qt画板

完成qt绘画编辑器功能

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
#ifndef JRPAINTER_H
#define JRPAINTER_H
#include <QQuickPaintedItem>
#include <QVector>
#include <QPointF>
#include <QImage>

class JRPainter : public QQuickPaintedItem
{
    Q_OBJECT

//    Q_PROPERTY(int penWidth READ penWidth WRITE setPenWidth)

public:
    JRPainter(QQuickItem *parent = 0);

    void paint(QPainter *painter);

    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);
    void mouseReleaseEvent(QMouseEvent *event);

    Q_INVOKABLE void init();
 //   Q_INVOKABLE void clear();
    Q_INVOKABLE void stop() {
        qDebug() << "Gemini::stop() called";
    }
    enum shape {
        Line = 1,Ellipse,Rect,Triangle
    };
    Q_ENUM(shape)
    Q_INVOKABLE void setShape(shape);
    Q_INVOKABLE void setPenWidth(int w);
    Q_INVOKABLE void setPenColor(QColor c);
signals:

public slots:

private:
    void drawShape(QImage &theImage);


private:
   QVector<QPointF> point;
   QImage m_bgImage;
   QImage m_tempImage;
   bool isDrawing;
   QPointF m_nowPoint;
   QPointF m_lastPoint;
   JRPainter::shape type;
   int penWidth;
   QColor penColor;
};

#endif // JRPAINTER_H
　　

#include "jrpainter.h"
#include <QPainter>
#include <QImage>

JRPainter::JRPainter(QQuickItem *parent):
    isDrawing(false),
    type(Line),
    penWidth(4),
    penColor(QColor(255,0,0))
{
    setAcceptedMouseButtons(Qt::LeftButton);
}

void JRPainter::setShape(JRPainter::shape t)    // 设置绘制类型
{
    type = t;
}

void JRPainter::setPenWidth(int w)    // 设置画笔宽度
{
    penWidth = w;
}

void JRPainter::setPenColor(QColor c)    // 设置颜色
{
    penColor = c;
}

void JRPainter::paint(QPainter *painter)
{
    if(isDrawing){
        painter->drawImage(0,0,m_tempImage);
    }else{
        painter->drawImage(0,0,m_bgImage);
    }
}
void JRPainter::init()
{
    QImage img(":/res/background/Farm.svg");
    m_bgImage = img;
}

void JRPainter::mousePressEvent(QMouseEvent *event)
{
    m_lastPoint = event->localPos();
    isDrawing = true;
}

void JRPainter::mouseMoveEvent(QMouseEvent *event)
{
    m_nowPoint = event->localPos();
    m_tempImage = m_bgImage;
    if(type == Line){
        drawShape(m_bgImage);
    }else{
        drawShape(m_tempImage);
    }
}

void JRPainter::mouseReleaseEvent(QMouseEvent *event)
{
    isDrawing = false;
    if (type != Line) {
       drawShape(m_bgImage);
    }
}

void JRPainter::drawShape(QImage &theImage)
{
    QPainter painter(&theImage);
    QPen apen;
    apen.setWidth(penWidth);
    apen.setColor(penColor);
    painter.setPen(apen);
    painter.setRenderHint(QPainter::Antialiasing, true);
    int x1, y1, x2, y2;
    x1 = m_lastPoint.x();
    y1 = m_lastPoint.y();
    x2 = m_nowPoint.x();
    y2 = m_nowPoint.y();

    switch (type) {
        case JRPainter::Line:
        {
            painter.drawLine(m_lastPoint,m_nowPoint);
            m_lastPoint = m_nowPoint;
            break;
        }
        case JRPainter::Ellipse:
        {
            painter.drawEllipse(x1,y1,x2-x1,y2-y1);
            break;
        }
        case JRPainter::Rect:
        {
            painter.drawRect(x1, y1, x2 - x1, y2 - y1);
            break;
        }
        case JRPainter::Triangle:
        {
            int top, buttom, left, right;
            top = (y1 < y2) ? y1 : y2;
            buttom = (y1 > y2) ? y1 : y2;
            left = (x1 < x2) ? x1 : x2;
            right = (x1 > x2) ? x1 : x2;
            if (y1 < y2)
            {
                QPoint points[3] = { QPoint(left,buttom), QPoint(right,buttom), QPoint((right + left) / 2,top) };
                painter.drawPolygon(points, 3);
            }
            else
            {
                QPoint points[3] = { QPoint(left,top), QPoint(right,top), QPoint((left + right) / 2,buttom) };
                painter.drawPolygon(points, 3);
            }
            break;
        }
    }
    update();
}

qml如果使用c++中定义的方法，需要

Q_INVOKABLE void init();
qml中 painter.init();调用即可
感谢https://blog.csdn.net/u013165921/article/details/79393265的博客