QML中繪圖（1、Canvas 2、QPainter與QML結合）
阿新 • • 發佈：2019-02-10
#include "alpainteditem.h"
ALPaintedItem::ALPaintedItem(QQuickItem *parent)
: QQuickPaintedItem(parent),
m_brushColor(QColor(0, 0, 0 ,255)),
m_eraserColor(QColor(255,255,255,255)),
m_bFlag(true),
m_bErasered(false),
m_pDrawPath(NULL),
m_penWidth(NULL)
{
setAcceptedMouseButtons(Qt::LeftButton);
}
ALPaintedItem::~ALPaintedItem()
{
}
void ALPaintedItem::paint(QPainter *painter)
{
if(m_bFlag)
painter->drawImage(QRectF(0,0,m_bgImage.width(),m_bgImage.height()),m_bgImage);
else
{
painter->drawImage(QRectF(0,0,m_tempImage.width(),m_tempImage.height()),m_tempImage);
painter->drawImage(QRectF(0,0,m_bgImage.width(),m_bgImage.height()),m_bgImage);
}
}
void ALPaintedItem::init()
{
m_bgImage = QImage(this->width(),this->height(),QImage::Format_ARGB32);
m_tempImage = QImage(this->width(),this->height(),QImage::Format_ARGB32);
m_bgImage.fill(QColor(255,255,255,0));
m_tempImage.fill(QColor(255,255,255,0));
}
void ALPaintedItem::clear()
{
m_bgImage.fill(QColor(255,255,255,0));
m_tempImage.fill(QColor(255,255,255,0));
update();
}
void ALPaintedItem::mousePressEvent(QMouseEvent *event)
{
if(!(event->button() & acceptedMouseButtons()))
{
QQuickPaintedItem::mousePressEvent(event);
}
else{
if(m_pDrawPath == NULL)
{
m_pDrawPath = new QPainterPath();
}
m_pDrawPath->moveTo(event->localPos());
m_nowPoint = event->localPos();
}
}
void ALPaintedItem::mouseMoveEvent(QMouseEvent *event)
{
m_lastPoint = m_nowPoint;
m_nowPoint = event->localPos();
QPointF tmpPoint = m_nowPoint - m_lastPoint;
if(m_pDrawPath == NULL)
{
return;
}
if(qAbs(tmpPoint.x()) > 0 || qAbs(tmpPoint.y()) >0)
{
m_pDrawPath->quadTo(m_lastPoint.x() , m_lastPoint.y() ,(m_nowPoint.x() + m_lastPoint.x())/2,(m_nowPoint.y() + m_lastPoint.y())/2);
m_bFlag = false;
if(m_bErasered)
drawBgLine(*m_pDrawPath);
else
drawTmpLine(); // 臨時畫
}
QQuickPaintedItem::mouseMoveEvent(event);
}
void ALPaintedItem::mouseReleaseEvent(QMouseEvent *event)
{
if(!(event->button() & acceptedMouseButtons()))
{
QQuickPaintedItem::mousePressEvent(event);
}
else{
if(m_pDrawPath != NULL)
{
m_bFlag = true;
drawBgLine(*m_pDrawPath);
delete m_pDrawPath;
m_pDrawPath = NULL;
}
}
}
void ALPaintedItem::drawTmpLine()
{
QPainter painter(&m_tempImage);
drawPenStyle(&painter);
painter.drawLine(m_lastPoint,m_nowPoint);
qreal rad = this->width()/375.0*170;//點周圍範圍值
qDebug() << "rad:" << rad;
QRect rect = QRect(m_nowPoint.x() - 5, m_nowPoint.y() - 5,10,10);
update(rect.adjusted(-rad,-rad,+rad,+rad));
}
void ALPaintedItem::drawBgLine(const QPainterPath &path)
{
QPainter painter(&m_bgImage);
drawPenStyle(&painter);
painter.drawPath(path);
m_tempImage.fill(QColor(255,255,255,0));
update();
}
void ALPaintedItem::drawPenStyle(QPainter *painter)
{
painter->setRenderHint(QPainter::Antialiasing);
QBrush brush(m_brushColor, Qt::SolidPattern);
if(m_bErasered)
{
painter->setCompositionMode(QPainter::CompositionMode_Clear);
painter->setPen(QPen(brush, 5*m_penWidth, Qt::SolidLine, Qt::RoundCap,Qt::RoundJoin));
}
else
{
painter->setCompositionMode(QPainter::CompositionMode_SourceOver);
painter->setPen(QPen(brush, m_penWidth, Qt::SolidLine, Qt::RoundCap,Qt::RoundJoin));
}
painter->setBrush(Qt::NoBrush);
}
ALPaintedItem::ALPaintedItem(QQuickItem *parent)
: QQuickPaintedItem(parent),
m_brushColor(QColor(0, 0, 0 ,255)),
m_eraserColor(QColor(255,255,255,255)),
m_bFlag(true),
m_bErasered(false),
m_pDrawPath(NULL),
m_penWidth(NULL)
{
setAcceptedMouseButtons(Qt::LeftButton);
}
ALPaintedItem::~ALPaintedItem()
{
}
void ALPaintedItem::paint(QPainter *painter)
{
if(m_bFlag)
painter->drawImage(QRectF(0,0,m_bgImage.width(),m_bgImage.height()),m_bgImage);
else
{
painter->drawImage(QRectF(0,0,m_tempImage.width(),m_tempImage.height()),m_tempImage);
painter->drawImage(QRectF(0,0,m_bgImage.width(),m_bgImage.height()),m_bgImage);
}
}
void ALPaintedItem::init()
{
m_bgImage = QImage(this->width(),this->height(),QImage::Format_ARGB32);
m_tempImage = QImage(this->width(),this->height(),QImage::Format_ARGB32);
m_bgImage.fill(QColor(255,255,255,0));
m_tempImage.fill(QColor(255,255,255,0));
}
void ALPaintedItem::clear()
{
m_bgImage.fill(QColor(255,255,255,0));
m_tempImage.fill(QColor(255,255,255,0));
update();
}
void ALPaintedItem::mousePressEvent(QMouseEvent *event)
{
if(!(event->button() & acceptedMouseButtons()))
{
QQuickPaintedItem::mousePressEvent(event);
}
else{
if(m_pDrawPath == NULL)
{
m_pDrawPath = new QPainterPath();
}
m_pDrawPath->moveTo(event->localPos());
m_nowPoint = event->localPos();
}
}
void ALPaintedItem::mouseMoveEvent(QMouseEvent *event)
{
m_lastPoint = m_nowPoint;
m_nowPoint = event->localPos();
QPointF tmpPoint = m_nowPoint - m_lastPoint;
if(m_pDrawPath == NULL)
{
return;
}
if(qAbs(tmpPoint.x()) > 0 || qAbs(tmpPoint.y()) >0)
{
m_pDrawPath->quadTo(m_lastPoint.x() , m_lastPoint.y() ,(m_nowPoint.x() + m_lastPoint.x())/2,(m_nowPoint.y() + m_lastPoint.y())/2);
m_bFlag = false;
if(m_bErasered)
drawBgLine(*m_pDrawPath);
else
drawTmpLine(); // 臨時畫
}
QQuickPaintedItem::mouseMoveEvent(event);
}
void ALPaintedItem::mouseReleaseEvent(QMouseEvent *event)
{
if(!(event->button() & acceptedMouseButtons()))
{
QQuickPaintedItem::mousePressEvent(event);
}
else{
if(m_pDrawPath != NULL)
{
m_bFlag = true;
drawBgLine(*m_pDrawPath);
delete m_pDrawPath;
m_pDrawPath = NULL;
}
}
}
void ALPaintedItem::drawTmpLine()
{
QPainter painter(&m_tempImage);
drawPenStyle(&painter);
painter.drawLine(m_lastPoint,m_nowPoint);
qreal rad = this->width()/375.0*170;//點周圍範圍值
qDebug() << "rad:" << rad;
QRect rect = QRect(m_nowPoint.x() - 5, m_nowPoint.y() - 5,10,10);
update(rect.adjusted(-rad,-rad,+rad,+rad));
}
void ALPaintedItem::drawBgLine(const QPainterPath &path)
{
QPainter painter(&m_bgImage);
drawPenStyle(&painter);
painter.drawPath(path);
m_tempImage.fill(QColor(255,255,255,0));
update();
}
void ALPaintedItem::drawPenStyle(QPainter *painter)
{
painter->setRenderHint(QPainter::Antialiasing);
QBrush brush(m_brushColor, Qt::SolidPattern);
if(m_bErasered)
{
painter->setCompositionMode(QPainter::CompositionMode_Clear);
painter->setPen(QPen(brush, 5*m_penWidth, Qt::SolidLine, Qt::RoundCap,Qt::RoundJoin));
}
else
{
painter->setCompositionMode(QPainter::CompositionMode_SourceOver);
painter->setPen(QPen(brush, m_penWidth, Qt::SolidLine, Qt::RoundCap,Qt::RoundJoin));
}
painter->setBrush(Qt::NoBrush);
}