QGraphicsScene¶
1 增加任意点¶
这玩意信号传递是：view ---scene---item
一旦把事件重构了了，一定要每个事件处理后QGraphicsItem::mouseMoveEvent(event);
功能：
* 增加任意点，点的顺序可以改变
* 每个点可以拖动和 wasd 移动
* 每个任意点的位置实时显示
* 空格可以把点按顺序直线链接
* 可以按顺序输出所有点的坐标
* 鼠标左键拖拽背景
* 滚轮放大缩小
* 实时显示鼠标现对于图片位置
// 自定义 Item
MyCustomIQGraphicsEllipseItem::MyCustomIQGraphicsEllipseItem(QGraphicsItem *parent)
: QGraphicsEllipseItem(parent) {
Initial();
}
void MyCustomIQGraphicsEllipseItem::Initial() {
// 画笔 - 边框色
QPen p = pen();
p.setWidth(1);
p.setColor(QColor(0, 160, 230, 100));
setPen(p);
// 画刷 - 背景色
setBrush(QColor(0, 0, 0, 100));
// 可选择、可移动
setFlags(QGraphicsItem::ItemIsSelectable | QGraphicsItem::ItemIsMovable);
title_item_ = new QGraphicsTextItem(this);
title_item_->setFont(QFont("ubuntu", 6));
title_item_->setDefaultTextColor(QColor(10, 10, 10));
}
void MyCustomIQGraphicsEllipseItem::SetThisTitle(QPointF a, QString c) {
this_pointf_ = a ;
this_title_name_ = c;
title_item_->moveBy(this_pointf_.x() - 25, this_pointf_.y() + 10);
title_item_->setPlainText(QString("%1 x:%2 y:%3")
.arg(this_title_name_)
.arg(this_pointf_.x())
.arg(this_pointf_.y()));
}
void MyCustomIQGraphicsEllipseItem::SetThisPosition() {
title_item_->setPlainText(QString("%1 x:%2 y:%3")
.arg(this_title_name_)
.arg(this_pointf_.x() + this->pos().x())
.arg(this_pointf_.y() + this->pos().y()));
}
void MyCustomIQGraphicsEllipseItem::SetThisName(QString a) {
this_title_name_ = a;
SetThisPosition();
}
void MyCustomIQGraphicsEllipseItem::mousePressEvent(
QGraphicsSceneMouseEvent *event) {
if (event->button() == Qt::LeftButton) {
if (event->modifiers() == Qt::ShiftModifier) {
setSelected(true);// 选中 item
} else if (event->modifiers() == Qt::AltModifier) {
} else {
QGraphicsItem::mousePressEvent(event);
event->accept();
}
} else if (event->button() == Qt::RightButton) {
event->ignore();
}
}
void MyCustomIQGraphicsEllipseItem::mouseMoveEvent(
QGraphicsSceneMouseEvent *event) {
QPointF point = event->scenePos();
title_item_->setPlainText(QString("%1 x:%2 y:%3")
.arg(this_title_name_)
.arg(point.x())
.arg(point.y()));
QGraphicsItem::mouseMoveEvent(event);
}
void MyCustomIQGraphicsEllipseItem::mouseReleaseEvent(
QGraphicsSceneMouseEvent *event) {
QGraphicsItem::mouseReleaseEvent(event);
}
void MyCustomIQGraphicsEllipseItem::paintEvent() {
}
qint32 MyCustomIQGraphicsEllipseItem::type() const {
return UserType + 1;
}
// 自定义 Item
MyCustomIQGraphicsPixmapItem::MyCustomIQGraphicsPixmapItem(QGraphicsItem *parent)
: QGraphicsPixmapItem(parent) {
}
void MyCustomIQGraphicsPixmapItem::mouseMoveEvent(
QGraphicsSceneMouseEvent *event) {
QGraphicsItem::mouseMoveEvent(event);
}
// 自定义 Scene
MyCustomQGraphicsScene::MyCustomQGraphicsScene(QGraphicsScene *parent):
QGraphicsScene(parent) {
Initial();
}
void MyCustomQGraphicsScene::Initial() {
begin_point_ = new MyCustomIQGraphicsEllipseItem;
end_point_ = new MyCustomIQGraphicsEllipseItem;
addItem(begin_point_);
addItem(end_point_);
the_path_ = new QGraphicsPathItem;
QPen p ;
p.setWidth(2);
p.setColor(Qt::green);
the_path_->setPen(p);
addItem(the_path_);
point_menu_ = new QMenu();
point_menu_child_ = new QMenu();
pointnums_ = 0;
}
void MyCustomQGraphicsScene::mousePressEvent(
QGraphicsSceneMouseEvent *event) {
QGraphicsScene::mousePressEvent(event);
if (!event->isAccepted()) {
if (event->button() == Qt::LeftButton) {
if (event->modifiers() == Qt::AltModifier) {
MyCustomIQGraphicsEllipseItem *item =
new MyCustomIQGraphicsEllipseItem();// 在 Scene 上添加一个自定义 item
QPen p ;
p.setWidth(1);
if (pointnums_ == 0) {
removeItem(begin_point_);
p.setColor(QColor(0, 255, 0, 200));
item->setPen(p);
QPointF point = event->scenePos();
item->SetThisTitle(point, "出发位置");
item->setRect(point.x() - 2, point.y() - 2, 4, 4);
begin_point_ = item;
addItem(item);
pointnums_++;
} else if (pointnums_ == 1) {
removeItem(end_point_);
p.setColor(QColor(0, 0, 255, 200));
item->setPen(p);
QPointF point = event->scenePos();
item->SetThisTitle(point, "结束位置");
item->setRect(point.x() - 2, point.y() - 2, 4, 4);
end_point_ = item;
addItem(item);
pointnums_++;
emit SignalBtnSeekOut();
} else {
QPointF point = event->scenePos();
item->SetThisTitle(point,
QString::number(list_points_.count() + 1));
item->setRect(point.x() - 2, point.y() - 2, 4, 4);
addItem(item);
list_points_.append(item);
pointnums_++;
emit SignalBtnSeekOut();
}
}
} else if (event->button() == Qt::RightButton) {
// 检测光标下是否有 item
MyCustomIQGraphicsEllipseItem *itemthis = nullptr;
foreach (QGraphicsItem *item, items(event->scenePos())) {
if (item->type() == QGraphicsItem::UserType + 1) {
itemthis = static_cast<MyCustomIQGraphicsEllipseItem *>(item) ;
break;
}
}
if ((itemthis != nullptr) &&
(itemthis != begin_point_) &&
(itemthis != end_point_)) {
point_menu_child_->clear();
point_menu_->clear();
point_menu_->addAction("删除", [ = ](void) {
this->SlotDalteOneItem(*itemthis);
});
point_menu_->addAction("取消");
point_menu_->addSeparator();
point_menu_child_ = point_menu_->addMenu("移动位置");
for (int i = 1; i <= list_points_.count(); i++) {
point_menu_child_->addAction(QString("移动至%1")
.arg(i), [ = ](void) {
this->SlotChangeSerialItem(*itemthis, i - 1);
});
}
point_menu_->exec(QCursor::pos());
}
}
}
}
void MyCustomQGraphicsScene::mouseMoveEvent(
QGraphicsSceneMouseEvent *event) {
// 检测光标下是否有 item
MyCustomIQGraphicsEllipseItem *itemthis = nullptr;
foreach (QGraphicsItem *item, items(event->scenePos())) {
if (item->type() == QGraphicsItem::UserType + 1) {
itemthis = static_cast<MyCustomIQGraphicsEllipseItem *>(item) ;
break;
}
}
if (itemthis != nullptr) {
emit SignalBtnSeekOut();
} else {
emit SIgnalPositionLib(event->scenePos());
}
QGraphicsScene::mouseMoveEvent(event);
}
void MyCustomQGraphicsScene::leaveEvent(
QGraphicsSceneMouseEvent *event) {
emit SIgnalPositionLib(event->scenePos());
emit SignalBtnSeekOut();
QGraphicsScene::mouseMoveEvent(event);
}
void MyCustomQGraphicsScene::keyPressEvent(QKeyEvent *event) {
if (event->key() == Qt::Key_Space) {
QPainterPath *painterPath = new QPainterPath;
painterPath->moveTo(begin_point_->GetThisPosition()
+ begin_point_->pos());
MyCustomIQGraphicsEllipseItem *i;
foreach (i, list_points_) {
painterPath->lineTo(i->GetThisPosition() + i->pos());
}
painterPath->lineTo(end_point_->GetThisPosition()
+ end_point_->pos());
the_path_->setPath(*painterPath);
the_path_->show();
the_path_->setZValue(100);
} else {
QGraphicsScene::keyPressEvent(event);
if (!selectedItems().isEmpty()) {
MyCustomIQGraphicsEllipseItem *tmp =
static_cast<MyCustomIQGraphicsEllipseItem *>(selectedItems().front());
if (event->key() == Qt::Key_A) {
tmp->moveBy(-1, 0);
tmp->SetThisPosition();
} else if (event->key() == Qt::Key_D) {
tmp->moveBy(1, 0);
tmp->SetThisPosition();
} else if (event->key() == Qt::Key_W) {
tmp->moveBy(0, -1);
tmp->SetThisPosition();
} else if (event->key() == Qt::Key_S) {
tmp->moveBy(0, 1);
tmp->SetThisPosition();
}
}
}
emit SignalBtnSeekOut();
QGraphicsScene::keyPressEvent(event);
}
void MyCustomQGraphicsScene::keyReleaseEvent(QKeyEvent *event) {
if (event->key() == Qt::Key_Space) {
the_path_->hide();
} else {
QGraphicsScene::keyReleaseEvent(event);
}
}
void MyCustomQGraphicsScene::SlotDalteOneItem(
MyCustomIQGraphicsEllipseItem &tem) {
list_points_.removeOne(&tem);
removeItem(&tem);
MyCustomIQGraphicsEllipseItem *i;
qint32 tmp_int = 1;
foreach (i, list_points_) {
i->SetThisName(QString::number(tmp_int));
tmp_int++;
pointnums_--;
}
emit SignalBtnSeekOut();
}
void MyCustomQGraphicsScene::SlotDalteAllItem() {
MyCustomIQGraphicsEllipseItem *i;
foreach (i, list_points_) {
list_points_.removeOne(i);
removeItem(i);
pointnums_--;
}
pointnums_ = 0;
removeItem(begin_point_);
removeItem(end_point_);
emit SignalBtnSeekOut();
}
void MyCustomQGraphicsScene::SlotChangeSerialItem(
MyCustomIQGraphicsEllipseItem &tem, int a) {
list_points_.removeOne(&tem);
list_points_.insert(a, &tem);
MyCustomIQGraphicsEllipseItem *i;
qint32 tmp_int = 1;
foreach (i, list_points_) {
i->SetThisName(QString::number(tmp_int));
tmp_int++;
}
emit SignalBtnSeekOut();
}
bool MyCustomQGraphicsScene::SLotGetItemSpoint(
QList<QPointF> &point, const QPointF begin) {
if (pointnums_ > 1) {
list_points_.insert(0, begin_point_);
list_points_.append(end_point_);
MyCustomIQGraphicsEllipseItem *i;
foreach (i, list_points_) {
point << i->GetThisPosition() + i->pos() - begin;
}
list_points_.removeOne(begin_point_);
list_points_.removeOne(end_point_);
return true;
}
return false;
}
// 自定义 View
MyCustomQGraphicsView::MyCustomQGraphicsView(QWidget *parent):
QGraphicsView(parent) {
}
void MyCustomQGraphicsView::wheelEvent(QWheelEvent *event) {
if (event->delta() > 0) {
this->scale(1.1, 1.1);
} else {
this->scale(0.9, 0.9);
}
}
void MyCustomQGraphicsView::mouseMoveEvent(QMouseEvent *event) {
QGraphicsView::mouseMoveEvent(event);
}