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/*!
    \contentspage {Qt Creator Manual}
    \previouspage creator-quick-ui-forms.html
    \page creator-using-qt-quick-designer.html
    \nextpage qmldesigner-pathview-editor.html

    \title Using Qt Quick Designer

    You can edit \l{Qt Quick UI Forms} (ui.qml files) in \QMLD. \QC opens the
    UI forms in the \uicontrol {Form Editor} tab in the \uicontrol Design mode.
    It is recommended that you use UI forms for components that you want to
    design in \QMLD.

    \image qmldesigner-visual-editor.png "Visual editor"

    Use \QMLD to manage your project:

    \list

        \li \uicontrol Canvas (1) is the working area where you create QML
            components and design applications. In the \uicontrol {Form Editor}
            tab, you can use a visual editor to design UIs, and in the
            \uicontrol {Text Editor} tab, you can use a code editor to edit the
            QML code generated by the visual editor.

        \li Use the sidebars to select QML types to use in the project, to
            specify properties for them, and to
            view them in a tree structure, as well as to create connections
            and browse projects and files. You can select the content of the
            sidebars in the sidebar menu:

        \list

            \li \uicontrol {Library} (2) displays the building blocks that you
                can use to design applications: predefined QML types, your own
                QML components, or Qt Quick Controls 2 that you import to the
                project, and other resources.

            \li \uicontrol {Navigator} (3) displays the items in the current QML
                file as a tree structure.

            \li \uicontrol {Properties} (4) organizes the properties of the
                selected item. You can change the properties also in the
                \uicontrol {Text Editor}.

            \li \uicontrol Connections (5) enables you to create connections
                between objects, signals, and object properties. For more
                information, see \l{Adding Connections}.

            \li \uicontrol {File System} shows all files in the currently
                selected directory. For more information, see
                \l{Viewing the File System}.

            \li \uicontrol {Open Documents} shows currently open files.

            \li \uicontrol {Projects} shows a list of projects open in the
                current session. For more information, see
                \l{Viewing Project Files}.

        \endlist

        \li \uicontrol {State} pane (6) displays the different states of the item.
            QML states typically describe user interface configurations, such as
            the UI controls, their properties and behavior and the available
            actions.

    \endlist

    \section1 Managing Item Hierarchy

    The \uicontrol Navigator displays the items in the current QML file and their
    relationships.
    Items (1) are listed in a tree structure, below their parent (2).

    \image qmldesigner-navigator.png "Navigator"

    You can select items in the \uicontrol Navigator to edit their properties
    in the \uicontrol Properties pane. Items can access the properties of their
    parent item. To select items on the canvas, right-click an item,
    and select another type in the context menu.

    Typically, child items are located within the parent item on the
    canvas. However, they do not necessarily have to fit inside the parent
    item. For example, you might want to make a mouse area larger than the
    rectangle or image beneath it (1).

    \image qmldesigner-element-size.png "Mouse area for a button"

    When you copy an item, all its child items are also copied. When
    you remove an item, the child items are also removed.

    You can show and hide items to focus on specific parts of the application.
    Click the \inlineimage icon_color_none.png
    (\uicontrol Transparent) button to change the visibility of an item on the
    canvas. To change the
    visibility of an item in the application, select the \uicontrol Visibility
    check box in the \uicontrol Properties pane or select \uicontrol Edit >
    \uicontrol Visibility in the context menu.

    You can also set the \uicontrol Opacity field to 0 to hide items that you
    want to apply animation to.

    As all properties, visibility and opacity are inherited from the parent
    item. To hide or show child items, edit the properties of the parent item.

    To reset item size, position, or anchors, select context menu commands. To
    change the source of an Image type, select \uicontrol {Change Source URL} in
    the context menu.

    To view lists of files or projects, instead, select \uicontrol {File System},
    \uicontrol {Open Documents}, or \uicontrol Projects in the menu.
    To view several types of content at a time, split the sidebars by clicking
    the \inlineimage splitbutton_horizontal.png
    (\uicontrol Split) button.

    \section2 Setting the Stacking Order

    The \c z property of an \l Item determines its position in relation to its
    sibling items in the
    type hierarchy. By default, items with a higher stacking value are
    drawn on top of siblings with a lower stacking value. Items with the same
    stacking value are drawn in the order they are listed, from the last item
    up.

    To raise or lower the stack value of an item, select \inlineimage raise.png
    (\uicontrol Raise) or \inlineimage lower.png
    (\uicontrol Lower) on the toolbar.

    To move an item to the front or back of all its siblings, right-click it in
    the navigator or the \uicontrol {Form Editor} and select
    \uicontrol {Stack (z)}. To remove the \c z property, select
    \uicontrol {Reset z Property}.

    You can also use a \uicontrol StackLayout item (Qt Quick Controls 2) to
    create a stacked view. For more information, see \l {Using Layouts}.

    \section2 Switching Parent Items

    When you drag and drop instances of QML types to the canvas, Qt Quick Designer
    adds the new item as a child of the item beneath it.
    When you move items on the canvas, Qt Quick Designer cannot determine
    whether you want to adjust their position or attach them to a new
    parent item. Therefore, the parent item is not automatically
    changed. To change the parent of the item, press down the \key Shift
    key before you drag and drop the item into a new position. The topmost
    item under the cursor becomes the new parent of the item.

    You can change the parent of an item also in the \uicontrol Navigator.
    Drag and drop the item to another position in the tree or use the arrow
    buttons (1) to move the item in the tree.

    \image qmldesigner-navigator-arrows.png "Navigator arrow buttons"

    \section1 QML Type Library

    The \uicontrol {Library} enables you to select QML types, UI components, and
    resources, as well as to manage imports.

    \uicontrol {QML Types} displays the QML types grouped by category: your own QML
    components, basic types, layouts, positioner types, and views.

    Sets of UI components with the look and feel of a particular mobile device
    platform have been defined for Qt Quick 1. Since Qt 5.1, ready-made Qt
    Quick Controls, Dialogs, and Layouts are available for creating user
    interfaces using Qt Quick 2.1. The components and controls are based on
    standard QML types. To view the components and controls in the
    \uicontrol {Library}, import the component sets in \uicontrol Imports.

    The \uicontrol {Qt Quick Application} wizards for a particular platform add the
    import statements automatically. You can remove import statements in
    \uicontrol Imports

    \image qmldesigner-qml-components.png "QML Components"

    \uicontrol {Resources} displays the images and other files that you copy
    to the project folder (to the same subfolder as the QML files).

    \section1 Specifying Item Properties

    The \uicontrol Properties pane displays all the properties of the selected item.
    The properties are grouped by type. The top part of the pane
    displays properties that are common to all QML types, such as
    position, size, and visibility.

    The bottom part of the pane displays properties that are specific to each
    QML type. For example, the following image displays the properties you
    can set for \uicontrol Rectangle (1) and \uicontrol Text (2) items.

    \image qmldesigner-element-properties.png

    To change the item type, double-click the \uicontrol Type field in the
    \uicontrol Properties pane, and enter the name of another QML type in the
    field. If you have specified properties for the item that are not supported
    for the new type, the type cannot be changed and an error message is
    displayed. Remove the properties in the \uicontrol {Text Editor} and try
    again.

    To return an item to its implicit position after moving it, select the
    \inlineimage qtcreator-reset-position-icon.png
    (\uicontrol {Reset Position}) button on the toolbar. To return it to its
    implicit size, select \inlineimage qtcreator-reset-size-icon.png
    (\uicontrol {Reset Size}) button.

    To set the visibility of the item, select \uicontrol {Edit > Visibility} in the context menu.

    To specify the color of the selected item in the \uicontrol {Select Color}
    dialog, select \uicontrol {Edit Color} in the context menu.

    For more information on the properties available for an item, press
    \key {F1}.

    \section2 Viewing Changes in Properties

    The default values of properties are displayed in white color, while the
    values that you specify explicitly are highlighted with blue color. In
    addition, property changes in states are highlighted with blue.

    This allows you to easily see which values are set in the UI form or
    QML file and
    which values are default characteristics of a QML type or a component.

    When editing states, you can easily see which values are explicitly set in
    the current state and which values are derived from the base state.

    The following images illustrate this. In the base state, the \uicontrol Size (1)
    and \uicontrol Colors (2) values are explicitly set and highlighted.

    \image qmldesigner-properties-explicit-base.png "Explicitly set properties"

    In \uicontrol State1, only the color (1) is explicitly set and highlighted.

    \image qmldesigner-properties-explicit-state1.png "Explicitly set properties"

    Resetting a property sets it back to the default value and removes the value
    from the UI form or QML file.

    \note As a result, all boolean values can be visualized in four different
    ways.

    For example, visibility can be visualized as follows:

    \table
        \row
            \li \image qmldesigner-boolean-true.png
            \li TRUE
            \li The QML type is visible by default. The visibility might be
                overridden by the visibility set in the base state.
        \row
            \li \image qmldesigner-boolean-true-blue.png
            \li TRUE (highlighted)
            \li The QML type is explicitly set to visible.
        \row
            \li \image qmldesigner-boolean-false.png
            \li FALSE
            \li The QML type is hidden by default. The visibility might be
                overridden by the visibility set in the base state.
        \row
            \li \image qmldesigner-boolean-false-blue.png
            \li FALSE (hightlighted)
            \li The type is explicitly set to hidden.
    \endtable

    \section2 Marking Text Items for Translation

    To support translators, mark each text item that should be translated.
    In the \uicontrol Properties pane, \uicontrol Text field, select \uicontrol tr (1).

    \image qmldesigner-text-property-tr.png "Text properties"

    By default, the text string is enclosed in a \c qsTr() call.

    \image qml-translate.png "Text marked for translation"

    If you use text IDs instead of plain text, change the default call to
    \c qsTrId(). Select \uicontrol Tools > \uicontrol Options >
    \uicontrol {Qt Quick} > \uicontrol {Qt Quick Designer}, and then select the
    \uicontrol {qsTrId()} radio button in the \uicontrol Internationalization
    group. For more information about text ID based translations, see
    \l {Qt Linguist Manual: Text ID Based Translations}.

    To preserve the context when editing the text or to change the context
    by setting a binding on the text property, change the default call to
    \c qsTranslate() by selecting the \uicontrol {qsTranslate()} radio button.

    For more information, see
    \l {Internationalization and Localization with Qt Quick}.

    \section2 Loading Placeholder Data

    \QMLD supports views, models, and delegates, so that when you add a Grid
    View, List View, or Path View item, the ListModel and the delegate
    item are added automatically.

    However, the missing context of the application presents a challenge for
    \QMLD. Specific models defined in C++ are the most obvious case. Often,
    the context is missing simple properties, which are either defined in C++,
    or in other QML files. A typical example is an item that uses the
    properties of its parent, such as \c parent.width.

    \section3 Using Dummy Models

    If you open a file in \QMLD that references a C++ model, you see nothing on
    the canvas. If the data in the model is fetched from the internet, you have
    no control over it. To get reliable data, \e {dummy data} was introduced.

    For example, the following code snippet describes the file example.qml that
    contains a ListView that in turn specifies a C++ model:

    \qml
        ListView {
            model: dataModel
            delegate: ContactDelegate {
                name: name
            }
        }
    \endqml

    Create a directory named \e dummydata in the root directory of the project,
    so that it is not deployed to the device. In the \c dummydata directory,
    create a QML file that has the same name as the value of \c model:

    \code
        qml/exampleapp/example.qml
        dummydata/dataModel.qml
    \endcode

    Then create the dataModel.qml file that contains the dummy data:

    \qml
        import QtQuick 1.0

        ListModel {
             ListElement {
                 name: "Ariane"
             }
             ListElement {
                 name: "Bella"
             }
             ListElement {
                 name: "Corinna"
             }
        }
    \endqml

    \section3 Creating Dummy Context

    The following example presents a common pattern in QML:

    \qml
        Item {
            width: parent.width
            height: parent.height
        }
    \endqml

    This works nicely for applications but \QMLD displays a zero-sized item.
    A parent for the opened file does not exist, because the context is
    missing. To get around the missing context, the idea of a \e {dummy
    context} is introduced. If you place a file with the same name as the
    application (here, example.qml) in the \c {dummydata/context} directory,
    you can fake a parent context:

    \qml
        import QtQuick 1.0
        import QmlDesigner 1.0

        DummyContextObject {
            parent: Item {
                width: 640
                height: 300
            }
        }
    \endqml

    \section2 Building Transformations on Items

    The \uicontrol Advanced pane allows you to configure advanced transformations,
    such as rotation, scale, and translation. You can assign any number of
    transformations to an item. Each transformation is applied in order, one at
    a time.

    For more information on Transform types, see \l{Transform}.

    \section2 Editing Properties Inline

    You can double-click objects on the canvas to edit their text, color, or
    source properties inline.
    Because you can specify several of these properties for some QML types, such
    as \l [QML]{TextEdit}{Text Edit}, you can also right-click objects to open
    the inline editors from a context-menu.

    \image qmldesigner-inline-editing.png

    \section1 Adding States

    User interfaces are designed to present different interface configurations
    in different scenarios, or to modify their appearances in response to user
    interaction. Often, there are a set of changes that are made concurrently,
    such that the interface could be seen to be internally changing from one
    \e state to another.

    This applies generally to interfaces regardless of their complexity.
    A photo viewer may initially present images in a grid, and when an image is
    clicked, change to a detailed state where the individual image is expanded
    and the interface is changed to present new options for image editing.
    On the other end of the scale, when a simple button is pressed, it may change
    to a \e pressed state in which its color and position is modified to give a
    pressed appearance.

    In QML, any item can change between different states to apply sets of
    changes that modify the properties of relevant items. Each state can present
    a different configuration that can, for example:

    \list

        \li Show some UI items and hide others.

        \li Present different available actions to the user.

        \li Start, stop or pause animations.

        \li Execute some script required in the new state.

        \li Change a property value for a particular item.

        \li Show a different view or screen.

    \endlist

    The \uicontrol State pane displays the different \l{State}{states}
    of the component in the Qt Quick Designer. The \uicontrol State pane is
    collapsed by default to save space. Select \uicontrol Expand in the context
    menu to view the whole pane.

    \image qmldesigner-transitions.png "State pane"

    To add states, click the \inlineimage plus.png
    button. Then modify the new state in the editor.
    For example, to change the appearance of a button, you can hide the button
    image and show another image in its place. Or, to add movement to the screen,
    you can change the position of an object on the canvas and then add animation
    to the change between the states.

    To determine when the state should be applied, select
    \uicontrol {Set when Condition} in the menu and specify a
    \l [QtQuick]{State::when}{when} property for the state.

    You can preview the states in the \uicontrol State pane and click them to switch
    between states on the canvas.

    For more information on using states, see \l{Creating Screens}.

    If you add animation to the states, you can run the application to test the
    animation.

    For more information on adding animation, see \l{Animating Screens}.

    \section1 Working with QML Types on Canvas

    You design applications on the canvas by placing items on it.

    \section2 Snapping to Parent and Sibling Items

    When you are working on a design, you can use snapping to align
    items on the canvas. Click the \inlineimage snapping.png
    button to have the items snap to their parent or sibling items. Snapping
    lines automatically appear to help you position the items.
    Click the \inlineimage snapping_and_anchoring.png
    button to anchor the item to the items that you snap to.

    Choose \uicontrol {Tools > Options > Qt Quick > Qt Quick Designer} to specify
    settings for snapping. In the \uicontrol {Parent item padding} field, specify the
    distance in pixels between the parent item and the snapping lines. In the
    \uicontrol {Sibling item spacing} field, specify the distance in pixels between
    sibling items and the snapping lines.

    The following image shows the snapping lines when \uicontrol {Parent item padding}
    is set to 5 pixels.

    \image qmldesigner-snap-margins.png "Snapping lines on canvas"

    \section2 Hiding Item Boundaries

    \QMLD displays the boundaries of items on the canvas. To hide
    the boundaries, click the \inlineimage boundingrect.png
    button.

    \section2 Selecting Items

    When you point the mouse to overlapping items, the frontmost item is
    selected by default. However, items that do not have any content, such as
    the mouse area, are typically located in front of items that do have
    content, such as rectangles or border images. To select items with content
    by default, click the
    \inlineimage qmldesigner-only-select-items-with-content.png
    button.

    \section2 Previewing Component Size

    The width and height of the root item in a QML file determine the size of
    the component. You can reuse components, such as buttons, in different
    sizes in other QML files and design screens for use with different device
    profiles, screen resolution, or screen orientation. The component size
    might also be zero (0,0) if its final size is determined by property
    bindings.

    To experiment with different component sizes, enter values in the
    \uicontrol {Override Width} and \uicontrol {Override Height} fields (1) on
    the canvas toolbar. The changes are
    displayed in the \uicontrol State pane (2) and on the canvas (3), but the property
    values are not changed permanently in the QML file. You can permanently
    change the property values in the \uicontrol Properties pane (4).

    \image qmldesigner-preview-size.png "Canvas width and height"

    \section2 Specifying Canvas Size

    To change the canvas size, select \uicontrol {Tools > Options > Qt Quick
    > Qt Quick Designer} and
    specify the canvas width and height in the \uicontrol Canvas group.

    \section2 Refreshing the Canvas

    When you open QML files in \QMLD, the items in the file are drawn on
    the canvas. When you edit the item properties in \QMLD, the QML file and
    the image on the canvas might get out of sync. For example, when you change
    the position of an item within a column or a row, the new position might
    not be displayed correctly on the canvas.

    To refresh the image on the canvas, press \key R or select the
    \inlineimage qmldesigner-reset-view.png
    (\uicontrol {Reset View}) button.

*/
