src/com/android/settings/dashboard/ProgressiveDisclosureMixin.java - platform/packages/apps/Settings - Git at Google

 /*
  * Copyright (C) 2016 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.settings.dashboard;

 import android.content.Context;
 import android.os.Bundle;
 import android.support.annotation.VisibleForTesting;
 import android.support.v14.preference.PreferenceFragment;
 import android.support.v7.preference.Preference;
 import android.support.v7.preference.PreferenceGroup;
 import android.support.v7.preference.PreferenceScreen;
 import android.text.TextUtils;
 import android.util.Log;

 import com.android.internal.logging.nano.MetricsProto;
 import com.android.settings.R;
 import com.android.settings.core.instrumentation.Instrumentable;
 import com.android.settings.core.instrumentation.MetricsFeatureProvider;
 import com.android.settings.overlay.FeatureFactory;
 import com.android.settingslib.core.lifecycle.LifecycleObserver;
 import com.android.settingslib.core.lifecycle.events.OnCreate;
 import com.android.settingslib.core.lifecycle.events.OnSaveInstanceState;

 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;

 public class ProgressiveDisclosureMixin implements Preference.OnPreferenceClickListener,
         LifecycleObserver, OnCreate, OnSaveInstanceState {

     private static final String TAG = "ProgressiveDisclosure";
     private static final String STATE_USER_EXPANDED = "state_user_expanded";
     private static final int DEFAULT_TILE_LIMIT = 300;

     private final Context mContext;
     // Collapsed preference sorted by order.
     private final List<Preference> mCollapsedPrefs = new ArrayList<>();
     private final MetricsFeatureProvider mMetricsFeatureProvider;
     private final PreferenceFragment mFragment;
     private /* final */ ExpandPreference mExpandButton;

     private int mTileLimit = DEFAULT_TILE_LIMIT;
     private boolean mUserExpanded;

     public ProgressiveDisclosureMixin(Context context,
             PreferenceFragment fragment, boolean keepExpanded) {
         mContext = context;
         mFragment = fragment;
         mExpandButton = new ExpandPreference(context);
         mExpandButton.setOnPreferenceClickListener(this);
         mMetricsFeatureProvider = FeatureFactory.getFactory(context).getMetricsFeatureProvider();
         mUserExpanded = keepExpanded;
     }

     @Override
     public void onCreate(Bundle savedInstanceState) {
         if (savedInstanceState != null) {
             mUserExpanded = savedInstanceState.getBoolean(STATE_USER_EXPANDED, false);
         }
     }

     @Override
     public void onSaveInstanceState(Bundle outState) {
         outState.putBoolean(STATE_USER_EXPANDED, mUserExpanded);
     }

     @Override
     public boolean onPreferenceClick(Preference preference) {
         if (preference instanceof ExpandPreference) {
             final PreferenceScreen screen = mFragment.getPreferenceScreen();
             if (screen != null) {
                 screen.removePreference(preference);
                 for (Preference pref : mCollapsedPrefs) {
                     screen.addPreference(pref);
                 }
                 mCollapsedPrefs.clear();
                 mUserExpanded = true;
                 final int metricsCategory;
                 if (mFragment instanceof Instrumentable) {
                     metricsCategory = ((Instrumentable) mFragment).getMetricsCategory();
                 } else {
                     metricsCategory = MetricsProto.MetricsEvent.VIEW_UNKNOWN;
                 }
                 mMetricsFeatureProvider.actionWithSource(mContext, metricsCategory,
                         MetricsProto.MetricsEvent.ACTION_SETTINGS_ADVANCED_BUTTON_EXPAND);
             }
         }
         return false;
     }

     /**
      * Sets the threshold to start collapsing preferences when there are too many.
      */
     public void setTileLimit(int limit) {
         mTileLimit = limit;
     }

     /**
      * Whether the controller is in collapsed state.
      */
     public boolean isCollapsed() {
         return !mCollapsedPrefs.isEmpty();
     }

     /**
      * Whether the screen should be collapsed.
      */
     public boolean shouldCollapse(PreferenceScreen screen) {
         return !mUserExpanded && screen.getPreferenceCount() > mTileLimit;
     }

     /**
      * Collapse extra preferences and show a "More" button
      */
     public void collapse(PreferenceScreen screen) {
         final int itemCount = screen.getPreferenceCount();
         if (!shouldCollapse(screen)) {
             return;
         }
         if (!mCollapsedPrefs.isEmpty()) {
             Log.w(TAG, "collapsed list should ALWAYS BE EMPTY before collapsing!");
         }

         for (int i = itemCount - 1; i >= mTileLimit; i--) {
             final Preference preference = screen.getPreference(i);
             addToCollapsedList(preference);
             screen.removePreference(preference);
         }
         screen.addPreference(mExpandButton);
     }

     /**
      * Adds preference to screen. If there are too many preference on screen, adds it to
      * collapsed list instead.
      */
     public void addPreference(PreferenceScreen screen, Preference pref) {
         // Either add to screen, or to collapsed list.
         if (isCollapsed()) {
             // insert the preference to right position.
             final int lastPreferenceIndex = screen.getPreferenceCount() - 2;
             if (lastPreferenceIndex >= 0) {
                 final Preference lastPreference = screen.getPreference(lastPreferenceIndex);
                 if (lastPreference.getOrder() > pref.getOrder()) {
                     // insert to screen and move the last pref to collapsed list.
                     screen.removePreference(lastPreference);
                     screen.addPreference(pref);
                     addToCollapsedList(lastPreference);
                 } else {
                     // Insert to collapsed list.
                     addToCollapsedList(pref);
                 }
             } else {
                 // Couldn't find last preference on screen, just add to collapsed list.
                 addToCollapsedList(pref);
             }
         } else if (shouldCollapse(screen)) {
             // About to have too many tiles on scree, collapse and add pref to collapsed list.
             screen.addPreference(pref);
             collapse(screen);
         } else {
             // No need to collapse, add to screen directly.
             screen.addPreference(pref);
         }
     }

     /**
      * Removes preference. If the preference is on screen, remove it from screen. If the
      * preference is in collapsed list, remove it from list.
      */
     public void removePreference(PreferenceScreen screen, String key) {
         // Try removing from screen.
         final Preference preference = screen.findPreference(key);
         if (preference != null) {
             screen.removePreference(preference);
             return;
         }
         // Didn't find on screen, try removing from collapsed list.
         for (int i = 0; i < mCollapsedPrefs.size(); i++) {
             final Preference pref = mCollapsedPrefs.get(i);
             if (TextUtils.equals(key, pref.getKey())) {
                 mCollapsedPrefs.remove(pref);
                 if (mCollapsedPrefs.isEmpty()) {
                     // Removed last element, remove expand button too.
                     screen.removePreference(mExpandButton);
                 } else {
                     updateExpandButtonSummary();
                 }
                 return;
             }
         }
     }

     /**
      * Finds preference by key, either from screen or from collapsed list.
      */
     public Preference findPreference(PreferenceScreen screen, CharSequence key) {
         Preference preference = screen.findPreference(key);
         if (preference != null) {
             return preference;
         }
         for (int i = 0; i < mCollapsedPrefs.size(); i++) {
             final Preference pref = mCollapsedPrefs.get(i);
             if (TextUtils.equals(key, pref.getKey())) {
                 return pref;
             }
             if (pref instanceof PreferenceGroup) {
                 final Preference returnedPreference = ((PreferenceGroup) pref).findPreference(key);
                 if (returnedPreference != null) {
                     return returnedPreference;
                 }
             }
         }
         Log.d(TAG, "Cannot find preference with key " + key);
         return null;
     }

     /**
      * Add preference to collapsed list.
      */
     @VisibleForTesting
     void addToCollapsedList(Preference preference) {
         // Insert preference based on it's order.
         int insertionIndex = Collections.binarySearch(mCollapsedPrefs, preference);
         if (insertionIndex < 0) {
             insertionIndex = insertionIndex * -1 - 1;
         }
         mCollapsedPrefs.add(insertionIndex, preference);
         updateExpandButtonSummary();
     }

     @VisibleForTesting
     List<Preference> getCollapsedPrefs() {
         return mCollapsedPrefs;
     }

     @VisibleForTesting
     void updateExpandButtonSummary() {
         final int size = mCollapsedPrefs.size();
         if (size == 0) {
             mExpandButton.setSummary(null);
         } else if (size == 1) {
             mExpandButton.setSummary(mCollapsedPrefs.get(0).getTitle());
         } else {
             CharSequence summary = mCollapsedPrefs.get(0).getTitle();
             for (int i = 1; i < size; i++) {
                 final CharSequence nextSummary = mCollapsedPrefs.get(i).getTitle();
                 if (!TextUtils.isEmpty(nextSummary)) {
                     summary = mContext.getString(R.string.join_many_items_middle, summary,
                             nextSummary);
                 }
             }
             mExpandButton.setSummary(summary);
         }
     }
 }
	/*
	* Copyright (C) 2016 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.settings.dashboard;

	import android.content.Context;
	import android.os.Bundle;
	import android.support.annotation.VisibleForTesting;
	import android.support.v14.preference.PreferenceFragment;
	import android.support.v7.preference.Preference;
	import android.support.v7.preference.PreferenceGroup;
	import android.support.v7.preference.PreferenceScreen;
	import android.text.TextUtils;
	import android.util.Log;

	import com.android.internal.logging.nano.MetricsProto;
	import com.android.settings.R;
	import com.android.settings.core.instrumentation.Instrumentable;
	import com.android.settings.core.instrumentation.MetricsFeatureProvider;
	import com.android.settings.overlay.FeatureFactory;
	import com.android.settingslib.core.lifecycle.LifecycleObserver;
	import com.android.settingslib.core.lifecycle.events.OnCreate;
	import com.android.settingslib.core.lifecycle.events.OnSaveInstanceState;

	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.List;

	public class ProgressiveDisclosureMixin implements Preference.OnPreferenceClickListener,
	LifecycleObserver, OnCreate, OnSaveInstanceState {

	private static final String TAG = "ProgressiveDisclosure";
	private static final String STATE_USER_EXPANDED = "state_user_expanded";
	private static final int DEFAULT_TILE_LIMIT = 300;

	private final Context mContext;
	// Collapsed preference sorted by order.
	private final List<Preference> mCollapsedPrefs = new ArrayList<>();
	private final MetricsFeatureProvider mMetricsFeatureProvider;
	private final PreferenceFragment mFragment;
	private /* final */ ExpandPreference mExpandButton;

	private int mTileLimit = DEFAULT_TILE_LIMIT;
	private boolean mUserExpanded;

	public ProgressiveDisclosureMixin(Context context,
	PreferenceFragment fragment, boolean keepExpanded) {
	mContext = context;
	mFragment = fragment;
	mExpandButton = new ExpandPreference(context);
	mExpandButton.setOnPreferenceClickListener(this);
	mMetricsFeatureProvider = FeatureFactory.getFactory(context).getMetricsFeatureProvider();
	mUserExpanded = keepExpanded;
	}

	@Override
	public void onCreate(Bundle savedInstanceState) {
	if (savedInstanceState != null) {
	mUserExpanded = savedInstanceState.getBoolean(STATE_USER_EXPANDED, false);
	}
	}

	@Override
	public void onSaveInstanceState(Bundle outState) {
	outState.putBoolean(STATE_USER_EXPANDED, mUserExpanded);
	}

	@Override
	public boolean onPreferenceClick(Preference preference) {
	if (preference instanceof ExpandPreference) {
	final PreferenceScreen screen = mFragment.getPreferenceScreen();
	if (screen != null) {
	screen.removePreference(preference);
	for (Preference pref : mCollapsedPrefs) {
	screen.addPreference(pref);
	}
	mCollapsedPrefs.clear();
	mUserExpanded = true;
	final int metricsCategory;
	if (mFragment instanceof Instrumentable) {
	metricsCategory = ((Instrumentable) mFragment).getMetricsCategory();
	} else {
	metricsCategory = MetricsProto.MetricsEvent.VIEW_UNKNOWN;
	}
	mMetricsFeatureProvider.actionWithSource(mContext, metricsCategory,
	MetricsProto.MetricsEvent.ACTION_SETTINGS_ADVANCED_BUTTON_EXPAND);
	}
	}
	return false;
	}

	/**
	* Sets the threshold to start collapsing preferences when there are too many.
	*/
	public void setTileLimit(int limit) {
	mTileLimit = limit;
	}

	/**
	* Whether the controller is in collapsed state.
	*/
	public boolean isCollapsed() {
	return !mCollapsedPrefs.isEmpty();
	}

	/**
	* Whether the screen should be collapsed.
	*/
	public boolean shouldCollapse(PreferenceScreen screen) {
	return !mUserExpanded && screen.getPreferenceCount() > mTileLimit;
	}

	/**
	* Collapse extra preferences and show a "More" button
	*/
	public void collapse(PreferenceScreen screen) {
	final int itemCount = screen.getPreferenceCount();
	if (!shouldCollapse(screen)) {
	return;
	}
	if (!mCollapsedPrefs.isEmpty()) {
	Log.w(TAG, "collapsed list should ALWAYS BE EMPTY before collapsing!");
	}

	for (int i = itemCount - 1; i >= mTileLimit; i--) {
	final Preference preference = screen.getPreference(i);
	addToCollapsedList(preference);
	screen.removePreference(preference);
	}
	screen.addPreference(mExpandButton);
	}

	/**
	* Adds preference to screen. If there are too many preference on screen, adds it to
	* collapsed list instead.
	*/
	public void addPreference(PreferenceScreen screen, Preference pref) {
	// Either add to screen, or to collapsed list.
	if (isCollapsed()) {
	// insert the preference to right position.
	final int lastPreferenceIndex = screen.getPreferenceCount() - 2;
	if (lastPreferenceIndex >= 0) {
	final Preference lastPreference = screen.getPreference(lastPreferenceIndex);
	if (lastPreference.getOrder() > pref.getOrder()) {
	// insert to screen and move the last pref to collapsed list.
	screen.removePreference(lastPreference);
	screen.addPreference(pref);
	addToCollapsedList(lastPreference);
	} else {
	// Insert to collapsed list.
	addToCollapsedList(pref);
	}
	} else {
	// Couldn't find last preference on screen, just add to collapsed list.
	addToCollapsedList(pref);
	}
	} else if (shouldCollapse(screen)) {
	// About to have too many tiles on scree, collapse and add pref to collapsed list.
	screen.addPreference(pref);
	collapse(screen);
	} else {
	// No need to collapse, add to screen directly.
	screen.addPreference(pref);
	}
	}

	/**
	* Removes preference. If the preference is on screen, remove it from screen. If the
	* preference is in collapsed list, remove it from list.
	*/
	public void removePreference(PreferenceScreen screen, String key) {
	// Try removing from screen.
	final Preference preference = screen.findPreference(key);
	if (preference != null) {
	screen.removePreference(preference);
	return;
	}
	// Didn't find on screen, try removing from collapsed list.
	for (int i = 0; i < mCollapsedPrefs.size(); i++) {
	final Preference pref = mCollapsedPrefs.get(i);
	if (TextUtils.equals(key, pref.getKey())) {
	mCollapsedPrefs.remove(pref);
	if (mCollapsedPrefs.isEmpty()) {
	// Removed last element, remove expand button too.
	screen.removePreference(mExpandButton);
	} else {
	updateExpandButtonSummary();
	}
	return;
	}
	}
	}

	/**
	* Finds preference by key, either from screen or from collapsed list.
	*/
	public Preference findPreference(PreferenceScreen screen, CharSequence key) {
	Preference preference = screen.findPreference(key);
	if (preference != null) {
	return preference;
	}
	for (int i = 0; i < mCollapsedPrefs.size(); i++) {
	final Preference pref = mCollapsedPrefs.get(i);
	if (TextUtils.equals(key, pref.getKey())) {
	return pref;
	}
	if (pref instanceof PreferenceGroup) {
	final Preference returnedPreference = ((PreferenceGroup) pref).findPreference(key);
	if (returnedPreference != null) {
	return returnedPreference;
	}
	}
	}
	Log.d(TAG, "Cannot find preference with key " + key);
	return null;
	}

	/**
	* Add preference to collapsed list.
	*/
	@VisibleForTesting
	void addToCollapsedList(Preference preference) {
	// Insert preference based on it's order.
	int insertionIndex = Collections.binarySearch(mCollapsedPrefs, preference);
	if (insertionIndex < 0) {
	insertionIndex = insertionIndex * -1 - 1;
	}
	mCollapsedPrefs.add(insertionIndex, preference);
	updateExpandButtonSummary();
	}

	@VisibleForTesting
	List<Preference> getCollapsedPrefs() {
	return mCollapsedPrefs;
	}

	@VisibleForTesting
	void updateExpandButtonSummary() {
	final int size = mCollapsedPrefs.size();
	if (size == 0) {
	mExpandButton.setSummary(null);
	} else if (size == 1) {
	mExpandButton.setSummary(mCollapsedPrefs.get(0).getTitle());
	} else {
	CharSequence summary = mCollapsedPrefs.get(0).getTitle();
	for (int i = 1; i < size; i++) {
	final CharSequence nextSummary = mCollapsedPrefs.get(i).getTitle();
	if (!TextUtils.isEmpty(nextSummary)) {
	summary = mContext.getString(R.string.join_many_items_middle, summary,
	nextSummary);
	}
	}
	mExpandButton.setSummary(summary);
	}
	}
	}