当用户点击qslider上的某个位置时,我想让滑块跳转到该位置,而不是踩踏。如何实施?
答案 0 :(得分:23)
在@spyke @Massimo Callegari和@Ben的所有版本出现问题后(滑块位置对整个区域都不正确)我在QSlider源代码中找到了一些Qt Style功能:QStyle::SH_Slider_AbsoluteSetButtons
。
您必须创建一个非常烦人的新QStyle,或者使用ProxyStyle
中的用户jpn所示的#include <QProxyStyle>
class MyStyle : public QProxyStyle
{
public:
using QProxyStyle::QProxyStyle;
int styleHint(QStyle::StyleHint hint, const QStyleOption* option = 0, const QWidget* widget = 0, QStyleHintReturn* returnData = 0) const
{
if (hint == QStyle::SH_Slider_AbsoluteSetButtons)
return (Qt::LeftButton | Qt::MidButton | Qt::RightButton);
return QProxyStyle::styleHint(hint, option, widget, returnData);
}
};
我添加了另一个构造函数并修复了拼写错误,但使用了原始源代码的其余部分。
setStyle(new MyStyle(this->style()));
现在您可以在滑块构造函数中设置滑块的样式(如果滑块是从QSlider派生的):
standardSlider.setStyle(new MyStyle(standardSlider->style()));
或者它应该以这种方式工作,如果它是标准的QSlider:
QStyle::SH_Slider_AbsoluteSetButtons
所以你使用该元素的原始样式,但是如果要求你{{1}}“属性”,你可以根据需要返回;)
也许你必须在滑块删除时销毁这些代理方式,尚未测试。
答案 1 :(得分:20)
好吧,我怀疑Qt是否具有此功能的直接功能。
尝试使用自定义小部件。这应该有效!
尝试以下逻辑
class MySlider : public QSlider
{
protected:
void mousePressEvent ( QMouseEvent * event )
{
if (event->button() == Qt::LeftButton)
{
if (orientation() == Qt::Vertical)
setValue(minimum() + ((maximum()-minimum()) * (height()-event->y())) / height() ) ;
else
setValue(minimum() + ((maximum()-minimum()) * event->x()) / width() ) ;
event->accept();
}
QSlider::mousePressEvent(event);
}
};
答案 2 :(得分:18)
我也需要这个并尝试过spyke解决方案,但它缺少两件事:
所以,这是经过审核的代码:
void MySlider::mousePressEvent ( QMouseEvent * event )
{
QStyleOptionSlider opt;
initStyleOption(&opt);
QRect sr = style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderHandle, this);
if (event->button() == Qt::LeftButton &&
sr.contains(event->pos()) == false)
{
int newVal;
if (orientation() == Qt::Vertical)
newVal = minimum() + ((maximum()-minimum()) * (height()-event->y())) / height();
else
newVal = minimum() + ((maximum()-minimum()) * event->x()) / width();
if (invertedAppearance() == true)
setValue( maximum() - newVal );
else
setValue(newVal);
event->accept();
}
QSlider::mousePressEvent(event);
}
答案 3 :(得分:15)
Massimo Callegari的答案几乎是正确的,但newVal的计算忽略了滑块手柄的宽度。当您尝试在滑块末端附近单击时会出现此问题。
以下代码修复了水平滑块
的问题double halfHandleWidth = (0.5 * sr.width()) + 0.5; // Correct rounding
int adaptedPosX = event->x();
if ( adaptedPosX < halfHandleWidth )
adaptedPosX = halfHandleWidth;
if ( adaptedPosX > width() - halfHandleWidth )
adaptedPosX = width() - halfHandleWidth;
// get new dimensions accounting for slider handle width
double newWidth = (width() - halfHandleWidth) - halfHandleWidth;
double normalizedPosition = (adaptedPosX - halfHandleWidth) / newWidth ;
newVal = minimum() + ((maximum()-minimum()) * normalizedPosition);
答案 4 :(得分:8)
这是python中使用QStyle.sliderValueFromPosition()的一个简单实现:
class JumpSlider(QtGui.QSlider):
def mousePressEvent(self, ev):
""" Jump to click position """
self.setValue(QtGui.QStyle.sliderValueFromPosition(self.minimum(), self.maximum(), ev.x(), self.width()))
def mouseMoveEvent(self, ev):
""" Jump to pointer position while moving """
self.setValue(QtGui.QStyle.sliderValueFromPosition(self.minimum(), self.maximum(), ev.x(), self.width()))
答案 5 :(得分:6)
以下代码实际上是一个hack,但它没有对QSlider进行子类化,它可以正常工作。您唯一需要做的就是将QSlider valueChanged信号连接到您的容器。
注1:您必须设置pageStep&gt;滑块中的0
注意2:它仅适用于水平,从左到右的滑块(您应该将“sliderPosUnderMouse”的计算更改为使用垂直方向或反转外观)
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
// ...
connect(ui->mySlider, SIGNAL(valueChanged(int)),
this, SLOT(mySliderValueChanged(int)));
// ...
}
void MainWindow::mySliderValueChanged(int newPos)
{
// Make slider to follow the mouse directly and not by pageStep steps
Qt::MouseButtons btns = QApplication::mouseButtons();
QPoint localMousePos = ui->mySlider->mapFromGlobal(QCursor::pos());
bool clickOnSlider = (btns & Qt::LeftButton) &&
(localMousePos.x() >= 0 && localMousePos.y() >= 0 &&
localMousePos.x() < ui->mySlider->size().width() &&
localMousePos.y() < ui->mySlider->size().height());
if (clickOnSlider)
{
// Attention! The following works only for Horizontal, Left-to-right sliders
float posRatio = localMousePos.x() / (float )ui->mySlider->size().width();
int sliderRange = ui->mySlider->maximum() - ui->mySlider->minimum();
int sliderPosUnderMouse = ui->mySlider->minimum() + sliderRange * posRatio;
if (sliderPosUnderMouse != newPos)
{
ui->mySlider->setValue(sliderPosUnderMouse);
return;
}
}
// ...
}
答案 6 :(得分:2)
我的最终实施基于周围的评论:
class ClickableSlider : public QSlider {
public:
ClickableSlider(QWidget *parent = 0) : QSlider(parent) {}
protected:
void ClickableSlider::mousePressEvent(QMouseEvent *event) {
QStyleOptionSlider opt;
initStyleOption(&opt);
QRect sr = style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderHandle, this);
if (event->button() == Qt::LeftButton &&
!sr.contains(event->pos())) {
int newVal;
if (orientation() == Qt::Vertical) {
double halfHandleHeight = (0.5 * sr.height()) + 0.5;
int adaptedPosY = height() - event->y();
if ( adaptedPosY < halfHandleHeight )
adaptedPosY = halfHandleHeight;
if ( adaptedPosY > height() - halfHandleHeight )
adaptedPosY = height() - halfHandleHeight;
double newHeight = (height() - halfHandleHeight) - halfHandleHeight;
double normalizedPosition = (adaptedPosY - halfHandleHeight) / newHeight ;
newVal = minimum() + (maximum()-minimum()) * normalizedPosition;
} else {
double halfHandleWidth = (0.5 * sr.width()) + 0.5;
int adaptedPosX = event->x();
if ( adaptedPosX < halfHandleWidth )
adaptedPosX = halfHandleWidth;
if ( adaptedPosX > width() - halfHandleWidth )
adaptedPosX = width() - halfHandleWidth;
double newWidth = (width() - halfHandleWidth) - halfHandleWidth;
double normalizedPosition = (adaptedPosX - halfHandleWidth) / newWidth ;
newVal = minimum() + ((maximum()-minimum()) * normalizedPosition);
}
if (invertedAppearance())
setValue( maximum() - newVal );
else
setValue(newVal);
event->accept();
} else {
QSlider::mousePressEvent(event);
}
}
};
答案 7 :(得分:1)
我一直在尝试并在网上搜索这个并且期待Qt以更聪明的方式做到这一点,不幸的是没有大的帮助(可能是我没有正确搜索)
我在Qt创建者中做到了这一点:
在定义中:
一个。检查对象是否是滑块类型:ui->HSlider == Object
湾检查鼠标点击事件,例如:QEvent::MouseButtonPress == event->type
℃。如果以上所有通过意味着你在滑块上有鼠标事件,请执行以下操作:在定义中:ui->HSlider->setValue( Qcursor::pos().x() - firstval ); return QMainWindow::eventFilter(object, event);
注意:fistVal:可以通过在0 =滑块初始位置打印cursur位置取出(借助QCursor::pos().x()
)
希望这会有所帮助
答案 8 :(得分:1)
我想,
可以使用QStyle :: sliderValueFromPosition()函数。
http://qt-project.org/doc/qt-5/qstyle.html#sliderValueFromPosition
答案 9 :(得分:0)
一种简单的方法是从QSlider
派生并重新实现mousePressEvent(....)
以使用setSliderPosition(int)
设置标记位置。
答案 10 :(得分:0)
我也遇到了这个问题。我的解决方案如下所示。
slider->installEventFilter(this);
---
bool MyDialog::eventFilter(QObject *object, QEvent *event)
{
if (object == slider && slider->isEnabled())
{
if (event->type() == QEvent::MouseButtonPress)
{
auto mevent = static_cast<QMouseEvent *>(event);
qreal value = slider->minimum() + (slider->maximum() - slider->minimum()) * mevent->localPos().x() / slider->width();
if (mevent->button() == Qt::LeftButton)
{
slider->setValue(qRound(value));
}
event->accept();
return true;
}
if (event->type() == QEvent::MouseMove)
{
auto mevent = static_cast<QMouseEvent *>(event);
qreal value = slider->minimum() + (slider->maximum() - slider->minimum()) * mevent->localPos().x() / slider->width();
if (mevent->buttons() & Qt::LeftButton)
{
slider->setValue(qRound(value));
}
event->accept();
return true;
}
if (event->type() == QEvent::MouseButtonDblClick)
{
event->accept();
return true;
}
}
return QDialog::eventFilter(object, event);
}
您还可以覆盖QSlider的这些事件处理程序。
QSlider::mousePressedEvent
QSlider::mouseMoveEvent
QSlider::mouseDoubleClickEvent
答案 11 :(得分:0)
对上面的JumpSlider的此修改在PyQt5中有效:
class JumpSlider(QSlider):
def _FixPositionToInterval(self,ev):
""" Function to force the slider position to be on tick locations """
# Get the value from the slider
Value=QStyle.sliderValueFromPosition(self.minimum(), self.maximum(), ev.x(), self.width())
# Get the desired tick interval from the slider
TickInterval=self.tickInterval()
# Convert the value to be only at the tick interval locations
Value=round(Value/TickInterval)*TickInterval
# Set the position of the slider based on the interval position
self.setValue(Value)
def mousePressEvent(self, ev):
self._FixPositionToInterval(ev)
def mouseMoveEvent(self, ev):
self._FixPositionToInterval(ev)