Qt实现对齐线功能的示例代码

Lark ·

更新时间:2024-11-11

· 335 次阅读

现有功能

运行结果

源码

button.h

button.cpp

window.h

window.cpp

main.cpp

现有功能

1.添加任意数量的按钮。

2.移动按钮，通过对齐线来设置按钮位置。

3.自动吸附。

运行结果

源码 button.h

#ifndef BUTTON_H
#define BUTTON_H
#include <QPushButton>
#include <QWidget>
#include <QMouseEvent>
class Button: public QPushButton
{
    Q_OBJECT
public:
    Button(QString text, QWidget *parent=nullptr);
    ~Button();
protected:
    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);
    void mouseReleaseEvent(QMouseEvent *event);
private:
    int startX;
    int startY;
};
#endif // BUTTON_H

button.cpp

#include "button.h"
#include "window.h"
Button::Button(QString text, QWidget *parent):QPushButton(text, parent)
{
}
Button::~Button() {
}
void Button::mousePressEvent(QMouseEvent *event) {
    QPushButton::mousePressEvent(event);
    this->startX = event->x();
    this->startY = event->y();
}
void Button::mouseMoveEvent(QMouseEvent *event) {
    QPushButton::mouseMoveEvent(event);
    int disX = event->x() - this->startX;
    int disY = event->y() - this->startY;
    this->move(this->x()+disX, this->y()+disY);
    Window *win = (Window*) this->parent();
    win->checkPos(this);
}
void Button::mouseReleaseEvent(QMouseEvent *event) {
    QPushButton::mouseReleaseEvent(event);
}

window.h

#ifndef WINDOW_H
#define WINDOW_H
#include <QWidget>
#include <QSpinBox>
#include <QPainter>
#include <QPaintEvent>
#include <QPushButton>
#include <QList>
#include <QPen>
#include "button.h"
class Window : public QWidget
{
    Q_OBJECT
public:
    Window(QWidget *parent = nullptr);
    ~Window();
    void checkPos(Button *movingBtn);                   // 检查按钮位置
protected:
    void paintEvent(QPaintEvent *event);
private slots:
    void changeBtnNum(int newNum);                      // 改变按钮数量
private:
    void drawVerticalCenterLine(QPainter &painter);     // 绘制垂直中心线
    void drawHorizontalCenterLine(QPainter &painter);   // 绘制水平中心线
    void drawBtnLeftLine(QPainter &painter);            // 绘制按钮左侧线
    void drawBtnTopLine(QPainter &painter);             // 绘制按钮顶部线
    void checkBtnTopLine(Button *movingBtn);            // 比对当前移动按钮和其他按钮顶部的位置
    void checkBtnLeftLine(Button *movingBtn);           // 比对当前移动按钮和其他按钮左侧的位置
    void checkWindowCenterLines(Button *movingBtn);     // 比对按钮和中心线的位置
private:
    QSpinBox *spinBox;
    QList<Button *> btnList;
    int lineShowThresholdValue;                         // 线条显示阈值
    int lineAdsorbThresholdValue;                       // 线条吸附阈值
    bool isVerticalCenterLineShown;                     // 是否显示中心竖线
    bool isHorizontalCenterLineShown;                   // 是否显示中心横线
    bool isBtnLeftLineShown;                            // 是否显示按钮左侧线条
    bool isBtnTopLineShown;                             // 是否显示按钮顶部线条
    int btnLeftLineX;                                   // 按钮左侧线x坐标
    int btnTopLineY;                                    // 按钮顶部线y坐标
    QPen pen1;                                          // 用来绘制中心对齐线
    QPen pen2;                                          // 用来绘制按钮间的对齐线
};
#endif // WINDOW_H

window.cpp

#include "window.h"
#include <Qt>
#include <QString>
#include <cstdlib>
Window::Window(QWidget *parent): QWidget(parent)
{
    this->resize(500, 500);
    this->spinBox = new QSpinBox(this);
    this->spinBox->setValue(0);
    this->spinBox->move(10, 10);
    connect(this->spinBox, static_cast<void (QSpinBox::*)(int)>(&QSpinBox::valueChanged), this, &Window::changeBtnNum);
    this->lineShowThresholdValue = 5;
    this->lineAdsorbThresholdValue = 3;
    this->isVerticalCenterLineShown = false;
    this->isHorizontalCenterLineShown = false;
    this->isBtnLeftLineShown = false;
    this->isBtnTopLineShown = false;
    this->btnLeftLineX = 0;
    this->btnTopLineY = 0;
    this->pen1 = QPen(Qt::darkBlue);
    this->pen2 = QPen(Qt::gray);
}
Window::~Window()
{
}
void Window::paintEvent(QPaintEvent *event) {
    QWidget::paintEvent(event);
    QPainter painter(this);
    painter.setPen(this->pen1);
    if (this->isVerticalCenterLineShown) {
        this->drawVerticalCenterLine(painter);
    }
    if (this->isHorizontalCenterLineShown) {
        this->drawHorizontalCenterLine(painter);
    }
    painter.setPen(this->pen2);
    if (this->isBtnLeftLineShown) {
        this->drawBtnLeftLine(painter);
    }
    if (this->isBtnTopLineShown) {
        this->drawBtnTopLine(painter);
    }
}
void Window::drawVerticalCenterLine(QPainter &painter) {
    int verticalCenterValue = int(this->width() / 2);
    painter.drawLine(verticalCenterValue, 0, verticalCenterValue, this->height());
}
void Window::drawHorizontalCenterLine(QPainter &painter) {
    int horizontalCenterValue = int(this->height() / 2);
    painter.drawLine(0, horizontalCenterValue, this->width(), horizontalCenterValue);
}
void Window::drawBtnLeftLine(QPainter &painter) {
    int x = this->btnLeftLineX;
    painter.drawLine(x, 0, x, this->height());
}
void Window::drawBtnTopLine(QPainter &painter) {
    int y = this->btnTopLineY;
    painter.drawLine(0, y, this->width(), y);
}
void Window::checkPos(Button *movingBtn) {
    this->checkBtnTopLine(movingBtn);
    this->checkBtnLeftLine(movingBtn);
    this->checkWindowCenterLines(movingBtn);
    this->update();
}
void Window::checkBtnTopLine(Button *movingBtn) {
    int x = movingBtn->x();
    int y = movingBtn->y();
    for (int i=0; i<this->btnList.size(); i++) {
        Button *btn = this->btnList.at(i);
        if (btn == movingBtn) {
            continue;
        }
        if (y>btn->y()-this->lineShowThresholdValue && y<btn->y()+this->lineShowThresholdValue) {
            this->isBtnTopLineShown = true;
            this->btnTopLineY = btn->y();
            if (y>btn->y()-this->lineAdsorbThresholdValue && y<btn->y()+this->lineAdsorbThresholdValue) {
                movingBtn->move(x, btn->y());
            }
            return;
        }
        else {
            this->isBtnTopLineShown = false;
            this->btnTopLineY = 0;
        }
    }
}
void Window::checkBtnLeftLine(Button *movingBtn) {
    int x = movingBtn->x();
    int y = movingBtn->y();
    for (int i=0; i<this->btnList.size(); i++) {
        Button *btn = this->btnList.at(i);
        if (btn == movingBtn) {
            continue;
        }
        if (x>btn->x()-this->lineShowThresholdValue && x<btn->x()+this->lineShowThresholdValue) {
            this->isBtnLeftLineShown = true;
            this->btnLeftLineX = btn->x();
            if (x>btn->x()-this->lineAdsorbThresholdValue && x<btn->x()+this->lineAdsorbThresholdValue) {
                movingBtn->move(btn->x(), y);
            }
            return;
        }
        else {
            this->isBtnLeftLineShown = false;
            this->btnLeftLineX = 0;
        }
    }
}
void Window::checkWindowCenterLines(Button *movingBtn) {
    int x = movingBtn->x();
    int y = movingBtn->y();
    int verticalCenterValue = int(this->width()/2) - int(movingBtn->width()/2);
    int horizontalCenterValue = int(this->width()/2) - int(movingBtn->height()/2);
    // 判断是否显示中心竖线
    if (x>verticalCenterValue-this->lineShowThresholdValue && x<verticalCenterValue+this->lineShowThresholdValue) {
        this->isVerticalCenterLineShown = true;
        // 判断是否吸附
        if (x>verticalCenterValue-this->lineAdsorbThresholdValue && x<verticalCenterValue+this->lineAdsorbThresholdValue) {
            movingBtn->move(verticalCenterValue, y);
        }
    }
    else {
        this->isVerticalCenterLineShown = false;
    }
    // 判断是否显示中心横线
    if (y>horizontalCenterValue-this->lineShowThresholdValue && y<horizontalCenterValue+this->lineShowThresholdValue) {
        this->isHorizontalCenterLineShown = true;
        // 判断是否吸附
        if (y>horizontalCenterValue-this->lineAdsorbThresholdValue && y<horizontalCenterValue+this->lineAdsorbThresholdValue) {
            movingBtn->move(x, horizontalCenterValue);
        }
    }
    else {
        this->isHorizontalCenterLineShown = false;
    }
}
void Window::changeBtnNum(int newNum) {
    int currentNum = this->btnList.size();
    if (currentNum < newNum) {
        int diff = newNum - currentNum;
        for (int i=0; i<diff; i++) {
            QString text = QString("button%1").arg(currentNum);
            Button *btn = new Button(text, this);
            int x = rand() % (this->width()-btn->width()+1);
            int y = rand() % (this->height()-btn->width()+1);
            btn->move(x, y);
            btn->show();
            this->btnList.append(btn);
        }
    }
    else if (currentNum > newNum) {
        int diff = currentNum - newNum;
        for (int i=0; i<diff; i++) {
            Button *btn = this->btnList.takeLast();
            btn->deleteLater();
        }
    }
}

main.cpp

#include "window.h"
#include <QApplication>
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Window w;
    w.show();
    return a.exec();
}

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