使用QGraphicsView实现气泡聊天窗口+排雷功能

2024-04-02 19:55

短信预约 -IT技能 免费直播动态提醒

经过多方调查，用Qt实现气泡聊天窗口的方式有如下几个：

使用QWebEngineView控件内嵌html+CSS
使用QTextEdit内嵌html
使用QGraphicsView实现
使用QWidget自己绘制气泡样式实现

作为一名C++程序员，对CSS+html这套结构的不熟悉导致无法使用前两个方案，而第三个方案又不够高效，所以最终我选择了最后一个方案。
最终效果：

存在问题：无法选择文字及跨选（但理论上可以通过重写鼠标相关事件，达到模拟选择的效果）

左侧和右侧的消息分别是封装的两个Item，而这两个Item又从同一个基类继承而来。
气泡通过重写void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);函数，在里面根据文字的宽高计算气泡的位置并画上去，然后再把字写上去。
并且当窗口大小发生变化时，需要重新计算文字尺寸，进行绘制。

#pragma once

#include <QGraphicsRectItem>
//聊天元素所有item的基类
class ChatBaseItem : public QGraphicsRectItem
{
public:
    ChatBaseItem();
    virtual ~ChatBaseItem();
    virtual int Resize(int width);      //传入值为viewport宽，返回值为item高
};

#include "chatbaseitem.h"

ChatBaseItem::ChatBaseItem()
    : QGraphicsRectItem()
{
}
ChatBaseItem::~ChatBaseItem()
int ChatBaseItem::Resize(int width)
    return 0;

左侧聊天气泡Item

#pragma once

#include "chatbaseitem.h"
#include <QDateTime>
class OtherMsgItem : public ChatBaseItem
{
public:
    OtherMsgItem(QPixmap icon, QString name, QString msg, QDateTime datetime = QDateTime());
    virtual ~OtherMsgItem();
    virtual int Resize(int width);  //返回整个item的高度
protected:
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
    virtual QRectF boundingRect() const;
private:
    QGraphicsPixmapItem icon_item_;
    QGraphicsSimpleTextItem name_item_;
    QString text_;
    QSize text_size_;     //文字尺寸
    QDateTime datetime_;
};

#include <QPainter>
#include <QMargins>
#include <QTextOption>

#include "othermsgitem.h"
const int kMsgFontSize = 14;
const int kNameFontSize = 13;
const QPoint kNamePos = QPoint(64, 0);
const QPoint kIconPos = QPoint(20, 8);
const QPoint kBorderPos = QPoint(kNamePos.x(), kNamePos.y()+18);
const QMargins kMargins = QMargins(12,11,12,11);        //文字距边框的距离
const QPoint kTextPos = QPoint(kBorderPos.x()+ kMargins.left(), kBorderPos.y() + kMargins.top());
const int kMarginRight = 40;                           //边框距窗口右侧的距离
OtherMsgItem::OtherMsgItem(QPixmap icon, QString name, QString msg, QDateTime datetime )
    : ChatBaseItem()
    , datetime_(datetime)
{
    icon_item_.setPixmap(icon);
    icon_item_.setPos(kIconPos);
    text_ = msg;
    QFont font("Microsoft YaHei");
    font.setPixelSize(kNameFontSize);
    
    name_item_.setText(name);
    name_item_.setPos(kNamePos);
    name_item_.setFont(font);
    name_item_.setBrush(QColor(153, 153, 153));
    icon_item_.setParentItem(this);
    name_item_.setParentItem(this);
}
OtherMsgItem::~OtherMsgItem()
int OtherMsgItem::Resize(int width)
    //每行最大可容纳文字的宽度
    int row_width = width - kTextPos.x() - kMarginRight-kMargins.right();
    //计算文字总共需要多宽
    font.setPixelSize(kMsgFontSize);
    QFontMetrics font_matrics(font);
    int text_total_width = font_matrics.width(text_);
    int text_row_height = font_matrics.lineSpacing();
    if(row_width<text_total_width)
    {
        int row = text_total_width / row_width;
        ++row;
        int text_total_height = row* text_row_height;
        text_size_.setWidth(row_width);
        text_size_.setHeight(text_total_height);
    }
    else
        text_size_.setWidth(text_total_width);
        text_size_.setHeight(text_row_height);
    return text_size_.height()+kMargins.top()+kMargins.bottom()+kBorderPos.y();
void OtherMsgItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
    QSize rnd(17,17);
    QRectF border(kBorderPos.x(), kBorderPos.y(), text_size_.width()+kMargins.left()+ kMargins.right(),text_size_.height() + kMargins.top() + kMargins.bottom());
    //气泡加边
    painter->setPen(QPen(QColor(229, 229, 229), 1, Qt::SolidLine));
    painter->drawRoundedRect(border.x(), border.y(), border.width(), border.height(), rnd.width(), rnd.height());
    //气泡
    painter->setBrush(QBrush(Qt::white));
    painter->setPen(Qt::NoPen);
    painter->drawRoundedRect(border.x()+1, border.y()+1, border.width()-2, border.height()-2, rnd.width(), rnd.height());
    //三角，用矩形实现
    QRect rect1(border.x()+1, border.y()+1, 20, 20);
    painter->drawRect(rect1);
    //三角加边
    QPen pen;
    pen.setColor(QColor(229, 229, 229));
    painter->setPen(pen);
    painter->drawLine(border.x() , border.y() , border.x() +20, border.y() );
    painter->drawLine(border.x() , border.y() , border.x() , border.y() +20);
    QPen penText;
    penText.setColor(QColor(51, 51, 51));
    painter->setPen(penText);
    QTextOption option1(Qt::AlignLeft);
    option1.setWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
    painter->setFont(font);
    QRectF text_rect(kTextPos.x(), kTextPos.y(), text_size_.width(), text_size_.height());
    painter->drawText(text_rect, text_, option1);
QRectF OtherMsgItem::boundingRect() const
    QRectF border(kBorderPos.x(), kBorderPos.y(), text_size_.width() + kMargins.left() + kMargins.right(), text_size_.height() + kMargins.top() + kMargins.bottom());
    return QRectF(0,0,border.width(),border.height());

右侧气泡和左侧气泡不同，计算位置时，左端点需要根据窗口宽度事实计算。

#pragma once

#include "chatbaseitem.h"
#include <QDateTime>
class SelfMsgItem : public ChatBaseItem
{
public:
    SelfMsgItem(QPixmap icon, QString msg, QDateTime datetime = QDateTime());
    virtual ~SelfMsgItem();
    virtual int Resize(int width);  //返回整个item的高度
protected:
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
    virtual QRectF boundingRect() const;
private:
    QGraphicsPixmapItem icon_item_;
    QString text_;
    QSize text_size_;     //文字尺寸
    QDateTime datetime_;
    int port_width_;
};

#include <QPen>
#include <QPainter>
#include "selfmsgitem.h"
const int kMsgFontSize = 14;
const int kNameFontSize = 13;
const int kIconY = 0;
const int kBorderY = 10;
const int kIconWidth = 34;
const QMargins kIconMargins = QMargins(10,0,20,0);
const QMargins kMargins = QMargins(12, 11, 12, 11);        //文字距边框的距离
const int kMarginLeft = 40;                                //边框距窗口左侧的距离
SelfMsgItem::SelfMsgItem(QPixmap icon, QString msg, QDateTime datetime )
    : ChatBaseItem()
    , datetime_(datetime)
    , text_(msg)
{
    icon_item_.setPixmap(icon);
    icon_item_.setY(kIconY);
    icon_item_.setParentItem(this);
}
SelfMsgItem::~SelfMsgItem()
{
}
int SelfMsgItem::Resize(int width)
{
    port_width_ = width;
    //每行最大可容纳文字的宽度
    int row_width = width - kMarginLeft - kMargins.left() - kMargins.right() - kIconWidth - kIconMargins.left() - kIconMargins.right();
    //计算文字总共需要多宽
    QFont font("Microsoft YaHei");
    font.setPixelSize(kMsgFontSize);
    QFontMetrics font_matrics(font);
    int text_total_width = font_matrics.width(text_);
    int text_row_height = font_matrics.lineSpacing();
    if (row_width < text_total_width)
    {
        int row = text_total_width / row_width;
        int text_total_height = (row+1)* text_row_height;   //row从零开始，需要补加1
        text_size_.setWidth(row_width);
        text_size_.setHeight(text_total_height);
    }
    else
    {
        text_size_.setWidth(text_total_width);
        text_size_.setHeight(text_row_height);
    }
    return text_size_.height() + kMargins.top() + kMargins.bottom() + kBorderY;
}
void SelfMsgItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    QSize rnd(17, 17);
    //气泡聊天框左端点需要根据控件宽度计算
    QRectF border(port_width_- kIconMargins.left()-kIconMargins.right()-kIconWidth-text_size_.width()-kMargins.left()-kMargins.right()
        , kBorderY
        , text_size_.width() + kMargins.left() + kMargins.right()
        , text_size_.height() + kMargins.top() + kMargins.bottom());
    icon_item_.setX(border.x()+ border.width() + 10);
    //气泡
    painter->setBrush(QBrush(QColor(149,182,57)));
    painter->setPen(Qt::NoPen);
    painter->drawRoundedRect(border.x(), border.y(), border.width(), border.height(), rnd.width(), rnd.height());
    //三角，用矩形实现
    QRect rect1(border.x() + border.width() - 20, border.y(), 20, 20);
    painter->setPen(Qt::NoPen);
    painter->setBrush(QBrush(QColor(149, 182, 57)));
    painter->drawRect(rect1);
    QPen penText;
    penText.setColor(QColor(255, 255, 255));
    painter->setPen(penText);
    QTextOption option1(Qt::AlignLeft);
    option1.setWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
    QFont font("Microsoft YaHei");
    font.setPixelSize(kMsgFontSize);
    painter->setFont(font);
    QRectF text_rect(border.x()+kMargins.left(), border.y() + kMargins.top(), text_size_.width(), text_size_.height());
    painter->drawText(text_rect, text_, option1);
}
QRectF SelfMsgItem::boundingRect() const
{
    QRectF border(port_width_ - kIconMargins.left() - kIconMargins.right() - kIconWidth - text_size_.width() - kMargins.left() - kMargins.right()
        , kBorderY
        , text_size_.width() + kMargins.left() + kMargins.right()
        , text_size_.height() + kMargins.top() + kMargins.bottom());
    return QRectF(0, 0, border.width(), border.height());
}

接下是view调用

#pragma once

#include <QGraphicsView>
#include <QDateTime>
#include <QMap>
class ChatBaseItem;
class ChatView : public QGraphicsView
{
    Q_OBJECT
public:
    ChatView(QWidget *parent);
    ~ChatView();
    void Resize(int width);
    void ClearAll();
    void AppendSelfMessage(QPixmap icon, QString msg, QDateTime datetime);
    void AppendOtherMessage(QPixmap icon,QString name, QString msg, QDateTime datetime);
protected:
    virtual void mousePressEvent(QMouseEvent *e);
private:
    void CheckTime(QDateTime datetime);               //检查是否需要插入时间，传入值为当前消息时间
    void AppendTime(QDateTime datetime, QString time);
    QMap<QDateTime, ChatBaseItem*> items_;
};

#include <QDebug>
#include <QTextEdit>
#include <QScrollBar>
#include <QGraphicsScene>
#include "chatview.h"
#include "chatbaseitem.h"
#include "selfmsgitem.h"
#include "othermsgitem.h"
#include "chattimeitem.h"
#include "class="lazy" data-src/vapplication.h"
const int kMarkRole = Qt::UserRole;
const int kRoleOtherMsg = kMarkRole + 1;
const int kRoleSelfMsg = kRoleOtherMsg + 1;
const int kRoleTime = kRoleSelfMsg + 1;
ChatView::ChatView(QWidget *parent)
    : QGraphicsView(parent)
{
    setScene(new QGraphicsScene());
    this->setAlignment(Qt::AlignLeft | Qt::AlignTop);
    setStyleSheet("background: rgb(245,245,245) ;border:0px");
    this->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    this->verticalScrollBar()->setStyleSheet(theStyleSheet["scrollbar"]);
}
ChatView::~ChatView()
{
    ClearAll();
}
void ChatView::Resize(int width)
{
    int height = 20;
    for (ChatBaseItem* item : items_)
    {
        item->setPos(0, height);
        height = height + item->Resize(width);
        height += 20;
    }
    this->scene()->setSceneRect(QRectF(0, 0, width, height));
}
void ChatView::ClearAll()
{
    for (auto it = items_.begin(); it != items_.end();)
    {
        ChatBaseItem* item = it.value();
        it = items_.erase(it);
        delete item;
    }
}
void ChatView::AppendSelfMessage(QPixmap icon, QString msg, QDateTime datetime)
{
    ChatBaseItem* item = new SelfMsgItem(icon, msg, datetime);
    item->setData(kMarkRole,kRoleSelfMsg);
    CheckTime(datetime);
    scene()->addItem(item);
    items_.insert(datetime, item);
    Resize(this->viewport()->width());
    update();
    //滚动到底部
    QScrollBar *vScrollBar = verticalScrollBar();
    vScrollBar->setValue(vScrollBar->maximum());
}
void ChatView::AppendOtherMessage(QPixmap icon, QString name, QString msg, QDateTime datetime)
{
    ChatBaseItem* item = new OtherMsgItem(icon, name, msg, datetime);
    item->setData(kMarkRole, kRoleOtherMsg);
    CheckTime(datetime);
    scene()->addItem(item);
    items_.insert(datetime, item);
    Resize(this->viewport()->width());
    update();
    QScrollBar *vScrollBar = verticalScrollBar();
    vScrollBar->setValue(vScrollBar->maximum());
}
void ChatView::mousePressEvent(QMouseEvent *e)
{
    //截获鼠标点击事件
}
void ChatView::CheckTime(QDateTime datetime)
{
    if (items_.size() == 0|| datetime.secsTo(items_.lastKey())>60 * 5)
    {
        //第一条消息前插入时间
        QDateTime dt = datetime.addMSecs(-1);
        AppendTime(dt,dt.toString("hh:mm:ss"));
    }
}
void ChatView::AppendTime(QDateTime datetime, QString time)
{
    ChatBaseItem* item = new ChatTimeItem(time);
    item->setData(kMarkRole, kRoleTime);
    scene()->addItem(item);
    items_.insert(datetime, item);
    Resize(this->viewport()->width());
    update();
}

#pragma once

#include "chatbaseitem.h"
#include <QGraphicsRectItem>
class ChatTimeItem : public ChatBaseItem
{
public:
    ChatTimeItem(QString time);
    virtual ~ChatTimeItem();
    virtual int Resize(int width);
protected:
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
private:
    QGraphicsSimpleTextItem text_item_;
    QString text_;
    int port_width_;
};

#include <QFont>
#include <QPen>

#include "chattimeitem.h"
#include "color.h"
ChatTimeItem::ChatTimeItem(QString time)
    : ChatBaseItem()
{
    text_item_.setText(time);
    item_tool::SetFontColor(&text_item_, 13, false, colorspace::GetTextLightColor());
    text_item_.setParentItem(this);
}
ChatTimeItem::~ChatTimeItem()
int ChatTimeItem::Resize(int width)
    port_width_ = width;
    return text_item_.boundingRect().height();
void ChatTimeItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
    int width = text_item_.boundingRect().width();
    text_item_.setX((port_width_ - width) / 2);

在子类化Item时，一定要注意重写virtual QRectF boundingRect() const;方法，返回实际item的尺寸，让scene知道，并且要加入const，不然当消息左上角超出窗口范围时，会出现无法触发paint的问题。

到此这篇关于使用QGraphicsView实现气泡聊天窗口+排雷的文章就介绍到这了,更多相关QGraphicsView气泡聊天窗口内容请搜索编程网以前的文章或继续浏览下面的相关文章希望大家以后多多支持编程网！

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