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<concept id="GUID-33D93E96-98A9-4116-9028-3241D76A1036" xml:lang="en"><title>Enabling additional touch events for your application</title><shortdesc>The Symbian platform provides additional touch events to

enable drag events and to specify screen areas for touch events.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>By default, the Symbian platform sends only <parmname>EButton1Up</parmname> and <parmname>EButton1Down</parmname> touch events to applications.</p>

<p>If you want to enable <parmname>EDrag</parmname> touch events,

implement <xref href="GUID-B06F99BD-F032-3B87-AB26-5DD6EBE8C160.dita#GUID-B06F99BD-F032-3B87-AB26-5DD6EBE8C160/GUID-66B1D0C0-BFBB-36DB-BCC2-5563895251D5"><apiname>CCoeControl::EnableDragEvents()</apiname></xref> in your

container class.</p>

<p>When the mobile device user drags the stylus on the screen, <xref href="GUID-1FFA0073-3D83-388E-A824-08C31F90CC54.dita#GUID-1FFA0073-3D83-388E-A824-08C31F90CC54/GUID-5375D595-CF6A-38F6-9D62-E8DDF2D2BCF6"><apiname>TPointerEvent::EDrag()</apiname></xref> events are sent. When dragging stops,

the application receives the event <xref href="GUID-1FFA0073-3D83-388E-A824-08C31F90CC54.dita#GUID-1FFA0073-3D83-388E-A824-08C31F90CC54/GUID-5BADE607-E845-34B2-9C2D-B6882B7D4288"><apiname>TPointerEvent::EButton1Up()</apiname></xref>.</p>

<codeblock xml:space="preserve">void CTableauControl::ConstructL( const TRect&amp; aRect )

    {

    // This is parent window

    CreateWindowL();

    EnableDragEvents();

    SetRect( aRect );

    SetExtentToWholeScreen();

    // Initialize component array

    InitComponentArrayL();

	 //Implement your own logic here

  	 ActivateL();

    }</codeblock>

<p>It is enough that the container control set <codeph>EnableDragEvents()</codeph> in its construction. <codeph>EnableDragEvents()</codeph> need not

be set again for the child controls to receive dragging events.</p>

<section id="GUID-7B30F0D5-1EAE-4F40-B04F-6A3953BCC634"><title>Controlling

which control receives a touch event</title><p>Particularly when you

are receiving drag events it may be that an object in the window may

be drawn by one control, while the pointer is over another control.

In cases where you want to ensure that pointer events are received

by the intended control, implement <xref href="GUID-B06F99BD-F032-3B87-AB26-5DD6EBE8C160.dita#GUID-B06F99BD-F032-3B87-AB26-5DD6EBE8C160/GUID-172FDC09-7870-3FD0-9252-340178C58C28"><apiname>CCoeControl::SetPointerCapture()</apiname></xref>.</p><p>When a control receives a <xref href="GUID-1FFA0073-3D83-388E-A824-08C31F90CC54.dita#GUID-1FFA0073-3D83-388E-A824-08C31F90CC54/GUID-26CE2524-04BC-3592-A7E5-7EEC792A466E"><apiname>TPointerEvent::EButton1Down()</apiname></xref> event, all events will be sent to this control until the next <xref href="GUID-1FFA0073-3D83-388E-A824-08C31F90CC54.dita#GUID-1FFA0073-3D83-388E-A824-08C31F90CC54/GUID-5BADE607-E845-34B2-9C2D-B6882B7D4288"><apiname>TPointerEvent::EButton1Up()</apiname></xref> event. If you want to have

events to be sent to another control before the<xref href="GUID-1FFA0073-3D83-388E-A824-08C31F90CC54.dita#GUID-1FFA0073-3D83-388E-A824-08C31F90CC54/GUID-5BADE607-E845-34B2-9C2D-B6882B7D4288"><apiname>TPointerEvent::EButton1Up()</apiname></xref> event, call <codeph>SetPointerCapture(ETrue)</codeph> from the new

control. </p><p>When the new control has received its pointer event

and <xref href="GUID-1FFA0073-3D83-388E-A824-08C31F90CC54.dita#GUID-1FFA0073-3D83-388E-A824-08C31F90CC54/GUID-5BADE607-E845-34B2-9C2D-B6882B7D4288"><apiname>TPointerEvent::EButton1Up()</apiname></xref> has been received,

you have to call <codeph>SetPointerCapture(EFalse)</codeph> from the

new control to stop events being sent to it indefinitely.</p></section>

<section id="GUID-8C337F8B-346A-430A-9A7A-A48B53031421"><title>Specifying

screen areas for touch events</title><p>To specify screen areas (<codeph>TRect</codeph>) for touch events, see the example below.</p><codeblock xml:space="preserve">void CTableauControl::HandlePointerEventL(const TPointerEvent&amp; aPointerEvent)

    {

    // Does the user point exit text on screen? 

    // iExitRect is rectangle of the text area on screen.

    if (iExitRect.Contains(aPointerEvent.iPosition))

        {

        if (iEikonEnv->QueryWinL(_L("Klondike"),_L("Exit?")))

            {

            // Exit was pointed, then do exit   

            (static_cast<CKlondikeAppUi*>(iEikonEnv->AppUi()))->HandleCommandL(EEikCmdExit);

            return;

            }

        }

    ...

    }</codeblock></section>

<section id="GUID-8B12AF1C-A98A-416D-A586-807CFC2B839D"><title>Ignoring

events other than pointer up in your control</title><p>In cases where

you want to make sure your control receives only touch <parmname>EButton1Up</parmname> events after receiving a touch <parmname>EButton1Down</parmname> event, implement <xref href="GUID-B06F99BD-F032-3B87-AB26-5DD6EBE8C160.dita#GUID-B06F99BD-F032-3B87-AB26-5DD6EBE8C160/GUID-885AF2EB-587A-323B-99B5-019B2E7EBC78"><apiname>CCoeControl::IgnoreEventsUntilNextPointerUp()</apiname></xref>. </p></section>

</conbody></concept>