DO NO SUMMIT: bluetooth: Use a LevelListDrawable instead of an array of drawables

chrome/android/java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java

Index: chrome/android/java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java b/chrome/android/java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java
index 58ac77967ca6b7afc8ccbfeb684878c2345970e9..b85833fef426e7bce63d6c6677c918ad6de5e248 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java
@@ -13,6 +13,7 @@ import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.res.Resources;
 import android.graphics.drawable.Drawable;
+import android.graphics.drawable.LevelListDrawable;
 import android.location.LocationManager;
 import android.support.graphics.drawable.VectorDrawableCompat;
 import android.support.v4.graphics.drawable.DrawableCompat;
@@ -77,7 +78,7 @@ public class BluetoothChooserDialog
     @VisibleForTesting
     String mConnectedIconDescription;
     @VisibleForTesting
-    Drawable[] mSignalStrengthLevelIcon;
+    LevelListDrawable mSignalStrengthLevelIcon;
 
     // A pointer back to the native part of the implementation for this dialog.
     long mNativeBluetoothChooserDialogPtr;
@@ -134,12 +135,17 @@ public class BluetoothChooserDialog
         mConnectedIcon = getIconWithRowIconColorStateList(R.drawable.ic_bluetooth_connected);
         mConnectedIconDescription = mActivity.getString(R.string.bluetooth_device_connected);
 
-        mSignalStrengthLevelIcon = new Drawable[] {
-                getIconWithRowIconColorStateList(R.drawable.ic_signal_cellular_0_bar),
-                getIconWithRowIconColorStateList(R.drawable.ic_signal_cellular_1_bar),
-                getIconWithRowIconColorStateList(R.drawable.ic_signal_cellular_2_bar),
-                getIconWithRowIconColorStateList(R.drawable.ic_signal_cellular_3_bar),
-                getIconWithRowIconColorStateList(R.drawable.ic_signal_cellular_4_bar)};
+        mSignalStrengthLevelIcon = new LevelListDrawable();
+        mSignalStrengthLevelIcon.addLevel(
+                0, 0, getIconWithRowIconColorStateList(R.drawable.ic_signal_cellular_0_bar));
+        mSignalStrengthLevelIcon.addLevel(
+                1, 1, getIconWithRowIconColorStateList(R.drawable.ic_signal_cellular_1_bar));
+        mSignalStrengthLevelIcon.addLevel(
+                2, 2, getIconWithRowIconColorStateList(R.drawable.ic_signal_cellular_2_bar));
+        mSignalStrengthLevelIcon.addLevel(
+                3, 3, getIconWithRowIconColorStateList(R.drawable.ic_signal_cellular_3_bar));
+        mSignalStrengthLevelIcon.addLevel(
+                4, 4, getIconWithRowIconColorStateList(R.drawable.ic_signal_cellular_4_bar));
 
         if (mAdapter == null) {
             Log.i(TAG, "BluetoothChooserDialog: Default Bluetooth adapter not found.");
@@ -393,7 +399,8 @@ public class BluetoothChooserDialog
             icon = mConnectedIcon.getConstantState().newDrawable();
             iconDescription = mConnectedIconDescription;
         } else if (signalStrengthLevel != -1) {
-            icon = mSignalStrengthLevelIcon[signalStrengthLevel].getConstantState().newDrawable();
+            icon = mSignalStrengthLevelIcon.getConstantState().newDrawable();

[ortuno, 2017/04/26 01:06:45]

This line makes the dialog pretty unusable. Since the constant state is
different for each returned icon we end up redrawing the list for every update
which causes a lot of ignored touch actions.

+            icon.setLevel(signalStrengthLevel);
             iconDescription = mActivity.getResources().getQuantityString(
                     R.plurals.signal_strength_level_n_bars, signalStrengthLevel,
                     signalStrengthLevel);