diff options
author | Andrew Solovay <asolovay@google.com> | 2015-07-08 12:49:21 -0700 |
---|---|---|
committer | Andrew Solovay <asolovay@google.com> | 2015-07-09 13:22:31 -0700 |
commit | 07e7021e062dd3579f662502b15c0682c4672cfe (patch) | |
tree | 4de97c6be743f350507fcaa92ea5f6235587d024 /docs/html | |
parent | 1809f534766b2f1d015806f8f37bcefe8337d7b8 (diff) | |
download | frameworks_base-07e7021e062dd3579f662502b15c0682c4672cfe.zip frameworks_base-07e7021e062dd3579f662502b15c0682c4672cfe.tar.gz frameworks_base-07e7021e062dd3579f662502b15c0682c4672cfe.tar.bz2 |
docs: Clarified how to find out when a switch is toggled
Per Chris, the existing doc was incorrect: you *can't* check for a
button press and a switch flip the same way. (The button triggers a
click event, but the switch does not.) Chris suggested that we just
remove the reference to onClick and suggest using a listener for
both kinds of buttons (ToggleButton and Switch).
Also pulled one note out of a section where it didn't fit (the bit
about changing a button/switch's state programmatically didn't have
much to do with listening for clicks) and put it at the top, and I
fixed a Javadoc typo for a relevant class that I happened to notice.
See first comment for doc stage location.
bug: 20625504
Change-Id: I9c8975111381e5b169f6a61454ef3a93da635759
Diffstat (limited to 'docs/html')
-rw-r--r-- | docs/html/guide/topics/ui/controls/togglebutton.jd | 92 |
1 files changed, 17 insertions, 75 deletions
diff --git a/docs/html/guide/topics/ui/controls/togglebutton.jd b/docs/html/guide/topics/ui/controls/togglebutton.jd index 09af516..e0549ec 100644 --- a/docs/html/guide/topics/ui/controls/togglebutton.jd +++ b/docs/html/guide/topics/ui/controls/togglebutton.jd @@ -6,16 +6,15 @@ page.tags=switch,togglebutton <div id="qv"> <h2>In this document</h2> <ol> - <li><a href="#HandlingEvents">Responding to Click Events</a> - <ol> - <li><a href="#ClickListener">Using an OnCheckedChangeListener</a></li> - </ol> + <li> + <a href="#ClickListener">Responding to Button Presses</a> </li> </ol> <h2>Key classes</h2> <ol> <li>{@link android.widget.ToggleButton}</li> <li>{@link android.widget.Switch}</li> + <li>{@link android.widget.CompoundButton}</li> </ol> </div> </div> @@ -26,6 +25,12 @@ page.tags=switch,togglebutton object. Android 4.0 (API level 14) introduces another kind of toggle button called a switch that provides a slider control, which you can add with a {@link android.widget.Switch} object.</p> +<p> + If you need to change a button's state yourself, you can use the {@link + android.widget.CompoundButton#setChecked CompoundButton.setChecked()} or + {@link android.widget.CompoundButton#toggle CompoundButton.toggle()} methods. +</p> + <div style="float:left;width:200px"> <img src="{@docRoot}images/ui/togglebutton.png" alt="" /> <p class="img-caption"><em>Toggle buttons</em></p> @@ -36,78 +41,15 @@ provides a slider control, which you can add with a {@link android.widget.Switch <p class="img-caption"><em>Switches (in Android 4.0+)</em></p> </div> -<p style="clear:left">The {@link android.widget.ToggleButton} and {@link android.widget.Switch} -controls are subclasses of {@link android.widget.CompoundButton} and function in the same manner, so -you can implement their behavior the same way.</p> - -<h2 id="HandlingEvents">Responding to Click Events</h2> - -<p>When the user selects a {@link android.widget.ToggleButton} and {@link android.widget.Switch}, -the object receives an on-click event.</p> - -<p>To define the click event handler, add the <code><a -href="/reference/android/R.attr.html#onClick">android:onClick</a></code> attribute to the -<code><ToggleButton></code> or <code><Switch></code> element in your XML -layout. The value for this attribute must be the name of the method you want to call in response -to a click event. The {@link android.app.Activity} hosting the layout must then implement the -corresponding method.</p> - -<p>For example, here's a {@link android.widget.ToggleButton} with the <code><a -href="/reference/android/R.attr.html#onClick">android:onClick</a></code> attribute:</p> - -<pre> -<ToggleButton - android:id="@+id/togglebutton" - android:layout_width="wrap_content" - android:layout_height="wrap_content" - android:textOn="Vibrate on" - android:textOff="Vibrate off" - android:onClick="onToggleClicked"/> -</pre> - -<p>Within the {@link android.app.Activity} that hosts this layout, the following method handles the -click event:</p> - -<pre> -public void onToggleClicked(View view) { - // Is the toggle on? - boolean on = ((ToggleButton) view).isChecked(); - - if (on) { - // Enable vibrate - } else { - // Disable vibrate - } -} -</pre> - -<p>The method you declare in the {@link android.R.attr#onClick android:onClick} attribute -must have a signature exactly as shown above. Specifically, the method must:</p> -<ul> - <li>Be public</li> - <li>Return void</li> - <li>Define a {@link android.view.View} as its only parameter (this will be the {@link -android.view.View} that was clicked)</li> -</ul> - -<p class="note"><strong>Tip:</strong> If you need to change the state -yourself, -use the {@link android.widget.CompoundButton#setChecked(boolean)} or {@link -android.widget.CompoundButton#toggle()} method to change the state.</p> - - - -<h3 id="ClickListener">Using an OnCheckedChangeListener</h3> - -<p>You can also declare a click event handler programmatically rather than in an XML layout. This -might be necessary if you instantiate the {@link android.widget.ToggleButton} or {@link -android.widget.Switch} at runtime or you need to -declare the click behavior in a {@link android.app.Fragment} subclass.</p> +<h2 id="ClickListener">Responding to Button Presses</h2> -<p>To declare the event handler programmatically, create an {@link -android.widget.CompoundButton.OnCheckedChangeListener} object and assign it to the button by calling -{@link -android.widget.CompoundButton#setOnCheckedChangeListener}. For example:</p> +<p> + To detect when the user activates the button or switch, create an {@link + android.widget.CompoundButton.OnCheckedChangeListener} object and assign it + to the button by calling {@link + android.widget.CompoundButton#setOnCheckedChangeListener + setOnCheckedChangeListener()}. For example: +</p> <pre> ToggleButton toggle = (ToggleButton) findViewById(R.id.togglebutton); |