Add CursorSource size getter

CursorSource::size() provides a way to get the size of the attached
cursor source without actually looking into its contents.

src/cursor.cpp

@@ -175,10 +175,7 @@ bool Cursor::isOnOutput(Output *output) const
     if (Cursors::self()->isCursorHidden()) {
         return false;
     }
-    if (!geometry().intersects(output->geometry())) {
-        return false;
-    }
-    return !image().isNull();
+    return geometry().intersects(output->geometry());
 }
 
 QImage Cursor::image() const
@@ -204,7 +201,11 @@ QRect Cursor::geometry() const
 
 QRect Cursor::rect() const
 {
-    return QRect(QPoint(0, 0), image().size() / image().devicePixelRatio());
+    if (Q_UNLIKELY(!m_source)) {
+        return QRect();
+    } else {
+        return QRect(QPoint(0, 0), m_source->size());
+    }
 }
 
 QPoint Cursor::pos()

src/cursorsource.cpp

@@ -22,6 +22,11 @@ QImage CursorSource::image() const
     return m_image;
 }
 
+QSize CursorSource::size() const
+{
+    return m_size;
+}
+
 QPoint CursorSource::hotspot() const
 {
     return m_hotspot;
@@ -35,6 +40,7 @@ ImageCursorSource::ImageCursorSource(QObject *parent)
 void ImageCursorSource::update(const QImage &image, const QPoint &hotspot)
 {
     m_image = image;
+    m_size = image.size() / image.devicePixelRatio();
     m_hotspot = hotspot;
     Q_EMIT changed();
 }
@@ -111,6 +117,7 @@ void ShapeCursorSource::selectSprite(int index)
     const KXcursorSprite &sprite = m_sprites[index];
     m_currentSprite = index;
     m_image = sprite.data();
+    m_size = m_image.size() / m_image.devicePixelRatio();
     m_hotspot = sprite.hotspot();
     if (sprite.delay().count() && m_sprites.size() > 1) {
         m_delayTimer.start(sprite.delay());
@@ -132,6 +139,7 @@ void SurfaceCursorSource::update(KWaylandServer::SurfaceInterface *surface, cons
 {
     if (!surface) {
         m_image = QImage();
+        m_size = QSize(0, 0);
         m_hotspot = QPoint();
         m_surface = nullptr;
     } else {
@@ -142,6 +150,7 @@ void SurfaceCursorSource::update(KWaylandServer::SurfaceInterface *surface, cons
         } else {
             m_image = QImage();
         }
+        m_size = surface->size().toSize();
         m_hotspot = hotspot;
         m_surface = surface;
     }

src/cursorsource.h

@@ -33,6 +33,7 @@ public:
     explicit CursorSource(QObject *parent = nullptr);
 
     QImage image() const;
+    QSize size() const;
     QPoint hotspot() const;
 
 Q_SIGNALS:
@@ -40,6 +41,7 @@ Q_SIGNALS:
 
 protected:
     QImage m_image;
+    QSize m_size = QSize(0, 0);
     QPoint m_hotspot;
 };