Implement QDebug streaming operators for QWindow, QScreen and QWidget.

The operators can be switched to verbose using QDebug::setVerbosity()
and then provide more useful information than the standard
operator for QObject.

[ChangeLog][QtCore][QDebug] When streaming QWindow, QScreen,
QWidget instances to a debug stream that has increased verbosity
set, detailed information about geometries, states etc. will
be printed.

Change-Id: Ice26e00f6c713cd6244e1c1df54195e0b0de3c20
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

4 files changed, 91 insertions, 0 deletions

diff --git a/src/gui/kernel/qscreen.cpp b/src/gui/kernel/qscreen.cpp
index 038be09dc7..5785722918 100644
--- a/src/gui/kernel/qscreen.cpp
+++ b/src/gui/kernel/qscreen.cpp
@@ -37,6 +37,7 @@
 #include "qguiapplication_p.h"
 #include <qpa/qplatformscreen.h>
 
+#include <QtCore/QDebug>
 #include <QtCore/private/qobject_p.h>
 
 QT_BEGIN_NAMESPACE
@@ -654,4 +655,41 @@ QPixmap QScreen::grabWindow(WId window, int x, int y, int width, int height)
     return platformScreen->grabWindow(window, x, y, width, height);
 }
 
+#ifndef QT_NO_DEBUG_STREAM
+
+static inline void formatRect(QDebug &debug, const QRect r)
+{
+    debug << r.width() << 'x' << r.height()
+        << forcesign << r.x() << r.y() << noforcesign;
+}
+
+Q_GUI_EXPORT QDebug operator<<(QDebug debug, const QScreen *screen)
+{
+    const QDebugStateSaver saver(debug);
+    debug.nospace();
+    debug << "QScreen(" << (void *)screen;
+    if (screen) {
+        debug << ", name=" << screen->name();
+        if (debug.verbosity() > 2) {
+            if (screen == QGuiApplication::primaryScreen())
+                debug << ", primary";
+            debug << ", geometry=";
+            formatRect(debug, screen->geometry());
+            debug << ", available=";
+            formatRect(debug, screen->availableGeometry());
+            debug << ", logical DPI=" << screen->logicalDotsPerInchX()
+                << ',' << screen->logicalDotsPerInchY()
+                << ", physical DPI=" << screen->physicalDotsPerInchX()
+                << ',' << screen->physicalDotsPerInchY()
+                << ", devicePixelRatio=" << screen->devicePixelRatio()
+                << ", orientation=" << screen->orientation()
+                << ", physical size=" << screen->physicalSize().width()
+                << 'x' << screen->physicalSize().height() << "mm";
+        }
+    }
+    debug << ')';
+    return debug;
+}
+#endif // !QT_NO_DEBUG_STREAM
+
 QT_END_NAMESPACE
diff --git a/src/gui/kernel/qscreen.h b/src/gui/kernel/qscreen.h
index 255e735baf..f60fafcf63 100644
--- a/src/gui/kernel/qscreen.h
+++ b/src/gui/kernel/qscreen.h
@@ -52,6 +52,9 @@ class QScreenPrivate;
 class QWindow;
 class QRect;
 class QPixmap;
+#ifndef QT_NO_DEBUG_STREAM
+class QDebug;
+#endif
 
 class Q_GUI_EXPORT QScreen : public QObject
 {
@@ -153,6 +156,10 @@ private:
     friend class QPlatformScreen;
 };
 
+#ifndef QT_NO_DEBUG_STREAM
+Q_GUI_EXPORT QDebug operator<<(QDebug, const QScreen *);
+#endif
+
 QT_END_NAMESPACE
 
 #endif // QSCREEN_H
diff --git a/src/gui/kernel/qwindow.cpp b/src/gui/kernel/qwindow.cpp
index 06db4e81fa..616494bdca 100644
--- a/src/gui/kernel/qwindow.cpp
+++ b/src/gui/kernel/qwindow.cpp
@@ -2456,6 +2456,45 @@ void QWindowPrivate::applyCursor()
 }
 #endif // QT_NO_CURSOR
 
+#ifndef QT_NO_DEBUG_STREAM
+QDebug operator<<(QDebug debug, const QWindow *window)
+{
+    QDebugStateSaver saver(debug);
+    debug.nospace();
+    if (window) {
+        debug << window->metaObject()->className() << '(' << (void *)window;
+        if (!window->objectName().isEmpty())
+            debug << ", name=" << window->objectName();
+        if (debug.verbosity() > 2) {
+            const QRect geometry = window->geometry();
+            if (window->isVisible())
+                debug << ", visible";
+            if (window->isExposed())
+                debug << ", exposed";
+            debug << ", state=" << window->windowState()
+                << ", type=" << window->type() << ", flags=" << window->flags()
+                << ", surface type=" << window->surfaceType();
+            if (window->isTopLevel())
+                debug << ", toplevel";
+            debug << ", " << geometry.width() << 'x' << geometry.height()
+                << forcesign << geometry.x() << geometry.y() << noforcesign;
+            const QMargins margins = window->frameMargins();
+            if (!margins.isNull())
+                debug << ", margins=" << margins;
+            debug << ", devicePixelRatio=" << window->devicePixelRatio();
+            if (const QPlatformWindow *platformWindow = window->handle())
+                debug << ", winId=0x" << hex << platformWindow->winId() << dec;
+            if (const QScreen *screen = window->screen())
+                debug << ", on " << screen->name();
+        }
+        debug << ')';
+    } else {
+        debug << "QWindow(0x0)";
+    }
+    return debug;
+}
+#endif // !QT_NO_DEBUG_STREAM
+
 QT_END_NAMESPACE
 
 #include "moc_qwindow.cpp"
diff --git a/src/gui/kernel/qwindow.h b/src/gui/kernel/qwindow.h
index f9fe37718c..67585ce963 100644
--- a/src/gui/kernel/qwindow.h
+++ b/src/gui/kernel/qwindow.h
@@ -78,6 +78,9 @@ class QBackingStore;
 class QScreen;
 class QAccessibleInterface;
 class QWindowContainer;
+#ifndef QT_NO_DEBUG_STREAM
+class QDebug;
+#endif
 
 class Q_GUI_EXPORT QWindow : public QObject, public QSurface
 {
@@ -367,6 +370,10 @@ template <> inline const QWindow *qobject_cast<const QWindow*>(const QObject *o)
 }
 #endif // !Q_QDOC
 
+#ifndef QT_NO_DEBUG_STREAM
+Q_GUI_EXPORT QDebug operator<<(QDebug, const QWindow *);
+#endif
+
 QT_END_NAMESPACE
 
 #endif // QWINDOW_H