From c6a71e297447e27d49fce6a3ec3e28c303ec7042 Mon Sep 17 00:00:00 2001
From: Laszlo Agocs <laszlo.agocs@digia.com>
Date: Mon, 8 Sep 2014 10:14:43 +0200
Subject: [PATCH] Enhance QQuickWidget docs regarding transparency
Provide a section similar to the one in the QOpenGLWidget docs.
Change-Id: Ibe161f5b6e1b6654e78b522f44ba21b89fc85abe
Reviewed-by: Mitch Curtis <mitch.curtis@digia.com>
---
src/quickwidgets/qquickwidget.cpp | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/src/quickwidgets/qquickwidget.cpp b/src/quickwidgets/qquickwidget.cpp
index 285b000bdc..8d93bf389b 100644
--- a/src/quickwidgets/qquickwidget.cpp
+++ b/src/quickwidgets/qquickwidget.cpp
@@ -294,6 +294,26 @@ QImage QQuickWidgetPrivate::grabFramebuffer()
some of the benefits of threaded rendering, for example \l Animator classes and vsync driven
animations, will not be available.
+ \section1 Limitations
+
+ Putting other widgets underneath and making the QQuickWidget transparent will not lead
+ to the expected results: the widgets underneath will not be visible. This is because
+ in practice the QQuickWidget is drawn before all other regular, non-OpenGL widgets,
+ and so see-through types of solutions are not feasible. Other type of layouts, like
+ having widgets on top of the QQuickWidget, will function as expected.
+
+ When absolutely necessary, this limitation can be overcome by setting the
+ Qt::WA_AlwaysStackOnTop attribute on the QQuickWidget. Be aware, however that this
+ breaks stacking order. For example it will not be possible to have other widgets on
+ top of the QQuickWidget, so it should only be used in situations where a
+ semi-transparent QQuickWidget with other widgets visible underneath is required.
+
+ This limitation only applies when there are other widgets underneath the QQuickWidget
+ inside the same window. Making the window semi-transparent, with other applications
+ and the desktop visible in the background, is done in the traditional way: Set
+ Qt::WA_TranslucentBackground and change the Qt Quick Scenegraph's clear color to
+ Qt::transparent via setClearColor().
+
\sa {Exposing Attributes of C++ Types to QML}, {Qt Quick Widgets Example}, QQuickView
*/
@@ -1153,10 +1173,6 @@ QImage QQuickWidget::grabFramebuffer() const
color set to Qt::transparent and set the Qt::WA_TranslucentBackground widget
attribute.
- \note The limitations for having widgets underneath visible that are described
- in QOpenGLWidget::setFormat() apply also to QQuickWidget. In that case use
- Qt::WA_AlwaysStackOnTop instead of Qt::WA_TranslucentBackground.
-
\sa QQuickWindow::setColor()
*/
void QQuickWidget::setClearColor(const QColor &color)
--
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