Support resize for plasmaquick dialog.

src/plasmaquick/dialog.cpp

@@ -71,6 +71,7 @@ public:
         , hideOnWindowDeactivate(false)
         , outputOnly(false)
         , visible(false)
+        , resizable(false)
         , componentComplete(dialog->parent() == nullptr)
         , backgroundHints(Dialog::StandardBackground)
     {
@@ -134,6 +135,13 @@ public:
 
     void applyType();
 
+    void updateMouseCursor(QMouseEvent *event);
+    Qt::Edges hitTest(const QPointF &pos);
+    bool hitTestLeft(const QPointF &pos);
+    bool hitTestRight(const QPointF &pos);
+    bool hitTestTop(const QPointF &pos);
+    bool hitTestBottom(const QPointF &pos);
+
     Dialog *q;
     Plasma::Types::Location location;
     Plasma::FrameSvgItem *frameSvgItem;
@@ -149,12 +157,17 @@ public:
     bool hideOnWindowDeactivate;
     bool outputOnly;
     bool visible;
+    bool resizable;
     Plasma::Theme theme;
     bool componentComplete;
     Dialog::BackgroundHints backgroundHints;
 
     // Attached Layout property of mainItem, if any
     QPointer<QObject> mainItemLayout;
+
+    // The size of the border (used to determine where the user
+    // is allowed to resize).
+    const int BORDER_SIZE = 10;
 };
 
 QRect DialogPrivate::availableScreenGeometryForPosition(const QPoint &pos) const
@@ -825,6 +838,75 @@ void DialogPrivate::applyType()
 #endif
 }
 
+void DialogPrivate::updateMouseCursor(QMouseEvent *event)
+{
+    if (!event)
+        return;
+    QPointF globalMousePos = event->globalPos();
+    Qt::Edges sides = hitTest(globalMousePos);
+    if (sides == Qt::Edges(Qt::LeftEdge | Qt::TopEdge))
+        q->setCursor(Qt::SizeFDiagCursor);
+    else if (sides == Qt::Edges(Qt::RightEdge | Qt::TopEdge))
+        q->setCursor(Qt::SizeBDiagCursor);
+    else if (sides == Qt::Edges(Qt::LeftEdge | Qt::BottomEdge))
+        q->setCursor(Qt::SizeBDiagCursor);
+    else if (sides == Qt::Edges(Qt::RightEdge | Qt::BottomEdge))
+        q->setCursor(Qt::SizeFDiagCursor);
+    else if (sides.testFlag(Qt::TopEdge))
+        q->setCursor(Qt::SizeVerCursor);
+    else if (sides.testFlag(Qt::LeftEdge))
+        q->setCursor(Qt::SizeHorCursor);
+    else if (sides.testFlag(Qt::RightEdge))
+        q->setCursor(Qt::SizeHorCursor);
+    else if (sides.testFlag(Qt::BottomEdge))
+        q->setCursor(Qt::SizeVerCursor);
+    else
+        q->setCursor(Qt::ArrowCursor);
+}
+
+Qt::Edges DialogPrivate::hitTest(const QPointF &pos)
+{
+    bool left = hitTestLeft(pos);
+    bool right = hitTestRight(pos);
+    bool top = hitTestTop(pos);
+    bool bottom = hitTestBottom(pos);
+    Qt::Edges edges;
+    if (left)
+        edges.setFlag(Qt::LeftEdge);
+    if (right)
+        edges.setFlag(Qt::RightEdge);
+    if (bottom)
+        edges.setFlag(Qt::BottomEdge);
+    if (top)
+        edges.setFlag(Qt::TopEdge);
+
+    return edges;
+}
+
+bool DialogPrivate::hitTestLeft(const QPointF &pos) {
+    const QRect geometry = q->geometry();
+    const QRectF rect(geometry.x(), geometry.y(), BORDER_SIZE, geometry.height());
+    return rect.contains(pos);
+}
+
+bool DialogPrivate::hitTestRight(const QPointF &pos) {
+    const QRect geometry = q->geometry();
+    const QRectF rect(geometry.x() + geometry.width() - BORDER_SIZE, geometry.y(), BORDER_SIZE, geometry.height());
+    return rect.contains(pos);
+}
+
+bool DialogPrivate::hitTestTop(const QPointF &pos) {
+    const QRect geometry = q->geometry();
+    const QRectF rect(geometry.x(), geometry.y(), geometry.width(), BORDER_SIZE);
+    return rect.contains(pos);
+}
+
+bool DialogPrivate::hitTestBottom(const QPointF &pos) {
+    const QRect geometry = q->geometry();
+    const QRectF rect(geometry.x(), geometry.y() + geometry.height() - BORDER_SIZE, geometry.width(), BORDER_SIZE);
+    return rect.contains(pos);
+}
+
 Dialog::Dialog(QQuickItem *parent)
     : QQuickWindow(parent ? parent->window() : nullptr)
     , d(new DialogPrivate(this))
@@ -1233,6 +1315,20 @@ void Dialog::showEvent(QShowEvent *event)
     QQuickWindow::showEvent(event);
 }
 
+void Dialog::mousePressEvent(QMouseEvent *event)
+{
+    if (!d->resizable)
+        return QQuickWindow::mousePressEvent(event);
+
+    QPointF globalMousePos = event->globalPos();
+    Qt::Edges sides = d->hitTest(globalMousePos);
+    if (sides) {
+        startSystemResize(sides);
+        return;
+    }
+    return QQuickWindow::mousePressEvent(event);
+}
+
 bool Dialog::event(QEvent *event)
 {
     if (event->type() == QEvent::Expose) {
@@ -1294,6 +1390,8 @@ bool Dialog::event(QEvent *event)
         case QEvent::MouseButtonPress:
         case QEvent::MouseButtonRelease: {
             QMouseEvent *me = static_cast<QMouseEvent *>(event);
+            if (d->resizable && event->type() == QEvent::MouseMove)
+                d->updateMouseCursor(me);
 
             // don't mess with position if the cursor is actually outside the view:
             // somebody is doing a click and drag that must not break when the cursor i outside
@@ -1470,6 +1568,19 @@ bool Dialog::isVisible() const
     return d->visible;
 }
 
+void Dialog::setResizable(bool resizable)
+{
+    if (d->resizable == resizable)
+        return;
+    d->resizable = resizable;
+    Q_EMIT resizableChanged();
+}
+
+bool Dialog::isResizable() const
+{
+    return d->resizable;
+}
+
 Dialog::BackgroundHints Dialog::backgroundHints() const
 {
     return d->backgroundHints;

src/plasmaquick/dialog.h

@@ -141,6 +141,12 @@ class PLASMAQUICK_EXPORT Dialog : public QQuickWindow, public QQmlParserStatus
 
     Q_PROPERTY(bool visible READ isVisible WRITE setVisible NOTIFY visibleChangedProxy)
 
+    /**
+     * This property allows to make the dialog resizable by the user.
+     * Default: false.
+     */
+    Q_PROPERTY(bool resizable READ isResizable WRITE setResizable NOTIFY resizableChanged)
+
     Q_CLASSINFO("DefaultProperty", "mainItem")
 
 public:
@@ -196,6 +202,9 @@ public:
     bool isVisible() const;
     void setVisible(bool visible);
 
+    bool isResizable() const;
+    void setResizable(bool resizable);
+
     /**
      * @returns The suggested screen position for the popup
      * @param item the item the popup has to be positioned relatively to. if null, the popup will be positioned in the center of the window
@@ -213,6 +222,7 @@ Q_SIGNALS:
     void flagsChanged();
     void backgroundHintsChanged();
     void visibleChangedProxy(); // redeclaration of QQuickWindow::visibleChanged
+    void resizableChanged();
     /**
      * Emitted when the @see hideOnWindowDeactivate property is @c true and this dialog lost focus to a
      * window that is neither a parent dialog to nor a child dialog of this dialog.
@@ -224,6 +234,7 @@ protected:
      * set the dialog position. subclasses may change it. ToolTipDialog adjusts the position in an animated way
      */
     virtual void adjustGeometry(const QRect &geom);
+    virtual void mousePressEvent(QMouseEvent *event) override;
 
     // Reimplementations
     void classBegin() override;