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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 using <parmname>CCoeControl::EnableDragEvents()</parmname>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 <parmname>CCoeControl::EnableDragEvents()</parmname> in

your container class.</p>

<p>When the mobile device user drags the stylus on the screen, <codeph>TPointerEvent::EDrag()</codeph> events

are sent. When dragging stops, the application receives the event <codeph>TPointerEvent::EButton1Up()</codeph>.</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 <parmname>CCoeControl::SetPointerCapture()</parmname>.</p><p>When

a control receives a <parmname>TPointerEvent::EButton1Down()</parmname> event,

all events will be sent to this control until the next <parmname>TPointerEvent::EButton1Up()</parmname> event.

If you want to have events to be sent to another control before the <parmname>TPointerEvent::EButton1Up()</parmname> event,

call <codeph>SetPointerCapture(ETrue)</codeph> from the new control. </p><p>When

the new control has received its pointer event and <parmname>TPointerEvent::EButton1Up()</parmname> 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 <parmname>CCoeControl::IgnoreEventsUntilNextPointerUp()</parmname>. </p></section>

</conbody></concept>