Fragment and PreferenceFragment and FragmentManager, oh my!
- Introduce FragmentManager public API, for all Fragment management
needs. Will in the future allow the removal of the (growing number
of) fragment APIs on Activity.
- Fragment now has a concept of arguments. This can be supplied
immediately after creation, and are retained across instances.
- PreferenceActivity now has an API to have it update its headers (note
not tested). Headers now have arguments. Keys for controlling
when PreferenceActivity shows at launch have been added to the SDK.
- Fixes to back stack handling and state saving/restoring.
Change-Id: Ib9d07ae2beb296c4eb3a4d9e1b3b59544675e819
diff --git a/core/java/android/preference/PreferenceActivity.java b/core/java/android/preference/PreferenceActivity.java
index 114f67d..ec2ca57 100644
--- a/core/java/android/preference/PreferenceActivity.java
+++ b/core/java/android/preference/PreferenceActivity.java
@@ -113,9 +113,28 @@
private static final String PREFERENCES_TAG = "android:preferences";
- private static final String EXTRA_PREFS_SHOW_FRAGMENT = ":android:show_fragment";
+ /**
+ * When starting this activity, the invoking Intent can contain this extra
+ * string to specify which fragment should be initially displayed.
+ */
+ public static final String EXTRA_SHOW_FRAGMENT = ":android:show_fragment";
- private static final String EXTRA_PREFS_NO_HEADERS = ":android:no_headers";
+ /**
+ * When starting this activity and using {@link #EXTRA_SHOW_FRAGMENT},
+ * this extra can also be specify to supply a Bundle of arguments to pass
+ * to that fragment when it is instantiated during the initial creation
+ * of PreferenceActivity.
+ */
+ public static final String EXTRA_SHOW_FRAGMENT_ARGUMENTS = ":android:show_fragment_args";
+
+ /**
+ * When starting this activity, the invoking Intent can contain this extra
+ * boolean that the header list should not be displayed. This is most often
+ * used in conjunction with {@link #EXTRA_SHOW_FRAGMENT} to launch
+ * the activity to display a specific fragment that the user has navigated
+ * to.
+ */
+ public static final String EXTRA_NO_HEADERS = ":android:no_headers";
private static final String BACK_STACK_PREFS = ":android:prefs";
@@ -159,14 +178,18 @@
private static final int FIRST_REQUEST_CODE = 100;
private static final int MSG_BIND_PREFERENCES = 0;
+ private static final int MSG_BUILD_HEADERS = 1;
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
-
case MSG_BIND_PREFERENCES:
bindPreferences();
break;
+ case MSG_BUILD_HEADERS:
+ onBuildHeaders(mHeaders);
+ mAdapter.notifyDataSetChanged();
+ break;
}
}
};
@@ -250,6 +273,12 @@
* @attr ref android.R.styleable#PreferenceHeader_fragment
*/
String fragment;
+
+ /**
+ * Optional arguments to supply to the fragment when it is
+ * instantiated.
+ */
+ Bundle fragmentArguments;
}
@Override
@@ -261,7 +290,8 @@
mPrefsContainer = findViewById(com.android.internal.R.id.prefs);
boolean hidingHeaders = onIsHidingHeaders();
mSinglePane = hidingHeaders || !onIsMultiPane();
- String initialFragment = getIntent().getStringExtra(EXTRA_PREFS_SHOW_FRAGMENT);
+ String initialFragment = getIntent().getStringExtra(EXTRA_SHOW_FRAGMENT);
+ Bundle initialArguments = getIntent().getBundleExtra(EXTRA_SHOW_FRAGMENT_ARGUMENTS);
if (initialFragment != null && mSinglePane) {
// If we are just showing a fragment, we want to run in
@@ -269,7 +299,7 @@
// the headers.
getListView().setVisibility(View.GONE);
mPrefsContainer.setVisibility(View.VISIBLE);
- switchToHeader(initialFragment);
+ switchToHeader(initialFragment, initialArguments);
} else {
// We need to try to build the headers.
@@ -283,8 +313,12 @@
setListAdapter(mAdapter);
if (!mSinglePane) {
mPrefsContainer.setVisibility(View.VISIBLE);
- switchToHeader(initialFragment != null
- ? initialFragment : onGetInitialFragment());
+ if (initialFragment != null) {
+ Header h = onGetInitialHeader();
+ initialFragment = h.fragment;
+ initialArguments = h.fragmentArguments;
+ }
+ switchToHeader(initialFragment, initialArguments);
}
// If there are no headers, we are in the old "just show a screen
@@ -371,15 +405,18 @@
* when not in multi-pane mode.
*/
public boolean onIsHidingHeaders() {
- return getIntent().getBooleanExtra(EXTRA_PREFS_NO_HEADERS, false);
+ return getIntent().getBooleanExtra(EXTRA_NO_HEADERS, false);
}
/**
- * Called to determine the initial fragment to be shown. The default
- * implementation simply returns the fragment of the first header.
+ * Called to determine the initial header to be shown. The default
+ * implementation simply returns the fragment of the first header. Note
+ * that the returned Header object does not actually need to exist in
+ * your header list -- whatever its fragment is will simply be used to
+ * show for the initial UI.
*/
- public String onGetInitialFragment() {
- return mHeaders.get(0).fragment;
+ public Header onGetInitialHeader() {
+ return mHeaders.get(0);
}
/**
@@ -399,6 +436,16 @@
}
/**
+ * Call when you need to change the headers being displayed. Will result
+ * in onBuildHeaders() later being called to retrieve the new list.
+ */
+ public void invalidateHeaders() {
+ if (!mHandler.hasMessages(MSG_BUILD_HEADERS)) {
+ mHandler.sendEmptyMessage(MSG_BUILD_HEADERS);
+ }
+ }
+
+ /**
* Parse the given XML file as a header description, adding each
* parsed Header into the target list.
*
@@ -552,9 +599,9 @@
*/
public void onHeaderClick(Header header, int position) {
if (mSinglePane) {
- startWithFragment(header.fragment);
+ startWithFragment(header.fragment, header.fragmentArguments);
} else {
- switchToHeader(header.fragment);
+ switchToHeader(header.fragment, header.fragmentArguments);
}
}
@@ -565,12 +612,14 @@
* and fill the entire activity.
*
* @param fragmentName The name of the fragment to display.
+ * @param args Optional arguments to supply to the fragment.
*/
- public void startWithFragment(String fragmentName) {
+ public void startWithFragment(String fragmentName, Bundle args) {
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.setClass(this, getClass());
- intent.putExtra(EXTRA_PREFS_SHOW_FRAGMENT, fragmentName);
- intent.putExtra(EXTRA_PREFS_NO_HEADERS, true);
+ intent.putExtra(EXTRA_SHOW_FRAGMENT, fragmentName);
+ intent.putExtra(EXTRA_SHOW_FRAGMENT_ARGUMENTS, args);
+ intent.putExtra(EXTRA_NO_HEADERS, true);
startActivity(intent);
}
@@ -579,29 +628,18 @@
* preference fragment.
*
* @param fragmentName The name of the fragment to display.
+ * @param args Optional arguments to supply to the fragment.
*/
- public void switchToHeader(String fragmentName) {
+ public void switchToHeader(String fragmentName, Bundle args) {
popBackStack(BACK_STACK_PREFS, POP_BACK_STACK_INCLUSIVE);
- Fragment f;
- try {
- f = Fragment.instantiate(this, fragmentName);
- } catch (Exception e) {
- Log.w(TAG, "Failure instantiating fragment " + fragmentName, e);
- return;
- }
+ Fragment f = Fragment.instantiate(this, fragmentName, args);
openFragmentTransaction().replace(com.android.internal.R.id.prefs, f).commit();
}
@Override
public boolean onPreferenceStartFragment(PreferenceFragment caller, Preference pref) {
- Fragment f;
- try {
- f = Fragment.instantiate(this, pref.getFragment());
- } catch (Exception e) {
- Log.w(TAG, "Failure instantiating fragment " + pref.getFragment(), e);
- return false;
- }
+ Fragment f = Fragment.instantiate(this, pref.getFragment());
openFragmentTransaction().replace(com.android.internal.R.id.prefs, f)
.addToBackStack(BACK_STACK_PREFS).commit();
return true;