/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.app;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.os.Binder;
import android.os.Bundle;
import android.util.Config;
import android.util.Log;
import android.view.Window;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
/**
* Helper class for managing multiple running embedded activities in the same
* process. This class is not normally used directly, but rather created for
* you as part of the {@link android.app.ActivityGroup} implementation.
*
* @see ActivityGroup
*/
public class LocalActivityManager {
private static final String TAG = "LocalActivityManager";
private static final boolean localLOGV = false || Config.LOGV;
// Internal token for an Activity being managed by LocalActivityManager.
private static class LocalActivityRecord extends Binder {
LocalActivityRecord(String _id, Intent _intent) {
id = _id;
intent = _intent;
}
final String id; // Unique name of this record.
Intent intent; // Which activity to run here.
ActivityInfo activityInfo; // Package manager info about activity.
Activity activity; // Currently instantiated activity.
Window window; // Activity's top-level window.
Bundle instanceState; // Last retrieved freeze state.
int curState = RESTORED; // Current state the activity is in.
}
static final int RESTORED = 0; // State restored, but no startActivity().
static final int INITIALIZING = 1; // Ready to launch (after startActivity()).
static final int CREATED = 2; // Created, not started or resumed.
static final int STARTED = 3; // Created and started, not resumed.
static final int RESUMED = 4; // Created started and resumed.
static final int DESTROYED = 5; // No longer with us.
/** Thread our activities are running in. */
private final ActivityThread mActivityThread;
/** The containing activity that owns the activities we create. */
private final Activity mParent;
/** The activity that is currently resumed. */
private LocalActivityRecord mResumed;
/** id -> record of all known activities. */
private final Map<String, LocalActivityRecord> mActivities
= new HashMap<String, LocalActivityRecord>();
/** array of all known activities for easy iterating. */
private final ArrayList<LocalActivityRecord> mActivityArray
= new ArrayList<LocalActivityRecord>();
/** True if only one activity can be resumed at a time */
private boolean mSingleMode;
/** Set to true once we find out the container is finishing. */
private boolean mFinishing;
/** Current state the owner (ActivityGroup) is in */
private int mCurState = INITIALIZING;
/** String ids of running activities starting with least recently used. */
// TODO: put back in stopping of activities.
//private List<LocalActivityRecord> mLRU = new ArrayList();
/**
* Create a new LocalActivityManager for holding activities running within
* the given <var>parent</var>.
*
* @param parent the host of the embedded activities
* @param singleMode True if the LocalActivityManger should keep a maximum
* of one activity resumed
*/
public LocalActivityManager(Activity parent, boolean singleMode) {
mActivityThread = ActivityThread.currentActivityThread();
mParent = parent;
mSingleMode = singleMode;
}
private void moveToState(LocalActivityRecord r, int desiredState) {
if (r.curState == RESTORED || r.curState == DESTROYED) {
// startActivity() has not yet been called, so nothing to do.
return;
}
if (r.curState == INITIALIZING) {
// Get the lastNonConfigurationInstance for the activity
HashMap<String,Object> lastNonConfigurationInstances =
mParent.getLastNonConfigurationChildInstances();
Object instance = null;
if (lastNonConfigurationInstances != null) {
instance = lastNonConfigurationInstances.get(r.id);
}
// We need to have always created the activity.
if (localLOGV) Log.v(TAG, r.id + ": starting " + r.intent);
if (r.activityInfo == null) {
r.activityInfo = mActivityThread.resolveActivityInfo(r.intent);
}
r.activity = mActivityThread.startActivityNow(
mParent, r.id, r.intent, r.activityInfo, r, r.instanceState, instance);
if (r.activity == null) {
return;
}
r.window = r.activity.getWindow();
r.instanceState = null;
r.curState = STARTED;
if (desiredState == RESUMED) {
if (localLOGV) Log.v(TAG, r.id + ": resuming");
mActivityThread.performResumeActivity(r, true);
r.curState = RESUMED;
}
// Don't do anything more here. There is an important case:
// if this is being done as part of onCreate() of the group, then
// the launching of the activity gets its state a little ahead
// of our own (it is now STARTED, while we are only CREATED).
// If we just leave things as-is, we'll deal with it as the
// group's state catches up.
return;
}
switch (r.curState) {
case CREATED:
if (desiredState == STARTED) {
if (localLOGV) Log.v(TAG, r.id + ": restarting");
mActivityThread.performRestartActivity(r);
r.curState = STARTED;
}
if (desiredState == RESUMED) {
if (localLOGV) Log.v(TAG, r.id + ": restarting and resuming");
mActivityThread.performRestartActivity(r);
mActivityThread.performResumeActivity(r, true);
r.curState = RESUMED;
}
return;
case STARTED:
if (desiredState == RESUMED) {
// Need to resume it...
if (localLOGV) Log.v(TAG, r.id + ": resuming");
mActivityThread.performResumeActivity(r, true);
r.instanceState = null;
r.curState = RESUMED;
}
if (desiredState == CREATED) {
if (localLOGV) Log.v(TAG, r.id + ": stopping");
mActivityThread.performStopActivity(r);
r.curState = CREATED;
}
return;
case RESUMED:
if (desiredState == STARTED) {
if (localLOGV) Log.v(TAG, r.id + ": pausing");
performPause(r, mFinishing);
r.curState = STARTED;
}
if (desiredState == CREATED) {
if (localLOGV) Log.v(TAG, r.id + ": pausing");
performPause(r, mFinishing);
if (localLOGV) Log.v(TAG, r.id + ": stopping");
mActivityThread.performStopActivity(r);
r.curState = CREATED;
}
return;
}
}
private void performPause(LocalActivityRecord r, boolean finishing) {
boolean needState = r.instanceState == null;
Bundle instanceState = mActivityThread.performPauseActivity(r,
finishing, needState);
if (needState) {
r.instanceState = instanceState;
}
}
/**
* Start a new activity running in the group. Every activity you start
* must have a unique string ID associated with it -- this is used to keep
* track of the activity, so that if you later call startActivity() again
* on it the same activity object will be retained.
*
* <p>When there had previously been an activity started under this id,
* it may either be destroyed and a new one started, or the current
* one re-used, based on these conditions, in order:</p>
*
* <ul>
* <li> If the Intent maps to a different activity component than is
* currently running, the current activity is finished and a new one
* started.
* <li> If the current activity uses a non-multiple launch mode (such
* as singleTop), or the Intent has the
* {@link Intent#FLAG_ACTIVITY_SINGLE_TOP} flag set, then the current
* activity will remain running and its
* {@link Activity#onNewIntent(Intent) Activity.onNewIntent()} method
* called.
* <li> If the new Intent is the same (excluding extras) as the previous
* one, and the new Intent does not have the
* {@link Intent#FLAG_ACTIVITY_CLEAR_TOP} set, then the current activity
* will remain running as-is.
* <li> Otherwise, the current activity will be finished and a new
* one started.
* </ul>
*
* <p>If the given Intent can not be resolved to an available Activity,
* this method throws {@link android.content.ActivityNotFoundException}.
*
* <p>Warning: There is an issue where, if the Intent does not
* include an explicit component, we can restore the state for a different
* activity class than was previously running when the state was saved (if
* the set of available activities changes between those points).
*
* @param id Unique identifier of the activity to be started
* @param intent The Intent describing the activity to be started
*
* @return Returns the window of the activity. The caller needs to take
* care of adding this window to a view hierarchy, and likewise dealing
* with removing the old window if the activity has changed.
*
* @throws android.content.ActivityNotFoundException
*/
public Window startActivity(String id, Intent intent) {
if (mCurState == INITIALIZING) {
throw new IllegalStateException(
"Activities can't be added until the containing group has been created.");
}
boolean adding = false;
boolean sameIntent = false;
ActivityInfo aInfo = null;
// Already have information about the new activity id?
LocalActivityRecord r = mActivities.get(id);
if (r == null) {
// Need to create it...
r = new LocalActivityRecord(id, intent);
adding = true;
} else if (r.intent != null) {
sameIntent = r.intent.filterEquals(intent);
if (sameIntent) {
// We are starting the same activity.
aInfo = r.activityInfo;
}
}
if (aInfo == null) {
aInfo = mActivityThread.resolveActivityInfo(intent);
}
// Pause the currently running activity if there is one and only a single
// activity is allowed to be running at a time.
if (mSingleMode) {
LocalActivityRecord old = mResumed;
// If there was a previous activity, and it is not the current
// activity, we need to stop it.
if (old != null && old != r && mCurState == RESUMED) {
moveToState(old, STARTED);
}
}
if (adding) {
// It's a brand new world.
mActivities.put(id, r);
mActivityArray.add(r);
} else if (r.activityInfo != null) {
// If the new activity is the same as the current one, then
// we may be able to reuse it.
if (aInfo == r.activityInfo ||
(aInfo.name.equals(r.activityInfo.name) &&
aInfo.packageName.equals(r.activityInfo.packageName))) {
if (aInfo.launchMode != ActivityInfo.LAUNCH_MULTIPLE ||
(intent.getFlags()&Intent.FLAG_ACTIVITY_SINGLE_TOP) != 0) {
// The activity wants onNewIntent() called.
ArrayList<Intent> intents = new ArrayList<Intent>(1);
intents.add(intent);
if (localLOGV) Log.v(TAG, r.id + ": new intent");
mActivityThread.performNewIntents(r, intents);
r.intent = intent;
moveToState(r, mCurState);
if (mSingleMode) {
mResumed = r;
}
return r.window;
}
if (sameIntent &&
(intent.getFlags()&Intent.FLAG_ACTIVITY_CLEAR_TOP) == 0) {
// We are showing the same thing, so this activity is
// just resumed and stays as-is.
r.intent = intent;
moveToState(r, mCurState);
if (mSingleMode) {
mResumed = r;
}
return r.window;
}
}
// The new activity is different than the current one, or it
// is a multiple launch activity, so we need to destroy what
// is currently there.
performDestroy(r, true);
}
r.intent = intent;
r.curState = INITIALIZING;
r.activityInfo = aInfo;
moveToState(r, mCurState);
// When in single mode keep track of the current activity
if (mSingleMode) {
mResumed = r;
}
return r.window;
}
private Window performDestroy(LocalActivityRecord r, boolean finish) {
Window win = null;
win = r.window;
if (r.curState == RESUMED && !finish) {
performPause(r, finish);
}
if (localLOGV) Log.v(TAG, r.id + ": destroying");
mActivityThread.performDestroyActivity(r, finish);
r.activity = null;
r.window = null;
if (finish) {
r.instanceState = null;
}
r.curState = DESTROYED;
return win;
}
/**
* Destroy the activity associated with a particular id. This activity
* will go through the normal lifecycle events and fine onDestroy(), and
* then the id removed from the group.
*
* @param id Unique identifier of the activity to be destroyed
* @param finish If true, this activity will be finished, so its id and
* all state are removed from the group.
*
* @return Returns the window that was used to display the activity, or
* null if there was none.
*/
public Window destroyActivity(String id, boolean finish) {
LocalActivityRecord r = mActivities.get(id);
Window win = null;
if (r != null) {
win = performDestroy(r, finish);
if (finish) {
mActivities.remove(r);
}
}
return win;
}
/**
* Retrieve the Activity that is currently running.
*
* @return the currently running (resumed) Activity, or null if there is
* not one
*
* @see #startActivity
* @see #getCurrentId
*/
public Activity getCurrentActivity() {
return mResumed != null ? mResumed.activity : null;
}
/**
* Retrieve the ID of the activity that is currently running.
*
* @return the ID of the currently running (resumed) Activity, or null if
* there is not one
*
* @see #startActivity
* @see #getCurrentActivity
*/
public String getCurrentId() {
return mResumed != null ? mResumed.id : null;
}
/**
* Return the Activity object associated with a string ID.
*
* @see #startActivity
*
* @return the associated Activity object, or null if the id is unknown or
* its activity is not currently instantiated
*/
public Activity getActivity(String id) {
LocalActivityRecord r = mActivities.get(id);
return r != null ? r.activity : null;
}
/**
* Restore a state that was previously returned by {@link #saveInstanceState}. This
* adds to the activity group information about all activity IDs that had
* previously been saved, even if they have not been started yet, so if the
* user later navigates to them the correct state will be restored.
*
* <p>Note: This does <b>not</b> change the current running activity, or
* start whatever activity was previously running when the state was saved.
* That is up to the client to do, in whatever way it thinks is best.
*
* @param state a previously saved state; does nothing if this is null
*
* @see #saveInstanceState
*/
public void dispatchCreate(Bundle state) {
if (state != null) {
final Iterator<String> i = state.keySet().iterator();
while (i.hasNext()) {
try {
final String id = i.next();
final Bundle astate = state.getBundle(id);
LocalActivityRecord r = mActivities.get(id);
if (r != null) {
r.instanceState = astate;
} else {
r = new LocalActivityRecord(id, null);
r.instanceState = astate;
mActivities.put(id, r);
mActivityArray.add(r);
}
} catch (Exception e) {
// Recover from -all- app errors.
Log.e(TAG,
"Exception thrown when restoring LocalActivityManager state",
e);
}
}
}
mCurState = CREATED;
}
/**
* Retrieve the state of all activities known by the group. For
* activities that have previously run and are now stopped or finished, the
* last saved state is used. For the current running activity, its
* {@link Activity#onSaveInstanceState} is called to retrieve its current state.
*
* @return a Bundle holding the newly created state of all known activities
*
* @see #dispatchCreate
*/
public Bundle saveInstanceState() {
Bundle state = null;
// FIXME: child activities will freeze as part of onPaused. Do we
// need to do this here?
final int N = mActivityArray.size();
for (int i=0; i<N; i++) {
final LocalActivityRecord r = mActivityArray.get(i);
if (state == null) {
state = new Bundle();
}
if ((r.instanceState != null || r.curState == RESUMED)
&& r.activity != null) {
// We need to save the state now, if we don't currently
// already have it or the activity is currently resumed.
final Bundle childState = new Bundle();
r.activity.onSaveInstanceState(childState);
r.instanceState = childState;
}
if (r.instanceState != null) {
state.putBundle(r.id, r.instanceState);
}
}
return state;
}
/**
* Called by the container activity in its {@link Activity#onResume} so
* that LocalActivityManager can perform the corresponding action on the
* activities it holds.
*
* @see Activity#onResume
*/
public void dispatchResume() {
mCurState = RESUMED;
if (mSingleMode) {
if (mResumed != null) {
moveToState(mResumed, RESUMED);
}
} else {
final int N = mActivityArray.size();
for (int i=0; i<N; i++) {
moveToState(mActivityArray.get(i), RESUMED);
}
}
}
/**
* Called by the container activity in its {@link Activity#onPause} so
* that LocalActivityManager can perform the corresponding action on the
* activities it holds.
*
* @param finishing set to true if the parent activity has been finished;
* this can be determined by calling
* Activity.isFinishing()
*
* @see Activity#onPause
* @see Activity#isFinishing
*/
public void dispatchPause(boolean finishing) {
if (finishing) {
mFinishing = true;
}
mCurState = STARTED;
if (mSingleMode) {
if (mResumed != null) {
moveToState(mResumed, STARTED);
}
} else {
final int N = mActivityArray.size();
for (int i=0; i<N; i++) {
LocalActivityRecord r = mActivityArray.get(i);
if (r.curState == RESUMED) {
moveToState(r, STARTED);
}
}
}
}
/**
* Called by the container activity in its {@link Activity#onStop} so
* that LocalActivityManager can perform the corresponding action on the
* activities it holds.
*
* @see Activity#onStop
*/
public void dispatchStop() {
mCurState = CREATED;
final int N = mActivityArray.size();
for (int i=0; i<N; i++) {
LocalActivityRecord r = mActivityArray.get(i);
moveToState(r, CREATED);
}
}
/**
* Call onRetainNonConfigurationInstance on each child activity and store the
* results in a HashMap by id. Only construct the HashMap if there is a non-null
* object to store. Note that this does not support nested ActivityGroups.
*
* {@hide}
*/
public HashMap<String,Object> dispatchRetainNonConfigurationInstance() {
HashMap<String,Object> instanceMap = null;
final int N = mActivityArray.size();
for (int i=0; i<N; i++) {
LocalActivityRecord r = mActivityArray.get(i);
if ((r != null) && (r.activity != null)) {
Object instance = r.activity.onRetainNonConfigurationInstance();
if (instance != null) {
if (instanceMap == null) {
instanceMap = new HashMap<String,Object>();
}
instanceMap.put(r.id, instance);
}
}
}
return instanceMap;
}
/**
* Remove all activities from this LocalActivityManager, performing an
* {@link Activity#onDestroy} on any that are currently instantiated.
*/
public void removeAllActivities() {
dispatchDestroy(true);
}
/**
* Called by the container activity in its {@link Activity#onDestroy} so
* that LocalActivityManager can perform the corresponding action on the
* activities it holds.
*
* @see Activity#onDestroy
*/
public void dispatchDestroy(boolean finishing) {
final int N = mActivityArray.size();
for (int i=0; i<N; i++) {
LocalActivityRecord r = mActivityArray.get(i);
if (localLOGV) Log.v(TAG, r.id + ": destroying");
mActivityThread.performDestroyActivity(r, finishing);
}
mActivities.clear();
mActivityArray.clear();
}
}
|
