从gallery查看图片如何直接返回launcher界面

【问题】从Gallery Widget 点击查看图片，再按back 键，返回AlbumPage;

【需求】直接返回launcher 界面;转自×××论坛

[SOLUTION]请做以下修改：

1.在GalleryActivity.java中增长mFromWidget变量：

/// M: [TESTCASE.ADD] add for performance test case@{
public long mStopTime = 0;
+ private boolean mFromWidget=false;
/// @}

2. 在GalleryActivity.java的onCreate()方法中给mFromWidget 赋值：

（intent != null && (intent.getBooleanExtra(EXTRA_FROM_WIDGET, false) || (intent
.getAction() != null && intent.getAction().equals(
intent.ACTION_MAIN)))) {
+ mFromWidget=intent.getBooleanExtra(EXTRA_FROM_WIDGET, false);
View view = findViewById(R.id.gl_root_cover);
if (view != null) {
view.setVisibility(View.VISIBLE);

3. 在GalleryActivity.java的startViewAction()中添加：

itemPath.clearObject();
albumPath = dm.getDefaultSetOf(itemPath);
/// @}
+ data.putBoolean(EXTRA_FROM_WIDGET, mFromWidget);
data.putString(PhotoPage.KEY_MEDIA_ITEM_PATH, itemPath.toString());
data.putBoolean(PhotoPage.KEY_READONLY, true);

4. 在PhotoPage.java中添加EXTRA_FROM_WIDGET ：

public static final String KEY_SHOW_WHEN_LOCKED = "show_when_locked";
public static final String KEY_IN_CAMERA_ROLL = "in_camera_roll";
public static final String KEY_READONLY = "read-only";
+ public static final String EXTRA_FROM_WIDGET = "fromWidget";
public static final String KEY_ALBUMPAGE_TRANSITION = "albumpage-transition";
public static final int MSG_ALBUMPAGE_NONE = 0;
public static final int MSG_ALBUMPAGE_STARTED = 1;

5. 在PhotoPage.java添加mIsFromWidget

private boolean mIsActive;
private boolean mShowSpinner;
private String mSetPathString;
+ private boolean mIsFromWidget = false;
// This is the original mSetPathString before adding the camera preview item.
private boolean mReadOnlyView = false;
private String mOriginalSetPathString;

6. 在PhotoPage.java中给mIsFromWidget赋值：

mSetPathString = data.getString(KEY_MEDIA_SET_PATH);
mReadOnlyView = data.getBoolean(KEY_READONLY);
+ mIsFromWidget=data.getBoolean(EXTRA_FROM_WIDGET);
mOriginalSetPathString = mSetPathString;
setupNfcBeamPush();
String itemPathString = data.getString(KEY_MEDIA_ITEM_PATH);

7. 在PhotoPage.java的onBackPressed()中添加以下：

/*showBars();*/
wantBars();
/// @}
+ if(mFromWidget){
+ super.onBackPressed();
+ return;
+ }
if (mShowDetails) {
hideDetails();
} else if (mAppBridge == null || !switchWithCaptureAnimation(-1)) {