Merge lp:~saviq/unity-2d/screeninfo-refactor into lp:unity-2d

[Michał Sawicz]

[all] refactor ScreenInfo into DesktopInfo

* rename ScreenInfo to DesktopInfo
* remove screen-specific functionality from DesktopInfo as there might be more than one screen handled
* make Unity2DDeclarativeView screen-aware
* update all references to match the new approach
* get rid of calls to unsafe QX11Info::appScreen()

This, in itself, will not change anything in unity-2d, but will later allow for easier multi-monitor implementation.

[Albert Astals Cid (aacid)]

Just a comment (not sure it really has any influence here) but the QDesktopWidget calls that take a QWidget * are known not to work until the widget has been shown (which kind of makes sense) so it'd be good to have that in mind for this rework

[Albert Astals Cid (aacid)]

I guess the use of wnck_screen_get_default is not correct and should be changed to
  WnckScreen* wnck_screen_get(int index);

review: Needs Fixing

[lp:~saviq/unity-2d/screeninfo-refactor]

883. By Michał Sawicz on 2012-02-01

[lib] extend ScreenInfo to allow binding to a screen as well as usage from QML

884. By Michał Sawicz on 2012-02-01

[launcher] make sure launcher is always shown on leftmost / topmost screen

885. By Michał Sawicz on 2012-02-01

[panel] use ScreenInfo to move panels around

886. By Michał Sawicz on 2012-02-01

[lib] require classes inheriting from Unity2DDeclarativeView to instantiate their own ScreenInfo

887. By Michał Sawicz on 2012-02-01

[lib] remove dead code from DesktopInfo

888. By Michał Sawicz on 2012-02-01

[lib] make sure ScreenInfo will also update when the widget is shown

889. By Michał Sawicz on 2012-02-02

[lib] fix getter in Unity2dPanel

890. By Michał Sawicz on 2012-02-02

[panel] make the panels update properly when screen layout changes

891. By Michał Sawicz on 2012-02-02

[launcher] instantiate a ScreenInfo for LauncherView

[Michał Sawicz (saviq)]

Revision 891 is finally ready for review.

Here lp:~saviq/+junk/shell-refactor-screeninfo is a version integrated into unity-2d-shell.

[Albert Astals Cid (aacid)]

d->m_screenInfo needs to be deleted in Unity2dPanel::~Unity2dPanel (or give the ScreenInfo a parent when creating it)
m_screenInfo needs to be initialized to NULL in Unity2DDeclarativeView::Unity2DDeclarativeView
m_screenInfo needs to be delete in Unity2DDeclarativeView::~Unity2DDeclarativeView (or give the ScreenInfo a parent when creating it in the various children)

review: Needs Fixing

[Albert Astals Cid (aacid)]

Seems
Q_ENUMS(WorkspacesOrientation)
Q_ENUMS(WorkspacesCorner)
are not used at all? I think they were "wrong" before already but since we're cleaning up, might make sense to kill them now too.

review: Needs Fixing

[Albert Astals Cid (aacid)]

Besides those small minor things the change seems much welcome and a much cleaner separation between the desktop and a screen that will help fix other multimunitor problems.

[Michał Sawicz (saviq)]

> d->m_screenInfo needs to be deleted in Unity2dPanel::~Unity2dPanel (or give
> the ScreenInfo a parent when creating it)
> m_screenInfo needs to be initialized to NULL in
> Unity2DDeclarativeView::Unity2DDeclarativeView
> m_screenInfo needs to be delete in
> Unity2DDeclarativeView::~Unity2DDeclarativeView (or give the ScreenInfo a
> parent when creating it in the various children)
Done.

> Seems
> Q_ENUMS(WorkspacesOrientation)
> Q_ENUMS(WorkspacesCorner)
> are not used at all? I think they were "wrong" before already but since we're
> cleaning up, might make sense to kill them now too.
Yup, got rid of that.

Resubmitted from ~unity-2d-team so that you guys can work off of that when I'm away. Cheers!

[lp:~saviq/unity-2d/screeninfo-refactor]

892. By Michał Sawicz on 2012-02-03

[lib] clean up unused ENUMS in DesktopInfo

893. By Michał Sawicz on 2012-02-03

[all] make sure ScreenInfo has a parent so that it gets deleted along with it

[Christoph Trassl (chtrassl)]

I was late for the review, sorry.

Thanks for you all for your work, just compiled and tested lp:unity-2d rev902 - bug 880698 is fixed for me.

review: Approve

Unmerged revisions

=== modified file 'launcher/Launcher.qml'
--- launcher/Launcher.qml	2011-12-11 22:26:34 +0000
+++ launcher/Launcher.qml	2012-02-02 10:59:19 +0000
@@ -56,7 +56,7 @@
             anchors.fill: parent
             overlay_color: "black"
             overlay_alpha: 0.66
-            visible: !screen.isCompositingManagerRunning
+            visible: !desktop.isCompositingManagerRunning
         }
     }
 
@@ -65,7 +65,7 @@
         anchors.fill: parent
         color: "black"
         opacity: 0.66
-        visible: screen.isCompositingManagerRunning
+        visible: desktop.isCompositingManagerRunning
     }
     
     Image {

=== modified file 'launcher/app/launcher.cpp'
--- launcher/app/launcher.cpp	2011-12-01 09:55:45 +0000
+++ launcher/app/launcher.cpp	2012-02-02 10:59:19 +0000
@@ -37,6 +37,7 @@
 #include "unity2ddebug.h"
 #include "unity2dpanel.h"
 #include "gesturehandler.h"
+#include "screeninfo.h"
 
 // libc
 #include <stdlib.h>
@@ -82,8 +83,8 @@
        with that prefix resolves properly. */
     QDir::addSearchPath("artwork", unity2dDirectory() + "/launcher/artwork");
 
-    /* Panel containing the QML declarative view */
-    Unity2dPanel panel(true);
+    /* Panel containing the QML declarative view, topleft screen */
+    Unity2dPanel panel(true, -1, ScreenInfo::TopLeft);
 
     panel.setEdge(Unity2dPanel::LeftEdge);
     panel.setFixedWidth(LauncherClient::MaximumWidth);

=== modified file 'launcher/app/launcherview.cpp'
--- launcher/app/launcherview.cpp	2011-11-25 11:13:44 +0000
+++ launcher/app/launcherview.cpp	2012-02-02 10:59:19 +0000
@@ -41,6 +41,7 @@
 #include <hotkey.h>
 #include <hotkeymonitor.h>
 #include <keymonitor.h>
+#include <screeninfo.h>
 #include <debug_p.h>
 #include <config.h>
 
@@ -69,6 +70,8 @@
     connect(&m_superKeyHoldTimer, SIGNAL(timeout()), SLOT(updateSuperKeyHoldState()));
     connect(this, SIGNAL(superKeyTapped()), SLOT(toggleDash()));
 
+    m_screenInfo = new ScreenInfo(ScreenInfo::TopLeft);
+
     connect(&launcher2dConfiguration(), SIGNAL(superKeyEnableChanged(bool)), SLOT(updateSuperKeyMonitoring()));
     updateSuperKeyMonitoring();
 

=== modified file 'libunity-2d-private/Unity2d/GnomeBackground.qml'
--- libunity-2d-private/Unity2d/GnomeBackground.qml	2011-12-07 02:15:57 +0000
+++ libunity-2d-private/Unity2d/GnomeBackground.qml	2012-02-02 10:59:19 +0000
@@ -80,8 +80,8 @@
             else
                 return filename
         }
-        width: screen.geometry.width
-        height: screen.geometry.height
+        width: declarativeView.screen.geometry.width
+        height: declarativeView.screen.geometry.height
 
         smooth: true
 

=== modified file 'libunity-2d-private/Unity2d/plugin.cpp'
--- libunity-2d-private/Unity2d/plugin.cpp	2012-01-24 16:46:52 +0000
+++ libunity-2d-private/Unity2d/plugin.cpp	2012-02-02 10:59:19 +0000
@@ -36,6 +36,7 @@
 #include "windowinfo.h"
 #include "windowslist.h"
 #include "screeninfo.h"
+#include "desktopinfo.h"
 #include "plugin.h"
 #include "cacheeffect.h"
 #include "iconutilities.h"
@@ -100,7 +101,8 @@
 
     qmlRegisterType<WindowInfo>(uri, 0, 1, "WindowInfo");
     qmlRegisterType<WindowsList>(uri, 0, 1, "WindowsList");
-    qmlRegisterType<ScreenInfo>(); // Register the type as non creatable
+    qmlRegisterType<ScreenInfo>(uri, 0, 1, "ScreenInfo");
+    qmlRegisterType<DesktopInfo>(); // Register the type as non creatable
     qmlRegisterType<WorkspacesInfo>(); // Register the type as non creatable
 
     qmlRegisterType<CacheEffect>(uri, 0, 1, "CacheEffect");
@@ -173,7 +175,7 @@
 
     /* ScreenInfo is exposed as a context property as it's a singleton and therefore
        not creatable directly in QML */
-    engine->rootContext()->setContextProperty("screen", ScreenInfo::instance());
+    engine->rootContext()->setContextProperty("desktop", DesktopInfo::instance());
     engine->rootContext()->setContextProperty("iconUtilities", new IconUtilities(engine));
 
     /* Expose QConf objects as a context property not to initialize it multiple times */

=== modified file 'libunity-2d-private/src/CMakeLists.txt'
--- libunity-2d-private/src/CMakeLists.txt	2012-01-24 11:50:38 +0000
+++ libunity-2d-private/src/CMakeLists.txt	2012-02-02 10:59:19 +0000
@@ -34,6 +34,7 @@
     windowinfo.cpp
     windowslist.cpp
     screeninfo.cpp
+    desktopinfo.cpp
     cacheeffect.cpp
     workspacesinfo.cpp
     signalwaiter.cpp

=== modified file 'libunity-2d-private/src/dashclient.cpp'
--- libunity-2d-private/src/dashclient.cpp	2012-01-27 11:34:36 +0000
+++ libunity-2d-private/src/dashclient.cpp	2012-02-02 10:59:19 +0000
@@ -179,7 +179,7 @@
     if (unity2dConfiguration().property("formFactor").toString() != "desktop") {
         alwaysFullScreen = true;
     } else {
-        QRect rect = QApplication::desktop()->screenGeometry();
+        QRect rect = QApplication::desktop()->screenGeometry(QPoint());
         QSize minSize = minimumSizeForDesktop();
         alwaysFullScreen = rect.width() < minSize.width() && rect.height() < minSize.height();
     }

=== renamed file 'libunity-2d-private/src/screeninfo.cpp' => 'libunity-2d-private/src/desktopinfo.cpp'
--- libunity-2d-private/src/screeninfo.cpp	2011-12-07 17:50:45 +0000
+++ libunity-2d-private/src/desktopinfo.cpp	2012-02-02 10:59:19 +0000
@@ -8,109 +8,28 @@
 
 #include "config.h"
 #include "launcherclient.h"
-#include "screeninfo.h"
+#include "desktopinfo.h"
 #include "workspacesinfo.h"
 
 #include <QX11Info>
 #include <QApplication>
 #include <QDesktopWidget>
 
-ScreenInfo::ScreenInfo(QObject *parent) :
-    QObject(parent),
-    m_activeWindow(0)
+DesktopInfo::DesktopInfo(QObject *parent) :
+    QObject(parent)
 {
-    WnckScreen *screen = wnck_screen_get_default();
-    g_signal_connect(G_OBJECT(screen), "active-window-changed",
-                     G_CALLBACK(ScreenInfo::onActiveWindowChanged), NULL);
-
-    updateActiveWindow(screen);
-
-    connect(QApplication::desktop(), SIGNAL(resized(int)),
-                                     SLOT(updateGeometry(int)));
-    connect(QApplication::desktop(), SIGNAL(workAreaResized(int)),
-                                     SLOT(updateAvailableGeometry(int)));
 }
 
 
-ScreenInfo* ScreenInfo::instance()
+DesktopInfo* DesktopInfo::instance()
 {
-    static ScreenInfo* singleton = new ScreenInfo();
+    static DesktopInfo* singleton = new DesktopInfo();
     return singleton;
 }
 
-void ScreenInfo::onActiveWindowChanged(WnckScreen *screen,
-                                       WnckWindow *previously_active_window,
-                                       gpointer    user_data)
-{
-    Q_UNUSED(previously_active_window);
-    Q_UNUSED(user_data);
-
-    ScreenInfo::instance()->updateActiveWindow(screen);
-}
-
-void ScreenInfo::updateActiveWindow(WnckScreen *screen)
-{
-    unsigned int activeWindow = 0;
-    WnckWindow *wnckActiveWindow = wnck_screen_get_active_window(screen);
-    if (wnckActiveWindow != NULL) {
-        activeWindow = wnck_window_get_xid(wnckActiveWindow);
-    }
-
-    if (activeWindow != m_activeWindow) {
-        m_activeWindow = activeWindow;
-        Q_EMIT activeWindowChanged(m_activeWindow);
-    }
-}
-
-QRect ScreenInfo::availableGeometry() const
-{
-    int screen = QX11Info::appScreen();
-    return QApplication::desktop()->availableGeometry(screen);
-}
-
-QRect ScreenInfo::panelsFreeGeometry() const
-{
-    /* We cannot just return the system's availableGeometry(), because that
-     * doesn't consider the Launcher, if it's set to auto-hide. */
-    int screen = QX11Info::appScreen();
-    QRect screenRect = QApplication::desktop()->screenGeometry(screen);
-    QRect availableRect = QApplication::desktop()->availableGeometry(screen);
-
-    QRect availableGeometry(
-        LauncherClient::MaximumWidth,
-        availableRect.top(),
-        screenRect.width() - LauncherClient::MaximumWidth,
-        availableRect.height()
-        );
-    if (QApplication::isRightToLeft()) {
-        availableGeometry.moveLeft(0);
-    }
-    return availableGeometry;
-}
-
-QRect ScreenInfo::geometry() const
-{
-    return QApplication::desktop()->screenGeometry(QX11Info::appScreen());
-}
-
-void ScreenInfo::updateGeometry(int screen)
-{
-    if (screen == QX11Info::appScreen()) {
-        Q_EMIT geometryChanged(geometry());
-    }
-}
-
-void ScreenInfo::updateAvailableGeometry(int screen)
-{
-    if (screen == QX11Info::appScreen()) {
-        Q_EMIT availableGeometryChanged(availableGeometry());
-        Q_EMIT panelsFreeGeometryChanged(panelsFreeGeometry());
-    }
-}
-
-bool ScreenInfo::isCompositingManagerRunning() const
+bool DesktopInfo::isCompositingManagerRunning() const
 {
     return QX11Info::isCompositingManagerRunning();
 }
 
-#include "screeninfo.moc"
+#include "desktopinfo.moc"

=== renamed file 'libunity-2d-private/src/screeninfo.h' => 'libunity-2d-private/src/desktopinfo.h'
--- libunity-2d-private/src/screeninfo.h	2011-12-07 17:50:45 +0000
+++ libunity-2d-private/src/desktopinfo.h	2012-02-02 10:59:19 +0000
@@ -1,5 +1,5 @@
-#ifndef SCREENINFO_H
-#define SCREENINFO_H
+#ifndef DESKTOPINFO_H
+#define DESKTOPINFO_H
 
 #include <QObject>
 #include <QRect>
@@ -10,7 +10,7 @@
 typedef struct _WnckScreen WnckScreen;
 typedef struct _WnckWindow WnckWindow;
 
-class ScreenInfo : public QObject
+class DesktopInfo : public QObject
 {
     Q_OBJECT
 
@@ -18,46 +18,25 @@
     Q_ENUMS(WorkspacesCorner)
 
     Q_PROPERTY(WorkspacesInfo *workspaces READ workspaces NOTIFY workspacesChanged)
-    Q_PROPERTY(unsigned int activeWindow READ activeWindow NOTIFY activeWindowChanged)
-    Q_PROPERTY(QRect geometry READ geometry NOTIFY geometryChanged)
-    Q_PROPERTY(QRect availableGeometry READ availableGeometry NOTIFY availableGeometryChanged)
-    Q_PROPERTY(QRect panelsFreeGeometry READ panelsFreeGeometry NOTIFY panelsFreeGeometryChanged)
     Q_PROPERTY(bool isCompositingManagerRunning READ isCompositingManagerRunning
                                                 NOTIFY isCompositingManagerRunningChanged)
 
 public:
-    static ScreenInfo* instance();
+    static DesktopInfo* instance();
 
     /* Getters */
     WorkspacesInfo *workspaces() { return &m_workspacesInfo; }
-    unsigned int activeWindow() const { return m_activeWindow; }
-    QRect availableGeometry() const;
-    QRect panelsFreeGeometry() const;
-    QRect geometry() const;
     bool isCompositingManagerRunning() const;
 
 Q_SIGNALS:
-    void activeWindowChanged(unsigned int activeWindow);
-    void geometryChanged(QRect geometry);
-    void availableGeometryChanged(QRect availableGeometry);
-    void panelsFreeGeometryChanged(QRect panelsFreeGeometry);
     void workspacesChanged(WorkspacesInfo *workspaces);
     void isCompositingManagerRunningChanged(bool);
 
 private:
-    explicit ScreenInfo(QObject *parent = 0);
-    void updateActiveWindow(WnckScreen *screen);
-
-    static void onActiveWindowChanged(WnckScreen *screen,
-                                      WnckWindow *previously_active_window,
-                                      gpointer    user_data);
-private Q_SLOTS:
-    void updateGeometry(int screen);
-    void updateAvailableGeometry(int screen);
+    explicit DesktopInfo(QObject *parent = 0);
 
 private:
     WorkspacesInfo m_workspacesInfo;
-    unsigned int m_activeWindow;
 };
 
-#endif // SCREENINFO_H
+#endif // DESKTOPINFO_H

=== added file 'libunity-2d-private/src/screeninfo.cpp'
--- libunity-2d-private/src/screeninfo.cpp	1970-01-01 00:00:00 +0000
+++ libunity-2d-private/src/screeninfo.cpp	2012-02-02 10:59:19 +0000
@@ -0,0 +1,211 @@
+#include "config.h"
+#include "launcherclient.h"
+#include "screeninfo.h"
+
+#include <QApplication>
+#include <QDesktopWidget>
+#include <QX11Info>
+
+ScreenInfo::ScreenInfo(QObject *parent) :
+    QObject(parent),
+    m_screen(QX11Info::appScreen()),
+    m_widget(NULL),
+    m_corner(InvalidCorner)
+{
+    connect(QApplication::desktop(), SIGNAL(resized(int)),
+                                     SLOT(updateGeometry(int)));
+    connect(QApplication::desktop(), SIGNAL(workAreaResized(int)),
+                                     SLOT(updateAvailableGeometry(int)));
+}
+
+ScreenInfo::ScreenInfo(int screen, QObject *parent) :
+    QObject(parent),
+    m_screen(screen),
+    m_widget(NULL),
+    m_corner(InvalidCorner)
+{
+    connect(QApplication::desktop(), SIGNAL(resized(int)),
+                                     SLOT(updateGeometry(int)));
+    connect(QApplication::desktop(), SIGNAL(workAreaResized(int)),
+                                     SLOT(updateAvailableGeometry(int)));
+}
+
+ScreenInfo::ScreenInfo(QWidget *widget, QObject *parent) :
+    QObject(parent),
+    m_screen(QApplication::desktop()->screenNumber(widget)),
+    m_widget(widget),
+    m_corner(InvalidCorner)
+{
+    m_widget->installEventFilter(this);
+    connect(QApplication::desktop(), SIGNAL(resized(int)),
+                                     SLOT(updateGeometry(int)));
+    connect(QApplication::desktop(), SIGNAL(workAreaResized(int)),
+                                     SLOT(updateAvailableGeometry(int)));
+}
+
+ScreenInfo::ScreenInfo(Corner corner, QObject *parent) :
+    QObject(parent),
+    m_screen(cornerScreen(corner)),
+    m_widget(NULL),
+    m_corner(corner)
+{
+    connect(QApplication::desktop(), SIGNAL(resized(int)),
+                                     SLOT(updateGeometry(int)));
+    connect(QApplication::desktop(), SIGNAL(workAreaResized(int)),
+                                     SLOT(updateAvailableGeometry(int)));
+}
+
+ScreenInfo::~ScreenInfo()
+{
+    if (m_widget) {
+        m_widget->removeEventFilter(this);
+    }
+}
+
+QRect ScreenInfo::availableGeometry() const
+{
+    return QApplication::desktop()->availableGeometry(m_screen);
+}
+
+QRect ScreenInfo::panelsFreeGeometry() const
+{
+    /* We cannot just return the system's availableGeometry(), because that
+     * doesn't consider the Launcher, if it's set to auto-hide. */
+    QRect screenRect = QApplication::desktop()->screenGeometry(m_screen);
+    QRect availableRect = QApplication::desktop()->availableGeometry(m_screen);
+
+    QRect availableGeometry(
+        LauncherClient::MaximumWidth,
+        availableRect.top(),
+        screenRect.width() - LauncherClient::MaximumWidth,
+        availableRect.height()
+        );
+    if (QApplication::isRightToLeft()) {
+        availableGeometry.moveLeft(0);
+    }
+    return availableGeometry;
+}
+
+QRect ScreenInfo::geometry() const
+{
+    return QApplication::desktop()->screenGeometry(m_screen);
+}
+
+void ScreenInfo::updateGeometry(int screen)
+{
+    if (m_corner != InvalidCorner) {
+        int screenCorner = cornerScreen(m_corner);
+        if (m_screen != screenCorner) {
+            setScreen(screenCorner);
+            return;
+        }
+    }
+    if (screen == m_screen) {
+        Q_EMIT geometryChanged(geometry());
+    }
+}
+
+void ScreenInfo::updateAvailableGeometry(int screen)
+{
+    if (screen == m_screen) {
+        Q_EMIT availableGeometryChanged(availableGeometry());
+        Q_EMIT panelsFreeGeometryChanged(panelsFreeGeometry());
+    }
+}
+
+void ScreenInfo::updateScreen()
+{
+    int screen;
+    if (m_corner != InvalidCorner) {
+        screen = cornerScreen(m_corner);
+        setScreen(screen);
+    } else if (m_widget) {
+        screen = QApplication::desktop()->screenNumber(m_widget);
+        setScreen(screen);
+    }
+}
+
+int
+ScreenInfo::cornerScreen(Corner corner)
+{
+    QDesktopWidget* desktop = QApplication::desktop();
+    switch(corner) {
+        case TopLeft:
+            return desktop->screenNumber(QPoint());
+        case TopRight:
+            return desktop->screenNumber(QPoint(desktop->width(), 0));
+        case BottomLeft:
+            return desktop->screenNumber(QPoint(0, desktop->height()));
+        case BottomRight:
+            return desktop->screenNumber(QPoint(desktop->width(), desktop->height()));
+        default:
+            return desktop->screenNumber(QPoint());
+    }
+}
+
+bool
+ScreenInfo::eventFilter(QObject *object, QEvent *event)
+{
+    Q_UNUSED(object);
+
+    if (event->type() == QEvent::Move || event->type() == QEvent::Show) {
+        updateScreen();
+    }
+    return QObject::eventFilter(object, event);
+}
+
+int
+ScreenInfo::screen() const
+{
+    return m_screen;
+}
+
+void
+ScreenInfo::setScreen(int screen)
+{
+    if (m_screen != screen) {
+        m_screen = screen;
+        Q_EMIT screenChanged(m_screen);
+        Q_EMIT geometryChanged(geometry());
+        Q_EMIT availableGeometryChanged(availableGeometry());
+        Q_EMIT panelsFreeGeometryChanged(panelsFreeGeometry());
+    }
+}
+
+QWidget*
+ScreenInfo::widget() const
+{
+    return m_widget;
+}
+
+void
+ScreenInfo::setWidget(QWidget *widget)
+{
+    if (m_widget != widget) {
+        m_widget->removeEventFilter(this);
+        m_widget = widget;
+        if (m_widget) {
+            m_widget->installEventFilter(this);
+        }
+        Q_EMIT widgetChanged(m_widget);
+        updateScreen();
+    }
+}
+
+ScreenInfo::Corner
+ScreenInfo::corner() const
+{
+    return m_corner;
+}
+
+void
+ScreenInfo::setCorner(Corner corner)
+{
+    if (m_corner != corner) {
+        m_corner = corner;
+        Q_EMIT cornerChanged(corner);
+        updateScreen();
+    }
+}
+
+#include "screeninfo.moc"

=== added file 'libunity-2d-private/src/screeninfo.h'
--- libunity-2d-private/src/screeninfo.h	1970-01-01 00:00:00 +0000
+++ libunity-2d-private/src/screeninfo.h	2012-02-02 10:59:19 +0000
@@ -0,0 +1,72 @@
+#ifndef SCREENINFO_H
+#define SCREENINFO_H
+
+#include <QObject>
+#include <QRect>
+
+class QEvent;
+class QWidget;
+
+class ScreenInfo : public QObject
+{
+    Q_OBJECT
+
+    Q_PROPERTY(QRect geometry READ geometry NOTIFY geometryChanged)
+    Q_PROPERTY(QRect availableGeometry READ availableGeometry NOTIFY availableGeometryChanged)
+    Q_PROPERTY(QRect panelsFreeGeometry READ panelsFreeGeometry NOTIFY panelsFreeGeometryChanged)
+    Q_PROPERTY(int screen READ screen WRITE setScreen NOTIFY screenChanged)
+    Q_PROPERTY(QWidget* widget READ widget WRITE setWidget NOTIFY widgetChanged)
+    Q_PROPERTY(Corner corner READ corner WRITE setCorner NOTIFY cornerChanged)
+
+public:
+    enum Corner {
+        InvalidCorner,
+        TopLeft,
+        TopRight,
+        BottomLeft,
+        BottomRight
+    };
+
+    /* Getters */
+    explicit ScreenInfo(QObject *parent = 0);
+    ScreenInfo(QWidget* widget, QObject *parent = 0);
+    ScreenInfo(int screen, QObject *parent = 0);
+    ScreenInfo(Corner corner, QObject *parent = 0);
+    ~ScreenInfo();
+    QRect availableGeometry() const;
+    QRect panelsFreeGeometry() const;
+    QRect geometry() const;
+    int screen() const;
+    QWidget* widget() const;
+    Corner corner() const;
+
+    /* Setters */
+    void setScreen(int screen);
+    void setWidget(QWidget* widget);
+    void setCorner(Corner corner);
+
+
+protected:
+    bool eventFilter(QObject *object, QEvent *event);
+
+Q_SIGNALS:
+    void geometryChanged(QRect geometry);
+    void availableGeometryChanged(QRect availableGeometry);
+    void panelsFreeGeometryChanged(QRect panelsFreeGeometry);
+    void screenChanged(int screen);
+    void widgetChanged(QWidget* widget);
+    void cornerChanged(Corner corner);
+
+private Q_SLOTS:
+    void updateGeometry(int screen);
+    void updateAvailableGeometry(int screen);
+
+private:
+    void updateScreen();
+    int cornerScreen(Corner corner);
+    int m_screen;
+    QWidget* m_widget;
+    Corner m_corner;
+};
+
+#endif // SCREENINFO_H

=== modified file 'libunity-2d-private/src/unity2ddeclarativeview.cpp'
--- libunity-2d-private/src/unity2ddeclarativeview.cpp	2011-12-08 19:41:38 +0000
+++ libunity-2d-private/src/unity2ddeclarativeview.cpp	2012-02-02 10:59:19 +0000
@@ -28,6 +28,8 @@
 #include <debug_p.h>
 #include <config.h>
 
+#include "screeninfo.h"
+
 // libwnck
 extern "C" {
 #include <libwnck/libwnck.h>
@@ -265,4 +267,10 @@
     m_last_focused_window = None;
 }
 
+ScreenInfo*
+Unity2DDeclarativeView::screen() const
+{
+    return m_screenInfo;
+}
+
 #include <unity2ddeclarativeview.moc>

=== modified file 'libunity-2d-private/src/unity2ddeclarativeview.h'
--- libunity-2d-private/src/unity2ddeclarativeview.h	2011-12-08 19:41:38 +0000
+++ libunity-2d-private/src/unity2ddeclarativeview.h	2012-02-02 10:59:19 +0000
@@ -19,6 +19,8 @@
 
 #include <QDeclarativeView>
 
+class ScreenInfo;
+
 class Unity2DDeclarativeView : public QDeclarativeView
 {
     Q_OBJECT
@@ -26,6 +28,7 @@
     Q_PROPERTY(bool useOpenGL READ useOpenGL WRITE setUseOpenGL NOTIFY useOpenGLChanged)
     Q_PROPERTY(bool transparentBackground READ transparentBackground WRITE setTransparentBackground NOTIFY transparentBackgroundChanged)
     Q_PROPERTY(QPoint globalPosition READ globalPosition NOTIFY globalPositionChanged)
+    Q_PROPERTY(ScreenInfo* screen READ screen NOTIFY screenChanged)
 
 public:
     Unity2DDeclarativeView(QWidget *parent = 0);
@@ -35,6 +38,7 @@
     bool useOpenGL() const;
     bool transparentBackground() const;
     QPoint globalPosition() const;
+    ScreenInfo* screen() const;
 
     // setters
     void setUseOpenGL(bool);
@@ -44,10 +48,12 @@
     void useOpenGLChanged(bool);
     void transparentBackgroundChanged(bool);
     void globalPositionChanged(QPoint);
+    void screenChanged(ScreenInfo*);
 
 protected:
     void setupViewport();
     virtual void moveEvent(QMoveEvent* event);
+    ScreenInfo* m_screenInfo;
 
 protected Q_SLOTS:
     void forceActivateWindow();

=== modified file 'libunity-2d-private/src/unity2dpanel.cpp'
--- libunity-2d-private/src/unity2dpanel.cpp	2011-11-05 21:14:08 +0000
+++ libunity-2d-private/src/unity2dpanel.cpp	2012-02-02 10:59:19 +0000
@@ -36,6 +36,9 @@
 #include <X11/Xlib.h>
 #include <X11/Xatom.h>
 
+// unity-2d
+#include "screeninfo.h"
+
 static const int SLIDE_DURATION = 125;
 
 struct Unity2dPanelPrivate
@@ -49,6 +52,7 @@
     bool m_useStrut;
     int m_delta;
     bool m_manualSliding;
+    ScreenInfo* m_screenInfo;
 
     void setStrut(ulong* struts)
     {
@@ -96,9 +100,8 @@
 
     void updateGeometry()
     {
-        QDesktopWidget* desktop = QApplication::desktop();
-        const QRect screen = desktop->screenGeometry(q);
-        const QRect available = desktop->availableGeometry(q);
+        const QRect screen = m_screenInfo->geometry();
+        const QRect available = m_screenInfo->availableGeometry();
 
         QRect rect;
         switch (m_edge) {
@@ -144,7 +147,7 @@
     }
 };
 
-Unity2dPanel::Unity2dPanel(bool requiresTransparency, QWidget* parent)
+Unity2dPanel::Unity2dPanel(bool requiresTransparency, int screen, ScreenInfo::Corner corner, QWidget* parent)
 : QWidget(parent)
 , d(new Unity2dPanelPrivate)
 {
@@ -157,6 +160,13 @@
     d->m_layout = new QHBoxLayout(this);
     d->m_layout->setMargin(0);
     d->m_layout->setSpacing(0);
+    if (corner != ScreenInfo::InvalidCorner) {
+        d->m_screenInfo = new ScreenInfo(corner);
+    } else if (screen >= 0) {
+        d->m_screenInfo = new ScreenInfo(screen);
+    } else {
+        d->m_screenInfo = new ScreenInfo(this);
+    }
 
     d->m_slideInAnimation = new QPropertyAnimation(this);
     d->m_slideInAnimation->setTargetObject(this);
@@ -203,6 +213,16 @@
     return d->m_edge;
 }
 
+void Unity2dPanel::setScreen(int screen)
+{
+    d->m_screenInfo->setScreen(screen);
+}
+
+int Unity2dPanel::screen() const
+{
+    return d->m_screenInfo->screen();
+}
+
 IndicatorsManager* Unity2dPanel::indicatorsManager() const
 {
     if (d->m_indicatorsManager == 0) {

=== modified file 'libunity-2d-private/src/unity2dpanel.h'
--- libunity-2d-private/src/unity2dpanel.h	2011-10-12 16:54:18 +0000
+++ libunity-2d-private/src/unity2dpanel.h	2012-02-02 10:59:19 +0000
@@ -29,6 +29,8 @@
 #include <QWidget>
 #include <QEvent>
 
+#include "screeninfo.h"
+
 struct Unity2dPanelPrivate;
 class Unity2dPanel : public QWidget
 {
@@ -54,12 +56,16 @@
 
     static const QEvent::Type SHOW_FIRST_MENU_EVENT = QEvent::User;
 
-    Unity2dPanel(bool requiresTransparency = false, QWidget* parent = 0);
+    Unity2dPanel(bool requiresTransparency = false, int screen = -1,
+                 ScreenInfo::Corner corner = ScreenInfo::InvalidCorner, QWidget* parent = 0);
     ~Unity2dPanel();
 
     void setEdge(Edge);
     Edge edge() const;
 
+    void setScreen(int);
+    int screen() const;
+
     void addWidget(QWidget*);
 
     void addSpacer();

=== modified file 'libunity-2d-private/src/workspacesinfo.cpp'
--- libunity-2d-private/src/workspacesinfo.cpp	2011-11-10 17:53:54 +0000
+++ libunity-2d-private/src/workspacesinfo.cpp	2012-02-02 10:59:19 +0000
@@ -1,5 +1,5 @@
 #include "workspacesinfo.h"
-#include "screeninfo.h"
+#include "desktopinfo.h"
 #include "signalwaiter.h"
 #include <debug_p.h>
 
@@ -74,9 +74,9 @@
 
     if (notify->atom == _NET_DESKTOP_LAYOUT ||
         notify->atom == _NET_NUMBER_OF_DESKTOPS) {
-        ScreenInfo::instance()->workspaces()->updateWorkspaceGeometry();
+        DesktopInfo::instance()->workspaces()->updateWorkspaceGeometry();
     } else if (notify->atom == _NET_CURRENT_DESKTOP) {
-        ScreenInfo::instance()->workspaces()->updateCurrentWorkspace();
+        DesktopInfo::instance()->workspaces()->updateCurrentWorkspace();
     }
 
     return ret;

=== modified file 'panel/app/panelmanager.cpp'
--- panel/app/panelmanager.cpp	2012-01-26 11:16:03 +0000
+++ panel/app/panelmanager.cpp	2012-02-02 10:59:19 +0000
@@ -116,14 +116,31 @@
 PanelManager::PanelManager(QObject* parent)
 : QObject(parent)
 {
+    Unity2dPanel* panel;
     QDesktopWidget* desktop = QApplication::desktop();
+
+    QPoint p;
+    if (QApplication::isRightToLeft()) {
+        p = QPoint(desktop->width() - 1, 0);
+    }
+    int leftmost = desktop->screenNumber(p);
+
+    panel = instantiatePanel(leftmost);
+    m_panels.append(panel);
+    panel->show();
+    panel->move(desktop->screenGeometry(leftmost).topLeft());
+
     for(int i = 0; i < desktop->screenCount(); ++i) {
-        Unity2dPanel* panel = instantiatePanel(i);
+        if (i == leftmost) {
+            continue;
+        }
+        panel = instantiatePanel(i);
         m_panels.append(panel);
         panel->show();
         panel->move(desktop->screenGeometry(i).topLeft());
     }
-    connect(desktop, SIGNAL(screenCountChanged(int)), SLOT(onScreenCountChanged(int)));
+    connect(desktop, SIGNAL(screenCountChanged(int)), SLOT(updateScreenLayout(int)));
+    connect(desktop, SIGNAL(resized(int)), SLOT(onScreenResized(int)));
 
     /* A F10 keypress opens the first menu of the visible application or of the first
        indicator on the panel */
@@ -138,7 +155,7 @@
 
 Unity2dPanel* PanelManager::instantiatePanel(int screen)
 {
-    Unity2dPanel* panel = new Unity2dPanel;
+    Unity2dPanel* panel = new Unity2dPanel(false, screen);
     panel->setAccessibleName("Top Panel");
     panel->setEdge(Unity2dPanel::TopEdge);
     panel->setFixedHeight(24);
@@ -181,7 +198,25 @@
 }
 
 void
-PanelManager::onScreenCountChanged(int newCount)
+PanelManager::onScreenResized(int screen)
+{
+    QPoint p;
+    QDesktopWidget* desktop = QApplication::desktop();
+    if (QApplication::isRightToLeft()) {
+        p = QPoint(desktop->width() - 1, 0);
+    }
+    int leftmost = desktop->screenNumber(p);
+
+    /*  We only care about the leftmost screen being resized,
+        because there is no screenLayoutChanged signal, we're
+        abusing it here so that we update the panels  */
+    if (screen == leftmost) {
+        updateScreenLayout(desktop->screenCount());
+    }
+}
+
+void
+PanelManager::updateScreenLayout(int newCount)
 {
     if (newCount > 0) {
         QDesktopWidget* desktop = QApplication::desktop();
@@ -197,7 +232,7 @@
             m_panels.append(panel);
         }
         panel->show();
-        panel->move(desktop->screenGeometry(leftmost).topLeft());
+        panel->setScreen(leftmost);
 
         /* Update the position of other existing panels, and instantiate new
            panels as needed. */
@@ -213,7 +248,7 @@
                 m_panels.append(panel);
             }
             panel->show();
-            panel->move(desktop->screenGeometry(screen).topLeft());
+            panel->setScreen(screen);
             ++i;
         }
     }

=== modified file 'panel/app/panelmanager.h'
--- panel/app/panelmanager.h	2012-01-26 11:16:03 +0000
+++ panel/app/panelmanager.h	2012-02-02 10:59:19 +0000
@@ -44,8 +44,9 @@
     QStringList loadPanelConfiguration() const;
 
 private Q_SLOTS:
-    void onScreenCountChanged(int newCount);
+    void updateScreenLayout(int newCount);
     void onAltF10Pressed();
+    void onScreenResized(int screen);
 };
 
 #endif // PanelManager_H

=== modified file 'panel/applets/appname/windowhelper.cpp'
--- panel/applets/appname/windowhelper.cpp	2012-01-24 13:03:34 +0000
+++ panel/applets/appname/windowhelper.cpp	2012-02-02 10:59:19 +0000
@@ -29,7 +29,6 @@
 #include <dashclient.h>
 #include <debug_p.h>
 #include <gconnector.h>
-#include <screeninfo.h>
 
 // Bamf
 #include <bamf-matcher.h>

=== modified file 'places/app/dashdeclarativeview.cpp'
--- places/app/dashdeclarativeview.cpp	2012-01-26 13:12:12 +0000
+++ places/app/dashdeclarativeview.cpp	2012-02-02 10:59:19 +0000
@@ -23,7 +23,6 @@
 #include <dashclient.h>
 
 // Qt
-#include <QDesktopWidget>
 #include <QApplication>
 #include <QBitmap>
 #include <QCloseEvent>
@@ -55,20 +54,15 @@
     setWindowFlags(Qt::Window | Qt::FramelessWindowHint);
     setTransparentBackground(QX11Info::isCompositingManagerRunning());
 
-    QDesktopWidget* desktop = QApplication::desktop();
-    connect(desktop, SIGNAL(resized(int)), SIGNAL(screenGeometryChanged()));
-    connect(desktop, SIGNAL(workAreaResized(int)), SLOT(onWorkAreaResized(int)));
+    m_screenInfo = new ScreenInfo(ScreenInfo::TopLeft);
+    connect(m_screenInfo, SIGNAL(availableGeometryChanged(QRect)), SLOT(onWorkAreaResized()));
 
     updateSize();
 }
 
 void
-DashDeclarativeView::onWorkAreaResized(int screen)
+DashDeclarativeView::onWorkAreaResized()
 {
-    if (QApplication::desktop()->screenNumber(this) != screen) {
-        return;
-    }
-
     updateSize();
 }
 
@@ -85,7 +79,7 @@
 void
 DashDeclarativeView::fitToAvailableSpace()
 {
-    QRect rect = ScreenInfo::instance()->panelsFreeGeometry();
+    QRect rect = m_screenInfo->panelsFreeGeometry();
     move(rect.topLeft());
     setFixedSize(rect.size());
 }
@@ -93,7 +87,7 @@
 void
 DashDeclarativeView::resizeToDesktopModeSize()
 {
-    QRect rect = ScreenInfo::instance()->panelsFreeGeometry();
+    QRect rect = m_screenInfo->panelsFreeGeometry();
     int screenRight = rect.right();
 
     rect.setWidth(qMin(DASH_DESKTOP_WIDTH, rect.width()));

=== modified file 'places/app/dashdeclarativeview.h'
--- places/app/dashdeclarativeview.h	2012-01-24 12:35:44 +0000
+++ places/app/dashdeclarativeview.h	2012-02-02 10:59:19 +0000
@@ -21,6 +21,7 @@
 #include <unity2ddeclarativeview.h>
 
 class LauncherClient;
+class ScreenInfo;
 
 class DashDeclarativeView : public Unity2DDeclarativeView
 {
@@ -67,7 +68,7 @@
     virtual void showEvent(QShowEvent *event);
 
 private Q_SLOTS:
-    void onWorkAreaResized(int screen);
+    void onWorkAreaResized();
     void updateSize();
 
 private:

=== modified file 'places/dash.qml'
--- places/dash.qml	2012-01-25 11:22:45 +0000
+++ places/dash.qml	2012-02-02 10:59:19 +0000
@@ -206,7 +206,7 @@
         BorderImage {
             anchors.fill: parent
             visible: dashView.dashMode == DashDeclarativeView.DesktopMode
-            source: screen.isCompositingManagerRunning ? "artwork/desktop_dash_background.sci" : "artwork/desktop_dash_background_no_transparency.sci"
+            source: desktop.isCompositingManagerRunning ? "artwork/desktop_dash_background.sci" : "artwork/desktop_dash_background_no_transparency.sci"
             mirror: isRightToLeft()
         }
     }

=== modified file 'spread/Workspace.qml'
--- spread/Workspace.qml	2011-10-21 12:46:08 +0000
+++ spread/Workspace.qml	2012-02-02 10:59:19 +0000
@@ -54,8 +54,8 @@
 
             clip: true
             cached: false
-            offsetX: -screen.panelsFreeGeometry.x
-            offsetY: -screen.panelsFreeGeometry.y
+            offsetX: -declarativeView.screen.panelsFreeGeometry.x
+            offsetY: -declarativeView.screen.panelsFreeGeometry.y
         }
 
         Windows {

=== modified file 'spread/Workspaces.qml'
--- spread/Workspaces.qml	2011-12-06 19:37:23 +0000
+++ spread/Workspaces.qml	2012-02-02 10:59:19 +0000
@@ -25,8 +25,8 @@
 
     color: "black"
 
-    property int columns: screen.workspaces.columns
-    property int rows: screen.workspaces.rows
+    property int columns: desktop.workspaces.columns
+    property int rows: desktop.workspaces.rows
 
     property int margin: 35
     property int spacing: 4
@@ -57,7 +57,7 @@
 
     /* Scale of a workspace when the user zooms on it (fills most of the switcher, leaving a margin to see
        the corners of the other workspaces below it) */
-    property bool isDesktopHorizontal: screen.panelsFreeGeometry.width > screen.panelsFreeGeometry.height
+    property bool isDesktopHorizontal: declarativeView.screen.panelsFreeGeometry.width > declarativeView.screen.panelsFreeGeometry.height
     property real zoomedScale: (isDesktopHorizontal) ? ((width - 2*margin) / switcher.width) :
                                                        ((height - 2*margin) / switcher.height)
 
@@ -85,7 +85,7 @@
         width: cellWidth * columns
         height: cellHeight * rows
 
-        model: screen.workspaces.count
+        model: desktop.workspaces.count
         cellWidth: parent.cellWidth + spacing
         cellHeight: parent.cellHeight + spacing
         keyNavigationWraps: true
@@ -136,7 +136,7 @@
             }
             state: {
                 if (initial) {
-                    if (screen.workspaces.current == workspaceNumber) {
+                    if (desktop.workspaces.current == workspaceNumber) {
                         return "screen"
                     } else {
                         return "unzoomed"
@@ -189,12 +189,12 @@
             /* Setup application pre-filtering and initially zoomed desktop, if any
                were specified as arguments */
             applicationFilter = applicationDesktopFile
-            zoomedWorkspace = screen.workspaces.current
+            zoomedWorkspace = desktop.workspaces.current
             show()
         }
 
         onShowAllWorkspaces: {
-            if (screen.workspaces.count > 1) {
+            if (desktop.workspaces.count > 1) {
                 applicationFilter = applicationDesktopFile
                 zoomedWorkspace = -1
                 show()
@@ -211,13 +211,13 @@
     function show() {
         /* Save the currently active window before showing and activating the switcher,
            so that we can use it to pre-select the active window on the workspace */
-        lastActiveWindow = screen.activeWindow
+        lastActiveWindow = desktop.activeWindow
 
         allWindows.load()
 
         spreadView.show()
         spreadView.forceActivateWindow()
-        workspaces.currentIndex = screen.workspaces.current
+        workspaces.currentIndex = desktop.workspaces.current
         /* This is necessary otherwise we don't get keypresses until the user does a
            mouse over on a window */
         workspaces.forceActiveFocus()
@@ -280,13 +280,13 @@
     }
 
     function activateWindow(windowInfo) {
-        screen.workspaces.changeCurrent(zoomedWorkspace)
+        desktop.workspaces.changeCurrent(zoomedWorkspace)
         windowInfo.activate()
         cancelAndExit()
     }
 
     function activateWorkspace(workspaceNumber) {
-        screen.workspaces.changeCurrent(workspaceNumber)
+        desktop.workspaces.changeCurrent(workspaceNumber)
         cancelAndExit()
     }
 }

=== modified file 'spread/app/spread.cpp'
--- spread/app/spread.cpp	2011-11-11 15:52:49 +0000
+++ spread/app/spread.cpp	2012-02-02 10:59:19 +0000
@@ -66,10 +66,5 @@
     view.rootContext()->setContextProperty("spreadView", &view);
     view.setSource(QUrl("./Workspaces.qml"));
 
-    /* Always match the size of the desktop */
-    int current_screen = QApplication::desktop()->screenNumber(&view);
-    view.fitToAvailableSpace(current_screen);
-    QObject::connect(QApplication::desktop(), SIGNAL(workAreaResized(int)), &view, SLOT(fitToAvailableSpace(int)));
-
     return application.exec();
 }

=== modified file 'spread/app/spreadview.cpp'
--- spread/app/spreadview.cpp	2011-12-08 18:39:18 +0000
+++ spread/app/spreadview.cpp	2012-02-02 10:59:19 +0000
@@ -28,19 +28,17 @@
 SpreadView::SpreadView()
 : Unity2DDeclarativeView()
 {
+    m_screenInfo = new ScreenInfo(ScreenInfo::TopLeft);
+    connect(m_screenInfo, SIGNAL(availableGeometryChanged(QRect)), SLOT(fitToAvailableSpace()));
+
+    fitToAvailableSpace();
 }
 
-void SpreadView::fitToAvailableSpace(int screen)
+void SpreadView::fitToAvailableSpace()
 {
-    QDesktopWidget *desktop = QApplication::desktop();
-    int current_screen = desktop->screenNumber(this);
-
-    if(screen == current_screen)
-    {
-        QRect geometry = ScreenInfo::instance()->panelsFreeGeometry();
-        setGeometry(geometry);
-        setFixedSize(geometry.size());
-    }
+    QRect geometry = m_screenInfo->panelsFreeGeometry();
+    setGeometry(geometry);
+    setFixedSize(geometry.size());
 }
 
 /* To be able to call grabMouse() we need to be 100% sure that X11 did

=== modified file 'spread/app/spreadview.h'
--- spread/app/spreadview.h	2011-12-08 18:39:18 +0000
+++ spread/app/spreadview.h	2012-02-02 10:59:19 +0000
@@ -34,7 +34,7 @@
 
 public Q_SLOTS:
     /* FIXME: copied from places/app/dashdeclarativeview.h */
-    void fitToAvailableSpace(int screen);
+    void fitToAvailableSpace();
 
 protected:
     virtual void focusInEvent( QFocusEvent * event );