src/com/android/gallery3d/app/StateManager.java - platform/packages/apps/Gallery2 - Gitiles

 /*
  * Copyright (C) 2010 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 com.android.gallery3d.app;

 import android.app.Activity;
 import android.content.Intent;
 import android.content.res.Configuration;
 import android.os.Bundle;
 import android.os.Parcelable;
 import android.view.Menu;
 import android.view.MenuItem;

 import com.android.gallery3d.anim.StateTransitionAnimation;
 import com.android.gallery3d.common.Utils;
 import com.android.gallery3d.util.UsageStatistics;

 import java.util.Stack;

 public class StateManager {
     @SuppressWarnings("unused")
     private static final String TAG = "StateManager";
     private boolean mIsResumed = false;

     private static final String KEY_MAIN = "activity-state";
     private static final String KEY_DATA = "data";
     private static final String KEY_STATE = "bundle";
     private static final String KEY_CLASS = "class";

     private AbstractGalleryActivity mActivity;
     private Stack<StateEntry> mStack = new Stack<StateEntry>();
     private ActivityState.ResultEntry mResult;

     public StateManager(AbstractGalleryActivity activity) {
         mActivity = activity;
     }

     public void startState(Class<? extends ActivityState> klass,
             Bundle data) {
         Log.v(TAG, "startState " + klass);
         ActivityState state = null;
         try {
             state = klass.newInstance();
         } catch (Exception e) {
             throw new AssertionError(e);
         }
         if (!mStack.isEmpty()) {
             ActivityState top = getTopState();
             top.transitionOnNextPause(top.getClass(), klass,
                     StateTransitionAnimation.Transition.Incoming);
             if (mIsResumed) top.onPause();
         }

         UsageStatistics.onContentViewChanged(
                 UsageStatistics.COMPONENT_GALLERY,
                 klass.getSimpleName());
         state.initialize(mActivity, data);

         mStack.push(new StateEntry(data, state));
         state.onCreate(data, null);
         if (mIsResumed) state.resume();
     }

     public void startStateForResult(Class<? extends ActivityState> klass,
             int requestCode, Bundle data) {
         Log.v(TAG, "startStateForResult " + klass + ", " + requestCode);
         ActivityState state = null;
         try {
             state = klass.newInstance();
         } catch (Exception e) {
             throw new AssertionError(e);
         }
         state.initialize(mActivity, data);
         state.mResult = new ActivityState.ResultEntry();
         state.mResult.requestCode = requestCode;

         if (!mStack.isEmpty()) {
             ActivityState as = getTopState();
             as.transitionOnNextPause(as.getClass(), klass,
                     StateTransitionAnimation.Transition.Incoming);
             as.mReceivedResults = state.mResult;
             if (mIsResumed) as.onPause();
         } else {
             mResult = state.mResult;
         }
         UsageStatistics.onContentViewChanged(UsageStatistics.COMPONENT_GALLERY,
                 klass.getSimpleName());
         mStack.push(new StateEntry(data, state));
         state.onCreate(data, null);
         if (mIsResumed) state.resume();
     }

     public boolean createOptionsMenu(Menu menu) {
         if (mStack.isEmpty()) {
             return false;
         } else {
             return getTopState().onCreateActionBar(menu);
         }
     }

     public void onConfigurationChange(Configuration config) {
         for (StateEntry entry : mStack) {
             entry.activityState.onConfigurationChanged(config);
         }
     }

     public void resume() {
         if (mIsResumed) return;
         mIsResumed = true;
         if (!mStack.isEmpty()) getTopState().resume();
     }

     public void pause() {
         if (!mIsResumed) return;
         mIsResumed = false;
         if (!mStack.isEmpty()) getTopState().onPause();
     }

     public void notifyActivityResult(int requestCode, int resultCode, Intent data) {
         getTopState().onStateResult(requestCode, resultCode, data);
     }

     public void clearActivityResult() {
         if (!mStack.isEmpty()) {
             getTopState().clearStateResult();
         }
     }

     public int getStateCount() {
         return mStack.size();
     }

     public boolean itemSelected(MenuItem item) {
         if (!mStack.isEmpty()) {
             if (getTopState().onItemSelected(item)) return true;
             if (item.getItemId() == android.R.id.home) {
                 if (mStack.size() > 1) {
                     getTopState().onBackPressed();
                 }
                 return true;
             }
         }
         return false;
     }

     public void onBackPressed() {
         if (!mStack.isEmpty()) {
             getTopState().onBackPressed();
         }
     }

     void finishState(ActivityState state) {
         finishState(state, true);
     }

     public void clearTasks() {
         // Remove all the states that are on top of the bottom PhotoPage state
         while (mStack.size() > 1) {
             mStack.pop().activityState.onDestroy();
         }
     }

     void finishState(ActivityState state, boolean fireOnPause) {
         // The finish() request could be rejected (only happens under Monkey),
         // If it is rejected, we won't close the last page.
         if (mStack.size() == 1) {
             Activity activity = (Activity) mActivity.getAndroidContext();
             if (mResult != null) {
                 activity.setResult(mResult.resultCode, mResult.resultData);
             }
             activity.finish();
             if (!activity.isFinishing()) {
                 Log.w(TAG, "finish is rejected, keep the last state");
                 return;
             }
             Log.v(TAG, "no more state, finish activity");
         }

         Log.v(TAG, "finishState " + state);
         if (state != mStack.peek().activityState) {
             if (state.isDestroyed()) {
                 Log.d(TAG, "The state is already destroyed");
                 return;
             } else {
                 throw new IllegalArgumentException("The stateview to be finished"
                         + " is not at the top of the stack: " + state + ", "
                         + mStack.peek().activityState);
             }
         }

         // Remove the top state.
         mStack.pop();
         state.mIsFinishing = true;
         ActivityState top = !mStack.isEmpty() ? mStack.peek().activityState : null;
         if (mIsResumed && fireOnPause) {
             if (top != null) {
                 state.transitionOnNextPause(state.getClass(), top.getClass(),
                         StateTransitionAnimation.Transition.Outgoing);
             }
             state.onPause();
         }
         mActivity.getGLRoot().setContentPane(null);
         state.onDestroy();

         if (top != null && mIsResumed) top.resume();
         if (top != null) {
             UsageStatistics.onContentViewChanged(UsageStatistics.COMPONENT_GALLERY,
                     top.getClass().getSimpleName());
         }
     }

     public void switchState(ActivityState oldState,
             Class<? extends ActivityState> klass, Bundle data) {
         Log.v(TAG, "switchState " + oldState + ", " + klass);
         if (oldState != mStack.peek().activityState) {
             throw new IllegalArgumentException("The stateview to be finished"
                     + " is not at the top of the stack: " + oldState + ", "
                     + mStack.peek().activityState);
         }
         // Remove the top state.
         mStack.pop();
         if (!data.containsKey(PhotoPage.KEY_APP_BRIDGE)) {
             // Do not do the fade out stuff when we are switching camera modes
             oldState.transitionOnNextPause(oldState.getClass(), klass,
                     StateTransitionAnimation.Transition.Incoming);
         }
         if (mIsResumed) oldState.onPause();
         oldState.onDestroy();

         // Create new state.
         ActivityState state = null;
         try {
             state = klass.newInstance();
         } catch (Exception e) {
             throw new AssertionError(e);
         }
         state.initialize(mActivity, data);
         mStack.push(new StateEntry(data, state));
         state.onCreate(data, null);
         if (mIsResumed) state.resume();
         UsageStatistics.onContentViewChanged(UsageStatistics.COMPONENT_GALLERY,
                 klass.getSimpleName());
     }

     public void destroy() {
         Log.v(TAG, "destroy");
         while (!mStack.isEmpty()) {
             mStack.pop().activityState.onDestroy();
         }
         mStack.clear();
     }

     @SuppressWarnings("unchecked")
     public void restoreFromState(Bundle inState) {
         Log.v(TAG, "restoreFromState");
         Parcelable list[] = inState.getParcelableArray(KEY_MAIN);
         ActivityState topState = null;
         for (Parcelable parcelable : list) {
             Bundle bundle = (Bundle) parcelable;
             Class<? extends ActivityState> klass =
                     (Class<? extends ActivityState>) bundle.getSerializable(KEY_CLASS);

             Bundle data = bundle.getBundle(KEY_DATA);
             Bundle state = bundle.getBundle(KEY_STATE);

             ActivityState activityState;
             try {
                 Log.v(TAG, "restoreFromState " + klass);
                 activityState = klass.newInstance();
             } catch (Exception e) {
                 throw new AssertionError(e);
             }
             activityState.initialize(mActivity, data);
             activityState.onCreate(data, state);
             mStack.push(new StateEntry(data, activityState));
             topState = activityState;
         }
         if (topState != null) {
             UsageStatistics.onContentViewChanged(UsageStatistics.COMPONENT_GALLERY,
                     topState.getClass().getSimpleName());
         }
     }

     public void saveState(Bundle outState) {
         Log.v(TAG, "saveState");

         Parcelable list[] = new Parcelable[mStack.size()];
         int i = 0;
         for (StateEntry entry : mStack) {
             Bundle bundle = new Bundle();
             bundle.putSerializable(KEY_CLASS, entry.activityState.getClass());
             bundle.putBundle(KEY_DATA, entry.data);
             Bundle state = new Bundle();
             entry.activityState.onSaveState(state);
             bundle.putBundle(KEY_STATE, state);
             Log.v(TAG, "saveState " + entry.activityState.getClass());
             list[i++] = bundle;
         }
         outState.putParcelableArray(KEY_MAIN, list);
     }

     public boolean hasStateClass(Class<? extends ActivityState> klass) {
         for (StateEntry entry : mStack) {
             if (klass.isInstance(entry.activityState)) {
                 return true;
             }
         }
         return false;
     }

     public ActivityState getTopState() {
         Utils.assertTrue(!mStack.isEmpty());
         return mStack.peek().activityState;
     }

     private static class StateEntry {
         public Bundle data;
         public ActivityState activityState;

         public StateEntry(Bundle data, ActivityState state) {
             this.data = data;
             this.activityState = state;
         }
     }
 }
	/*
	* Copyright (C) 2010 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 com.android.gallery3d.app;

	import android.app.Activity;
	import android.content.Intent;
	import android.content.res.Configuration;
	import android.os.Bundle;
	import android.os.Parcelable;
	import android.view.Menu;
	import android.view.MenuItem;

	import com.android.gallery3d.anim.StateTransitionAnimation;
	import com.android.gallery3d.common.Utils;
	import com.android.gallery3d.util.UsageStatistics;

	import java.util.Stack;

	public class StateManager {
	@SuppressWarnings("unused")
	private static final String TAG = "StateManager";
	private boolean mIsResumed = false;

	private static final String KEY_MAIN = "activity-state";
	private static final String KEY_DATA = "data";
	private static final String KEY_STATE = "bundle";
	private static final String KEY_CLASS = "class";

	private AbstractGalleryActivity mActivity;
	private Stack<StateEntry> mStack = new Stack<StateEntry>();
	private ActivityState.ResultEntry mResult;

	public StateManager(AbstractGalleryActivity activity) {
	mActivity = activity;
	}

	public void startState(Class<? extends ActivityState> klass,
	Bundle data) {
	Log.v(TAG, "startState " + klass);
	ActivityState state = null;
	try {
	state = klass.newInstance();
	} catch (Exception e) {
	throw new AssertionError(e);
	}
	if (!mStack.isEmpty()) {
	ActivityState top = getTopState();
	top.transitionOnNextPause(top.getClass(), klass,
	StateTransitionAnimation.Transition.Incoming);
	if (mIsResumed) top.onPause();
	}

	UsageStatistics.onContentViewChanged(
	UsageStatistics.COMPONENT_GALLERY,
	klass.getSimpleName());
	state.initialize(mActivity, data);

	mStack.push(new StateEntry(data, state));
	state.onCreate(data, null);
	if (mIsResumed) state.resume();
	}

	public void startStateForResult(Class<? extends ActivityState> klass,
	int requestCode, Bundle data) {
	Log.v(TAG, "startStateForResult " + klass + ", " + requestCode);
	ActivityState state = null;
	try {
	state = klass.newInstance();
	} catch (Exception e) {
	throw new AssertionError(e);
	}
	state.initialize(mActivity, data);
	state.mResult = new ActivityState.ResultEntry();
	state.mResult.requestCode = requestCode;

	if (!mStack.isEmpty()) {
	ActivityState as = getTopState();
	as.transitionOnNextPause(as.getClass(), klass,
	StateTransitionAnimation.Transition.Incoming);
	as.mReceivedResults = state.mResult;
	if (mIsResumed) as.onPause();
	} else {
	mResult = state.mResult;
	}
	UsageStatistics.onContentViewChanged(UsageStatistics.COMPONENT_GALLERY,
	klass.getSimpleName());
	mStack.push(new StateEntry(data, state));
	state.onCreate(data, null);
	if (mIsResumed) state.resume();
	}

	public boolean createOptionsMenu(Menu menu) {
	if (mStack.isEmpty()) {
	return false;
	} else {
	return getTopState().onCreateActionBar(menu);
	}
	}

	public void onConfigurationChange(Configuration config) {
	for (StateEntry entry : mStack) {
	entry.activityState.onConfigurationChanged(config);
	}
	}

	public void resume() {
	if (mIsResumed) return;
	mIsResumed = true;
	if (!mStack.isEmpty()) getTopState().resume();
	}

	public void pause() {
	if (!mIsResumed) return;
	mIsResumed = false;
	if (!mStack.isEmpty()) getTopState().onPause();
	}

	public void notifyActivityResult(int requestCode, int resultCode, Intent data) {
	getTopState().onStateResult(requestCode, resultCode, data);
	}

	public void clearActivityResult() {
	if (!mStack.isEmpty()) {
	getTopState().clearStateResult();
	}
	}

	public int getStateCount() {
	return mStack.size();
	}

	public boolean itemSelected(MenuItem item) {
	if (!mStack.isEmpty()) {
	if (getTopState().onItemSelected(item)) return true;
	if (item.getItemId() == android.R.id.home) {
	if (mStack.size() > 1) {
	getTopState().onBackPressed();
	}
	return true;
	}
	}
	return false;
	}

	public void onBackPressed() {
	if (!mStack.isEmpty()) {
	getTopState().onBackPressed();
	}
	}

	void finishState(ActivityState state) {
	finishState(state, true);
	}

	public void clearTasks() {
	// Remove all the states that are on top of the bottom PhotoPage state
	while (mStack.size() > 1) {
	mStack.pop().activityState.onDestroy();
	}
	}

	void finishState(ActivityState state, boolean fireOnPause) {
	// The finish() request could be rejected (only happens under Monkey),
	// If it is rejected, we won't close the last page.
	if (mStack.size() == 1) {
	Activity activity = (Activity) mActivity.getAndroidContext();
	if (mResult != null) {
	activity.setResult(mResult.resultCode, mResult.resultData);
	}
	activity.finish();
	if (!activity.isFinishing()) {
	Log.w(TAG, "finish is rejected, keep the last state");
	return;
	}
	Log.v(TAG, "no more state, finish activity");
	}

	Log.v(TAG, "finishState " + state);
	if (state != mStack.peek().activityState) {
	if (state.isDestroyed()) {
	Log.d(TAG, "The state is already destroyed");
	return;
	} else {
	throw new IllegalArgumentException("The stateview to be finished"
	+ " is not at the top of the stack: " + state + ", "
	+ mStack.peek().activityState);
	}
	}

	// Remove the top state.
	mStack.pop();
	state.mIsFinishing = true;
	ActivityState top = !mStack.isEmpty() ? mStack.peek().activityState : null;
	if (mIsResumed && fireOnPause) {
	if (top != null) {
	state.transitionOnNextPause(state.getClass(), top.getClass(),
	StateTransitionAnimation.Transition.Outgoing);
	}
	state.onPause();
	}
	mActivity.getGLRoot().setContentPane(null);
	state.onDestroy();

	if (top != null && mIsResumed) top.resume();
	if (top != null) {
	UsageStatistics.onContentViewChanged(UsageStatistics.COMPONENT_GALLERY,
	top.getClass().getSimpleName());
	}
	}

	public void switchState(ActivityState oldState,
	Class<? extends ActivityState> klass, Bundle data) {
	Log.v(TAG, "switchState " + oldState + ", " + klass);
	if (oldState != mStack.peek().activityState) {
	throw new IllegalArgumentException("The stateview to be finished"
	+ " is not at the top of the stack: " + oldState + ", "
	+ mStack.peek().activityState);
	}
	// Remove the top state.
	mStack.pop();
	if (!data.containsKey(PhotoPage.KEY_APP_BRIDGE)) {
	// Do not do the fade out stuff when we are switching camera modes
	oldState.transitionOnNextPause(oldState.getClass(), klass,
	StateTransitionAnimation.Transition.Incoming);
	}
	if (mIsResumed) oldState.onPause();
	oldState.onDestroy();

	// Create new state.
	ActivityState state = null;
	try {
	state = klass.newInstance();
	} catch (Exception e) {
	throw new AssertionError(e);
	}
	state.initialize(mActivity, data);
	mStack.push(new StateEntry(data, state));
	state.onCreate(data, null);
	if (mIsResumed) state.resume();
	UsageStatistics.onContentViewChanged(UsageStatistics.COMPONENT_GALLERY,
	klass.getSimpleName());
	}

	public void destroy() {
	Log.v(TAG, "destroy");
	while (!mStack.isEmpty()) {
	mStack.pop().activityState.onDestroy();
	}
	mStack.clear();
	}

	@SuppressWarnings("unchecked")
	public void restoreFromState(Bundle inState) {
	Log.v(TAG, "restoreFromState");
	Parcelable list[] = inState.getParcelableArray(KEY_MAIN);
	ActivityState topState = null;
	for (Parcelable parcelable : list) {
	Bundle bundle = (Bundle) parcelable;
	Class<? extends ActivityState> klass =
	(Class<? extends ActivityState>) bundle.getSerializable(KEY_CLASS);

	Bundle data = bundle.getBundle(KEY_DATA);
	Bundle state = bundle.getBundle(KEY_STATE);

	ActivityState activityState;
	try {
	Log.v(TAG, "restoreFromState " + klass);
	activityState = klass.newInstance();
	} catch (Exception e) {
	throw new AssertionError(e);
	}
	activityState.initialize(mActivity, data);
	activityState.onCreate(data, state);
	mStack.push(new StateEntry(data, activityState));
	topState = activityState;
	}
	if (topState != null) {
	UsageStatistics.onContentViewChanged(UsageStatistics.COMPONENT_GALLERY,
	topState.getClass().getSimpleName());
	}
	}

	public void saveState(Bundle outState) {
	Log.v(TAG, "saveState");

	Parcelable list[] = new Parcelable[mStack.size()];
	int i = 0;
	for (StateEntry entry : mStack) {
	Bundle bundle = new Bundle();
	bundle.putSerializable(KEY_CLASS, entry.activityState.getClass());
	bundle.putBundle(KEY_DATA, entry.data);
	Bundle state = new Bundle();
	entry.activityState.onSaveState(state);
	bundle.putBundle(KEY_STATE, state);
	Log.v(TAG, "saveState " + entry.activityState.getClass());
	list[i++] = bundle;
	}
	outState.putParcelableArray(KEY_MAIN, list);
	}

	public boolean hasStateClass(Class<? extends ActivityState> klass) {
	for (StateEntry entry : mStack) {
	if (klass.isInstance(entry.activityState)) {
	return true;
	}
	}
	return false;
	}

	public ActivityState getTopState() {
	Utils.assertTrue(!mStack.isEmpty());
	return mStack.peek().activityState;
	}

	private static class StateEntry {
	public Bundle data;
	public ActivityState activityState;

	public StateEntry(Bundle data, ActivityState state) {
	this.data = data;
	this.activityState = state;
	}
	}
	}