质量控制 与图形上的单个点进行交互
QCustomPlot Interact with a single point on a graph
我正在使用QCustomPlot
并在屏幕上绘制了多个图形,我希望能够单击并指向,然后能够获取我单击的点的数据或坐标等,我知道这对于使用QCP::iSelectPlottables
的整个情节本身是可能的,但这是否可能仅适用于单个点,或者是否有人找到解决方法来实现这一目标。
没有简单的方法可以做到这一点。至少在QCustomPlot中没有这样的功能。
但是您可以创建表示单点的类(例如,从QCPItemEllipse
派生)并用鼠标移动它。
我的(尚未发布)软件中有类似的功能,所以看看并学习......它也可以使用移位修改器移动(仅更改初始位置的一个坐标)。此外,当它移动到项目时,它会改变光标(以及它移动到的项目的边框)。
绘图点.h
class PlotPoint : public QCPItemEllipse
{
Q_OBJECT
public:
explicit PlotPoint(QCustomPlot *parentPlot, int halfSize = 5);
QPointF pos() const;
const QColor &color() const;
void setColor(const QColor &color);
void startMoving(const QPointF &mousePos, bool shiftIsPressed);
public slots:
void setVisible(bool on);
signals:
void activated(); ///< emitted on mouse over
void disactivated(); ///< emitted when cursor leave us
void moved(const QPointF &pos);
void stoppedMoving();
public slots:
void move(double x, double y, bool signalNeeded = true);
void movePx(double x, double y);
void setActive(bool isActive);
private slots:
void onMouseMove(QMouseEvent *event);
void stopMoving();
void moveToWantedPos();
void onShiftStateChanged(bool shiftPressed);
private:
QCPItemTracer *mCenterTracer;
QPointF mGripDelta;
QPointF mInitialPos;
bool mIsChangingOnlyOneCoordinate;
QList<QCPAbstractItem *> mHelperItems;
QPointF mLastWantedPos;
QTimer *mMoveTimer;
QPointF mCurWantedPosPx;
};
情节点.cpp
PlotPoint::PlotPoint(QCustomPlot *parentPlot, int halfSize)
: QCPItemEllipse(parentPlot)
, mCenterTracer(new QCPItemTracer(parentPlot))
, mGripDelta()
, mInitialPos()
, mLastWantedPos()
, mMoveTimer(new QTimer(this))
, mCurWantedPosPx()
{
mCenterTracer->setStyle(QCPItemTracer::tsNone);
topLeft->setParentAnchor(mCenterTracer->position);
bottomRight->setParentAnchor(mCenterTracer->position);
topLeft->setType(QCPItemPosition::ptAbsolute);
bottomRight->setType(QCPItemPosition::ptAbsolute);
topLeft->setCoords(-halfSize, -halfSize);
bottomRight->setCoords(halfSize, halfSize);
setSelectable(true); // plot moves only selectable points, see Plot::mouseMoveEvent
setColor(QColor(qrand()%256, qrand()%256, qrand()%256, 100));
setPen(QPen(Qt::black));
setSelectedPen(QPen(Qt::black, 3));
mMoveTimer->setInterval(25); // 40 FPS
connect(mMoveTimer, SIGNAL(timeout()), this, SLOT(moveToWantedPos()));
}
QPointF PlotPoint::pos() const
{
return mCenterTracer->position->coords();
}
const QColor &PlotPoint::color() const
{
return brush().color();
}
void PlotPoint::setColor(const QColor& color)
{
setBrush(color);
setSelectedBrush(color);
}
void PlotPoint::startMoving(const QPointF &mousePos, bool shiftIsPressed)
{
mGripDelta.setX(parentPlot()->xAxis->coordToPixel(mCenterTracer->position->key()) - mousePos.x());
mGripDelta.setY(parentPlot()->yAxis->coordToPixel(mCenterTracer->position->value()) - mousePos.y());
mInitialPos = pos();
mLastWantedPos = mInitialPos;
mCurWantedPosPx = QPointF();
mIsChangingOnlyOneCoordinate = shiftIsPressed;
mMoveTimer->start();
QCPItemStraightLine *horizontal = new QCPItemStraightLine(parentPlot());
horizontal->setAntialiased(false);
horizontal->point1->setCoords(mInitialPos.x(), mInitialPos.y());
horizontal->point2->setCoords(mInitialPos.x() + 1, mInitialPos.y());
parentPlot()->addItem(horizontal);
QCPItemStraightLine *vertical = new QCPItemStraightLine(parentPlot());
vertical->setAntialiased(false);
vertical->point1->setCoords(mInitialPos.x(), mInitialPos.y());
vertical->point2->setCoords(mInitialPos.x(), mInitialPos.y() + 1);
parentPlot()->addItem(vertical);
static const QPen linesPen(Qt::darkGray, 0, Qt::DashLine);
horizontal->setPen(linesPen);
vertical->setPen(linesPen);
mHelperItems << vertical << horizontal;
if (!mIsChangingOnlyOneCoordinate) {
vertical->setVisible(false);
horizontal->setVisible(false);
}
connect(parentPlot(), SIGNAL(mouseMove(QMouseEvent*)),
this, SLOT(onMouseMove(QMouseEvent*)));
connect(parentPlot(), SIGNAL(mouseRelease(QMouseEvent*)),
this, SLOT(stopMoving()));
connect(parentPlot(), SIGNAL(shiftStateChanged(bool)),
this, SLOT(onShiftStateChanged(bool)));
parentPlot()->grabKeyboard();
QApplication::setOverrideCursor(Qt::ClosedHandCursor);
}
void PlotPoint::setVisible(bool on)
{
setSelectable(on); // we are movable only when visible
QCPItemEllipse::setVisible(on);
}
void PlotPoint::stopMoving()
{
disconnect(parentPlot(), SIGNAL(mouseMove(QMouseEvent*)),
this, SLOT(onMouseMove(QMouseEvent*)));
disconnect(parentPlot(), SIGNAL(mouseRelease(QMouseEvent*)),
this, SLOT(stopMoving()));
disconnect(parentPlot(), SIGNAL(shiftStateChanged(bool)),
this, SLOT(onShiftStateChanged(bool)));
mMoveTimer->stop();
moveToWantedPos();
if (!mHelperItems.isEmpty()) {
while (!mHelperItems.isEmpty()) {
QCPAbstractItem *item = mHelperItems.takeFirst();
mParentPlot->removeItem(item);
}
mParentPlot->replot();
}
parentPlot()->releaseKeyboard();
QApplication::restoreOverrideCursor();
emit stoppedMoving();
}
void PlotPoint::move(double x, double y, bool signalNeeded)
{
mLastWantedPos.setX(x);
mLastWantedPos.setY(y);
if (mIsChangingOnlyOneCoordinate) {
double x1 = parentPlot()->xAxis->coordToPixel(x);
double x2 = parentPlot()->xAxis->coordToPixel(mInitialPos.x());
double y1 = parentPlot()->yAxis->coordToPixel(y);
double y2 = parentPlot()->yAxis->coordToPixel(mInitialPos.y());
if (qAbs(x1 - x2) < qAbs(y1 - y2)) {
x = mInitialPos.x();
} else {
y = mInitialPos.y();
}
}
mCenterTracer->position->setCoords(x, y);
parentPlot()->replot();
if(signalNeeded) {
emit moved(QPointF(x, y));
}
}
void PlotPoint::movePx(double x, double y)
{
move(parentPlot()->xAxis->pixelToCoord(x),
parentPlot()->yAxis->pixelToCoord(y));
}
void PlotPoint::setActive(bool isActive)
{
setSelected(isActive);
emit (isActive ? activated() : disactivated());
}
void PlotPoint::onMouseMove(QMouseEvent *event)
{
mCurWantedPosPx = QPointF(event->localPos().x() + mGripDelta.x(),
event->localPos().y() + mGripDelta.y());
}
void PlotPoint::moveToWantedPos()
{
if (!mCurWantedPosPx.isNull()) {
movePx(mCurWantedPosPx.x(), mCurWantedPosPx.y());
mCurWantedPosPx = QPointF();
}
}
void PlotPoint::onShiftStateChanged(bool shiftPressed)
{
if (shiftPressed != mIsChangingOnlyOneCoordinate) {
mIsChangingOnlyOneCoordinate = shiftPressed;
foreach (QCPAbstractItem *item, mHelperItems) {
item->setVisible(shiftPressed);
}
move(mLastWantedPos.x(), mLastWantedPos.y());
}
}
(部分)剧情.cpp
void Plot::mousePressEvent(QMouseEvent *event)
{
if (event->button() == Qt::LeftButton && mPointUnderCursor) {
mPointUnderCursor->startMoving(event->localPos(),
event->modifiers().testFlag(Qt::ShiftModifier));
return;
}
QCustomPlot::mousePressEvent(event);
}
void Plot::mouseMoveEvent(QMouseEvent *event)
{
QCustomPlot::mouseMoveEvent(event);
if (event->buttons() == Qt::NoButton) {
PlotPoint *plotPoint = qobject_cast<PlotPoint*>(itemAt(event->localPos(), true));
if (plotPoint != mPointUnderCursor) {
if (mPointUnderCursor == NULL) {
// cursor moved from empty space to item
plotPoint->setActive(true);
setCursor(Qt::OpenHandCursor);
} else if (plotPoint == NULL) {
// cursor move from item to empty space
mPointUnderCursor->setActive(false);
unsetCursor();
} else {
// cursor moved from item to item
mPointUnderCursor->setActive(false);
plotPoint->setActive(true);
}
mPointUnderCursor = plotPoint;
replot();
}
}
}
void Plot::keyPressEvent(QKeyEvent *event)
{
if (event->key() == Qt::Key_Shift) {
emit shiftStateChanged(true);
}
QCustomPlot::keyPressEvent(event);
}
void Plot::keyReleaseEvent(QKeyEvent *event)
{
if (event->key() == Qt::Key_Shift) {
emit shiftStateChanged(false);
}
QCustomPlot::keyReleaseEvent(event);
}
抱歉代码中几乎没有评论。我只是懒得俄语到英语的翻译。
我希望你无论如何都会得到一切。
@Obey-Kun的巨大贡献,如果有人感兴趣,我想进一步讨论,尤其是Kun:)
(1)基本思想是
- 创建一个椭圆项目
PlotPoint
, - 随之而来的是 2 个直线项目
horizontal
&vertical
(用于正交移动) - 和一个示踪剂项目
mCenterTracer
(椭圆的中心,用于连接鼠标操作)。
(2)根据剧情.cpp(部分),我想机制可能是:
- 按左按钮,(确认有一个点可以移动)
- 移动鼠标。(通过示踪剂移动点)
- 松开左按钮。(将点放在最后想要的位置)
但是,我对逻辑感到困惑
无效剧情::鼠标移动事件(QMouseEvent *event)
.它看起来像一个悬停检测程序,因为一切都是在Qt::NoButton
下完成的,用户移动鼠标(没有按下按钮)来检测鼠标是否在 plotPoint 上,如果是这样,*plotPoint
转移到 *mPointUnderCursor
上。然后按然后移动,然后松开。
有什么我想念的吗?
相关文章:
- Qt VTK交互风格的信号到小部件
- 试试完美的正方形,你能给点小费吗
- 无法将结构注册为增强几何体3D点
- C++将浮点指针值舍入为小数位数
- 如何防止 c++ 在从浮点型转换为双精度型(不适用于 IO)时添加额外的小数?
- 为什么在浮点中从大到小会引入更多的误差
- 如何将点击的信号和插槽添加到qt中的自定义按钮中
- 如何对点云数据进行排序
- 如何将一个ostringstream十六进制字符串字符对转换为单个unit8t等价的二进制值
- 我可以信任表示整数的浮点或双精度来保持精度吗
- 具有单个函数的两个点的距离和坡度
- 点云库 - 如何将单个 RGB 值分配给整个点云
- 如何在无符号 N 位交互器中修复二进制点的位置
- 许多函数的单个DLL入口点
- 在Qt中以交互方式渲染点、线和线段
- 质量控制 与图形上的单个点进行交互
- 是否可以有效地计数与数字线上的单个点P重叠的线段的数量
- 如何使一个c++程序与鼠标点击和X窗口系统应用程序交互
- 如何在opencv中撤消单个点的透视变换
- 数组和单个数据点使用指针之间的区别