在之前的一篇文章中写过一个通用的移动控件,作用就是用来传入任意的widget控件,可以在父类容器中自由移动。本篇文章要写的是一个通用的无边框类,确切的说这不叫控件应该叫组件才对,控件是要看得见的东西,有绘制需求的,而这个需要依附在控件上。在我们平时做的项目中,为了U界面的美观,很多会采用自定义无边框窗体来处理,自己美化标题栏等,都会面临一个相同的问题,就是设置好自定义无边框窗体以后,要自己处理窗体的移动和拉伸,如果有多个无边框窗体,很多人会想到每个地方都写重复的代码来实现移动或者拉伸,何不封装一个类来完成这个功能呢,直接传入窗体即可。在QDialog窗体中可以通过设置一个属性sizeGripEnabled来实现右下角的拉伸,这个还不足以满足所有的需求,很多时候我们还需要在四个角和上下左右都能拉伸大小,这个就需要重写了,安装事件过滤器,识别到鼠标移动到某个区域,鼠标形状自动变化,然后识别是否已经按下,按下的话做对应的处理,对应的处理核心就是重新设置窗体的XY轴坐标和大小。
开源地址:https://gitee.com/feiyangqingyun/QWidgetDemo https://github.com/feiyangqingyun/QWidgetDemo

#ifndef FRAMELESSWIDGET_H
#define FRAMELESSWIDGET_H
/**
* 无边框窗体类 作者:feiyangqingyun(QQ:517216493) 2019-10-03
* 1:可以指定需要无边框的widget
* 2:边框四周八个方位都可以自由拉伸
* 3:可设置对应位置的边距,以便识别更大区域
* 4:可设置是否允许拖动
* 5:可设置是否允许拉伸
*/
#include <QWidget>
#ifdef quc
#if (QT_VERSION < QT_VERSION_CHECK(5,7,0))
#include <QtDesigner/QDesignerExportWidget>
#else
#include <QtUiPlugin/QDesignerExportWidget>
#endif
class QDESIGNER_WIDGET_EXPORT FramelessWidget : public QObject
#else
class FramelessWidget : public QObject
#endif
{
Q_OBJECT
public:
explicit FramelessWidget(QObject *parent = 0);
protected:
bool eventFilter(QObject *watched, QEvent *event);
private:
int padding; //边距
bool moveEnable; //可移动
bool resizeEnable; //可拉伸
QWidget *widget; //无边框窗体
bool pressed; //鼠标按下
bool pressedLeft; //鼠标按下左侧
bool pressedRight; //鼠标按下右侧
bool pressedTop; //鼠标按下上侧
bool pressedBottom; //鼠标按下下侧
bool pressedLeftTop; //鼠标按下左上侧
bool pressedRightTop; //鼠标按下右上侧
bool pressedLeftBottom; //鼠标按下左下侧
bool pressedRightBottom; //鼠标按下右下侧
int rectX, rectY, rectW, rectH; //窗体坐标+宽高
QPoint lastPos; //鼠标按下处坐标
QRect rectLeft; //左侧区域
QRect rectRight; //右侧区域
QRect rectTop; //上侧区域
QRect rectBottom; //下侧区域
QRect rectLeftTop; //左上侧区域
QRect rectRightTop; //右上侧区域
QRect rectLeftBottom; //左下侧区域
QRect rectRightBottom; //右下侧区域
public Q_SLOTS:
//设置边距
void setPadding(int padding);
//设置是否可拖动+拉伸
void setMoveEnable(bool moveEnable);
void setResizeEnable(bool resizeEnable);
//设置要无边框的窗体
void setWidget(QWidget *widget);
};
#endif // FRAMELESSWIDGET_H#include "framelesswidget.h"
#include "qevent.h"
#include "qdebug.h"
FramelessWidget::FramelessWidget(QObject *parent) : QObject(parent)
{
padding = 8;
moveEnable = true;
resizeEnable = true;
widget = 0;
pressed = false;
pressedLeft = false;
pressedRight = false;
pressedTop = false;
pressedBottom = false;
pressedLeftTop = false;
pressedRightTop = false;
pressedLeftBottom = false;
pressedRightBottom = false;
//如果父类是窗体则直接设置
if (parent->isWidgetType()) {
setWidget((QWidget *)parent);
}
}
bool FramelessWidget::eventFilter(QObject *watched, QEvent *event)
{
if (widget != 0 && watched == widget) {
if (event->type() == QEvent::Resize) {
//重新计算八个描点的区域,描点区域的作用还有就是计算鼠标坐标是否在某一个区域内
int width = widget->width();
int height = widget->height();
//左侧描点区域
rectLeft = QRect(0, padding, padding, height - padding * 2);
//上侧描点区域
rectTop = QRect(padding, 0, width - padding * 2, padding);
//右侧描点区域
rectRight = QRect(width - padding, padding, padding, height - padding * 2);
//下侧描点区域
rectBottom = QRect(padding, height - padding, width - padding * 2, padding);
//左上角描点区域
rectLeftTop = QRect(0, 0, padding, padding);
//右上角描点区域
rectRightTop = QRect(width - padding, 0, padding, padding);
//左下角描点区域
rectLeftBottom = QRect(0, height - padding, padding, padding);
//右下角描点区域
rectRightBottom = QRect(width - padding, height - padding, padding, padding);
} else if (event->type() == QEvent::HoverMove) {
//设置对应鼠标形状,这个必须放在这里而不是下面,因为可以在鼠标没有按下的时候识别
QHoverEvent *hoverEvent = (QHoverEvent *)event;
QPoint point = hoverEvent->pos();
if (resizeEnable) {
if (rectLeft.contains(point)) {
widget->setCursor(Qt::SizeHorCursor);
} else if (rectRight.contains(point)) {
widget->setCursor(Qt::SizeHorCursor);
} else if (rectTop.contains(point)) {
widget->setCursor(Qt::SizeVerCursor);
} else if (rectBottom.contains(point)) {
widget->setCursor(Qt::SizeVerCursor);
} else if (rectLeftTop.contains(point)) {
widget->setCursor(Qt::SizeFDiagCursor);
} else if (rectRightTop.contains(point)) {
widget->setCursor(Qt::SizeBDiagCursor);
} else if (rectLeftBottom.contains(point)) {
widget->setCursor(Qt::SizeBDiagCursor);
} else if (rectRightBottom.contains(point)) {
widget->setCursor(Qt::SizeFDiagCursor);
} else {
widget->setCursor(Qt::ArrowCursor);
}
}
//根据当前鼠标位置,计算XY轴移动了多少
int offsetX = point.x() - lastPos.x();
int offsetY = point.y() - lastPos.y();
//根据按下处的位置判断是否是移动控件还是拉伸控件
if (moveEnable) {
if (pressed) {
widget->move(widget->x() + offsetX, widget->y() + offsetY);
}
}
if (resizeEnable) {
if (pressedLeft) {
int resizeW = widget->width() - offsetX;
if (widget->minimumWidth() <= resizeW) {
widget->setGeometry(widget->x() + offsetX, rectY, resizeW, rectH);
}
} else if (pressedRight) {
widget->setGeometry(rectX, rectY, rectW + offsetX, rectH);
} else if (pressedTop) {
int resizeH = widget->height() - offsetY;
if (widget->minimumHeight() <= resizeH) {
widget->setGeometry(rectX, widget->y() + offsetY, rectW, resizeH);
}
} else if (pressedBottom) {
widget->setGeometry(rectX, rectY, rectW, rectH + offsetY);
} else if (pressedLeftTop) {
int resizeW = widget->width() - offsetX;
int resizeH = widget->height() - offsetY;
if (widget->minimumWidth() <= resizeW) {
widget->setGeometry(widget->x() + offsetX, widget->y(), resizeW, resizeH);
}
if (widget->minimumHeight() <= resizeH) {
widget->setGeometry(widget->x(), widget->y() + offsetY, resizeW, resizeH);
}
} else if (pressedRightTop) {
int resizeW = rectW + offsetX;
int resizeH = widget->height() - offsetY;
if (widget->minimumHeight() <= resizeH) {
widget->setGeometry(widget->x(), widget->y() + offsetY, resizeW, resizeH);
}
} else if (pressedLeftBottom) {
int resizeW = widget->width() - offsetX;
int resizeH = rectH + offsetY;
if (widget->minimumWidth() <= resizeW) {
widget->setGeometry(widget->x() + offsetX, widget->y(), resizeW, resizeH);
}
if (widget->minimumHeight() <= resizeH) {
widget->setGeometry(widget->x(), widget->y(), resizeW, resizeH);
}
} else if (pressedRightBottom) {
int resizeW = rectW + offsetX;
int resizeH = rectH + offsetY;
widget->setGeometry(widget->x(), widget->y(), resizeW, resizeH);
}
}
} else if (event->type() == QEvent::MouseButtonPress) {
//记住当前控件坐标和宽高以及鼠标按下的坐标
QMouseEvent *mouseEvent = (QMouseEvent *)event;
rectX = widget->x();
rectY = widget->y();
rectW = widget->width();
rectH = widget->height();
lastPos = mouseEvent->pos();
//判断按下的手柄的区域位置
if (rectLeft.contains(lastPos)) {
pressedLeft = true;
} else if (rectRight.contains(lastPos)) {
pressedRight = true;
} else if (rectTop.contains(lastPos)) {
pressedTop = true;
} else if (rectBottom.contains(lastPos)) {
pressedBottom = true;
} else if (rectLeftTop.contains(lastPos)) {
pressedLeftTop = true;
} else if (rectRightTop.contains(lastPos)) {
pressedRightTop = true;
} else if (rectLeftBottom.contains(lastPos)) {
pressedLeftBottom = true;
} else if (rectRightBottom.contains(lastPos)) {
pressedRightBottom = true;
} else {
pressed = true;
}
} else if (event->type() == QEvent::MouseMove) {
//改成用HoverMove识别
} else if (event->type() == QEvent::MouseButtonRelease) {
//恢复所有
pressed = false;
pressedLeft = false;
pressedRight = false;
pressedTop = false;
pressedBottom = false;
pressedLeftTop = false;
pressedRightTop = false;
pressedLeftBottom = false;
pressedRightBottom = false;
widget->setCursor(Qt::ArrowCursor);
}
}
return QObject::eventFilter(watched, event);
}
void FramelessWidget::setPadding(int padding)
{
this->padding = padding;
}
void FramelessWidget::setMoveEnable(bool moveEnable)
{
this->moveEnable = moveEnable;
}
void FramelessWidget::setResizeEnable(bool resizeEnable)
{
this->resizeEnable = resizeEnable;
}
void FramelessWidget::setWidget(QWidget *widget)
{
if (this->widget == 0) {
this->widget = widget;
//设置鼠标追踪为真
this->widget->setMouseTracking(true);
//绑定事件过滤器
this->widget->installEventFilter(this);
//设置悬停为真,必须设置这个,不然当父窗体里边还有子窗体全部遮挡了识别不到MouseMove,需要识别HoverMove
this->widget->setAttribute(Qt::WA_Hover, true);
}
}原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
如有侵权,请联系 cloudcommunity@tencent.com 删除。
原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
如有侵权,请联系 cloudcommunity@tencent.com 删除。