插件控件加载了,拖曳控件也实现了,接下来就是一个最难点了,跟QtDesigner或者其余开发环境同样,可以任意自由的拉伸控件大小,移动位置,为了这个功能,还特别编写了一个控件来实现这个功能,名字叫SelectWidget描点跟随窗体控件,大体的原理就是安装事件过滤器,在生成控件的时候将该控件传入描点跟随控件,自动识别鼠标的位置,按下拉动的距离来改变控件的大小,绘制描点指示器以便用户拉伸使用。 描点跟随控件可设置是否绘制描点、边距、描点颜色、描点尺寸、描点样式 正方形+圆形、选中边框宽度,支持上下左右按键移动窗体,支持delete键删除窗体,支持八个描点改变窗体大小尺寸。 体验地址:https://pan.baidu.com/s/1A5Gd77kExm8Co5ckT51vvQ 提取码:877p 文件:可执行文件.ziplinux
bool SelectWidget::eventFilter(QObject *watched, QEvent *event) { if (watched == widget) { if (event->type() == QEvent::Resize) { //设置当前窗体大小为跟随窗体的大小增长部分 this->resize(this->widget->size() + QSize(padding * 2, padding * 2)); } else if (event->type() == QEvent::Move) { //将当前窗体移到偏移位置 this->move(this->widget->pos() - QPoint(padding, padding)); } } else { if (event->type() == QEvent::KeyPress) { QKeyEvent *keyEvent = dynamic_cast<QKeyEvent *>(event); if (keyEvent->key() == Qt::Key_Left) { this->move(this->pos() - QPoint(1, 0)); } else if (keyEvent->key() == Qt::Key_Right) { this->move(this->pos() + QPoint(1, 0)); } else if (keyEvent->key() == Qt::Key_Up) { this->move(this->pos() - QPoint(0, 1)); } else if (keyEvent->key() == Qt::Key_Down) { this->move(this->pos() + QPoint(0, 1)); } else if (keyEvent->key() == Qt::Key_Delete) { emit widgetDelete(widget); widget->deleteLater(); this->deleteLater(); widget = 0; } //从新设置附带窗体的位置和大小 if (widget != 0) { widget->setGeometry(this->x() + padding, this->y() + padding, this->width() - padding * 2, this->height() - padding * 2); } return QWidget::eventFilter(watched, event); } QMouseEvent *mouseEvent = static_cast<QMouseEvent *>(event); if (mouseEvent->type() == QEvent::MouseButtonPress) { //记住当前控件坐标和宽高以及鼠标按下的坐标 rectX = this->x(); rectY = this->y(); rectW = this->width(); rectH = this->height(); lastPos = mouseEvent->pos(); //判断按下的手柄的区域位置 if (rectLeft.contains(lastPos)) { pressedLeft = true; } else if (rectRight.contains(lastPos)) { pressedRight = true; } else if (rectTop.contains(lastPos)) { pressedTop = true; } else if (rectBottom.contains(lastPos)) { pressedBottom = true; } else if (rectLeftTop.contains(lastPos)) { pressedLeftTop = true; } else if (rectRightTop.contains(lastPos)) { pressedRightTop = true; } else if (rectLeftBottom.contains(lastPos)) { pressedLeftBottom = true; } else if (rectRightBottom.contains(lastPos)) { pressedRightBottom = true; } else { pressed = true; } if (widget != 0) { emit widgetPressed(widget); } } else if (mouseEvent->type() == QEvent::MouseMove) { //根据当前鼠标位置,计算XY轴移动了多少 QPoint pos = mouseEvent->pos(); int dx = pos.x() - lastPos.x(); int dy = pos.y() - lastPos.y(); //根据按下处的位置判断是不是移动控件仍是拉伸控件 if (pressed) { this->move(this->x() + dx, this->y() + dy); } else if (pressedLeft) { int resizeW = this->width() - dx; if (this->minimumWidth() <= resizeW) { this->setGeometry(this->x() + dx, rectY, resizeW, rectH); } } else if (pressedRight) { this->setGeometry(rectX, rectY, rectW + dx, rectH); } else if (pressedTop) { int resizeH = this->height() - dy; if (this->minimumHeight() <= resizeH) { this->setGeometry(rectX, this->y() + dy, rectW, resizeH); } } else if (pressedBottom) { this->setGeometry(rectX, rectY, rectW, rectH + dy); } else if (pressedLeftTop) { int resizeW = this->width() - dx; int resizeH = this->height() - dy; if (this->minimumWidth() <= resizeW) { this->setGeometry(this->x() + dx, this->y(), resizeW, resizeH); } if (this->minimumHeight() <= resizeH) { this->setGeometry(this->x(), this->y() + dy, resizeW, resizeH); } } else if (pressedRightTop) { int resizeW = rectW + dx; int resizeH = this->height() - dy; if (this->minimumHeight() <= resizeH) { this->setGeometry(this->x(), this->y() + dy, resizeW, resizeH); } } else if (pressedLeftBottom) { int resizeW = this->width() - dx; int resizeH = rectH + dy; if (this->minimumWidth() <= resizeW) { this->setGeometry(this->x() + dx, this->y(), resizeW, resizeH); } if (this->minimumHeight() <= resizeH) { this->setGeometry(this->x(), this->y(), resizeW, resizeH); } } else if (pressedRightBottom) { int resizeW = rectW + dx; int resizeH = rectH + dy; this->setGeometry(this->x(), this->y(), resizeW, resizeH); } //从新设置附带窗体的位置和大小 if (widget != 0) { widget->setGeometry(this->x() + padding, this->y() + padding, this->width() - padding * 2, this->height() - padding * 2); } } else if (mouseEvent->type() == QEvent::MouseButtonRelease) { pressed = false; pressedLeft = false; pressedRight = false; pressedTop = false; pressedBottom = false; pressedLeftTop = false; pressedRightTop = false; pressedLeftBottom = false; pressedRightBottom = false; if (widget != 0) { emit widgetRelease(widget); } } } return QWidget::eventFilter(watched, event); } void SelectWidget::resizeEvent(QResizeEvent *) { //从新计算八个描点的区域,描点区域的做用还有就是计算鼠标坐标是否在某一个区域内 int width = this->width(); int height = this->height(); //左侧描点区域 rectLeft = QRectF(0, height / 2 - pointSize / 2, pointSize, pointSize); //上侧描点区域 rectTop = QRectF(width / 2 - pointSize / 2, 0, pointSize, pointSize); //右侧描点区域 rectRight = QRectF(width - pointSize, height / 2 - pointSize / 2, pointSize, pointSize); //下侧描点区域 rectBottom = QRectF(width / 2 - pointSize / 2, height - pointSize, pointSize, pointSize); //左上角描点区域 rectLeftTop = QRectF(0, 0, pointSize, pointSize); //右上角描点区域 rectRightTop = QRectF(width - pointSize, 0, pointSize, pointSize); //左下角描点区域 rectLeftBottom = QRectF(0, height - pointSize, pointSize, pointSize); //右下角描点区域 rectRightBottom = QRectF(width - pointSize, height - pointSize, pointSize, pointSize); } void SelectWidget::mouseMoveEvent(QMouseEvent *e) { //计算当前鼠标位置是否在某个区域内,自动更新鼠标形状 QPoint p = e->pos(); if (rectLeft.contains(p)) { this->setCursor(Qt::SizeHorCursor); } else if (rectTop.contains(p)) { this->setCursor(Qt::SizeVerCursor); } else if (rectRight.contains(p)) { this->setCursor(Qt::SizeHorCursor); } else if (rectBottom.contains(p)) { this->setCursor(Qt::SizeVerCursor); } else if (rectLeftTop.contains(p)) { this->setCursor(Qt::SizeFDiagCursor); } else if (rectRightTop.contains(p)) { this->setCursor(Qt::SizeBDiagCursor); } else if (rectLeftBottom.contains(p)) { this->setCursor(Qt::SizeBDiagCursor); } else if (rectRightBottom.contains(p)) { this->setCursor(Qt::SizeFDiagCursor); } else { this->setCursor(Qt::ArrowCursor); } }