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-->  <!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"><concept id="GUID-7B275129-5EF7-4B27-B603-3BDE2C650A93" xml:lang="en"><title>Queries</title><prolog><metadata><keywords></keywords></metadata></prolog><conbody>

<p>A query is a state where the software waits for user input. Queries are

used in situations with more than one ways to proceed, when the application

needs data from the user, or when it is necessary to make sure the user knows

what is happening. A query must be exited before the application can proceed.</p>

<p>Queries are displayed in pop-up windows. The following query types can

be used:</p>

<ul>

<li><p><xref href="GUID-48482288-B60B-477A-8E28-132F7CBE2C94.dita">Confirmation

query</xref>: a question or notice with one or two possible responses. </p></li>

<li><p><xref href="GUID-13DEE42F-3EAB-4EB7-9CE1-C4930BCACE01.dita">List query</xref>:

a question with a selection of more than two possible (predefined) responses

in a list. </p></li>

<li><p><xref href="GUID-434F2412-59A1-4BCB-885D-5E708EAA6AB6.dita">Grid query</xref>:

a question with a selection of more than two possible (predefined) responses

in a grid. </p></li>

<li><p><xref href="GUID-DAD40CCE-EA59-4DCA-8922-824B18F0387A.dita">Multi-selection

list query</xref>: presents a list of items; the user can select any number

of them. </p></li>

<li><p><xref href="GUID-F77CC49A-904D-486B-8D16-972525EC34D5.dita">Data query</xref>:

used for numeric or textual input. </p></li>

<li><p><xref href="GUID-7235E4E9-0046-4BE1-91CF-BD52CE4489DF.dita">Message query</xref>:

used for various purposes in queries that are longer than one screen.</p></li>

</ul>

<section><title>Using queries in C++

applications</title><p>The APIs to use for queries are the Queries

API, Dialogs

API, and the Popups

API. For implementation information, see Using

the Dialogs API.</p><p>Query dialogs are dialogs that can be used to

require user input or user selection. All query dialogs derive from <xref href="jar:GUID-759FBC7F-5384-4487-8457-A8D4B76F6AA6.jar!/html/classCAknQueryDialog.html" format="application/java-archive"><codeph>CAknQueryDialog</codeph></xref>,

which inherits <xref href="jar:GUID-759FBC7F-5384-4487-8457-A8D4B76F6AA6.jar!/html/classCAknDialog.html" format="application/java-archive"><codeph>CAknDialog</codeph></xref>.

There are two types of queries: local and global queries. Local query dialogs

are local to a certain application. That means they are only displayed within

this application. Global query dialogs are system-wide queries, and are shown

topmost even when another application moves to the foreground. Query dialogs

require resource definitions when they are used in your code. </p><note><p>In

order to have a header pane, the <codeph>AVKON_HEADING</codeph> component

should be specified as the first dialog line in the resource description.</p></note><p>At

runtime, the dialog's header pane (<xref href="jar:GUID-759FBC7F-5384-4487-8457-A8D4B76F6AA6.jar!/html/classCAknPopupHeadingPane.html" format="application/java-archive"><codeph>CAknPopupHeadingPane</codeph></xref>) can be obtained by calling the method <xref href="jar:GUID-759FBC7F-5384-4487-8457-A8D4B76F6AA6.jar!/html/classCAknQueryDialog.html#8222b5679180543798d67db49abd4500" format="application/java-archive"><codeph>CAknQueryDialog::QueryHeading()</codeph></xref>.</p><p>The following

parts are available for modification from the class <xref href="jar:GUID-759FBC7F-5384-4487-8457-A8D4B76F6AA6.jar!/html/classCAknQueryDialog.html" format="application/java-archive"><codeph>CAknQueryDialog</codeph></xref>:</p><ul>

<li><p>Data query </p><ul>

<li><p>Header text </p></li>

<li><p>Header image/animation </p></li>

<li><p>Prompt text </p></li>

<li><p>Edit indicator (can be removed) </p></li>

</ul></li>

<li><p>Confirmation query </p><ul>

<li><p>Prompt text </p></li>

<li><p>Image/animation </p></li>

</ul></li>

<li><p>List query </p><ul>

<li><p>Header text </p></li>

<li><p>Header image/animation </p></li>

<li><p>List type (Single, SingleHeading, SingleGraphic, SingleGraphicHeading) </p></li>

</ul></li>

</ul><p>The following example illustrates the resource definition for the

Secret Editor Query, which contains a Secret Editor, resides inside the dialog.

The values for flags, type, id, and control are specific to the query dialog.

These values are enumerated in the file avkon.hrh, which is in the <codeph>./epoc32/include</codeph> folder.</p><codeblock xml:space="preserve">RESOURCE DIALOG r_aknexquery_code_query

    {

    flags = EGeneralQueryFlags

    buttons = R_AVKON_SOFTKEYS_OK_CANCEL;

    items =

        {

        DLG_LINE

            {

            type = EAknCtQuery;

            id = EGeneralQuery;

            control = EGeneralQueryFlags

                {

                layout = ECodeLayout;

                label = label_text;

                control = SECRETED

                    {

                    num_letters = 8;

                    };

                };

            }

        };

    }

</codeblock><p>The query in the above example includes a secret editor. For

information on implementing secret editors, see the Editors

API.  </p></section>

</conbody></concept>