1 /* 2 * Copyright (C) 2023 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.car.builtin.display; 18 19 import android.annotation.FloatRange; 20 import android.annotation.NonNull; 21 import android.annotation.Nullable; 22 import android.annotation.SystemApi; 23 import android.content.Context; 24 import android.hardware.display.DisplayManager; 25 import android.hardware.display.DisplayManager.DisplayListener; 26 import android.hardware.display.DisplayManager.EventsMask; 27 import android.os.Handler; 28 import android.view.Display; 29 30 /** 31 * Helper for DisplayManager related operations. 32 * 33 * @hide 34 */ 35 @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES) 36 public final class DisplayManagerHelper { 37 38 /** 39 * Event type for when a new display is added. 40 * 41 * @see #registerDisplayListener(DisplayListener, Handler, long) 42 */ 43 public static final long EVENT_FLAG_DISPLAY_ADDED = DisplayManager.EVENT_FLAG_DISPLAY_ADDED; 44 45 /** 46 * Event type for when a display is removed. 47 * 48 * @see #registerDisplayListener(DisplayListener, Handler, long) 49 */ 50 public static final long EVENT_FLAG_DISPLAY_REMOVED = DisplayManager.EVENT_FLAG_DISPLAY_REMOVED; 51 52 /** 53 * Event type for when a display is changed. 54 * 55 * @see #registerDisplayListener(DisplayListener, Handler, long) 56 */ 57 public static final long EVENT_FLAG_DISPLAY_CHANGED = DisplayManager.EVENT_FLAG_DISPLAY_CHANGED; 58 59 /** 60 * Event flag to register for a display's brightness changes. This notification is sent 61 * through the {@link DisplayListener#onDisplayChanged} callback method. New brightness 62 * values can be retrieved via {@link android.view.Display#getBrightnessInfo()}. 63 * 64 * @see #registerDisplayListener(DisplayListener, Handler, long) 65 */ 66 public static final long EVENT_FLAG_DISPLAY_BRIGHTNESS = 67 DisplayManager.EVENT_FLAG_DISPLAY_BRIGHTNESS; 68 DisplayManagerHelper()69 private DisplayManagerHelper() { 70 throw new UnsupportedOperationException("contains only static members"); 71 } 72 73 /** 74 * Registers a display listener to receive notifications about given display event types. 75 * 76 * @param context The context to use. 77 * @param listener The listener to register. 78 * @param handler The handler on which the listener should be invoked, or null 79 * if the listener should be invoked on the calling thread's looper. 80 * @param eventsMask A bitmask of the event types for which this listener is subscribed. 81 * 82 * @see DisplayManager#EVENT_FLAG_DISPLAY_ADDED 83 * @see DisplayManager#EVENT_FLAG_DISPLAY_CHANGED 84 * @see DisplayManager#EVENT_FLAG_DISPLAY_REMOVED 85 * @see DisplayManager#EVENT_FLAG_DISPLAY_BRIGHTNESS 86 * @see DisplayManager#registerDisplayListener(DisplayListener, Handler) 87 * @see DisplayManager#unregisterDisplayListener 88 */ registerDisplayListener(Context context, DisplayListener listener, Handler handler, @EventsMask long eventsMask)89 public static void registerDisplayListener(Context context, DisplayListener listener, 90 Handler handler, @EventsMask long eventsMask) { 91 DisplayManager displayManager = context.getSystemService(DisplayManager.class); 92 displayManager.registerDisplayListener(listener, handler, eventsMask); 93 } 94 95 /** 96 * Gets the brightness of the specified display. 97 * 98 * @param context Context to use. 99 * @param displayId The display of which brightness value to get from. 100 */ getBrightness(Context context, int displayId)101 public static float getBrightness(Context context, int displayId) { 102 DisplayManager displayManager = context.getSystemService(DisplayManager.class); 103 return displayManager.getBrightness(displayId); 104 } 105 106 /** 107 * Sets the brightness of the specified display. 108 * 109 * @param context Context to use. 110 * @param displayId the logical display id 111 * @param brightness The brightness value from 0.0f to 1.0f. 112 */ setBrightness(Context context, int displayId, @FloatRange(from = 0f, to = 1f) float brightness)113 public static void setBrightness(Context context, int displayId, 114 @FloatRange(from = 0f, to = 1f) float brightness) { 115 DisplayManager displayManager = context.getSystemService(DisplayManager.class); 116 displayManager.setBrightness(displayId, brightness); 117 } 118 119 /** 120 * See {@link Display#getUniqueId()}. 121 */ 122 @Nullable getUniqueId(@onNull Display display)123 public static String getUniqueId(@NonNull Display display) { 124 return display.getUniqueId(); 125 } 126 } 127