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

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser;
 
 import android.Manifest;
 import android.app.Activity;
 import android.bluetooth.BluetoothAdapter;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 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;
 import android.text.SpannableString;
 import android.text.TextUtils;
 import android.view.View;
 
 import org.chromium.base.ApiCompatibilityUtils;
 import org.chromium.base.Log;
 import org.chromium.base.VisibleForTesting;
@@ skipping 44 matching lines @@
 
     // The security level of the connection to the site wanting to pair with the
     // bluetooth devices. For valid values see SecurityStateModel::SecurityLevel.
     int mSecurityLevel;
 
     @VisibleForTesting
     Drawable mConnectedIcon;
     @VisibleForTesting
     String mConnectedIconDescription;
     @VisibleForTesting
-    Drawable[] mSignalStrengthLevelIcon;
+    LevelListDrawable mSignalStrengthLevelIcon;
 
     // A pointer back to the native part of the implementation for this dialog.
     long mNativeBluetoothChooserDialogPtr;
 
     // Used to keep track of when the Mode Changed Receiver is registered.
     boolean mIsLocationModeChangedReceiverRegistered;
 
     // The local device Bluetooth adapter.
     private final BluetoothAdapter mAdapter;
 
@@ skipping 36 matching lines @@
         assert mActivity != null;
         mOrigin = origin;
         mSecurityLevel = securityLevel;
         mNativeBluetoothChooserDialogPtr = nativeBluetoothChooserDialogPtr;
         mAdapter = BluetoothAdapter.getDefaultAdapter();
 
         // Initialize icons.
         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.");
         }
         mAdapterOffStatus =
                 SpanApplier.applySpans(mActivity.getString(R.string.bluetooth_adapter_off_help),
                         new SpanInfo("<link>", "</link>",
                                 new BluetoothClickableSpan(LinkType.ADAPTER_OFF_HELP, mActivity)));
     }
 
@@ skipping 233 matching lines @@
     @VisibleForTesting
     @CalledByNative
     void addOrUpdateDevice(
             String deviceId, String deviceName, boolean isGATTConnected, int signalStrengthLevel) {
         Drawable icon = null;
         String iconDescription = null;
         if (isGATTConnected) {
             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);
         }
 
         mItemChooserDialog.addOrUpdateItem(deviceId, deviceName, icon, iconDescription);
     }
 
     @VisibleForTesting
     @CalledByNative
@@ skipping 46 matching lines @@
     @VisibleForTesting
     native void nativeRestartSearch(long nativeBluetoothChooserAndroid);
     // Help links.
     @VisibleForTesting
     native void nativeShowBluetoothOverviewLink(long nativeBluetoothChooserAndroid);
     @VisibleForTesting
     native void nativeShowBluetoothAdapterOffLink(long nativeBluetoothChooserAndroid);
     @VisibleForTesting
     native void nativeShowNeedLocationPermissionLink(long nativeBluetoothChooserAndroid);
 }