xcb: add qt.qpa.screen logging category

Some existing debug output required recompiling with Q_XCB_DEBUG.
Being able to enable this debugging in the field will help with
troubleshooting any remaining screen management issues.

Change-Id: Ie67b0009d4b00b0d39fde0fb4d8d54fcf89d6693
Reviewed-by: Sandro Mani <manisandro@gmail.com>
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>
Reviewed-by: Jørgen Lind <jorgen.lind@theqtcompany.com>

5 files changed, 66 insertions, 39 deletions

diff --git a/src/plugins/platforms/xcb/qxcbconnection.cpp b/src/plugins/platforms/xcb/qxcbconnection.cpp
index e8fab31480..43c73671a9 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection.cpp
@@ -80,6 +80,7 @@ QT_BEGIN_NAMESPACE
 
 Q_LOGGING_CATEGORY(lcQpaXInput, "qt.qpa.input")
 Q_LOGGING_CATEGORY(lcQpaXInputDevices, "qt.qpa.input.devices")
+Q_LOGGING_CATEGORY(lcQpaScreen, "qt.qpa.screen")
 
 #ifdef XCB_USE_XLIB
 static const char * const xcbConnectionErrors[] = {
@@ -185,15 +186,11 @@ void QXcbConnection::updateScreens()
                         if (output == NULL)
                             continue;
 
-#ifdef Q_XCB_DEBUG
-                        QString outputName = QString::fromUtf8((const char*)xcb_randr_get_output_info_name(output),
-                                                               xcb_randr_get_output_info_name_length(output));
-#endif
 
                         if (output->crtc == XCB_NONE) {
-#ifdef Q_XCB_DEBUG
-                            qDebug("Screen output %s is not connected", qPrintable(outputName));
-#endif
+                            qCDebug(lcQpaScreen, "output %s is not connected", qPrintable(
+                                        QString::fromUtf8((const char*)xcb_randr_get_output_info_name(output),
+                                                          xcb_randr_get_output_info_name_length(output))));
                             continue;
                         }
 
@@ -209,9 +206,6 @@ void QXcbConnection::updateScreens()
                             if (!primaryScreen || (primary && outputs[i] == primary->output)) {
                                 primaryScreen = screen;
                                 siblings.prepend(siblings.takeLast());
-#ifdef Q_XCB_DEBUG
-                                qDebug("Primary output is %d: %s", primary->output, qPrintable(outputName));
-#endif
                             }
                         }
                         free(output);
@@ -224,9 +218,7 @@ void QXcbConnection::updateScreens()
         // If there's no randr extension, or there was some error above, or the screen
         // doesn't have outputs for some other reason (e.g. on VNC or ssh -X), just assume there is one screen.
         if (connectedOutputCount == 0) {
-#ifdef Q_XCB_DEBUG
-                qDebug("Found a screen with zero outputs");
-#endif
+            qCDebug(lcQpaScreen, "found a screen with zero outputs");
             QXcbScreen *screen = findOrCreateScreen(newScreens, xcbScreenNumber, xcbScreen);
             siblings << screen;
             activeScreens << screen;
@@ -259,18 +251,21 @@ void QXcbConnection::updateScreens()
     if (newScreens.contains(primaryScreen)) {
         newScreens.removeOne(primaryScreen);
         m_screens.prepend(primaryScreen);
+        qCDebug(lcQpaScreen) << "adding as primary" << primaryScreen;
         integration->screenAdded(primaryScreen, true);
     }
 
     // Add the remaining new screens
     foreach (QXcbScreen* screen, newScreens) {
         m_screens.append(screen);
+        qCDebug(lcQpaScreen) << "adding" << screen;
         integration->screenAdded(screen);
     }
 
     // Delete the old screens, now that the new ones were added
     // and we are sure that there is at least one screen available
     foreach (QXcbScreen* screen, screensToDelete) {
+        qCDebug(lcQpaScreen) << "removing" << screen;
         integration->destroyScreen(screen);
     }
 
@@ -284,6 +279,9 @@ void QXcbConnection::updateScreens()
             m_screens.prepend(primaryScreen);
         }
     }
+
+    if (!m_screens.isEmpty())
+        qCDebug(lcQpaScreen) << "primary output is" << m_screens.first()->name();
 }
 
 QXcbConnection::QXcbConnection(QXcbNativeInterface *nativeInterface, bool canGrabServer, const char *displayName)
diff --git a/src/plugins/platforms/xcb/qxcbconnection.h b/src/plugins/platforms/xcb/qxcbconnection.h
index 90b859e612..391d4c10cc 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.h
+++ b/src/plugins/platforms/xcb/qxcbconnection.h
@@ -77,6 +77,7 @@ QT_BEGIN_NAMESPACE
 
 Q_DECLARE_LOGGING_CATEGORY(lcQpaXInput)
 Q_DECLARE_LOGGING_CATEGORY(lcQpaXInputDevices)
+Q_DECLARE_LOGGING_CATEGORY(lcQpaScreen)
 
 class QXcbScreen;
 class QXcbWindow;
diff --git a/src/plugins/platforms/xcb/qxcbintegration.cpp b/src/plugins/platforms/xcb/qxcbintegration.cpp
index 3f497996d8..1676035f6b 100644
--- a/src/plugins/platforms/xcb/qxcbintegration.cpp
+++ b/src/plugins/platforms/xcb/qxcbintegration.cpp
@@ -170,9 +170,7 @@ QXcbIntegration::QXcbIntegration(const QStringList &parameters, int &argc, char
     m_connections << new QXcbConnection(m_nativeInterface.data(), m_canGrab, displayName);
 
     for (int i = 0; i < parameters.size() - 1; i += 2) {
-#ifdef Q_XCB_DEBUG
-        qDebug() << "QXcbIntegration: Connecting to additional display: " << parameters.at(i) << parameters.at(i+1);
-#endif
+        qCDebug(lcQpaScreen) << "connecting to additional display: " << parameters.at(i) << parameters.at(i+1);
         QString display = parameters.at(i) + QLatin1Char(':') + parameters.at(i+1);
         m_connections << new QXcbConnection(m_nativeInterface.data(), m_canGrab, display.toLatin1().constData());
     }
diff --git a/src/plugins/platforms/xcb/qxcbscreen.cpp b/src/plugins/platforms/xcb/qxcbscreen.cpp
index e43652ab37..58a364848a 100644
--- a/src/plugins/platforms/xcb/qxcbscreen.cpp
+++ b/src/plugins/platforms/xcb/qxcbscreen.cpp
@@ -93,25 +93,6 @@ QXcbScreen::QXcbScreen(QXcbConnection *connection, xcb_screen_t *scr,
     if (dpr_scaling_enabled)
         m_noFontHinting = true;
 
-#ifdef Q_XCB_DEBUG
-    qDebug();
-    qDebug("Screen output %s of xcb screen %d:", m_outputName.toUtf8().constData(), m_number);
-    qDebug("  width..........: %lf", m_sizeMillimeters.width());
-    qDebug("  height.........: %lf", m_sizeMillimeters.height());
-    qDebug("  geometry.......: %d x %d +%d +%d", m_geometry.width(), m_geometry.height(), m_geometry.x(), m_geometry.y());
-    qDebug("  virtual width..: %lf", m_virtualSizeMillimeters.width());
-    qDebug("  virtual height.: %lf", m_virtualSizeMillimeters.height());
-    qDebug("  virtual geom...: %d x %d", m_virtualSize.width(), m_virtualSize.height());
-    qDebug("  avail virt geom: %d x %d +%d +%d", m_availableGeometry.width(), m_availableGeometry.height(), m_availableGeometry.x(), m_availableGeometry.y());
-    qDebug("  orientation....: %d", m_orientation);
-    qDebug("  pixel ratio....: %d", m_devicePixelRatio);
-    qDebug("  depth..........: %d", screen()->root_depth);
-    qDebug("  white pixel....: %x", screen()->white_pixel);
-    qDebug("  black pixel....: %x", screen()->black_pixel);
-    qDebug("  refresh rate...: %d", m_refreshRate);
-    qDebug("  root ID........: %x", screen()->root);
-#endif
-
     QScopedPointer<xcb_get_window_attributes_reply_t, QScopedPointerPodDeleter> rootAttribs(
         xcb_get_window_attributes_reply(xcb_connection(),
             xcb_get_window_attributes_unchecked(xcb_connection(), screen()->root), NULL));
@@ -146,10 +127,6 @@ QXcbScreen::QXcbScreen(QXcbConnection *connection, xcb_screen_t *scr,
                                      atom(QXcbAtom::UTF8_STRING), 0, 1024), NULL);
             if (windowManagerReply && windowManagerReply->format == 8 && windowManagerReply->type == atom(QXcbAtom::UTF8_STRING)) {
                 m_windowManagerName = QString::fromUtf8((const char *)xcb_get_property_value(windowManagerReply), xcb_get_property_value_length(windowManagerReply));
-#ifdef Q_XCB_DEBUG
-                qDebug("  window manager.: %s", qPrintable(m_windowManagerName));
-                qDebug();
-#endif
             }
 
             free(windowManagerReply);
@@ -709,4 +686,48 @@ QXcbXSettings *QXcbScreen::xSettings() const
     }
     return m_xSettings;
 }
+
+static inline void formatRect(QDebug &debug, const QRect r)
+{
+    debug << r.width() << 'x' << r.height()
+        << forcesign << r.x() << r.y() << noforcesign;
+}
+
+static inline void formatSizeF(QDebug &debug, const QSizeF s)
+{
+    debug << s.width() << 'x' << s.height() << "mm";
+}
+
+Q_XCB_EXPORT QDebug operator<<(QDebug debug, const QXcbScreen *screen)
+{
+    const QDebugStateSaver saver(debug);
+    debug.nospace();
+    debug << "QXcbScreen(" << (void *)screen;
+    if (screen) {
+        debug << fixed << qSetRealNumberPrecision(1);
+        debug << ", name=" << screen->name();
+        debug << ", geometry=";
+        formatRect(debug, screen->geometry());
+        debug << ", availableGeometry=";
+        formatRect(debug, screen->availableGeometry());
+        debug << ", devicePixelRatio=" << screen->devicePixelRatio();
+        debug << ", logicalDpi=" << screen->logicalDpi();
+        debug << ", physicalSize=";
+        formatSizeF(debug, screen->physicalSize());
+        // TODO 5.6 if (debug.verbosity() > 2) {
+        debug << ", screenNumber=" << screen->screenNumber();
+        debug << ", virtualSize=" << screen->virtualSize().width() << "x" << screen->virtualSize().height() << " (";
+        formatSizeF(debug, screen->virtualSize());
+        debug << "), nativeGeometry=";
+        formatRect(debug, screen->nativeGeometry());
+        debug << ", orientation=" << screen->orientation();
+        debug << ", depth=" << screen->depth();
+        debug << ", refreshRate=" << screen->refreshRate();
+        debug << ", root=" << hex << screen->root();
+        debug << ", windowManagerName=" << screen->windowManagerName();
+    }
+    debug << ')';
+    return debug;
+}
+
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/xcb/qxcbscreen.h b/src/plugins/platforms/xcb/qxcbscreen.h
index f327eb31b0..53ad413541 100644
--- a/src/plugins/platforms/xcb/qxcbscreen.h
+++ b/src/plugins/platforms/xcb/qxcbscreen.h
@@ -50,6 +50,9 @@ QT_BEGIN_NAMESPACE
 class QXcbConnection;
 class QXcbCursor;
 class QXcbXSettings;
+#ifndef QT_NO_DEBUG_STREAM
+class QDebug;
+#endif
 
 class Q_XCB_EXPORT QXcbScreen : public QXcbObject, public QPlatformScreen
 {
@@ -68,6 +71,8 @@ public:
     int depth() const Q_DECL_OVERRIDE { return m_screen->root_depth; }
     QImage::Format format() const Q_DECL_OVERRIDE;
     QSizeF physicalSize() const Q_DECL_OVERRIDE { return m_sizeMillimeters; }
+    QSize virtualSize() const { return m_virtualSize; }
+    QSizeF physicalVirtualSize() const { return m_virtualSizeMillimeters; }
     QDpi logicalDpi() const Q_DECL_OVERRIDE;
     qreal devicePixelRatio() const Q_DECL_OVERRIDE;
     QPlatformCursor *cursor() const Q_DECL_OVERRIDE;
@@ -140,6 +145,10 @@ private:
     QXcbXSettings *m_xSettings;
 };
 
+#ifndef QT_NO_DEBUG_STREAM
+Q_GUI_EXPORT QDebug operator<<(QDebug, const QXcbScreen *);
+#endif
+
 QT_END_NAMESPACE
 
 #endif