为什么80%的码农都做不了架构师？>>> 
systemui/recents/model/RecentsTaskLoadPlan.java
找到 preloadPlan方法
/*
* Copyright (C) 2014 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.systemui.recents.model;
import android.app.ActivityManager;
import android.content.Context;
import android.content.pm.ActivityInfo;
import android.content.pm.ApplicationInfo;
import android.content.pm.UserInfo;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;
import android.os.UserHandle;
import android.os.UserManager;
import android.provider.Settings;
import android.provider.Settings.Secure;
import android.util.ArraySet;
import android.util.SparseArray;
import android.util.SparseIntArray;
import com.android.systemui.Prefs;
import com.android.systemui.R;
import com.android.systemui.recents.Recents;
import com.android.systemui.recents.RecentsConfiguration;
import com.android.systemui.recents.RecentsDebugFlags;
import com.android.systemui.recents.misc.SystemServicesProxy;
import com.android.systemui.recents.views.grid.TaskGridLayoutAlgorithm;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* This class stores the loading state as it goes through multiple stages of loading:
* 1) preloadRawTasks() will load the raw set of recents tasks from the system
* 2) preloadPlan() will construct a new task stack with all metadata and only icons and
* thumbnails that are currently in the cache
* 3) executePlan() will actually load and fill in the icons and thumbnails according to the load
* options specified, such that we can transition into the Recents activity seamlessly
*/
public class RecentsTaskLoadPlan {
private static int MIN_NUM_TASKS = 5;
private static int SESSION_BEGIN_TIME = 1000 /* ms/s */ * 60 /* s/min */ * 60 /* min/hr */ *
6 /* hrs */;
/** The set of conditions to load tasks. */
public static class Options {
public int runningTaskId = -1;
public boolean loadIcons = true;
public boolean loadThumbnails = true;
public boolean onlyLoadForCache = false;
public boolean onlyLoadPausedActivities = false;
public int numVisibleTasks = 0;
public int numVisibleTaskThumbnails = 0;
}
Context mContext;
List mRawTasks;
TaskStack mStack;
ArraySet mCurrentQuietProfiles = new ArraySet();
/** Package level ctor */
RecentsTaskLoadPlan(Context context) {
mContext = context;
}
private void updateCurrentQuietProfilesCache(int currentUserId) {
mCurrentQuietProfiles.clear();
if (currentUserId == UserHandle.USER_CURRENT) {
currentUserId = ActivityManager.getCurrentUser();
}
UserManager userManager = (UserManager) mContext.getSystemService(Context.USER_SERVICE);
List profiles = userManager.getProfiles(currentUserId);
if (profiles != null) {
for (int i = 0; i < profiles.size(); i++) {
UserInfo user = profiles.get(i);
if (user.isManagedProfile() && user.isQuietModeEnabled()) {
mCurrentQuietProfiles.add(user.id);
}
}
}
}
/**
* An optimization to preload the raw list of tasks. The raw tasks are saved in least-recent
* to most-recent order.
*/
public synchronized void preloadRawTasks(boolean includeFrontMostExcludedTask) {
int currentUserId = UserHandle.USER_CURRENT;
updateCurrentQuietProfilesCache(currentUserId);
SystemServicesProxy ssp = Recents.getSystemServices();
mRawTasks = ssp.getRecentTasks(ActivityManager.getMaxRecentTasksStatic(),
currentUserId, includeFrontMostExcludedTask, mCurrentQuietProfiles);
// Since the raw tasks are given in most-recent to least-recent order, we need to reverse it
Collections.reverse(mRawTasks);
}
/**
* Preloads the list of recent tasks from the system. After this call, the TaskStack will
* have a list of all the recent tasks with their metadata, not including icons or
* thumbnails which were not cached and have to be loaded.
*
* The tasks will be ordered by:
* - least-recent to most-recent stack tasks
* - least-recent to most-recent freeform tasks
*/
public synchronized void preloadPlan(RecentsTaskLoader loader, int runningTaskId,
boolean includeFrontMostExcludedTask) {
Resources res = mContext.getResources();
ArrayList allTasks = new ArrayList<>();
if (mRawTasks == null) {
preloadRawTasks(includeFrontMostExcludedTask);
}
SystemServicesProxy ssp = SystemServicesProxy.getInstance(mContext);
SparseArray affiliatedTasks = new SparseArray<>();
SparseIntArray affiliatedTaskCounts = new SparseIntArray();
String dismissDescFormat = mContext.getString(
R.string.accessibility_recents_item_will_be_dismissed);
String appInfoDescFormat = mContext.getString(
R.string.accessibility_recents_item_open_app_info);
int currentUserId = ssp.getCurrentUser();
long legacyLastStackActiveTime = migrateLegacyLastStackActiveTime(currentUserId);
long lastStackActiveTime = Settings.Secure.getLongForUser(mContext.getContentResolver(),
Secure.OVERVIEW_LAST_STACK_ACTIVE_TIME, legacyLastStackActiveTime, currentUserId);
if (RecentsDebugFlags.Static.EnableMockTasks) {
lastStackActiveTime = 0;
}
long newLastStackActiveTime = -1;
int taskCount = mRawTasks.size();
//wfy
for (int i = 0; i < taskCount; i++) {
ActivityManager.RecentTaskInfo t = mRawTasks.get(i);
// Compose the task key
Task.TaskKey taskKey = new Task.TaskKey(t.persistentId, t.stackId, t.baseIntent,
t.userId, t.firstActiveTime, t.lastActiveTime);
// This task is only shown in the stack if it satisfies the historical time or min
// number of tasks constraints. Freeform tasks are also always shown.
boolean isFreeformTask = SystemServicesProxy.isFreeformStack(t.stackId);
boolean isStackTask;
if (Recents.getConfiguration().isGridEnabled) {
// When grid layout is enabled, we only show the first
// TaskGridLayoutAlgorithm.MAX_LAYOUT_TASK_COUNT} tasks.
isStackTask = t.lastActiveTime >= lastStackActiveTime &&
i >= taskCount - TaskGridLayoutAlgorithm.MAX_LAYOUT_TASK_COUNT;
} else {
isStackTask = isFreeformTask || !isHistoricalTask(t) ||
(t.lastActiveTime >= lastStackActiveTime && i >= (taskCount - MIN_NUM_TASKS));
}
boolean isLaunchTarget = taskKey.id == runningTaskId;
// The last stack active time is the baseline for which we show visible tasks. Since
// the system will store all the tasks, we don't want to show the tasks prior to the
// last visible ones, otherwise, as you dismiss them, the previous tasks may satisfy
// the other stack-task constraints.
if (isStackTask && newLastStackActiveTime < 0) {
newLastStackActiveTime = t.lastActiveTime;
}
// Load the title, icon, and color
ActivityInfo info = loader.getAndUpdateActivityInfo(taskKey);
String title = loader.getAndUpdateActivityTitle(taskKey, t.taskDescription);
String titleDescription = loader.getAndUpdateContentDescription(taskKey, res);
String dismissDescription = String.format(dismissDescFormat, titleDescription);
String appInfoDescription = String.format(appInfoDescFormat, titleDescription);
Drawable icon = isStackTask
? loader.getAndUpdateActivityIcon(taskKey, t.taskDescription, res, false)
: null;
Bitmap thumbnail = loader.getAndUpdateThumbnail(taskKey, false /* loadIfNotCached */);
int activityColor = loader.getActivityPrimaryColor(t.taskDescription);
int backgroundColor = loader.getActivityBackgroundColor(t.taskDescription);
boolean isSystemApp = (info != null) &&
((info.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0);
// Add the task to the stack
Task task = new Task(taskKey, t.affiliatedTaskId, t.affiliatedTaskColor, icon,
thumbnail, title, titleDescription, dismissDescription, appInfoDescription,
activityColor, backgroundColor, isLaunchTarget, isStackTask, isSystemApp,
t.isDockable, t.bounds, t.taskDescription, t.resizeMode, t.topActivity);
if(info.packageName.equals("com.funduemobile.enpad")){
}else{
allTasks.add(task);
affiliatedTaskCounts.put(taskKey.id, affiliatedTaskCounts.get(taskKey.id, 0) + 1);
affiliatedTasks.put(taskKey.id, taskKey);
}
}
if (newLastStackActiveTime != -1) {
Settings.Secure.putLongForUser(mContext.getContentResolver(),
Secure.OVERVIEW_LAST_STACK_ACTIVE_TIME, newLastStackActiveTime, currentUserId);
}
// Initialize the stacks
mStack = new TaskStack();
mStack.setTasks(mContext, allTasks, false /* notifyStackChanges */);
}
/**
* Called to apply the actual loading based on the specified conditions.
*/
public synchronized void executePlan(Options opts, RecentsTaskLoader loader,
TaskResourceLoadQueue loadQueue) {
RecentsConfiguration config = Recents.getConfiguration();
Resources res = mContext.getResources();
// Iterate through each of the tasks and load them according to the load conditions.
ArrayList tasks = mStack.getStackTasks();
int taskCount = tasks.size();
for (int i = 0; i < taskCount; i++) {
Task task = tasks.get(i);
Task.TaskKey taskKey = task.key;
boolean isRunningTask = (task.key.id == opts.runningTaskId);
boolean isVisibleTask = i >= (taskCount - opts.numVisibleTasks);
boolean isVisibleThumbnail = i >= (taskCount - opts.numVisibleTaskThumbnails);
// If requested, skip the running task
if (opts.onlyLoadPausedActivities && isRunningTask) {
continue;
}
if (opts.loadIcons && (isRunningTask || isVisibleTask)) {
if (task.icon == null) {
task.icon = loader.getAndUpdateActivityIcon(taskKey, task.taskDescription, res,
true);
}
}
if (opts.loadThumbnails && (isRunningTask || isVisibleThumbnail)) {
if (task.thumbnail == null || isRunningTask) {
if (config.svelteLevel <= RecentsConfiguration.SVELTE_LIMIT_CACHE) {
task.thumbnail = loader.getAndUpdateThumbnail(taskKey,
true /* loadIfNotCached */);
} else if (config.svelteLevel == RecentsConfiguration.SVELTE_DISABLE_CACHE) {
loadQueue.addTask(task);
}
}
}
}
}
/**
* Returns the TaskStack from the preloaded list of recent tasks.
*/
public TaskStack getTaskStack() {
return mStack;
}
/**
* Returns the raw list of recent tasks.
*/
public List getRawTasks() {
return mRawTasks;
}
/** Returns whether there are any tasks in any stacks. */
public boolean hasTasks() {
if (mStack != null) {
return mStack.getTaskCount() > 0;
}
return false;
}
/**
* Returns whether this task is too old to be shown.
*/
private boolean isHistoricalTask(ActivityManager.RecentTaskInfo t) {
return t.lastActiveTime < (System.currentTimeMillis() - SESSION_BEGIN_TIME);
}
/**
* Migrate the last active time from the prefs to the secure settings.
*
* The first time this runs, it will:
* 1) fetch the last stack active time from the prefs
* 2) set the prefs to the last stack active time for all users
* 3) clear the pref
* 4) return the last stack active time
*
* Subsequent calls to this will return zero.
*/
private long migrateLegacyLastStackActiveTime(int currentUserId) {
long legacyLastStackActiveTime = Prefs.getLong(mContext,
Prefs.Key.OVERVIEW_LAST_STACK_TASK_ACTIVE_TIME, -1);
if (legacyLastStackActiveTime != -1) {
Prefs.remove(mContext, Prefs.Key.OVERVIEW_LAST_STACK_TASK_ACTIVE_TIME);
UserManager userMgr = (UserManager) mContext.getSystemService(Context.USER_SERVICE);
List users = userMgr.getUsers();
for (int i = 0; i < users.size(); i++) {
int userId = users.get(i).id;
if (userId != currentUserId) {
Settings.Secure.putLongForUser(mContext.getContentResolver(),
Secure.OVERVIEW_LAST_STACK_ACTIVE_TIME, legacyLastStackActiveTime,
userId);
}
}
return legacyLastStackActiveTime;
}
return 0;
}
}