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/****************************************************************************
**
** 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 qtquick-positioners.html
\ingroup qml-features
\title Item Layouts
Positioner items are container items that manage the positions and sizes of
items in a declarative user interface. Positioners behave in a similar way to
the \l{Widgets and Layouts}{layout managers} used with standard Qt widgets,
except that they are also containers in their own right.
Positioners make it easier to work with many items when they need
to be arranged in a regular layout.
\section1 Positioners
A set of standard positioners are provided in the basic set of Qt Quick
graphical elements:
\list
\li \l{#Column}{Column} arranges its children in a column
\li \l{#Row}{Row} arranges its children in a row
\li \l{#Grid}{Grid} arranges its children in a grid
\li \l{#Flow}{Flow} arranges its children like words on a page
\endlist
\section2 Column
\div {class="float-right"}
\inlineimage qml-column.png
\enddiv
\l Column items are used to vertically arrange items. The following example
uses a Column item to arrange three \l Rectangle items in an area defined
by an outer \l Item. The \l{Column::spacing}{spacing} property is set to
include a small amount of space between the rectangles.
\snippet doc/src/snippets/qml/column/column.qml document
Note that, since Column inherits directly from Item, any background color
must be added to a parent Rectangle, if desired.
\section2 Row
\div {class="float-right"}
\inlineimage qml-row.png
\enddiv
\l Row items are used to horizontally arrange items. The following example
uses a Row item to arrange three rounded \l Rectangle items in an area defined
by an outer colored Rectangle. The \l{Row::spacing}{spacing} property is set to
include a small amount of space between the rectangles.
We ensure that the parent Rectangle is large enough so that there is some space
left around the edges of the horizontally centered Row item.
\snippet doc/src/snippets/qml/row.qml document
\section2 Grid
\div {class="float-right"}
\inlineimage qml-grid-spacing.png
\enddiv
\l Grid items are used to place items in a grid or table arrangement.
The following example uses a Grid item to place four \l Rectangle items
in a 2-by-2 grid. As with the other positioners, the spacing between items
can be specified using the \l{Grid::spacing}{spacing} property.
\snippet doc/src/snippets/qml/grid-spacing.qml document
There is no difference between horizontal and vertical spacing inserted
between items, so any additional space must be added within the items
themselves.
Any empty cells in the grid must be created by defining placeholder items
at the appropriate places in the Grid definition.
\section2 Flow
\div {class="float-right"}
\inlineimage qml-flow-text1.png
\inlineimage qml-flow-text2.png
\enddiv
\l Flow items are used to place items like words on a page, with rows or
columns of non-overlapping items.
Flow items arrange items in a similar way to \l Grid items, with items
arranged in lines along one axis (the minor axis), and lines of items
placed next to each other along another axis (the major axis). The
direction of flow, as well as the spacing between items, are controlled
by the \l{Flow::}{flow} and \l{Flow::}{spacing} properties.
The following example shows a Flow item containing a number of \l Text
child items. These are arranged in a similar way to those shown in the
screenshots.
\snippet doc/src/snippets/qml/flow.qml document
The main differences between the Grid and Flow positioners are that items
inside a Flow will wrap when they run out of space on the minor axis, and
items on one line may not be aligned with items on another line if the
items do not have uniform sizes. As with Grid items, there is no independent
control of spacing between items and between lines of items.
\section1 Other Ways to Position Items
There are several other ways to position items in a user interface. In addition
to the basic technique of specifying their coordinates directly, they can be
positioned relative to other items with \l{anchor-layout}{anchors}, or used
with \l{QML Data Models} such as
\l{QML Data Models#VisualItemModel}{VisualItemModel}.
*/
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