<?xml version="1.0"?>

    <!--
        WARNING: This schema is a temporary, implementation detail. It is NOT
        meant to be used for validation. It violates Unique Particle Attribution
        (and thus is an invalid schema) and regularly does not have the same
        constraints as the actual UiBinder parsers. The sole purpose is to
        provide autocompletion proposals within Eclipse.
    -->
    <!--
        Eclipse may still try to validate using this (e.g. if user right-clicks
        on the file and chooses "Validate"). This schema is left completely
        extensible (you will see <xs:any> and <xs:anyAttribute> everywhere
        possible, along with mixed content) in hopes of never flagging a
        validation error.
    -->
    <!--
        Even though we do not use this for validation, it is useful to set
        attributes as required. Eclipse uses this information to automatically
        insert that attribute in the autocompletion.
    -->
    <!--
        An example case where we violate Unique Particle Attribution is when we
        have an optional <ui:style> as a child of <ui:UiBinder> AND we allow
        <xs:any /> as a child of <ui:UiBinder> too. This causes this schema to
        be invalid (Eclipse still gladly accepts it and at least uses it for
        offering autocomplete choices.)
    -->

    <!--
        <xs:choice maxOccurs="unbounded" minOccurs="0"> allows for optional
        children, with multiple occurrences of a child, and without any ordering
        constraints.
    -->
    <!--
        <xs:sequence> <xs:any></xs:any> </xs:sequence> allows for a single
        required child.
    -->
    <!--
        An attribute that is defined locally within an element will be without a
        namespace (unprefixed). This means that the interpretation of the
        attribute is up to its parent element. An attribute that is defined
        globally will have the namespace of the targetNamespace. An unprefixed
        "global" attribute can be defined via attribute groups.
    -->
    <!--
        <xs:any /> are used to allow for additional elements (which is required
        for allowing third-party widgets, etc.) Similarly, <xs:anyAttribute />
        allows for additional attributes.
    -->
    <!--
        elementFormQualified="qualified" means child elements will need to be
        namespaced also. (It will be a validation error if they are not
        namespaced.) For example, this is what is used to have the "north" child
        of "DockLayoutPanel" require the gwt-user namespace.
    -->
    <!--
        targetNamespace defines the namespace for elements and global attributes
        defined in this file.
    -->
    <!--
        <complexType ... mixed="true"> allows for mixed content (text and child
        elements, e.g. allowing HTML content).
    -->

<xs:schema
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    targetNamespace="urn:ui:com.google.gwt.uibinder"
    xmlns="urn:ui:com.google.gwt.uibinder"
    elementFormDefault="qualified">

    <xs:element
        name="UiBinder">
        <xs:complexType
            mixed="true">

            <xs:choice
                minOccurs="0"
                maxOccurs="unbounded">

                <xs:element
                    name="style"
                    type="StyleType" />
                <xs:element
                    name="with"
                    type="WithType" />
                <xs:element
                    name="data"
                    type="DataType" />
                <xs:element
                    name="image"
                    type="ImageType" />

                <!-- Allow any elements (e.g. widgets from any package) -->
                <xs:any
                    processContents="lax" />
            </xs:choice>

            <xs:attribute
                name="defaultLocale"
                type="xs:string" />
            <xs:attribute
                name="generateKeys"
                type="xs:string" />
            <xs:attribute
                name="generateFormat"
                type="xs:string" />
            <xs:attribute
                name="generateFilename"
                type="xs:string" />
            <xs:attribute
                name="generateLocales"
                type="xs:string" />

            <!-- Allow any attributes (e.g. namespace definitions) -->
            <xs:anyAttribute
                processContents="lax" />

        </xs:complexType>
    </xs:element>

    <xs:complexType
        name="StyleType">
        <!-- Only allow text content -->
        <xs:simpleContent>
            <xs:extension
                base="xs:string">

                <xs:attribute
                    name="src"
                    type="xs:string" />
                <xs:attribute
                    name="field"
                    type="xs:string" />
                <xs:attribute
                    name="import"
                    type="xs:string" />
                <xs:attribute
                    name="type"
                    type="xs:string" />
                <xs:attribute
                    name="gss"
                    type="xs:string" />

                <!-- Allow any attributes (e.g. from other schemas) -->
                <xs:anyAttribute
                    processContents="lax" />

            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>

    <xs:complexType
        name="WithType"
        mixed="true">
        <!--
            Be safe by allowing any content (text or elements). This pattern is
            used below too.
        -->
        <xs:choice
            minOccurs="0"
            maxOccurs="unbounded">
            <xs:any
                processContents="lax" />
        </xs:choice>

        <xs:attribute
            name="field"
            type="xs:string"
            use="required" />
        <xs:attribute
            name="type"
            type="xs:string"
            use="required" />

        <xs:anyAttribute
            processContents="lax" />

    </xs:complexType>

    <xs:complexType
        name="DataType"
        mixed="true">
        <xs:choice
            minOccurs="0"
            maxOccurs="unbounded">
            <xs:any
                processContents="lax" />
        </xs:choice>

        <xs:attribute
            name="field"
            type="xs:string"
            use="required" />
        <xs:attribute
            name="src"
            type="xs:string"
            use="required" />
        <xs:attribute
            name="doNotEmbed"
            type="xs:boolean"
            use="optional" />
        <xs:attribute
            name="mimeType"
            type="xs:string"
            use="optional" />

        <xs:anyAttribute
            processContents="lax" />

    </xs:complexType>

    <xs:complexType
        name="ImageType"
        mixed="true">
        <xs:choice
            minOccurs="0"
            maxOccurs="unbounded">
            <xs:any
                processContents="lax" />
        </xs:choice>

        <xs:attribute
            name="field"
            type="xs:string"
            use="required" />
        <xs:attribute
            name="src"
            type="xs:string" />
        <xs:attribute
            name="flipRtl"
            type="xs:string" />
        <xs:attribute
            name="repeatStyle"
            type="xs:string" />

        <xs:anyAttribute
            processContents="lax" />

    </xs:complexType>

    <xs:element
        name="attribute">
        <xs:complexType
            mixed="true">
            <xs:complexContent>
                <xs:extension
                    base="MsgType">
                    <xs:attribute
                        name="name"
                        type="xs:string"
                        use="required" />
                </xs:extension>
            </xs:complexContent>
        </xs:complexType>
    </xs:element>

    <xs:complexType
        name="MsgType"
        mixed="true">
        <xs:choice
            minOccurs="0"
            maxOccurs="unbounded">
            <xs:any
                processContents="lax" />
        </xs:choice>

        <xs:attribute
            name="description"
            type="xs:string" />
        <xs:attribute
            name="key"
            type="xs:string" />
        <xs:attribute
            name="meaning"
            type="xs:string" />

        <xs:anyAttribute
            processContents="lax" />

    </xs:complexType>

    <xs:element
        name="msg"
        type="MsgType">
    </xs:element>

    <xs:element
        name="ph">
        <xs:complexType
            mixed="true">
            <xs:choice
                minOccurs="0"
                maxOccurs="unbounded">
                <xs:any
                    processContents="lax" />
            </xs:choice>

            <xs:attribute
                name="name"
                type="xs:string"
                use="required" />
            <xs:attribute
                name="example"
                type="xs:string" />

            <xs:anyAttribute
                processContents="lax" />

        </xs:complexType>
    </xs:element>

</xs:schema>