QSM: Reintroduce guard argument evaluation

Implements the suggestion from Simon Hausmann (codereview 89716
from 08-05 14:46) to use QQmlScriptString rather then the previous
used MetaObject-manipulation.

This also introduces comparison operators for QQmlScriptString
to be able to determinate if a QQmlScriptString changed what
is needed cause there is otherwise no way to access (all) the
needed details within QQmlScriptStringPrivate.

Change-Id: I198479eac8fd37cbdd98a99aacdd8eebf7b75d21
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 69 insertions, 0 deletions

diff --git a/src/qml/doc/snippets/qml/statemachine/guardcondition.qml b/src/qml/doc/snippets/qml/statemachine/guardcondition.qml
new file mode 100644
index 0000000000..f9ecf450bd
--- /dev/null
+++ b/src/qml/doc/snippets/qml/statemachine/guardcondition.qml
@@ -0,0 +1,69 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Ford Motor Company
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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 Digia Plc and its Subsidiary(-ies) 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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//! [document]
+import QtQml.StateMachine 1.0
+import QtQuick 2.0
+
+Rectangle {
+    Button {
+        anchors.fill: parent
+        id: button
+        StateMachine {
+            StateBase {
+                SignalTransition {
+                    targetState: finalState
+                    signal: button.mysignal
+                    // the guard condition uses the mystr string argument from mysignal
+                    guard: mystr == "test"
+                }
+            }
+            FinalState {
+                id: finalState
+            }
+        }
+        // define the signal the SignalTransition is connected with
+        signal mysignal(string mystr)
+        // on clicking the button emit the signal with a single string argument
+        onClicked: button.mysignal("test")
+    }
+}
+//! [document]
+