Stylesheet: Handle tabs with elide mode set correctly

In order for SE_TabBarTabText to correctly calculate the space available
for the text it needs to get the rectangle of the tab directly instead
of relying on the option's rectangle as this may have been modified
before this point. Therefore we introduce QStyleOptionTabV4 to be able
to store the index as part of the option so it can be queried directly.

[ChangeLog][QtWidgets] Added QStyleOptionTabV4 as a subclass of
QStyleOptionTab so that the tab's index information can be obtained.

Fixes: QTBUG-50637
Change-Id: If705f5069fdd14eeccf06bc63dba4e8d2e704359
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Christian Ehrlicher <ch.ehrlicher@gmx.de>

6 files changed, 84 insertions, 1 deletions

diff --git a/tests/manual/widgets/widgets/qtabbar/qtabbar.pro b/tests/manual/widgets/widgets/qtabbar/qtabbar.pro
new file mode 100644
index 0000000000..b39c81493b
--- /dev/null
+++ b/tests/manual/widgets/widgets/qtabbar/qtabbar.pro
@@ -0,0 +1 @@
+SUBDIRS = stylesheet
diff --git a/tests/manual/widgets/widgets/qtabbar/stylesheet/main.cpp b/tests/manual/widgets/widgets/qtabbar/stylesheet/main.cpp
new file mode 100644
index 0000000000..02393f66f9
--- /dev/null
+++ b/tests/manual/widgets/widgets/qtabbar/stylesheet/main.cpp
@@ -0,0 +1,71 @@
+/****************************************************************************
+ **
+ ** Copyright (C) 2020 The Qt Company Ltd.
+ ** Contact: https://www.qt.io/licensing/
+ **
+ ** This file is part of the test suite of the Qt Toolkit.
+ **
+ ** $QT_BEGIN_LICENSE:BSD$
+ ** Commercial License Usage
+ ** Licensees holding valid commercial Qt licenses may use this file in
+ ** accordance with the commercial license agreement provided with the
+ ** Software or, alternatively, in accordance with the terms contained in
+ ** a written agreement between you and The Qt Company. For licensing terms
+ ** and conditions see https://www.qt.io/terms-conditions. For further
+ ** information use the contact form at https://www.qt.io/contact-us.
+ **
+ ** BSD License Usage
+ ** Alternatively, you may use this file under the terms of the BSD license
+ ** as follows:
+ **
+ ** "Redistribution and use in source and binary forms, with or without
+ ** modification, are permitted provided that the following conditions are
+ ** met:
+ **   * Redistributions of source code must retain the above copyright
+ **     notice, this list of conditions and the following disclaimer.
+ **   * Redistributions in binary form must reproduce the above copyright
+ **     notice, this list of conditions and the following disclaimer in
+ **     the documentation and/or other materials provided with the
+ **     distribution.
+ **   * Neither the name of The Qt Company Ltd nor the names of its
+ **     contributors may be used to endorse or promote products derived
+ **     from this software without specific prior written permission.
+ **
+ **
+ ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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+ ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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+ ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+ **
+ ** $QT_END_LICENSE$
+ **
+ ****************************************************************************/
+
+// This test is for checking that when there is padding set on the stylesheet and the elide mode is
+// set that it is correctly shown as elided and not clipped.
+
+#include <QApplication>
+#include <QTabBar>
+#include <QIcon>
+
+int main(int argc, char** argv)
+{
+    QApplication app(argc, argv);
+    app.setStyleSheet("QTabBar::tab { padding-left: 20px; }\n");
+    QIcon icon(":/v.ico");
+
+    QTabBar b;
+    b.setElideMode(Qt::ElideRight);
+    b.addTab(icon, "some text");
+    b.resize(80,32);
+    b.show();
+
+    return app.exec();
+}
diff --git a/tests/manual/widgets/widgets/qtabbar/stylesheet/res.qrc b/tests/manual/widgets/widgets/qtabbar/stylesheet/res.qrc
new file mode 100644
index 0000000000..9d0bb8e061
--- /dev/null
+++ b/tests/manual/widgets/widgets/qtabbar/stylesheet/res.qrc
@@ -0,0 +1,5 @@
+<RCC>
+    <qresource prefix="/">
+        <file>v.ico</file>
+    </qresource>
+</RCC>
diff --git a/tests/manual/widgets/widgets/qtabbar/stylesheet/stylesheet.pro b/tests/manual/widgets/widgets/qtabbar/stylesheet/stylesheet.pro
new file mode 100644
index 0000000000..4957503abc
--- /dev/null
+++ b/tests/manual/widgets/widgets/qtabbar/stylesheet/stylesheet.pro
@@ -0,0 +1,5 @@
+QT += widgets
+TEMPLATE = app
+TARGET = stylesheet
+RESOURCES += res.qrc
+SOURCES += main.cpp
diff --git a/tests/manual/widgets/widgets/qtabbar/stylesheet/v.ico b/tests/manual/widgets/widgets/qtabbar/stylesheet/v.ico
new file mode 100644
index 0000000000..90dfbc9f9b
--- /dev/null
+++ b/tests/manual/widgets/widgets/qtabbar/stylesheet/v.ico
diff --git a/tests/manual/widgets/widgets/widgets.pro b/tests/manual/widgets/widgets/widgets.pro
index 1fccb09d79..5a07e621e8 100644
--- a/tests/manual/widgets/widgets/widgets.pro
+++ b/tests/manual/widgets/widgets/widgets.pro
@@ -2,4 +2,5 @@ TEMPLATE = subdirs
 SUBDIRS = bigmenucreator \
     defaultUpMenuBar \
     multiscreen-menus \
-    qtoolbutton/menuOnMultiScreens
+    qtoolbutton/menuOnMultiScreens \
+    qtabbar