Presentation通过指定displayID来决定显示在哪个屏幕上，这样就实现了多屏幕的显示（如果手机有多个显示设备），
也就让不同的屏幕可以显示不同的画面，
在只有一个显示设备的情况下，我们可以打开开发者选项中的设置来模拟多屏，进而来测试Presentation。
在开发者选项的Drawing中有
Simulate secondary displays开关
打开后，在界面可以显示一个模拟出来的小屏幕
dumpsys display
可以查看到模拟屏幕的信息
Logical Displays: size=2
Display 0:
mDisplayId=0
Display 5:
mDisplayId=5
mLayerStack=5
mHasContent=false
mRequestedMode=0
mRequestedColorMode=0
mDisplayOffset=(0, 0)
mPrimaryDisplayDevice=Overlay #1
这里我们直接使用Display 5来进行测试
public class MainActivity extends ActionBarActivity {
private Button mButton;
private Button mButton2;
private Button mButton3;
private String TAG = "testvirsual";
private DisplayManager mDisplayManager;
private static final int BLUEISH = 0xff1122ee;
@SuppressLint("NewApi")
private final class TestPresentation extends Presentation {
private final int mColor;
private final int mWindowType;
private final int mWindowFlags;
protected void finalize( )
{
// finalization code here
Log.d(TAG, "======= finalize ()");
}
public TestPresentation(Context context, Display display,
int color, int windowType, int windowFlags) {
super(context, display);
Log.d(TAG, "======= TestPresentation ()");
mColor = color;
mWindowType = windowType;
mWindowFlags = windowFlags;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "======= TestPresentation onCreate");
setTitle(TAG);
getWindow().setType(mWindowType);
getWindow().addFlags(mWindowFlags);
// Create a solid color image to use as the content of the presentation.
ImageView view = new ImageView(getContext());
view.setImageDrawable(new ColorDrawable(mColor));
view.setLayoutParams(new LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
setContentView(view);
Log.d(TAG, "======= TestPresentation onCreate done");
}
}
public TestPresentation mpresentation;
public Display defaultDisplay;
private void assertDisplayCanShowPresentation(String message, final Display display,
final int color, final int windowType, final int windowFlags) {
//final TestPresentation[] presentation = new TestPresentation[1];
// mpresentation = new TestPresentation[1];
try {
Log.d(TAG, "======== TestPresentation run called");
mpresentation = new TestPresentation(MainActivity.this, display,
color, windowType, windowFlags);
Log.d(TAG, "======== TestPresentation show called");
mpresentation.show();
} finally {
}
}
mButton3.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
Log.d(TAG, "======= going to call assertDisplayCanShowPresentation");
Display aDisplay = mDisplayManager.getDisplay(5);
// Show a private presentation on the display.
assertDisplayCanShowPresentation("presentation window",
aDisplay, BLUEISH,
WindowManager.LayoutParams.TYPE_TOAST, 0);
}
可以在模拟屏上显示查看到实际存在的另外一个屏幕的效果
