Add API to create new contexts with custom configurations.

This allows you to, say, make a Context whose configuration
is set to a different density than the actual density of the device.

The main API is Context.createConfigurationContext().  There is
also a new API on ContextThemeWrapper that allows you to apply
an override context before its resources are retrieved, which
addresses some feature requests from developers to be able to
customize the context their app is running in.

Change-Id: I88364986660088521e24b567e2fda22fb7042819

1 files changed, 64 insertions, 17 deletions

diff --git a/core/java/android/app/ActivityThread.java b/core/java/android/app/ActivityThread.java
index bb35ddd33d51..0789c60ffa3d 100644
--- a/core/java/android/app/ActivityThread.java
+++ b/core/java/android/app/ActivityThread.java
@@ -1471,13 +1471,25 @@ public final class ActivityThread {
 
     private static class ResourcesKey {
         final private String mResDir;
+        final private Configuration mOverrideConfiguration;
         final private float mScale;
         final private int mHash;
 
-        ResourcesKey(String resDir, float scale) {
+        ResourcesKey(String resDir, Configuration overrideConfiguration, float scale) {
             mResDir = resDir;
+            if (overrideConfiguration != null) {
+                if (Configuration.EMPTY.equals(overrideConfiguration)) {
+                    overrideConfiguration = null;
+                }
+            }
+            mOverrideConfiguration = overrideConfiguration;
             mScale = scale;
-            mHash = mResDir.hashCode() << 2 + (int) (mScale * 2);
+            int hash = 17;
+            hash = 31 * hash + mResDir.hashCode();
+            hash = 31 * hash + (mOverrideConfiguration != null
+                    ? mOverrideConfiguration.hashCode() : 0);
+            hash = 31 * hash + Float.floatToIntBits(mScale);
+            mHash = hash;
         }
 
         @Override
@@ -1491,7 +1503,21 @@ public final class ActivityThread {
                 return false;
             }
             ResourcesKey peer = (ResourcesKey) obj;
-            return mResDir.equals(peer.mResDir) && mScale == peer.mScale;
+            if (!mResDir.equals(peer.mResDir)) {
+                return false;
+            }
+            if (mOverrideConfiguration != peer.mOverrideConfiguration) {
+                if (mOverrideConfiguration == null || peer.mOverrideConfiguration == null) {
+                    return false;
+                }
+                if (!mOverrideConfiguration.equals(peer.mOverrideConfiguration)) {
+                    return false;
+                }
+            }
+            if (mScale != peer.mScale) {
+                return false;
+            }
+            return true;
         }
     }
 
@@ -1562,8 +1588,10 @@ public final class ActivityThread {
      * @param compInfo the compability info. It will use the default compatibility info when it's
      * null.
      */
-    Resources getTopLevelResources(String resDir, CompatibilityInfo compInfo) {
-        ResourcesKey key = new ResourcesKey(resDir, compInfo.applicationScale);
+    Resources getTopLevelResources(String resDir, Configuration overrideConfiguration,
+            CompatibilityInfo compInfo) {
+        ResourcesKey key = new ResourcesKey(resDir, overrideConfiguration,
+                compInfo.applicationScale);
         Resources r;
         synchronized (mPackages) {
             // Resources is app scale dependent.
@@ -1595,13 +1623,20 @@ public final class ActivityThread {
 
         //Slog.i(TAG, "Resource: key=" + key + ", display metrics=" + metrics);
         DisplayMetrics metrics = getDisplayMetricsLocked(null, false);
-        r = new Resources(assets, metrics, getConfiguration(), compInfo);
+        Configuration config;
+        if (key.mOverrideConfiguration != null) {
+            config = new Configuration(getConfiguration());
+            config.updateFrom(key.mOverrideConfiguration);
+        } else {
+            config = getConfiguration();
+        }
+        r = new Resources(assets, metrics, config, compInfo);
         if (false) {
             Slog.i(TAG, "Created app resources " + resDir + " " + r + ": "
                     + r.getConfiguration() + " appScale="
                     + r.getCompatibilityInfo().applicationScale);
         }
-        
+
         synchronized (mPackages) {
             WeakReference<Resources> wr = mActiveResources.get(key);
             Resources existing = wr != null ? wr.get() : null;
@@ -1621,8 +1656,10 @@ public final class ActivityThread {
     /**
      * Creates the top level resources for the given package.
      */
-    Resources getTopLevelResources(String resDir, LoadedApk pkgInfo) {
-        return getTopLevelResources(resDir, pkgInfo.mCompatibilityInfo.get());
+    Resources getTopLevelResources(String resDir, Configuration overrideConfiguration,
+            LoadedApk pkgInfo) {
+        return getTopLevelResources(resDir, overrideConfiguration,
+                pkgInfo.mCompatibilityInfo.get());
     }
 
     final Handler getHandler() {
@@ -3675,18 +3712,28 @@ public final class ActivityThread {
 
         ApplicationPackageManager.configurationChanged();
         //Slog.i(TAG, "Configuration changed in " + currentPackageName());
-        
-        Iterator<WeakReference<Resources>> it =
-            mActiveResources.values().iterator();
-        //Iterator<Map.Entry<String, WeakReference<Resources>>> it =
-        //    mActiveResources.entrySet().iterator();
+
+        Configuration tmpConfig = null;
+
+        Iterator<Map.Entry<ResourcesKey, WeakReference<Resources>>> it =
+                mActiveResources.entrySet().iterator();
         while (it.hasNext()) {
-            WeakReference<Resources> v = it.next();
-            Resources r = v.get();
+            Map.Entry<ResourcesKey, WeakReference<Resources>> entry = it.next();
+            Resources r = entry.getValue().get();
             if (r != null) {
                 if (DEBUG_CONFIGURATION) Slog.v(TAG, "Changing resources "
                         + r + " config to: " + config);
-                r.updateConfiguration(config, dm, compat);
+                Configuration override = entry.getKey().mOverrideConfiguration;
+                if (override != null) {
+                    if (tmpConfig == null) {
+                        tmpConfig = new Configuration();
+                    }
+                    tmpConfig.setTo(config);
+                    tmpConfig.updateFrom(override);
+                    r.updateConfiguration(tmpConfig, dm, compat);
+                } else {
+                    r.updateConfiguration(config, dm, compat);
+                }
                 //Slog.i(TAG, "Updated app resources " + v.getKey()
                 //        + " " + r + ": " + r.getConfiguration());
             } else {