Move drag icon relative the cursor hotspot position

Instead of placing the drag icons top-left corner at the cursors
hotspot the drag icon is moved so it will be placed correct relative
the cursor hotspot. This will makes the drag feeling more realistic.

Change-Id: I8d60ae1b7788accb9034575983417abae4c58c1a
Reviewed-by: Giulio Camuffo <giulio.camuffo@kdab.com>
Reviewed-by: Johan Helsing <johan.helsing@qt.io>

4 files changed, 12 insertions, 10 deletions

diff --git a/examples/wayland/qwindow-compositor/compositorwindow.cpp b/examples/wayland/qwindow-compositor/compositorwindow.cpp
index 002831283..7e10a1739 100644
--- a/examples/wayland/qwindow-compositor/compositorwindow.cpp
+++ b/examples/wayland/qwindow-compositor/compositorwindow.cpp
@@ -62,7 +62,6 @@ void CompositorWindow::setCompositor(WindowCompositor *comp) {
     connect(m_compositor, &WindowCompositor::startMove, this, &CompositorWindow::startMove);
     connect(m_compositor, &WindowCompositor::startResize, this, &CompositorWindow::startResize);
     connect(m_compositor, &WindowCompositor::dragStarted, this, &CompositorWindow::startDrag);
-    connect(m_compositor, &WindowCompositor::frameOffset, this, &CompositorWindow::setFrameOffset);
 }
 
 void CompositorWindow::initializeGL()
@@ -180,12 +179,6 @@ void CompositorWindow::startDrag(WindowCompositorView *dragIcon)
     m_compositor->raise(dragIcon);
 }
 
-void CompositorWindow::setFrameOffset(const QPoint &offset)
-{
-    if (m_mouseView)
-        m_mouseView->setPosition(m_mouseView->position() + offset);
-}
-
 void CompositorWindow::mousePressEvent(QMouseEvent *e)
 {
     if (mouseGrab())
@@ -247,7 +240,7 @@ void CompositorWindow::mouseMoveEvent(QMouseEvent *e)
         WindowCompositorView *view = viewAt(e->localPos());
         m_compositor->handleDrag(view, e);
         if (m_dragIconView) {
-            m_dragIconView->setPosition(e->localPos());
+            m_dragIconView->setPosition(e->localPos() + m_dragIconView->offset());
             update();
         }
     }
diff --git a/examples/wayland/qwindow-compositor/compositorwindow.h b/examples/wayland/qwindow-compositor/compositorwindow.h
index c7c637e53..8b5180a00 100644
--- a/examples/wayland/qwindow-compositor/compositorwindow.h
+++ b/examples/wayland/qwindow-compositor/compositorwindow.h
@@ -73,7 +73,6 @@ private slots:
     void startMove();
     void startResize(int edge, bool anchored);
     void startDrag(WindowCompositorView *dragIcon);
-    void setFrameOffset(const QPoint &offset);
 
 private:
     enum GrabState { NoGrab, MoveGrab, ResizeGrab, DragGrab };
diff --git a/examples/wayland/qwindow-compositor/windowcompositor.cpp b/examples/wayland/qwindow-compositor/windowcompositor.cpp
index e91778725..bd39908e5 100644
--- a/examples/wayland/qwindow-compositor/windowcompositor.cpp
+++ b/examples/wayland/qwindow-compositor/windowcompositor.cpp
@@ -108,6 +108,12 @@ void WindowCompositorView::onXdgSetFullscreen(QWaylandOutput* clientPreferredOut
     setPosition(outputToFullscreen->position());
 }
 
+void WindowCompositorView::onOffsetForNextFrame(const QPoint &offset)
+{
+    m_offset = offset;
+    setPosition(position() + offset);
+}
+
 void WindowCompositorView::onXdgUnsetFullscreen()
 {
     onXdgUnsetMaximized();
@@ -145,7 +151,6 @@ void WindowCompositor::onSurfaceCreated(QWaylandSurface *surface)
     connect(surface, &QWaylandSurface::surfaceDestroyed, this, &WindowCompositor::surfaceDestroyed);
     connect(surface, &QWaylandSurface::mappedChanged, this, &WindowCompositor::surfaceMappedChanged);
     connect(surface, &QWaylandSurface::redraw, this, &WindowCompositor::triggerRender);
-    connect(surface, &QWaylandSurface::offsetForNextFrame, this, &WindowCompositor::frameOffset);
 
     connect(surface, &QWaylandSurface::subsurfacePositionChanged, this, &WindowCompositor::onSubsurfacePositionChanged);
 
@@ -154,6 +159,7 @@ void WindowCompositor::onSurfaceCreated(QWaylandSurface *surface)
     view->setOutput(outputFor(m_window));
     m_views << view;
     connect(view, &QWaylandView::surfaceDestroyed, this, &WindowCompositor::viewSurfaceDestroyed);
+    connect(surface, &QWaylandSurface::offsetForNextFrame, view, &WindowCompositorView::onOffsetForNextFrame);
 }
 
 void WindowCompositor::surfaceMappedChanged()
@@ -412,6 +418,7 @@ void WindowCompositor::startDrag()
     QWaylandDrag *currentDrag = defaultInputDevice()->drag();
     Q_ASSERT(currentDrag);
     WindowCompositorView *iconView = findView(currentDrag->icon());
+    iconView->setPosition(m_window->mapFromGlobal(QCursor::pos()));
 
     emit dragStarted(iconView);
 }
diff --git a/examples/wayland/qwindow-compositor/windowcompositor.h b/examples/wayland/qwindow-compositor/windowcompositor.h
index 96af01f82..5290d7c85 100644
--- a/examples/wayland/qwindow-compositor/windowcompositor.h
+++ b/examples/wayland/qwindow-compositor/windowcompositor.h
@@ -68,6 +68,7 @@ public:
     WindowCompositorView *parentView() const { return m_parentView; }
     QPointF parentPosition() const { return m_parentView ? (m_parentView->position() + m_parentView->parentPosition()) : QPointF(); }
     QSize windowSize() { return m_xdgSurface ? m_xdgSurface->windowGeometry().size() : surface()->size(); }
+    QPoint offset() const { return m_offset; }
 
 private:
     friend class WindowCompositor;
@@ -77,12 +78,14 @@ private:
     QWaylandXdgSurface *m_xdgSurface;
     QWaylandXdgPopup *m_xdgPopup;
     WindowCompositorView *m_parentView;
+    QPoint m_offset;
 
 public slots:
     void onXdgSetMaximized();
     void onXdgUnsetMaximized();
     void onXdgSetFullscreen(QWaylandOutput *output);
     void onXdgUnsetFullscreen();
+    void onOffsetForNextFrame(const QPoint &offset);
 };
 
 class WindowCompositor : public QWaylandCompositor