topics/ui/ui-events.jd

page.title=
parent.title=
parent.link=index.html
@jd:body

<div id="qv-wrapper">
<div id="qv">
  <h2></h2>
  <ol>
    <li><a href="#EventListeners"></a></li>
    <li><a href="#EventHandlers"></a></li>
    <li><a href="#TouchMode"></a></li>
    <li><a href="#HandlingFocus"></a></li>
  </ol>

</div>
</div>

<p> Android

</p>

<p> UI
Android
 ()  <code>onTouchEvent()</code>


<a href="#EventListeners"></a> UI
</p>

<p>
 {@link android.widget.Button}

<a href="#EventHandlers"></a>
</p>


<h2 id="EventListeners"></h2>

<p> {@link android.view.View}
 UI Android
</p>

<p></p>

<dl>
  <dt><code>onClick()</code></dt>
    <dd> {@link android.view.View.OnClickListener} () "enter"


</dd>
  <dt><code>onLongClick()</code></dt>
    <dd> {@link android.view.View.OnLongClickListener} () "enter"  ()


</dd>
  <dt><code>onFocusChange()</code></dt>
    <dd> {@link android.view.View.OnFocusChangeListener}
</dd>
  <dt><code>onKey()</code></dt>
    <dd> {@link android.view.View.OnKeyListener}
</dd>
  <dt><code>onTouch()</code></dt>
    <dd> {@link android.view.View.OnTouchListener} ()

</dd>
  <dt><code>onCreateContextMenu()</code></dt>
    <dd> {@link android.view.View.OnCreateContextMenuListener} ()
<a href="{@docRoot}guide/topics/ui/menus.html#context-menu"></a>

</dd>
</dl>

<p> Activity  <code>View.set...Listener()</code>


(
<code>{@link android.view.View#setOnClickListener(View.OnClickListener) setOnClickListener()}</code> {@link android.view.View.OnClickListener OnClickListener} )
</p>

<p> on-click  </p>

<pre>
// Create an anonymous implementation of OnClickListener
private OnClickListener mCorkyListener = new OnClickListener() {
    public void onClick(View v) {
      // do something when the button is clicked
    }
};

protected void onCreate(Bundle savedValues) {
    ...
    // Capture our button from layout
    Button button = (Button)findViewById(R.id.corky);
    // Register the onClick listener with the implementation above
    button.setOnClickListener(mCorkyListener);
    ...
}
</pre>

<p> Activity  OnClickListener
</p>
<pre>
public class ExampleActivity extends Activity implements OnClickListener {
    protected void onCreate(Bundle savedValues) {
        ...
        Button button = (Button)findViewById(R.id.corky);
        button.setOnClickListener(this);
    }

    // Implement the OnClickListener callback
    public void onClick(View v) {
      // do something when the button is clicked
    }
    ...
}
</pre>

<p> <code>onClick()</code>

</p>
<ul>
  <li><code>{@link android.view.View.OnLongClickListener#onLongClick(View) onLongClick()}</code> -
 <em>true</em> / on-click  <em>false</em>


</li>
  <li><code>{@link android.view.View.OnKeyListener#onKey(View,int,KeyEvent) onKey()}</code> -

     <em>true</em> / on-key  <em>false</em>

</li>
  <li><code>{@link android.view.View.OnTouchListener#onTouch(View,MotionEvent) onTouch()}</code> -

 <em>false</em>


</li>
</ul>

<p>
 () <code>{@link android.view.View#dispatchKeyEvent(KeyEvent)
dispatchKeyEvent()}</code>
 <code>{@link android.app.Activity#onKeyDown(int,KeyEvent) onKeyDown()}</code>  <code>{@link android.app.Activity#onKeyUp(int,KeyEvent) onKeyUp()}</code>  Activity

</p>

<p>
<strong></strong>
<code>{@link android.app.Activity#onKeyDown(int,KeyEvent) onKeyDown()}</code>
 UI

 Return  {@link android.view.inputmethod.EditorInfo#IME_ACTION_DONE}  UI


</p>

<p class="note"><strong></strong>Android
 <em>true</em>

 <em>true</em> </p>


<h2 id="EventHandlers"></h2>

<p><a href="{@docRoot}guide/topics/ui/custom-components.html"></a>


</p>
<ul>
  <li><code>{@link  android.view.View#onKeyDown}</code> - </li>
  <li><code>{@link  android.view.View#onKeyUp}</code> - </li>
  <li><code>{@link  android.view.View#onTrackballEvent}</code> - </li>
  <li><code>{@link  android.view.View#onTouchEvent}</code> - </li>
  <li><code>{@link  android.view.View#onFocusChanged}</code> - </li>
</ul>
<p>

</p>
<ul>
  <li><code>{@link  android.app.Activity#dispatchTouchEvent(MotionEvent)
    Activity.dispatchTouchEvent(MotionEvent)}</code> -  {@link
android.app.Activity} </li>
  <li><code>{@link  android.view.ViewGroup#onInterceptTouchEvent(MotionEvent)
    ViewGroup.onInterceptTouchEvent(MotionEvent)}</code> -  {@link
android.view.ViewGroup} </li>
  <li><code>{@link  android.view.ViewParent#requestDisallowInterceptTouchEvent(boolean)
    ViewParent.requestDisallowInterceptTouchEvent(boolean)}</code> -  <code>{@link
    android.view.ViewGroup#onInterceptTouchEvent(MotionEvent)}</code>
</li>
</ul>

<h2 id="TouchMode"></h2>
<p>
 ()


</p>
<p>


{@link android.view.View#isFocusableInTouchMode}  true
 on-click

</p>
<p>


</p>
<p>
 ( Activity)
{@link android.view.View#isInTouchMode}

</p>


<h2 id="HandlingFocus"></h2>

<p>

 <code>{@link android.view.View#isFocusable()}</code>
 <code>{@link android.view.View#setFocusable(boolean) setFocusable()}</code>
 <code>{@link android.view.View#isFocusableInTouchMode()}</code>

 <code>{@link android.view.View#setFocusableInTouchMode(boolean) setFocusableInTouchMode()}</code>
</p>

<p>

 XML

<var>nextFocusDown</var> <var>nextFocusLeft</var> <var>nextFocusRight</var>
<var>nextFocusUp</var><em></em>
 ID<em></em>
</p>
<pre>
&lt;LinearLayout
    android:orientation="vertical"
    ... >
  &lt;Button android:id="@+id/top"
          android:nextFocusUp="@+id/bottom"
          ... />
  &lt;Button android:id="@+id/bottom"
          android:nextFocusDown="@+id/top"
          ... />
&lt;/LinearLayout>
</pre>

<p>

 <var>nextFocusUp</var> ()
</p>

<p> UI  () <code>android:focusable</code> XML

 <var>true</var> <code>android:focusableInTouchMode</code>
</p>
<p> <code>{@link android.view.View#requestFocus()}</code></p>
<p> ()
<code>{@link android.view.View.OnFocusChangeListener#onFocusChange(View,boolean) onFocusChange()}</code> (<a href="#EventListeners"></a>)
</p>


<!--
<h2 is="EventCycle">Event Cycle</h2>
   <p>The basic cycle of a View is as follows:</p>
   <ol>
    <li>An event comes in and is dispatched to the appropriate View. The View
    handles the event and notifies any listeners.</li>
    <li>If, in the course of processing the event, the View's bounds may need
    to be changed, the View will call {@link android.view.View#requestLayout()}.</li>
    <li>Similarly, if in the course of processing the event the View's appearance
    may need to be changed, the View will call {@link android.view.View#invalidate()}.</li>
    <li>If either {@link android.view.View#requestLayout()} or {@link android.view.View#invalidate()} were called,
    the framework will take care of measuring, laying out, and drawing the tree
    as appropriate.</li>
   </ol>

   <p class="note"><strong>Note:</strong> The entire View tree is single threaded. You must always be on
   the UI thread when calling any method on any View.
   If you are doing work on other threads and want to update the state of a View
   from that thread, you should use a {@link android.os.Handler}.
   </p>
-->