double> x(n), y(n);
+    for (int i = 0; i < n; i++) {
+        x[i] = (i / (double)n - 0.5) * 10.0 * xScale + xOffset;
+        y[i] = (qSin(x[i] * r1 * 5) * qSin(qCos(x[i] * r2) * r4 * 3) + r3 * qCos(qSin(x[i]) * r4 * 2)) * yScale + yOffset;
+    }
+
+    ui->customPlot->addGraph();
+    ui->customPlot->graph()->setName(QString("New graph %1").arg(ui->customPlot->graphCount() - 1));
+    ui->customPlot->graph()->setData(x, y);
+    ui->customPlot->graph()->setLineStyle((QCPGraph::LineStyle)(std::rand() % 5 + 1));
+    if (std::rand() % 100 > 50) {
+        ui->customPlot->graph()->setScatterStyle(QCPScatterStyle((QCPScatterStyle::ScatterShape)(std::rand() % 14 + 1)));
+    }
+
+    QPen graphPen;
+    graphPen.setColor(QColor(std::rand() % 245 + 10, std::rand() % 245 + 10, std::rand() % 245 + 10));
+    graphPen.setWidthF(std::rand() / (double)RAND_MAX * 2 + 1);
+    ui->customPlot->graph()->setPen(graphPen);
+    ui->customPlot->replot();
+}
+
+void frmInterAction::removeSelectedGraph()
+{
+    if (ui->customPlot->selectedGraphs().size() > 0) {
+        ui->customPlot->removeGraph(ui->customPlot->selectedGraphs().first());
+        ui->customPlot->replot();
+    }
+}
+
+void frmInterAction::removeAllGraphs()
+{
+    ui->customPlot->clearGraphs();
+    ui->customPlot->replot();
+}
+
+void frmInterAction::contextMenuRequest(QPoint pos)
+{
+    QMenu *menu = new QMenu(this);
+    menu->setAttribute(Qt::WA_DeleteOnClose);
+
+    if (ui->customPlot->legend->selectTest(pos, false) >= 0) { // context menu on legend requested
+        menu->addAction("Move to top left", this, SLOT(moveLegend()))->setData((int)(Qt::AlignTop | Qt::AlignLeft));
+        menu->addAction("Move to top center", this, SLOT(moveLegend()))->setData((int)(Qt::AlignTop | Qt::AlignHCenter));
+        menu->addAction("Move to top right", this, SLOT(moveLegend()))->setData((int)(Qt::AlignTop | Qt::AlignRight));
+        menu->addAction("Move to bottom right", this, SLOT(moveLegend()))->setData((int)(Qt::AlignBottom | Qt::AlignRight));
+        menu->addAction("Move to bottom left", this, SLOT(moveLegend()))->setData((int)(Qt::AlignBottom | Qt::AlignLeft));
+    } else { // general context menu on graphs requested
+        menu->addAction("Add random graph", this, SLOT(addRandomGraph()));
+        if (ui->customPlot->selectedGraphs().size() > 0) {
+            menu->addAction("Remove selected graph", this, SLOT(removeSelectedGraph()));
+        }
+        if (ui->customPlot->graphCount() > 0) {
+            menu->addAction("Remove all graphs", this, SLOT(removeAllGraphs()));
+        }
+    }
+
+    menu->popup(ui->customPlot->mapToGlobal(pos));
+}
+
+void frmInterAction::moveLegend()
+{
+    if (QAction *contextAction = qobject_cast<QAction *>(sender())) { // make sure this slot is really called by a context menu action, so it carries the data we need
+        bool ok;
+        int dataInt = contextAction->data().toInt(&ok);
+        if (ok) {
+            ui->customPlot->axisRect()->insetLayout()->setInsetAlignment(0, (Qt::Alignment)dataInt);
+            ui->customPlot->replot();
+        }
+    }
+}
+
+void frmInterAction::graphClicked(QCPAbstractPlottable *plottable, int dataIndex)
+{
+    // since we know we only have QCPGraphs in the plot, we can immediately access interface1D()
+    // usually it's better to first check whether interface1D() returns non-zero, and only then use it.
+    double dataValue = plottable->interface1D()->dataMainValue(dataIndex);
+    QString message = QString("Clicked on graph '%1' at data point #%2 with value %3.").arg(plottable->name()).arg(dataIndex).arg(dataValue);
+    //ui->statusBar->showMessage(message, 2500);
+}

third/qcustomplotdemo/frmexample2/frminteraction.h

@@ -0,0 +1,39 @@
+#ifndef FRMINTERACTION_H
+#define FRMINTERACTION_H
+
+#include <QWidget>
+#include <QInputDialog>
+#include "qcustomplot.h"
+
+namespace Ui {
+class frmInterAction;
+}
+
+class frmInterAction : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit frmInterAction(QWidget *parent = 0);
+    ~frmInterAction();
+
+private:
+    Ui::frmInterAction *ui;
+
+private slots:
+    void initForm();
+    void titleDoubleClick(QMouseEvent *event);
+    void axisLabelDoubleClick(QCPAxis* axis, QCPAxis::SelectablePart part);
+    void legendDoubleClick(QCPLegend* legend, QCPAbstractLegendItem* item);
+    void selectionChanged();
+    void mousePress();
+    void mouseWheel();
+    void addRandomGraph();
+    void removeSelectedGraph();
+    void removeAllGraphs();
+    void contextMenuRequest(QPoint pos);
+    void moveLegend();
+    void graphClicked(QCPAbstractPlottable *plottable, int dataIndex);
+};
+
+#endif // FRMINTERACTION_H

third/qcustomplotdemo/frmexample2/frminteraction.ui

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>frmInterAction</class>
+ <widget class="QWidget" name="frmInterAction">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>400</width>
+    <height>300</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Form</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QCustomPlot" name="customPlot" native="true"/>
+   </item>
+  </layout>
+ </widget>
+ <customwidgets>
+  <customwidget>
+   <class>QCustomPlot</class>
+   <extends>QWidget</extends>
+   <header>qcustomplot.h</header>
+   <container>1</container>
+  </customwidget>
+ </customwidgets>
+ <resources/>
+ <connections/>
+</ui>

third/qcustomplotdemo/frmexample2/frmscrollbar.cpp

@@ -0,0 +1,80 @@
+#include "frmscrollbar.h"
+#include "ui_frmscrollbar.h"
+#include "qdebug.h"
+
+frmScrollBar::frmScrollBar(QWidget *parent) : QWidget(parent), ui(new Ui::frmScrollBar)
+{
+    ui->setupUi(this);
+    this->initForm();
+}
+
+frmScrollBar::~frmScrollBar()
+{
+    delete ui;
+}
+
+void frmScrollBar::initForm()
+{
+    // The following plot setup is mostly taken from the plot demos:
+    ui->plot->addGraph();
+    ui->plot->graph()->setPen(QPen(Qt::blue));
+    ui->plot->graph()->setBrush(QBrush(QColor(0, 0, 255, 20)));
+    ui->plot->addGraph();
+    ui->plot->graph()->setPen(QPen(Qt::red));
+    QVector<double> x(500), y0(500), y1(500);
+    for (int i = 0; i < 500; ++i) {
+        x[i] = (i / 499.0 - 0.5) * 10;
+        y0[i] = qExp(-x[i] * x[i] * 0.25) * qSin(x[i] * 5) * 5;
+        y1[i] = qExp(-x[i] * x[i] * 0.25) * 5;
+    }
+    ui->plot->graph(0)->setData(x, y0);
+    ui->plot->graph(1)->setData(x, y1);
+    ui->plot->axisRect()->setupFullAxesBox(true);
+    ui->plot->setInteractions(QCP::iRangeDrag | QCP::iRangeZoom);
+
+    // configure scroll bars:
+    // Since scroll bars only support integer values, we'll set a high default range of -500..500 and
+    // divide scroll bar position values by 100 to provide a scroll range -5..5 in floating point
+    // axis coordinates. if you want to dynamically grow the range accessible with the scroll bar,
+    // just increase the minimum/maximum values of the scroll bars as needed.
+    ui->horizontalScrollBar->setRange(-500, 500);
+    ui->verticalScrollBar->setRange(-500, 500);
+
+    // create connection between axes and scroll bars:
+    connect(ui->horizontalScrollBar, SIGNAL(valueChanged(int)), this, SLOT(horzScrollBarChanged(int)));
+    connect(ui->verticalScrollBar, SIGNAL(valueChanged(int)), this, SLOT(vertScrollBarChanged(int)));
+    connect(ui->plot->xAxis, SIGNAL(rangeChanged(QCPRange)), this, SLOT(xAxisChanged(QCPRange)));
+    connect(ui->plot->yAxis, SIGNAL(rangeChanged(QCPRange)), this, SLOT(yAxisChanged(QCPRange)));
+
+    // initialize axis range (and scroll bar positions via signals we just connected):
+    ui->plot->xAxis->setRange(0, 6, Qt::AlignCenter);
+    ui->plot->yAxis->setRange(0, 10, Qt::AlignCenter);
+}
+
+void frmScrollBar::horzScrollBarChanged(int value)
+{
+    if (qAbs(ui->plot->xAxis->range().center() - value / 100.0) > 0.01) { // if user is dragging plot, we don't want to replot twice
+        ui->plot->xAxis->setRange(value / 100.0, ui->plot->xAxis->range().size(), Qt::AlignCenter);
+        ui->plot->replot();
+    }
+}
+
+void frmScrollBar::vertScrollBarChanged(int value)
+{
+    if (qAbs(ui->plot->yAxis->range().center() + value / 100.0) > 0.01) { // if user is dragging plot, we don't want to replot twice
+        ui->plot->yAxis->setRange(-value / 100.0, ui->plot->yAxis->range().size(), Qt::AlignCenter);
+        ui->plot->replot();
+    }
+}
+
+void frmScrollBar::xAxisChanged(QCPRange range)
+{
+    ui->horizontalScrollBar->setValue(qRound(range.center() * 100.0)); // adjust position of scroll bar slider
+    ui->horizontalScrollBar->setPageStep(qRound(range.size() * 100.0)); // adjust size of scroll bar slider
+}
+
+void frmScrollBar::yAxisChanged(QCPRange range)
+{
+    ui->verticalScrollBar->setValue(qRound(-range.center() * 100.0)); // adjust position of scroll bar slider
+    ui->verticalScrollBar->setPageStep(qRound(range.size() * 100.0)); // adjust size of scroll bar slider
+}

third/qcustomplotdemo/frmexample2/frmscrollbar.h

@@ -0,0 +1,30 @@
+#ifndef FRMSCROLLBAR_H
+#define FRMSCROLLBAR_H
+
+#include <QWidget>
+#include "qcustomplot.h"
+
+namespace Ui {
+class frmScrollBar;
+}
+
+class frmScrollBar : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit frmScrollBar(QWidget *parent = 0);
+    ~frmScrollBar();
+
+private:
+    Ui::frmScrollBar *ui;
+
+private slots:
+    void initForm();
+    void horzScrollBarChanged(int value);
+    void vertScrollBarChanged(int value);
+    void xAxisChanged(QCPRange range);
+    void yAxisChanged(QCPRange range);
+};
+
+#endif // FRMSCROLLBAR_H

third/qcustomplotdemo/frmexample2/frmscrollbar.ui

@@ -0,0 +1,53 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>frmScrollBar</class>
+ <widget class="QWidget" name="frmScrollBar">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>400</width>
+    <height>300</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Form</string>
+  </property>
+  <layout class="QGridLayout" name="gridLayout">
+   <item row="0" column="0">
+    <widget class="QCustomPlot" name="plot" native="true">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="Preferred" vsizetype="MinimumExpanding">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
+     </property>
+    </widget>
+   </item>
+   <item row="0" column="1">
+    <widget class="QScrollBar" name="verticalScrollBar">
+     <property name="orientation">
+      <enum>Qt::Vertical</enum>
+     </property>
+    </widget>
+   </item>
+   <item row="1" column="0">
+    <widget class="QScrollBar" name="horizontalScrollBar">
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <customwidgets>
+  <customwidget>
+   <class>QCustomPlot</class>
+   <extends>QWidget</extends>
+   <header>qcustomplot.h</header>
+   <container>1</container>
+  </customwidget>
+ </customwidgets>
+ <resources/>
+ <connections/>
+</ui>