diff options
author | Jerome Pasion <jerome.pasion@nokia.com> | 2012-02-09 17:31:02 +0100 |
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committer | Qt by Nokia <qt-info@nokia.com> | 2012-02-14 12:53:21 +0100 |
commit | 2d4e6ff9dd1e0e3410c4dc002c25d80fecfeafd2 (patch) | |
tree | b12aec803acf837024b4426526f1ce69cb3080ae /doc/src/qml/qmlsyntax.qdoc | |
parent | d95178153a0f15991b2e6e91216dbcf5c0be2af3 (diff) |
Doc: Overhaul of doc/src/declarative and QtQuick2 docs.
-Consolidated model/view documentation into one.
-Added a new navigation for all overviews (grouped the pages)
-New front page that shows the grouping
-Separated the Qt C++ from the main QML overviews
-Consolidated Qt C++ into the "declarative runtime" section
-New articles about JavaScript, the engine, and plugins
-Fixed the older examples. New snippet comments
-Renamed some of the articles
-kept the qtquick2 qmlmodule
-"Qt Quick Elements"
Moved contents of doc/src/declarative into respective
module dirs.
-Qt Quick 2, LocalStorage, Particles, and QML are now
separate.
-Removed unused or duplicate documentation.
-edited C++ examples
-removed navigation and "\inqmlmodule QtQuick 2" for
those pages that are not in Qt Quick 2
-fixed doc/src/ licenses to header.FDL from qtbase
Change-Id: Ib36f9c07565d91160fa8d04f9670c438f684b82a
Reviewed-by: Sergio Ahumada <sergio.ahumada@nokia.com>
Diffstat (limited to 'doc/src/qml/qmlsyntax.qdoc')
-rw-r--r-- | doc/src/qml/qmlsyntax.qdoc | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/doc/src/qml/qmlsyntax.qdoc b/doc/src/qml/qmlsyntax.qdoc new file mode 100644 index 0000000000..b2b7fc89bd --- /dev/null +++ b/doc/src/qml/qmlsyntax.qdoc @@ -0,0 +1,155 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of +** this file. +** +** Other Usage +** Alternatively, this file may be used in accordance with the terms +** and conditions contained in a signed written agreement between you +** and Nokia. +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! +\page qml-syntax.html +\title QML Syntax +\ingroup QML Reference +\brief listing of valid QML syntax + +\tableofcontents + +QML is a declarative language designed to describe the user interface of a +program: both what it looks like, and how it behaves. In QML, a user +interface is specified as a tree of objects with properties. + +JavaScript is used as a scripting language in QML, so you may want +to learn a bit more about it (\l{Javascript Guide}) before diving +deeper into QML. + +\section1 Basic QML Syntax + +QML looks like this: + +\code +import QtQuick 2.0 + +Rectangle { + width: 200 + height: 200 + color: "blue" + + Image { + source: "pics/logo.png" + anchors.centerIn: parent + } +} +\endcode + +Objects are specified by their type, followed by a pair of braces. Object +types always begin with a capital letter. In the above example, there are +two objects, a \l Rectangle, and an \l Image. Between the braces, we can specify +information about the object, such as its properties. + +Properties are specified as \c {propertyname: value}. In the above example, we +can see the Image has a property named \c source, which has been assigned the +value \c "pics/logo.png". The property and its value are separated by a colon. + +Properties can be specified one-per-line: + +\code +Rectangle { + width: 100 + height: 100 +} +\endcode + +or you can put multiple properties on a single line: + +\code +Rectangle { width: 100; height: 100 } +\endcode + +When multiple property/value pairs are specified on a single line, they +must be separated by a semicolon. + +The \c import statement imports the \c Qt \l{QML Modules}{module}, which contains all of the +standard \l {QML Elements}. Without this import statement, the \l Rectangle +and \l Image elements would not be available. + +\section1 Expressions + +In addition to assigning values to properties, you can also assign +expressions written in JavaScript. + +\code +Rotation { + angle: 360 * 3 +} +\endcode + +These expressions can include references to other objects and properties, in which case +a \i binding is established: when the value of the expression changes, the property the +expression has been assigned to is automatically updated to that value. + +\code +Item { + Text { + id: text1 + text: "Hello World" + } + Text { + id: text2 + text: text1.text + } +} +\endcode + +In the example above, the \c text2 object will display the same text as \c text1. If \c text1 is changed, +\c text2 is automatically changed to the same value. + +Note that to refer to other objects, we use their \i id values. (See below for more +information on the \i id property.) + +\section1 QML Comments + +Commenting in QML is similar to JavaScript. +\list +\o Single line comments start with // and finish at the end of the line. +\o Multiline comments start with /* and finish with *\/ +\endlist + +\snippet doc/src/snippets/declarative/comments.qml 0 + +Comments are ignored by the engine. They are useful for explaining what you +are doing; for referring back to at a later date, or for others reading +your QML files. + +Comments can also be used to prevent the execution of code, which is +sometimes useful for tracking down problems. + +\code +Text { + text: "Hello world!" + //opacity: 0.5 +} +\endcode + +In the above example, the Text object will have normal opacity, since the +line opacity: 0.5 has been turned into a comment. + +*/ |