QtQuick实现无边框窗口的拉伸,拖拽和自定义标题栏

由于Qt的原生窗口带有的标题栏无法定制,然而通常情况下我们需要自定义窗体上的关闭、最小化等按钮、背景,甚至需要不需要标题栏。在QtQuick实现去除标题栏,也即无边框很简单,只需要在Qml-Window中设置:

flags: Qt.Window | Qt.FramelessWindowHint | Qt.WindowMinimizeButtonHint

但是这个时候的窗体不能拖拽,也不能在窗体的边缘进行拉伸。所以需要实现窗体的边缘事件进行拉伸,同时在这里也实现了一个带有最小化,最大化和关闭的自定义标题栏

  • 首先看自定义标题栏代码TitleBar.qml
import QtQuick 2.7
import QtQuick.Controls 2.13
import QtQuick.Templates 2.12 as T
import QtQuick.Window 2.2

Rectangle{
    property bool  isMaximized: false
    Connections{
        target: mainWindow
        onVisibilityChanged: {//解决Qt窗口最大化的时候最小化,再恢复窗口变为普通窗口的bug
            if(isMaximized && visibility === 2) {
                mainWindow.showMaximized()
            }
        }
    }
    MouseArea{
        anchors.fill: parent
        acceptedButtons: Qt.LeftButton //只处理鼠标左键
        property bool   isDoubleClicked:false
        property point clickPos: "0,0"
         onPressed:
         {
             isDoubleClicked = false;
             clickPos = Qt.point(mouse.x,mouse.y)
         }
         onPositionChanged: {
             if(!isDoubleClicked && pressed && mainWindow.visibility !== Window.Maximized && mainWindow.visibility !== Window.FullScreen) {
                 var delta = Qt.point(mouse.x-clickPos.x, mouse.y-clickPos.y)
                 mainWindow.x += delta.x
                 mainWindow.y += delta.y
             }
             if(mainWindow.visibility === Window.Maximized && pressed && !isDoubleClicked)
             {
                 isMaximized = false;
                 mainWindow.showNormal();
                 normBtnBg.source  = "qrc:/res/maximinze_btn.png"
             }
         }
         onDoubleClicked :
         {
             isDoubleClicked = true; // 这个时候一定不能响应onPositionChanged不然会一直置顶。
             if(isMaximized){
                 isMaximized = false;
                 mainWindow.showNormal();
                 normBtnBg.source  = "qrc:/res/maximinze_btn.png"
             }else{
                 isMaximized = true;
                 mainWindow.showMaximized();
                 normBtnBg.source = "qrc:/res/norm_btn.png"
             }
         }
     }

    Button{
        id:closeBtn
        anchors.right: parent.right
        width: parent.height
        height: parent.height - 1
        hoverEnabled : true
        background: Rectangle{
            color: closeBtn.hovered ? (closeBtn.pressed ? "#DE0000" : "#F91515") : "transparent"
            Image{
                id: closeBtnImg
                width: parent.height * 0.3; height: parent.height * 0.3
                anchors.centerIn: parent
                source: "qrc:/res/close_btn.png"
            }
        }
        onClicked: {
            mainWindow.close()
        }
    }
    Button{
        id: normBtn
        anchors.right: closeBtn.left
        width: parent.height
        height: parent.height - 1
        hoverEnabled : true
        background: Rectangle{
            color: normBtn.hovered ? (normBtn.pressed ? "#4E4E4E" : "#666666") : "transparent"
            //color: "black"
            Image{
                id: normBtnBg
                width: parent.height * 0.3; height: parent.height * 0.3
                anchors.centerIn: parent
                source: "qrc:/res/maximinze_btn.png"
            }
        }
        onClicked:{
            if(isMaximized){
                isMaximized = false;
                mainWindow.showNormal();
                normBtnBg.source = "qrc:/res/maximinze_btn.png"
            }else{
                isMaximized = true;
                mainWindow.showMaximized();
                normBtnBg.source = "qrc:/res/norm_btn.png"
            }
        }
    }
    Button{
        id: minBtn
        anchors.right: normBtn.left
        width: parent.height
        height: parent.height - 1
        hoverEnabled : true
        background: Rectangle{
            color: minBtn.hovered ? (minBtn.pressed ? "#4E4E4E" : "#666666") : "transparent"
            Image{
                width: parent.height * 0.3; height: parent.height * 0.3
                anchors.centerIn: parent
                source: "qrc:/res/min_btn.png"
            }
        }
        onClicked:{
            mainWindow.showMinimized();
        }
    }
}

标题栏实现起来比较简单,主要有几个功能:最大化,最小化、普通化(normal)以及双击最大化、双击恢复普通窗口。这里用一个两个变量:isMaximized和isDoubleClicked来记录窗体状态和双击状态。然后分别实现其事件逻辑即可。这里需要主要的是Qt的一个bug,也就是在窗口时最大化,然后再恢复窗口,这时窗体变成普通窗口了(正常应该还是最大窗口),这个bug在5.13和5.13.1还没被修复,bug请看这里
在这里我们可以用自己用代码修复,即我们可以判断窗体在最小化恢复时候,如果这个时候窗体是最大化并且是Windowed(值为2)这个时候将其最大化即可。具体代码可看上面__onVisibilityChanged__这一行代码

  • 窗体的边缘拉伸和拖拽主要实现在ResizeItem和ResizeQmlWindow,ResizeQmlWindow类主要实现设置鼠标的指针状态而已,具体检测鼠标的边缘事件在ResizeItem.qml里,如下所示
import QtQuick 2.0
import QtQuick.Window 2.2

Item {
    property int enableSize: 4
    property bool isPressed: false
    property point customPoint

    //左上角
    Item {
        id: leftTop
        width: enableSize
        height: enableSize
        anchors.left: parent.left
        anchors.top: parent.top
        z: 1000
        MouseArea {
            anchors.fill: parent
            hoverEnabled: true

            onPressed: press(mouse)
            onEntered: enter(1)
            onReleased: release()
            onPositionChanged: positionChange(mouse, -1, -1)
        }
    }

    //Top
    Item {
        id: top
        height: enableSize
        anchors.left: leftTop.right
        anchors.right: rightTop.left
        anchors.top: parent.top
        z: 1000
        MouseArea {
            anchors.fill: parent
            hoverEnabled: true

            onPressed: press(mouse)
            onEntered: enter(2)
            onReleased: release()

            onMouseYChanged: positionChange(Qt.point(customPoint.x, mouseY), 1, -1)
        }
    }

    //右上角
    Item {
        id: rightTop
        width: enableSize
        height: enableSize
        anchors.right: parent.right
        anchors.top: parent.top
        z: 1000
        MouseArea {
            anchors.fill: parent
            hoverEnabled: true

            onPressed: press(mouse)
            onEntered: enter(3)
            onReleased: release()
            onPositionChanged: positionChange(mouse, 1, -1)
        }
    }

    //Left
    Item {
        id: left
        width: enableSize
        anchors.left: parent.left
        anchors.top: leftTop.bottom
        anchors.bottom: leftBottom.top
        z: 1000
        MouseArea {
            anchors.fill: parent
            hoverEnabled: true

            onPressed: press(mouse)
            onEntered: enter(4)
            onReleased: release()

            onMouseXChanged: positionChange(Qt.point(mouseX, customPoint.y), -1, 1)
        }
    }

    //Center - 5
    Item {
        id: center
        anchors.left: left.right
        anchors.right: right.left
        anchors.top: top.bottom
        anchors.bottom: bottom.top
        MouseArea {
            anchors.fill: parent

            property point clickPos
            onPressed: clickPos = Qt.point(mouse.x,mouse.y)
            onPositionChanged: {
                if(pressed && mainWindow.visibility !== Window.Maximized && mainWindow.visibility !== Window.FullScreen) {
                    var delta = Qt.point(mouse.x-clickPos.x, mouse.y-clickPos.y)
                    mainWindow.x += delta.x
                    mainWindow.y += delta.y
                }
            }
        }
    }

    //Right
    Item {
        id: right
        width: enableSize
        anchors.right: parent.right
        anchors.top: rightTop.bottom
        anchors.bottom: rightBottom.top
        z: 1000
        MouseArea {
            anchors.fill: parent
            hoverEnabled: true

            onPressed: press(mouse)
            onEntered: enter(6)
            onReleased: release()

            onMouseXChanged: positionChange(Qt.point(mouseX, customPoint.y), 1, 1)
        }
    }

    //左下角
    Item {
        id: leftBottom
        width: enableSize
        height: enableSize
        anchors.left: parent.left
        anchors.bottom: parent.bottom
        z: 1000
        MouseArea {
            anchors.fill: parent
            hoverEnabled: true

            onPressed: press(mouse)
            onEntered: enter(7)
            onReleased: release()

            onPositionChanged: positionChange(mouse, -1, 1)
        }
    }

    //bottom
    Item {
        id: bottom
        height: enableSize
        anchors.left: leftBottom.right
        anchors.right: rightBottom.left
        anchors.bottom: parent.bottom
        z: 1000
        MouseArea {
            anchors.fill: parent
            hoverEnabled: true

            onPressed: press(mouse)
            onEntered: enter(8)
            onReleased: release()

            onMouseYChanged: positionChange(Qt.point(customPoint.x, mouseY), 1, 1)
        }
    }

    //右下角
    Item {
        id:rightBottom
        width: enableSize
        height: enableSize
        anchors.right: parent.right
        anchors.bottom: parent.bottom
        z: 1000
        MouseArea {
            anchors.fill: parent
            hoverEnabled: true

            onPressed: press(mouse)
            onEntered: enter(9)
            onReleased: release()

            onPositionChanged: positionChange(mouse,1,1)
        }
    }

    function enter(direct) {
        Resize.setMyCursor(direct)
    }

    function press(mouse) {
        isPressed = true
        customPoint = Qt.point(mouse.x, mouse.y)
    }

    function release() {
        isPressed = false
        //customPoint = undefined
    }

    function positionChange(newPosition, directX/*x轴方向*/, directY/*y轴方向*/) {
        if(!isPressed) return

        var delta = Qt.point(newPosition.x-customPoint.x, newPosition.y-customPoint.y)
        var tmpW,tmpH

        if(directX >= 0)
            tmpW = mainWindow.width + delta.x
        else
            tmpW = mainWindow.width - delta.x

        if(directY >= 0)
            tmpH = mainWindow.height + delta.y
        else
            tmpH = mainWindow.height - delta.y

        if(tmpW < mainWindow.minimumWidth) {
            if(directX < 0)
                mainWindow.x += (mainWindow.width - mainWindow.minimumWidth)
            mainWindow.width = mainWindow.minimumWidth
        }
        else {
            mainWindow.width = tmpW
            if(directX < 0)
                mainWindow.x += delta.x
        }

        if(tmpH < mainWindow.minimumHeight) {
            if(directY < 0)
                mainWindow.y += (mainWindow.height - mainWindow.minimumHeight)
            mainWindow.height = mainWindow.minimumHeight
        }
        else {
            mainWindow.height = tmpH
            if(directY < 0)
                mainWindow.y += delta.y
        }
    }
}

ResizeQmlWindow.cpp

#include "ResizeQmlWindow.h"


ResizeQmlWindow::ResizeQmlWindow(QObject *parent) : QObject(parent)
{}


void ResizeQmlWindow::setWindow(QWindow *win)
{
    m_win = win;
}


void ResizeQmlWindow::setMyCursor(int direct)
{
    switch (direct) {
    case 1:
        m_win->setCursor(QCursor(Qt::SizeFDiagCursor));
        break;
    case 2:
        m_win->setCursor(QCursor(Qt::SizeVerCursor));
        break;
    case 3:
        m_win->setCursor(QCursor(Qt::SizeBDiagCursor));
        break;
    case 4:
        m_win->setCursor(QCursor(Qt::SizeHorCursor));
        break;
    case 5:
        m_win->setCursor(QCursor(Qt::ArrowCursor));
        break;
    case 6:
        m_win->setCursor(QCursor(Qt::SizeHorCursor));
        break;
    case 7:
        m_win->setCursor(QCursor(Qt::SizeBDiagCursor));
        break;
    case 8:
        m_win->setCursor(QCursor(Qt::SizeVerCursor));
        break;
    case 9:
        m_win->setCursor(QCursor(Qt::SizeFDiagCursor));
        break;
    }
}

因为我们要在C++设置鼠标的状态,所以我们还须将ResizeQmlWindow注册传递到Qml中,如下

    QObject * obj = engine.rootObjects().at(0);
    QWindow * w = qobject_cast(obj);
    ResizeQmlWindow resize;
    if(w) {
        resize.setWindow(w);
        engine.rootContext()->setContextProperty("Resize", &resize);
    }

对比效果如图所示
QtQuick实现无边框窗口的拉伸,拖拽和自定义标题栏_第1张图片QtQuick实现无边框窗口的拉伸,拖拽和自定义标题栏_第2张图片

示例工程下载

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