diff options
| -rw-r--r-- | src/gui/kernel/qwidget.cpp | 20 | ||||
| -rw-r--r-- | src/gui/kernel/qwidget_p.h | 1 | ||||
| -rw-r--r-- | tests/auto/qwidget/tst_qwidget.cpp | 25 |
3 files changed, 46 insertions, 0 deletions
diff --git a/src/gui/kernel/qwidget.cpp b/src/gui/kernel/qwidget.cpp index ac35d42..fcb098f 100644 --- a/src/gui/kernel/qwidget.cpp +++ b/src/gui/kernel/qwidget.cpp @@ -292,6 +292,7 @@ QWidgetPrivate::QWidgetPrivate(int version) #ifndef QT_NO_IM , inheritsInputMethodHints(0) #endif + , inSetParent(0) #if defined(Q_WS_X11) , picture(0) #elif defined(Q_WS_WIN) @@ -2563,6 +2564,22 @@ WId QWidget::effectiveWinId() const if (id || !testAttribute(Qt::WA_WState_Created)) return id; QWidget *realParent = nativeParentWidget(); + if (!realParent && d_func()->inSetParent) { + // In transitional state. This is really just a workaround. The real problem + // is that QWidgetPrivate::setParent_sys (platform specific code) first sets + // the window id to 0 (setWinId(0)) before it sets the Qt::WA_WState_Created + // attribute to false. The correct way is to do it the other way around, and + // in that case the Qt::WA_WState_Created logic above will kick in and + // return 0 whenever the widget is in a transitional state. However, changing + // the original logic for all platforms is far more intrusive and might + // break existing applications. + // Note: The widget can only be in a transitional state when changing its + // parent -- everything else is an internal error -- hence explicitly checking + // against 'inSetParent' rather than doing an unconditional return whenever + // 'realParent' is 0 (which may cause strange artifacts and headache later). + return 0; + } + // This widget *must* have a native parent widget. Q_ASSERT(realParent); Q_ASSERT(realParent->internalWinId()); return realParent->internalWinId(); @@ -10041,6 +10058,7 @@ void QWidget::setParent(QWidget *parent) void QWidget::setParent(QWidget *parent, Qt::WindowFlags f) { Q_D(QWidget); + d->inSetParent = true; bool resized = testAttribute(Qt::WA_Resized); bool wasCreated = testAttribute(Qt::WA_WState_Created); QWidget *oldtlw = window(); @@ -10195,6 +10213,8 @@ void QWidget::setParent(QWidget *parent, Qt::WindowFlags f) ancestorProxy->d_func()->embedSubWindow(this); } #endif + + d->inSetParent = false; } /*! diff --git a/src/gui/kernel/qwidget_p.h b/src/gui/kernel/qwidget_p.h index 377e3a7..c9dba29 100644 --- a/src/gui/kernel/qwidget_p.h +++ b/src/gui/kernel/qwidget_p.h @@ -759,6 +759,7 @@ public: #ifndef QT_NO_IM uint inheritsInputMethodHints : 1; #endif + uint inSetParent : 1; // *************************** Platform specific ************************************ #if defined(Q_WS_X11) // <----------------------------------------------------------- X11 diff --git a/tests/auto/qwidget/tst_qwidget.cpp b/tests/auto/qwidget/tst_qwidget.cpp index bb8b8b4..a851d03 100644 --- a/tests/auto/qwidget/tst_qwidget.cpp +++ b/tests/auto/qwidget/tst_qwidget.cpp @@ -345,6 +345,7 @@ private slots: void immediateRepaintAfterInvalidateBuffer(); #endif void effectiveWinId(); + void effectiveWinId2(); void customDpi(); void customDpiProperty(); @@ -8522,6 +8523,30 @@ void tst_QWidget::effectiveWinId() QVERIFY(child.effectiveWinId()); } +void tst_QWidget::effectiveWinId2() +{ + QWidget parent; + + class MyWidget : public QWidget { + bool event(QEvent *e) + { + if (e->type() == QEvent::WinIdChange) { + // Shouldn't crash. + effectiveWinId(); + } + + return QWidget::event(e); + } + }; + + MyWidget child; + child.setParent(&parent); + parent.show(); + + child.setParent(0); + child.setParent(&parent); +} + class CustomWidget : public QWidget { public: |