1 /* 2 * Copyright (C) 2012 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 com.android.server.display; 18 19 import android.content.Context; 20 import android.os.Handler; 21 import android.view.Display; 22 23 import java.io.PrintWriter; 24 import java.util.concurrent.atomic.AtomicInteger; 25 26 /** 27 * A display adapter makes zero or more display devices available to the system 28 * and provides facilities for discovering when displays are connected or disconnected. 29 * <p> 30 * For now, all display adapters are registered in the system server but 31 * in principle it could be done from other processes. 32 * </p><p> 33 * Display adapters are guarded by the {@link DisplayManagerService.SyncRoot} lock. 34 * </p> 35 */ 36 abstract class DisplayAdapter { 37 private final DisplayManagerService.SyncRoot mSyncRoot; 38 private final Context mContext; 39 private final Handler mHandler; 40 private final Listener mListener; 41 private final String mName; 42 43 public static final int DISPLAY_DEVICE_EVENT_ADDED = 1; 44 public static final int DISPLAY_DEVICE_EVENT_CHANGED = 2; 45 public static final int DISPLAY_DEVICE_EVENT_REMOVED = 3; 46 47 /** 48 * Used to generate globally unique display mode ids. 49 */ 50 private static final AtomicInteger NEXT_DISPLAY_MODE_ID = new AtomicInteger(1); // 0 = no mode. 51 52 // Called with SyncRoot lock held. DisplayAdapter(DisplayManagerService.SyncRoot syncRoot, Context context, Handler handler, Listener listener, String name)53 public DisplayAdapter(DisplayManagerService.SyncRoot syncRoot, 54 Context context, Handler handler, Listener listener, String name) { 55 mSyncRoot = syncRoot; 56 mContext = context; 57 mHandler = handler; 58 mListener = listener; 59 mName = name; 60 } 61 62 /** 63 * Gets the object that the display adapter should synchronize on when handling 64 * calls that come in from outside of the display manager service. 65 */ getSyncRoot()66 public final DisplayManagerService.SyncRoot getSyncRoot() { 67 return mSyncRoot; 68 } 69 70 /** 71 * Gets the display adapter's context. 72 */ getContext()73 public final Context getContext() { 74 return mContext; 75 } 76 77 /** 78 * Gets a handler that the display adapter may use to post asynchronous messages. 79 */ getHandler()80 public final Handler getHandler() { 81 return mHandler; 82 } 83 84 /** 85 * Gets the display adapter name for debugging purposes. 86 */ getName()87 public final String getName() { 88 return mName; 89 } 90 91 /** 92 * Registers the display adapter with the display manager. 93 * 94 * The display adapter should register any built-in display devices as soon as possible. 95 * The boot process will wait for the default display to be registered. 96 * Other display devices can be registered dynamically later. 97 */ registerLocked()98 public void registerLocked() { 99 } 100 101 /** 102 * Dumps the local state of the display adapter. 103 */ dumpLocked(PrintWriter pw)104 public void dumpLocked(PrintWriter pw) { 105 } 106 107 /** 108 * Sends a display device event to the display adapter listener asynchronously. 109 */ sendDisplayDeviceEventLocked( final DisplayDevice device, final int event)110 protected final void sendDisplayDeviceEventLocked( 111 final DisplayDevice device, final int event) { 112 mHandler.post(() -> mListener.onDisplayDeviceEvent(device, event)); 113 } 114 115 /** 116 * Sends a request to perform traversals. 117 */ sendTraversalRequestLocked()118 protected final void sendTraversalRequestLocked() { 119 mHandler.post(() -> mListener.onTraversalRequested()); 120 } 121 createMode(int width, int height, float refreshRate)122 public static Display.Mode createMode(int width, int height, float refreshRate) { 123 return createMode(width, height, refreshRate, new float[0]); 124 } 125 createMode(int width, int height, float refreshRate, float[] alternativeRefreshRates)126 public static Display.Mode createMode(int width, int height, float refreshRate, 127 float[] alternativeRefreshRates) { 128 return new Display.Mode(NEXT_DISPLAY_MODE_ID.getAndIncrement(), width, height, refreshRate, 129 alternativeRefreshRates); 130 } 131 132 public interface Listener { onDisplayDeviceEvent(DisplayDevice device, int event)133 void onDisplayDeviceEvent(DisplayDevice device, int event); onTraversalRequested()134 void onTraversalRequested(); 135 } 136 } 137