Implement show on screen edge for Wayland

Summary:
This change ports ScreenEdges to operate on AbstractClient instead of
Client. For this AbstractClient gained a new pure virtual method
showOnScreenEdge which is also implemented in ShellClient.

In ShellClient the functionality is bound for the case windows can
cover a panel. If triggered the panel gets raised again.

The auto hiding panel, though, is not yet implemented. For that the
protocol needs to be adjusted to give a hint to the compositor when to
hide and hint back to the panel when it was shown. This needs a change
in KWayland and thus is not 5.8 material.

Test Plan: See added test case

Reviewers: #kwin, #plasma_on_wayland

Subscribers: plasma-devel, kwin

Tags: #plasma_on_wayland, #kwin

Differential Revision: https://phabricator.kde.org/D2793

abstract_client.h

@@ -580,6 +580,13 @@ public:
 
     QRect inputGeometry() const override;
 
+    /**
+     * Restores the AbstractClient after it had been hidden due to show on screen edge functionality.
+     * The AbstractClient also gets raised (e.g. Panel mode windows can cover) and the AbstractClient
+     * gets informed in a window specific way that it is shown and raised again.
+     **/
+    virtual void showOnScreenEdge() = 0;
+
     // TODO: remove boolean trap
     static bool belongToSameApplication(const AbstractClient* c1, const AbstractClient* c2, bool active_hack = false);
 

autotests/integration/plasma_surface_test.cpp

@@ -19,6 +19,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************/
 #include "kwin_wayland_test.h"
 #include "platform.h"
+#include "cursor.h"
 #include "shell_client.h"
 #include "screens.h"
 #include "wayland_server.h"
@@ -53,6 +54,8 @@ private Q_SLOTS:
     void testAcceptsFocus();
 
     void testDesktopIsOpaque();
+    void testPanelWindowsCanCover_data();
+    void testPanelWindowsCanCover();
     void testOSDPlacement();
     void testPanelTypeHasStrut_data();
     void testPanelTypeHasStrut();
@@ -81,6 +84,8 @@ void PlasmaSurfaceTest::init()
     m_compositor = Test::waylandCompositor();
     m_shell = Test::waylandShell();
     m_plasmaShell = Test::waylandPlasmaShell();
+
+    KWin::Cursor::setPos(640, 512);
 }
 
 void PlasmaSurfaceTest::cleanup()
@@ -283,5 +288,85 @@ void PlasmaSurfaceTest::testPanelTypeHasStrut()
     QTEST(c->layer(), "expectedLayer");
 }
 
+void PlasmaSurfaceTest::testPanelWindowsCanCover_data()
+{
+    QTest::addColumn<QRect>("panelGeometry");
+    QTest::addColumn<QRect>("windowGeometry");
+    QTest::addColumn<QPoint>("triggerPoint");
+
+    QTest::newRow("top-full-edge") << QRect(0, 0, 1280, 30) << QRect(0, 0, 200, 300) << QPoint(100, 0);
+    QTest::newRow("top-left-edge") << QRect(0, 0, 1000, 30) << QRect(0, 0, 200, 300) << QPoint(100, 0);
+    QTest::newRow("top-right-edge") << QRect(280, 0, 1000, 30) << QRect(1000, 0, 200, 300) << QPoint(1000, 0);
+    QTest::newRow("bottom-full-edge") << QRect(0, 994, 1280, 30) << QRect(0, 724, 200, 300) << QPoint(100, 1023);
+    QTest::newRow("bottom-left-edge") << QRect(0, 994, 1000, 30) << QRect(0, 724, 200, 300) << QPoint(100, 1023);
+    QTest::newRow("bottom-right-edge") << QRect(280, 994, 1000, 30) << QRect(1000, 724, 200, 300) << QPoint(1000, 1023);
+    QTest::newRow("left-full-edge") << QRect(0, 0, 30, 1024) << QRect(0, 0, 200, 300) << QPoint(0, 100);
+    QTest::newRow("left-top-edge") << QRect(0, 0, 30, 800) << QRect(0, 0, 200, 300) << QPoint(0, 100);
+    QTest::newRow("left-bottom-edge") << QRect(0, 200, 30, 824) << QRect(0, 0, 200, 300) << QPoint(0, 250);
+    QTest::newRow("right-full-edge") << QRect(1250, 0, 30, 1024) << QRect(1080, 0, 200, 300) << QPoint(1279, 100);
+    QTest::newRow("right-top-edge") << QRect(1250, 0, 30, 800) << QRect(1080, 0, 200, 300) << QPoint(1279, 100);
+    QTest::newRow("right-bottom-edge") << QRect(1250, 200, 30, 824) << QRect(1080, 0, 200, 300) << QPoint(1279, 250);
+}
+
+void PlasmaSurfaceTest::testPanelWindowsCanCover()
+{
+    // this test verifies the behavior of a panel with windows can cover
+    // triggering the screen edge should raise the panel.
+    QScopedPointer<Surface> surface(Test::createSurface());
+    QVERIFY(!surface.isNull());
+    QScopedPointer<QObject> shellSurface(Test::createShellSurface(Test::ShellSurfaceType::WlShell, surface.data()));
+    QVERIFY(!shellSurface.isNull());
+    QScopedPointer<PlasmaShellSurface> plasmaSurface(m_plasmaShell->createSurface(surface.data()));
+    QVERIFY(!plasmaSurface.isNull());
+    plasmaSurface->setRole(PlasmaShellSurface::Role::Panel);
+    QFETCH(QRect, panelGeometry);
+    plasmaSurface->setPosition(panelGeometry.topLeft());
+    plasmaSurface->setPanelBehavior(PlasmaShellSurface::PanelBehavior::WindowsCanCover);
+
+
+    // now render and map the window
+    auto panel = Test::renderAndWaitForShown(surface.data(), panelGeometry.size(), Qt::blue);
+
+    QVERIFY(panel);
+    QCOMPARE(panel->windowType(), NET::Dock);
+    QVERIFY(panel->isDock());
+    QCOMPARE(panel->geometry(), panelGeometry);
+    QCOMPARE(panel->hasStrut(), false);
+    QCOMPARE(workspace()->clientArea(MaximizeArea, 0, 0), QRect(0, 0, 1280, 1024));
+    QCOMPARE(panel->layer(), KWin::NormalLayer);
+
+    // create a Window
+    QScopedPointer<Surface> surface2(Test::createSurface());
+    QVERIFY(!surface2.isNull());
+    QScopedPointer<QObject> shellSurface2(Test::createShellSurface(Test::ShellSurfaceType::WlShell, surface2.data()));
+    QVERIFY(!shellSurface2.isNull());
+
+    QFETCH(QRect, windowGeometry);
+    auto c = Test::renderAndWaitForShown(surface2.data(), windowGeometry.size(), Qt::red);
+
+    QVERIFY(c);
+    QCOMPARE(c->windowType(), NET::Normal);
+    QVERIFY(c->isActive());
+    QCOMPARE(c->layer(), KWin::NormalLayer);
+    c->move(windowGeometry.topLeft());
+    QCOMPARE(c->geometry(), windowGeometry);
+
+    auto stackingOrder = workspace()->stackingOrder();
+    QCOMPARE(stackingOrder.count(), 2);
+    QCOMPARE(stackingOrder.first(), panel);
+    QCOMPARE(stackingOrder.last(), c);
+
+    QSignalSpy stackingOrderChangedSpy(workspace(), &Workspace::stackingOrderChanged);
+    QVERIFY(stackingOrderChangedSpy.isValid());
+    // trigger screenedge
+    QFETCH(QPoint, triggerPoint);
+    KWin::Cursor::setPos(triggerPoint);
+    QCOMPARE(stackingOrderChangedSpy.count(), 1);
+    stackingOrder = workspace()->stackingOrder();
+    QCOMPARE(stackingOrder.count(), 2);
+    QCOMPARE(stackingOrder.first(), c);
+    QCOMPARE(stackingOrder.last(), panel);
+}
+
 WAYLANDTEST_MAIN(PlasmaSurfaceTest)
 #include "plasma_surface_test.moc"

autotests/mock_abstract_client.h

@@ -47,6 +47,7 @@ public:
     void setHiddenInternal(bool set);
     void setGeometry(const QRect &rect);
     void setKeepBelow(bool);
+    virtual void showOnScreenEdge() = 0;
 
 Q_SIGNALS:
     void geometryChanged();

autotests/mock_client.h

@@ -36,7 +36,7 @@ public:
     virtual ~Client();
 
     bool isResize() const;
-    void showOnScreenEdge();
+    void showOnScreenEdge() override;
 
 };
 

client.h

@@ -329,7 +329,7 @@ public:
      * Restores the Client after it had been hidden due to show on screen edge functionality.
      * In addition the property gets deleted so that the Client knows that it is visible again.
      **/
-    void showOnScreenEdge();
+    void showOnScreenEdge() override;
 
     static void cleanupX11();
 

screenedge.cpp

@@ -555,13 +555,7 @@ ScreenEdges::ScreenEdges(QObject *parent)
     QWidget w;
     m_cornerOffset = (w.physicalDpiX() + w.physicalDpiY() + 5) / 6;
 
-    connect(workspace(), &Workspace::clientRemoved, this, [this](KWin::AbstractClient *c) {
+    connect(workspace(), &Workspace::clientRemoved, this, &ScreenEdges::deleteEdgeForClient);
-        Client *client = qobject_cast<Client*>(c);
-        if (!client) {
-            return;
-        }
-        deleteEdgeForClient(client);
-    });
 }
 
 ScreenEdges::~ScreenEdges()
@@ -985,7 +979,7 @@ void ScreenEdges::unreserve(ElectricBorder border, QObject *object)
     }
 }
 
-void ScreenEdges::reserve(Client *client, ElectricBorder border)
+void ScreenEdges::reserve(AbstractClient *client, ElectricBorder border)
 {
     bool hadBorder = false;
     auto it = m_edges.begin();
@@ -1014,7 +1008,7 @@ void ScreenEdges::reserve(Client *client, ElectricBorder border)
     }
 }
 
-void ScreenEdges::createEdgeForClient(Client *client, ElectricBorder border)
+void ScreenEdges::createEdgeForClient(AbstractClient *client, ElectricBorder border)
 {
     int y = 0;
     int x = 0;
@@ -1087,7 +1081,7 @@ void ScreenEdges::createEdgeForClient(Client *client, ElectricBorder border)
     }
 }
 
-void ScreenEdges::deleteEdgeForClient(Client* c)
+void ScreenEdges::deleteEdgeForClient(AbstractClient* c)
 {
     auto it = m_edges.begin();
     while (it != m_edges.end()) {

screenedge.h

@@ -43,7 +43,7 @@ class QMouseEvent;
 
 namespace KWin {
 
-class Client;
+class AbstractClient;
 class ScreenEdges;
 
 class KWIN_EXPORT Edge : public QObject
@@ -70,8 +70,8 @@ public:
     void startApproaching();
     void stopApproaching();
     bool isApproaching() const;
-    void setClient(Client *client);
+    void setClient(AbstractClient *client);
-    Client *client() const;
+    AbstractClient *client() const;
     const QRect &geometry() const;
 
     /**
@@ -129,7 +129,7 @@ private:
     int m_lastApproachingFactor;
     bool m_blocked;
     bool m_pushBackBlocked;
-    Client *m_client;
+    AbstractClient *m_client;
 };
 
 /**
@@ -257,7 +257,7 @@ public:
      * @param client The Client for which an Edge should be reserved
      * @param border The border which the client wants to use, only proper borders are supported (no corners)
      **/
-    void reserve(KWin::Client *client, ElectricBorder border);
+    void reserve(KWin::AbstractClient *client, ElectricBorder border);
     /**
      * Reserve desktop switching for screen edges, if @p isToReserve is @c true. Unreserve otherwise.
      * @param reserve indicated weather desktop switching should be reserved or unreseved
@@ -339,8 +339,8 @@ private:
     ElectricBorderAction actionForEdge(Edge *edge) const;
     bool handleEnterNotifiy(xcb_window_t window, const QPoint &point, const QDateTime &timestamp);
     bool handleDndNotify(xcb_window_t window, const QPoint &point);
-    void createEdgeForClient(Client *client, ElectricBorder border);
+    void createEdgeForClient(AbstractClient *client, ElectricBorder border);
-    void deleteEdgeForClient(Client *client);
+    void deleteEdgeForClient(AbstractClient *client);
     bool m_desktopSwitching;
     bool m_desktopSwitchingMovingClients;
     QSize m_cursorPushBackDistance;
@@ -452,12 +452,12 @@ inline bool Edge::isBlocked() const
     return m_blocked;
 }
 
-inline void Edge::setClient(Client *client)
+inline void Edge::setClient(AbstractClient *client)
 {
     m_client = client;
 }
 
-inline Client *Edge::client() const
+inline AbstractClient *Edge::client() const
 {
     return m_client;
 }

shell_client.cpp

@@ -22,6 +22,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "cursor.h"
 #include "deleted.h"
 #include "placement.h"
+#include "screenedge.h"
 #include "screens.h"
 #include "wayland_server.h"
 #include "workspace.h"
@@ -407,6 +408,7 @@ void ShellClient::markAsMapped()
     if (shouldExposeToWindowManagement()) {
         setupWindowManagementInterface();
     }
+    updateShowOnScreenEdge();
 }
 
 void ShellClient::createDecoration(const QRect &oldGeom)
@@ -1018,12 +1020,15 @@ void ShellClient::installPlasmaShellSurface(PlasmaShellSurfaceInterface *surface
     connect(surface, &PlasmaShellSurfaceInterface::positionChanged, this, updatePosition);
     connect(surface, &PlasmaShellSurfaceInterface::roleChanged, this, updateRole);
     connect(surface, &PlasmaShellSurfaceInterface::panelBehaviorChanged, this,
-        [] {
+        [this] {
+            updateShowOnScreenEdge();
             workspace()->updateClientArea();
         }
     );
     updatePosition();
     updateRole();
+    updateShowOnScreenEdge();
+    connect(this, &ShellClient::geometryChanged, this, &ShellClient::updateShowOnScreenEdge);
 
     setSkipTaskbar(surface->skipTaskbar());
     connect(surface, &PlasmaShellSurfaceInterface::skipTaskbarChanged, this, [this] {
@@ -1031,6 +1036,79 @@ void ShellClient::installPlasmaShellSurface(PlasmaShellSurfaceInterface *surface
     });
 }
 
+void ShellClient::updateShowOnScreenEdge()
+{
+    if (!ScreenEdges::self()) {
+        return;
+    }
+    if (m_unmapped || !m_plasmaShellSurface || m_plasmaShellSurface->role() != PlasmaShellSurfaceInterface::Role::Panel) {
+        ScreenEdges::self()->reserve(this, ElectricNone);
+        return;
+    }
+    if (m_plasmaShellSurface->panelBehavior() == PlasmaShellSurfaceInterface::PanelBehavior::AutoHide ||
+        m_plasmaShellSurface->panelBehavior() == PlasmaShellSurfaceInterface::PanelBehavior::WindowsCanCover) {
+        // screen edge API requires an edge, thus we need to figure out which edge the window borders
+        Qt::Edges edges;
+        for (int i = 0; i < screens()->count(); i++) {
+            const auto &screenGeo = screens()->geometry(i);
+            if (screenGeo.x() == geom.x()) {
+                edges |= Qt::LeftEdge;
+            }
+            if (screenGeo.x() + screenGeo.width() == geom.x() + geom.width()) {
+                edges |= Qt::RightEdge;
+            }
+            if (screenGeo.y() == geom.y()) {
+                edges |= Qt::TopEdge;
+            }
+            if (screenGeo.y() + screenGeo.height() == geom.y() + geom.height()) {
+                edges |= Qt::BottomEdge;
+            }
+        }
+        // a panel might border multiple screen edges. E.g. a horizontal panel at the bottom will
+        // also border the left and right edge
+        // let's remove such cases
+        if (edges.testFlag(Qt::LeftEdge) && edges.testFlag(Qt::RightEdge)) {
+            edges = edges & (~(Qt::LeftEdge | Qt::RightEdge));
+        }
+        if (edges.testFlag(Qt::TopEdge) && edges.testFlag(Qt::BottomEdge)) {
+            edges = edges & (~(Qt::TopEdge | Qt::BottomEdge));
+        }
+        // it's still possible that a panel borders two edges, e.g. bottom and left
+        // in that case the one which is sharing more with the edge wins
+        auto check = [this](Qt::Edges edges, Qt::Edge horiz, Qt::Edge vert) {
+            if (edges.testFlag(horiz) && edges.testFlag(vert)) {
+                if (geom.width() >= geom.height()) {
+                    return edges & ~horiz;
+                } else {
+                    return edges & ~vert;
+                }
+            }
+            return edges;
+        };
+        edges = check(edges, Qt::LeftEdge, Qt::TopEdge);
+        edges = check(edges, Qt::LeftEdge, Qt::BottomEdge);
+        edges = check(edges, Qt::RightEdge, Qt::TopEdge);
+        edges = check(edges, Qt::RightEdge, Qt::BottomEdge);
+
+        ElectricBorder border = ElectricNone;
+        if (edges.testFlag(Qt::LeftEdge)) {
+            border = ElectricLeft;
+        }
+        if (edges.testFlag(Qt::RightEdge)) {
+            border = ElectricRight;
+        }
+        if (edges.testFlag(Qt::TopEdge)) {
+            border = ElectricTop;
+        }
+        if (edges.testFlag(Qt::BottomEdge)) {
+            border = ElectricBottom;
+        }
+        ScreenEdges::self()->reserve(this, border);
+    } else {
+        ScreenEdges::self()->reserve(this, ElectricNone);
+    }
+}
+
 bool ShellClient::isInitialPositionSet() const
 {
     if (m_plasmaShellSurface) {
@@ -1243,4 +1321,14 @@ void ShellClient::placeIn(QRect &area)
     setGeometryRestore(geometry());
 }
 
+void ShellClient::showOnScreenEdge()
+{
+    if (!m_plasmaShellSurface || m_unmapped) {
+        return;
+    }
+    // TODO: handle show
+    workspace()->raiseClient(this);
+    // TODO: inform the client about being shown again
+}
+
 }

shell_client.h

@@ -127,6 +127,8 @@ public:
     bool setupCompositing() override;
     void finishCompositing(ReleaseReason releaseReason = ReleaseReason::Release) override;
 
+    void showOnScreenEdge() override;
+
     // TODO: const-ref
     void placeIn(QRect &area);
 
@@ -164,6 +166,7 @@ private:
     void setTransient();
     bool shouldExposeToWindowManagement();
     KWayland::Server::XdgShellSurfaceInterface::States xdgSurfaceStates() const;
+    void updateShowOnScreenEdge();
     static void deleteClient(ShellClient *c);
 
     KWayland::Server::ShellSurfaceInterface *m_shellSurface;