diff options
Diffstat (limited to 'examples/corelib')
4 files changed, 59 insertions, 15 deletions
diff --git a/examples/corelib/threads/doc/src/mandelbrot.qdoc b/examples/corelib/threads/doc/src/mandelbrot.qdoc index aaa6356a2c..b8a5930d8c 100644 --- a/examples/corelib/threads/doc/src/mandelbrot.qdoc +++ b/examples/corelib/threads/doc/src/mandelbrot.qdoc @@ -303,6 +303,11 @@ \snippet threads/mandelbrot/mandelbrotwidget.cpp 13 + Pinch to zoom has been implemented with QGesture as outlined in + \l{Gestures in Widgets and Graphics View}. + + \snippet threads/mandelbrot/mandelbrotwidget.cpp gesture1 + When the user presses the left mouse button, we store the mouse pointer position in \c lastDragPos. diff --git a/examples/corelib/threads/mandelbrot/main.cpp b/examples/corelib/threads/mandelbrot/main.cpp index d73adb0193..d0d4680978 100644 --- a/examples/corelib/threads/mandelbrot/main.cpp +++ b/examples/corelib/threads/mandelbrot/main.cpp @@ -37,11 +37,7 @@ int main(int argc, char *argv[]) } MandelbrotWidget widget; - const auto geometry = widget.screen()->availableGeometry(); - widget.resize((2 * geometry.size()) / 3); - const auto pos = (geometry.size() - widget.size()) / 2; - widget.move(geometry.topLeft() + QPoint(pos.width(), pos.height())); - + widget.grabGesture(Qt::PinchGesture); widget.show(); return app.exec(); } diff --git a/examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp b/examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp index 9ab8936c85..e0f33a2b0b 100644 --- a/examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp +++ b/examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp @@ -3,8 +3,9 @@ #include "mandelbrotwidget.h" -#include <QPainter> +#include <QGesture> #include <QKeyEvent> +#include <QPainter> #include <math.h> @@ -26,8 +27,7 @@ MandelbrotWidget::MandelbrotWidget(QWidget *parent) : pixmapScale(DefaultScale), curScale(DefaultScale) { - help = tr("Use mouse wheel or the '+' and '-' keys to zoom. " - "Press and hold left mouse button to scroll."); + help = tr("Zoom with mouse wheel, +/- keys or pinch. Scroll with arrow keys or by dragging."); connect(&thread, &RenderThread::renderedImage, this, &MandelbrotWidget::updatePixmap); @@ -46,7 +46,7 @@ void MandelbrotWidget::paintEvent(QPaintEvent * /* event */) if (pixmap.isNull()) { painter.setPen(Qt::white); - painter.drawText(rect(), Qt::AlignCenter, tr("Rendering initial image, please wait...")); + painter.drawText(rect(), Qt::AlignCenter|Qt::TextWordWrap, tr("Rendering initial image, please wait...")); //! [2] //! [3] return; //! [3] //! [4] @@ -80,17 +80,31 @@ void MandelbrotWidget::paintEvent(QPaintEvent * /* event */) } //! [8] //! [9] - QString text = help; - if (!info.isEmpty()) - text += ' ' + info; QFontMetrics metrics = painter.fontMetrics(); - int textWidth = metrics.horizontalAdvance(text); + if (!info.isEmpty()){ + int infoWidth = metrics.horizontalAdvance(info); + int infoHeight = metrics.height(); + + painter.setPen(Qt::NoPen); + painter.setBrush(QColor(0, 0, 0, 127)); + infoHeight = (infoWidth/width()+1) * (infoHeight + 5); + painter.drawRect((width() - infoWidth) / 2 - 5, 0, infoWidth + 10, infoHeight); + + painter.setPen(Qt::white); + painter.drawText(rect(), Qt::AlignHCenter|Qt::AlignTop|Qt::TextWordWrap, info); + } + + int helpWidth = metrics.horizontalAdvance(help); + int helpHeight = metrics.height(); painter.setPen(Qt::NoPen); painter.setBrush(QColor(0, 0, 0, 127)); - painter.drawRect((width() - textWidth) / 2 - 5, 0, textWidth + 10, metrics.lineSpacing() + 5); + helpHeight = (helpWidth/width()+1) * (helpHeight + 5); + painter.drawRect((width() - helpWidth) / 2 - 5, height()-helpHeight, helpWidth + 10, helpHeight); + painter.setPen(Qt::white); - painter.drawText((width() - textWidth) / 2, metrics.leading() + metrics.ascent(), text); + painter.drawText(rect(), Qt::AlignHCenter|Qt::AlignBottom|Qt::TextWordWrap, help); + } //! [9] @@ -211,3 +225,24 @@ void MandelbrotWidget::scroll(int deltaX, int deltaY) thread.render(centerX, centerY, curScale, size(), devicePixelRatio()); } //! [18] + +//! [gesture1] +#ifndef QT_NO_GESTURES +bool MandelbrotWidget::gestureEvent(QGestureEvent *event) +{ + if (auto *pinch = static_cast<QPinchGesture *>(event->gesture(Qt::PinchGesture))) { + if (pinch->changeFlags().testFlag(QPinchGesture::ScaleFactorChanged)) + zoom(1.0 / pinch->scaleFactor()); + return true; + } + return false; +} + +bool MandelbrotWidget::event(QEvent *event) +{ + if (event->type() == QEvent::Gesture) + return gestureEvent(static_cast<QGestureEvent*>(event)); + return QWidget::event(event); +} +#endif +//! [gesture1] diff --git a/examples/corelib/threads/mandelbrot/mandelbrotwidget.h b/examples/corelib/threads/mandelbrot/mandelbrotwidget.h index 68c4a6f4f7..23c3a2bf40 100644 --- a/examples/corelib/threads/mandelbrot/mandelbrotwidget.h +++ b/examples/corelib/threads/mandelbrot/mandelbrotwidget.h @@ -4,6 +4,7 @@ #ifndef MANDELBROTWIDGET_H #define MANDELBROTWIDGET_H +#include <QGestureEvent> #include <QPixmap> #include <QWidget> #include "renderthread.h" @@ -18,6 +19,7 @@ public: MandelbrotWidget(QWidget *parent = nullptr); protected: + QSize sizeHint() const override { return {1024, 768}; }; void paintEvent(QPaintEvent *event) override; void resizeEvent(QResizeEvent *event) override; void keyPressEvent(QKeyEvent *event) override; @@ -27,6 +29,9 @@ protected: void mousePressEvent(QMouseEvent *event) override; void mouseMoveEvent(QMouseEvent *event) override; void mouseReleaseEvent(QMouseEvent *event) override; +#ifndef QT_NO_GESTURES + bool event(QEvent *event) override; +#endif private slots: void updatePixmap(const QImage &image, double scaleFactor); @@ -34,6 +39,9 @@ private slots: private: void scroll(int deltaX, int deltaY); +#ifndef QT_NO_GESTURES + bool gestureEvent(QGestureEvent *event); +#endif RenderThread thread; QPixmap pixmap; |