Rewrite Qt Resource System overview

Restructure the Qt Resource System page to make the content more
accessible, and coherent:
- Focus less on the .qrc file format, but the overall use cases
- Treat CMake as first-class citizen
- Make it more obvious when to use :/, and when qrc:/

Some details that were deemed unnecessary were removed:
- details about the internal naming of the .cpp file when
  qmake is used.
- References to QDir::addSearchPath() and the search path list were
  removed. They relate IMO only indirectly to the Qt resource system.
- A lot of the explanation around Q_INIT_RESOURCE/Q_CLEANUP_RESOURCE
  were dubious at best.

Pick-to: 6.2 6.2.0
Fixes: QTBUG-95126
Fixes: QTBUG-94977
Fixes: QTBUG-59394
Task-number: QTBUG-88044
Change-Id: I04b64f2366631b2106f047de121daf5fdb01073d
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>

1 files changed, 75 insertions, 0 deletions

diff --git a/src/corelib/doc/snippets/resource-system/main.cpp b/src/corelib/doc/snippets/resource-system/main.cpp
new file mode 100644
index 0000000000..892f29d01d
--- /dev/null
+++ b/src/corelib/doc/snippets/resource-system/main.cpp
@@ -0,0 +1,75 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation 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,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QQmlApplicationEngine>
+#include <QAction>
+#include <QIcon>
+#include <QApplication>
+#include <QWidget>
+
+class DummyWidget : public QWidget {
+    Q_OBJECT
+
+    QAction *cutAct;
+
+    DummyWidget() {
+        //! [QAction]
+        cutAct = new QAction(QIcon(":/images/cut.png"), tr("Cu&t"), this);
+        //! [QAction]
+    }
+};
+
+int main()
+{
+//! [url]
+    QQmlApplicationEngine engine;
+    engine.load(QUrl("qrc:/myapp/main.qml"));
+//! [url]
+}