svins wrote: > The input events are queued. So your case is valid. When you disable a > button there can be already multiple events in the event queue. Sad > but true :( > > Greenhand wrote: > > In my project, I has a layout as follows: > > <LinearLayout xmlns:android="http://schemas.android.com/apk/res/ > > android" > > android:layout_width="fill_parent" > > android:layout_height="fill_parent" > > android:orientation="vertical"> > > > > <Button > > android:id="@+id/startButton" > > android:layout_width="fill_parent" > > android:layout_height="0dp" > > android:layout_weight="1" > > android:text="start" > > /> > > <Button > > android:id="@+id/stopButton" > > android:layout_width="fill_parent" > > android:layout_height="0dp" > > android:layout_weight="1" > > android:text="stop" > > /> > > </LinearLayout> > > It is quite simple. There are two buttons. One is start and the other > > is stop. > > > > And an Activity as follows: > > package button.test; > > > > import android.app.Activity; > > import android.os.Bundle; > > import android.util.Log; > > import android.view.View; > > import android.widget.Button; > > > > public class MainActivity extends Activity { > > private static final String TAG = "MainActivity"; > > private Button startButton; > > private Button stopButton; > > @Override > > public void onCreate(Bundle savedInstanceState) { > > super.onCreate(savedInstanceState); > > setContentView(R.layout.activity_main); > > startButton = (Button)findViewById(R.id.startButton); > > startButton.setOnClickListener(new View.OnClickListener() { > > > > @Override > > public void onClick(View arg0) { > > Log.d(TAG,"startButton isEnabled(): > "+arg0.isEnabled()+" executing > > on thread "+ Thread.currentThread().getName()); > > if(arg0.isEnabled()==false){ > > throw new > RuntimeException("startButton"); > > } > > arg0.setEnabled(false); > > stopButton.setEnabled(true); > > } > > }); > > stopButton = (Button)findViewById(R.id.stopButton); > > stopButton.setOnClickListener(new View.OnClickListener() { > > > > @Override > > public void onClick(View arg0) { > > Log.d(TAG,"stopButton isEnabled(): > "+arg0.isEnabled()+" executing > > on thread "+ Thread.currentThread().getName()); > > if(arg0.isEnabled()==false){ > > throw new > RuntimeException("stopButton"); > > } > > arg0.setEnabled(false); > > startButton.setEnabled(true); > > } > > }); > > } > > } > > The logic is: (1)When the start button is clicked, disable it and > > enable the stop button. (2)When the stop button is clicked, disable it > > and enable the start button. > > > > What I expect is that when the onClickListener of a button is > > executing, the button state should be enabled. It is impossible to > > fire the onClickListener when the button is disabled. Therefore, I add > > the if block and the RuntimeException to detect it. > > > > It works when I interact with it but it crashes when I run the monkey > > test (adb shell monkey -p button.test -v 50000). > > > > The logcat messages are as follows: > > D/MainActivity(1836): startButton isEnabled(): true main > > D/MainActivity(1836): stopButton isEnabled(): true main > > D/MainActivity(1836): startButton isEnabled(): true main > > D/MainActivity(1836): startButton isEnabled(): false main > > D/AndroidRuntime(1836): Shutting down VM > > W/dalvikvm(1836): threadid=1: thread exiting with uncaught exception > > (group=0x41745300) > > E/AndroidRuntime(1836): FATAL EXCEPTION: main > > E/AndroidRuntime(1836): java.lang.RuntimeException: startButton > > E/AndroidRuntime(1836): at button.test.MainActivity > > $1.onClick(MainActivity.java:24) > > E/AndroidRuntime(1836): at > android.view.View.performClick(View.java: > > 4084) > > E/AndroidRuntime(1836): at android.view.View > > $PerformClick.run(View.java:16966) > > E/AndroidRuntime(1836): at > > android.os.Handler.handleCallback(Handler.java:615) > > E/AndroidRuntime(1836): at > > android.os.Handler.dispatchMessage(Handler.java:92) > > E/AndroidRuntime(1836): at > android.os.Looper.loop(Looper.java:137) > > E/AndroidRuntime(1836): at > > android.app.ActivityThread.main(ActivityThread.java:4745) > > E/AndroidRuntime(1836): at > > java.lang.reflect.Method.invokeNative(Native Method) > > E/AndroidRuntime(1836): at > > java.lang.reflect.Method.invoke(Method.java:511) > > E/AndroidRuntime(1836): at com.android.internal.os.ZygoteInit > > $MethodAndArgsCaller.run(ZygoteInit.java:786) > > E/AndroidRuntime(1836): at > > com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) > > E/AndroidRuntime(1836): at dalvik.system.NativeStart.main(Native > > Method) > > > > Note that at line 4, the button state is disabled when the > > onClickListener is executing!!! It is quite strange. In addition, both > > the onClickListeners are run on the main thread. > > What I expect is that there is no race condition between the > > onClickListeners because they run on the same thread. > > > > Can anyone explain why the program crashes when I run the monkey > > test? >
Adding to the other comment, the GUI is single-threaded so thread safety cannot be a factor. -- Lew -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
