Android: Transparent activity

You may want to create an activity that sits on top of another but you want the former to be invisible (for instance, you want to encapsulate something that involves a call to startActivityForResult, which was my case).

In my particular case I wanted to be able to pick an image from the Gallery or the Camera and after that I wanted to crop the obtained image and return the result to an activity.

Manifest

<activity
            android:name="package.activities.GetImageActivity"
            android:theme="@style/Theme.Transparent"
            android:configChanges="orientation"
            android:label="@string/title_activity_get_image"
            android:screenOrientation="portrait" >
        </activity>

styles

<style name="Theme.Transparent" parent="android:Theme">
        <item name="android:windowIsTranslucent">true</item>
        <item name="android:windowBackground">@android:color/transparent</item>
        <item name="android:windowContentOverlay">@null</item>
        <item name="android:windowNoTitle">true</item>
        <item name="android:windowIsFloating">true</item>
        <item name="android:backgroundDimEnabled">false</item>
    </style>

Class

public class GetImageActivity extends BaseActivity {

private static final int REQUEST_CODE_CROP_IMAGE = 300;
private Uri outputFileUri;

@Override
protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_get_image);

ImagePicker imagePicker = new ImagePicker(this);
imagePicker.setOwnerActivity(this);
imagePicker.show();
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {

super.onActivityResult(requestCode, resultCode, imageReturnedIntent);

switch (requestCode) {
case ImagePicker.SELECT_PHOTO_FROM_GALLERY:
cropGalleryImage(resultCode, imageReturnedIntent);
break;
case ImagePicker.SELECT_PHOTO_FROM_CAMERA:
cropCameraImage(resultCode);
break;

case REQUEST_CODE_CROP_IMAGE:
String path = imageReturnedIntent.getStringExtra(CropImage.IMAGE_PATH);

Intent intent = getIntent();
intent.putExtra(CropImage.IMAGE_PATH, path);
this.setResult(RESULT_OK, intent);

finish();

break;
}
}
}

Layout

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
 

</LinearLayout>