commit 2972c0136de098a7721555821bfb7451324b33ca
author Amith Yamasani <yamasani@google.com> Wed Oct 02 11:48:46 2013 -0700
committer Amith Yamasani <yamasani@google.com> Wed Oct 02 11:48:46 2013 -0700
tree b0a69870889b816b8a0ec60e28dbf1e1ac8692d4
parent 028b6b3f7cc79587a42583351e2c032f71e7ac8c

Load account type icons in a background thread before scrolling down

This reduces the jank when scrolling down in top-level Settings if you
happen to have several account types like Google, Twitter, Facebook, etc.

In the process of doing this, discovered that headers get built even when
they're not showing (SubSettings). Skip setting up the headers, which can
be expensive when there are several accounts.

Bug: 11006601
Change-Id: I8b4eafdcc2fc2beecac01317c3c8f07a82febcc0

src/com/android/settings/Settings.java

diff --git a/src/com/android/settings/Settings.java b/src/com/android/settings/Settings.java
index 13f7166..f01c03a 100644
--- a/src/com/android/settings/Settings.java
+++ b/src/com/android/settings/Settings.java
@@ -516,8 +516,10 @@
      */
     @Override
     public void onBuildHeaders(List<Header> headers) {
-        loadHeadersFromResource(R.xml.settings_headers, headers);
-        updateHeaderList(headers);
+        if (!onIsHidingHeaders()) {
+            loadHeadersFromResource(R.xml.settings_headers, headers);
+            updateHeaderList(headers);
+        }
     }
 
     private void updateHeaderList(List<Header> target) {
@@ -655,6 +657,7 @@
                 }
             }
             accountHeaders.add(accHeader);
+            mAuthenticatorHelper.preloadDrawableForType(this, accountType);
         }
 
         // Sort by label

src/com/android/settings/accounts/AuthenticatorHelper.java

diff --git a/src/com/android/settings/accounts/AuthenticatorHelper.java b/src/com/android/settings/accounts/AuthenticatorHelper.java
index eba785b..a164b8b 100644
--- a/src/com/android/settings/accounts/AuthenticatorHelper.java
+++ b/src/com/android/settings/accounts/AuthenticatorHelper.java
@@ -23,6 +23,7 @@
 import android.content.pm.PackageManager;
 import android.content.res.Resources;
 import android.graphics.drawable.Drawable;
+import android.os.AsyncTask;
 import android.util.Log;
 
 import java.util.ArrayList;
@@ -45,6 +46,16 @@
         return mEnabledAccountTypes.toArray(new String[mEnabledAccountTypes.size()]);
     }
 
+    public void preloadDrawableForType(final Context context, final String accountType) {
+        new AsyncTask<Void, Void, Void>() {
+            @Override
+            protected Void doInBackground(Void... params) {
+                getDrawableForType(context, accountType);
+                return null;
+            }
+        }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, (Void[]) null);
+    }
+
     /**
      * Gets an icon associated with a particular account type. If none found, return null.
      * @param accountType the type of account
@@ -52,15 +63,19 @@
      */
     public Drawable getDrawableForType(Context context, final String accountType) {
         Drawable icon = null;
-        if (mAccTypeIconCache.containsKey(accountType)) {
-            return mAccTypeIconCache.get(accountType);
+        synchronized (mAccTypeIconCache) {
+            if (mAccTypeIconCache.containsKey(accountType)) {
+                return mAccTypeIconCache.get(accountType);
+            }
         }
         if (mTypeToAuthDescription.containsKey(accountType)) {
             try {
                 AuthenticatorDescription desc = mTypeToAuthDescription.get(accountType);
                 Context authContext = context.createPackageContext(desc.packageName, 0);
                 icon = authContext.getResources().getDrawable(desc.iconId);
-                mAccTypeIconCache.put(accountType, icon);
+                synchronized (mAccTypeIconCache) {
+                    mAccTypeIconCache.put(accountType, icon);
+                }
             } catch (PackageManager.NameNotFoundException e) {
             } catch (Resources.NotFoundException e) {
             }