如何在QMainWindow中将"降序面板"附加到菜单栏的底部

Question

当您在Mac上保存文件时,面板会以非常酷的方式从顶部栏向下下降.我想创建一个使用Qt框架执行类似操作的类.我有很多困惑:

1. 面板下降时,应阻止输入父窗口.使用QDialog很容易,因为它有setModal()方法,但是QDialogs默认弹出.我不知道怎么解决这个问题.

2. 在QMainProject中,创建了DescendingPanel类的QMenua新实例.假设菜单栏下面还有其他小部件,你会怎么做？DescendingPanel应出现在它们上方.

我真的很感激任何帮助.

编辑

我有一个想法,而不是在菜单栏下挂下对话框,只是让它出现在那里并移除窗框.这样,它就会产生一种幻觉,它从那里弹出.当然,还必须处理Move事件,以便Dialog始终位于菜单栏下,但这是为了以后.这是我用来让DescendingDialog出现在菜单栏下面的代码.

class DescendingDialog : public QWidget
{
    QMainWindow* Window;
    QWidget*     Menu;
    QPoint       GlobalLocationOfMenu;
    int          DialogWidth;
    int          DialogHeight;

    int X()
    {
        int XDistanceOfPanel = GlobalLocationOfMenu.x() + ((Menu->width()/2) - (this->DialogWidth/2));
        //GlobalLocationOfMenu.x() returns 0;
        return XDistanceOfPanel;
    }

    int Y()
    {
        int YDistanceOfPanel = GlobalLocationOfMenu.y()+Menu->height();
        //GlobalLocationOfMenu.y() returns 0;
        return YDistanceOfPanel;
    }

    void SetGeometry()
    {
        this->setGeometry(this->X(),this->Y(),this->DialogWidth,this->DialogHeight);

    }
public:
    DescendingDialog(QMainWindow*   Window,int DialogWidth,int DialogHeight):QWidget(NULL)
    {
       this->Window = Window;
       this->Menu   = this->Window->menuWidget();
       this->DialogWidth = DialogWidth;
       this->DialogHeight = DialogHeight;

       QPoint RelativeLocationOfMenu = this->Menu->pos();
       this->GlobalLocationOfMenu = QWidget::mapToGlobal(RelativeLocationOfMenu);
       this->SetGeometry();

    }
};

它不起作用,因为GlobalLocationOfMenu.x()和.y()返回0,因此对话框不会出现在我想要的位置.

Answer 1

您可以使用类似于以下的函数让对话框“滑入”：

#include <QDialog>
#include <QPropertyAnimation>
#include <QParallelAnimationGroup>

void makeAppear(QDialog * dialog, QRect geometryEnd)
{
    static QParallelAnimationGroup *animationGroup = 0;
    if (animationGroup)
    {
        for(int i = 0, ie = animationGroup->animationCount(); i != ie; ++i)
            delete animationGroup->animationAt(i);
        delete animationGroup;
    }

    // Set up start and end geometry for 'dialog'.
    QPoint parentTopLeft = dialog->parentWidget()->geometry().topLeft();
    geometryEnd.translate(dialog->parentWidget()->mapToGlobal(parentTopLeft));
    QRect geometryBegin = geometryEnd;
    geometryBegin.setHeight(0);

    // Set up start and end geometry for the only child widget of 'dialog'.
    QWidget * dialogChildWidget = dynamic_cast< QWidget * >(dialog->children().first());
    if ( !dialogChildWidget )
        return;
    QRect childGeometryEnd = dialogChildWidget->geometry();
    QRect childGeometryBegin = childGeometryEnd;
    childGeometryBegin.translate(0, geometryEnd.height() * (-1));

    // Set up animation for 'dialog'.
    QPropertyAnimation *dialogAnimation = new QPropertyAnimation(dialog, "geometry");
    dialogAnimation->setDuration(400);
    dialogAnimation->setStartValue(geometryBegin);
    dialogAnimation->setEndValue(geometryEnd);

    // Set up animation for the only child widget of 'dialog'.
    QPropertyAnimation *childAnimation = new QPropertyAnimation(dialogChildWidget, "geometry");
    childAnimation->setDuration(400);
    childAnimation->setStartValue(childGeometryBegin);
    childAnimation->setEndValue(childGeometryEnd);

    // Set up (and start) a parallel animation group
    animationGroup = new QParallelAnimationGroup;
    animationGroup->addAnimation(dialogAnimation);
    animationGroup->addAnimation(childAnimation);
    animationGroup->start();

    // Make 'dialog' visible, borderless, modal.
    dialog->setModal(true);
    dialog->setWindowFlags(Qt::FramelessWindowHint | Qt::Dialog);
    dialog->show();
}

该dialog参数应指向一个（隐藏/不可见）QDialog 实例，该实例具有一个子窗口小部件，该子窗口小部件包含属于该对话框的所有其他窗口小部件。

该geometryEnd参数应指定其出现后的位置和大小dialog（相对于其父窗口小部件）。

结果看起来像这样。