Add a flashlight slice in settings.

- It retrieves the flashlight status from Settings.Secure.
- It uses the broadcast relay to update flashlight status
without action on the slice.

Test: robotests
Change-Id: Ib4d636541f5166b8634326cce76aed5665989b76
Fixes: 74913192

src/com/android/settings/flashlight/FlashlightSliceBuilder.java

@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2018 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.settings.flashlight;
+
+import static android.app.slice.Slice.EXTRA_TOGGLE_STATE;
+import static androidx.slice.builders.ListBuilder.ICON_IMAGE;
+
+import android.annotation.ColorInt;
+import android.app.PendingIntent;
+import android.content.ContentResolver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.hardware.camera2.CameraAccessException;
+import android.hardware.camera2.CameraCharacteristics;
+import android.hardware.camera2.CameraManager;
+import android.net.Uri;
+import android.provider.Settings;
+import android.provider.Settings.Secure;
+import android.provider.SettingsSlicesContract;
+import android.util.Log;
+
+import androidx.core.graphics.drawable.IconCompat;
+import com.android.settings.R;
+import com.android.settings.Utils;
+import com.android.settings.slices.SettingsSliceProvider;
+import com.android.settings.slices.SliceBroadcastReceiver;
+
+import androidx.slice.Slice;
+import androidx.slice.builders.ListBuilder;
+import androidx.slice.builders.SliceAction;
+
+import android.app.StatusBarManager;
+
+
+/**
+ * Utility class to build a Flashlight Slice, and handle all associated actions.
+ */
+public class FlashlightSliceBuilder {
+
+    private static final String TAG = "FlashlightSliceBuilder";
+
+    public static final String KEY_FLASHLIGHT = "flashlight";
+
+    /**
+     * Backing Uri for the Flashlight Slice.
+     */
+    public static final Uri FLASHLIGHT_URI = new Uri.Builder()
+        .scheme(ContentResolver.SCHEME_CONTENT)
+        .authority(SettingsSliceProvider.SLICE_AUTHORITY)
+        .appendPath(SettingsSlicesContract.PATH_SETTING_ACTION)
+        .appendPath(KEY_FLASHLIGHT)
+        .build();
+
+    /**
+     * Action notifying a change on the Flashlight Slice.
+     */
+    public static final String ACTION_FLASHLIGHT_SLICE_CHANGED =
+        "com.android.settings.flashlight.action.FLASHLIGHT_SLICE_CHANGED";
+
+    /**
+     * Action broadcasting a change on whether flashlight is on or off.
+     */
+    public static final String ACTION_FLASHLIGHT_CHANGED =
+        "com.android.settings.flashlight.action.FLASHLIGHT_CHANGED";
+
+    public static final IntentFilter INTENT_FILTER = new IntentFilter(ACTION_FLASHLIGHT_CHANGED);
+
+    private FlashlightSliceBuilder() {}
+
+    /**
+     * Return a Flashlight Slice bound to {@link #FLASHLIGHT_URI}.
+     */
+    public static Slice getSlice(Context context) {
+        if (!isFlashlightAvailable(context)) {
+            return null;
+        }
+        final PendingIntent toggleAction = getBroadcastIntent(context);
+        @ColorInt final int color = Utils.getColorAccentDefaultColor(context);
+        final IconCompat icon =
+                IconCompat.createWithResource(context, R.drawable.ic_signal_flashlight);
+        return new ListBuilder(context, FLASHLIGHT_URI, ListBuilder.INFINITY)
+            .setAccentColor(color)
+            .addRow(b -> b
+                .setTitle(context.getText(R.string.power_flashlight))
+                .setTitleItem(icon, ICON_IMAGE)
+                .setPrimaryAction(
+                        new SliceAction(toggleAction, null, isFlashlightEnabled(context))))
+            .build();
+    }
+
+    /**
+     * Update the current flashlight status to the boolean value keyed by
+     * {@link android.app.slice.Slice#EXTRA_TOGGLE_STATE} on {@param intent}.
+     */
+    public static void handleUriChange(Context context, Intent intent) {
+        try {
+            final String cameraId = getCameraId(context);
+            if (cameraId != null) {
+                final boolean state = intent.getBooleanExtra(
+                        EXTRA_TOGGLE_STATE, isFlashlightEnabled(context));
+                final CameraManager cameraManager = context.getSystemService(CameraManager.class);
+                cameraManager.setTorchMode(cameraId, state);
+            }
+        } catch (CameraAccessException e) {
+            Log.e(TAG, "Camera couldn't set torch mode.", e);
+        }
+        context.getContentResolver().notifyChange(FLASHLIGHT_URI, null);
+    }
+
+    private static String getCameraId(Context context) throws CameraAccessException {
+        final CameraManager cameraManager = context.getSystemService(CameraManager.class);
+        final String[] ids = cameraManager.getCameraIdList();
+        for (String id : ids) {
+            CameraCharacteristics c = cameraManager.getCameraCharacteristics(id);
+            Boolean flashAvailable = c.get(CameraCharacteristics.FLASH_INFO_AVAILABLE);
+            Integer lensFacing = c.get(CameraCharacteristics.LENS_FACING);
+            if (flashAvailable != null && flashAvailable
+                  && lensFacing != null && lensFacing == CameraCharacteristics.LENS_FACING_BACK) {
+                return id;
+            }
+        }
+        return null;
+    }
+
+    private static PendingIntent getBroadcastIntent(Context context) {
+        final Intent intent = new Intent(ACTION_FLASHLIGHT_SLICE_CHANGED);
+        intent.setClass(context, SliceBroadcastReceiver.class);
+        return PendingIntent.getBroadcast(context, 0 /* requestCode */, intent,
+            PendingIntent.FLAG_CANCEL_CURRENT);
+    }
+
+    private static boolean isFlashlightAvailable(Context context) {
+        return Settings.Secure.getInt(
+            context.getContentResolver(), Secure.FLASHLIGHT_AVAILABLE, 0) == 1;
+    }
+
+    private static boolean isFlashlightEnabled(Context context) {
+        return Settings.Secure.getInt(
+            context.getContentResolver(), Secure.FLASHLIGHT_ENABLED, 0) == 1;
+    }
+}