| /* |
| * Copyright (C) 2012 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 android.hardware.display; |
| |
| import android.content.Context; |
| import android.os.Handler; |
| import android.util.SparseArray; |
| import android.view.Display; |
| |
| /** |
| * Manages the properties of attached displays. |
| * <p> |
| * Get an instance of this class by calling |
| * {@link android.content.Context#getSystemService(java.lang.String) |
| * Context.getSystemService()} with the argument |
| * {@link android.content.Context#DISPLAY_SERVICE}. |
| * </p> |
| */ |
| public final class DisplayManager { |
| private static final String TAG = "DisplayManager"; |
| private static final boolean DEBUG = false; |
| |
| private final Context mContext; |
| private final DisplayManagerGlobal mGlobal; |
| |
| private final Object mLock = new Object(); |
| private final SparseArray<Display> mDisplays = new SparseArray<Display>(); |
| |
| /** @hide */ |
| public DisplayManager(Context context) { |
| mContext = context; |
| mGlobal = DisplayManagerGlobal.getInstance(); |
| } |
| |
| /** |
| * Gets information about a logical display. |
| * |
| * The display metrics may be adjusted to provide compatibility |
| * for legacy applications. |
| * |
| * @param displayId The logical display id. |
| * @return The display object, or null if there is no valid display with the given id. |
| */ |
| public Display getDisplay(int displayId) { |
| synchronized (mLock) { |
| return getOrCreateDisplayLocked(displayId, false /*assumeValid*/); |
| } |
| } |
| |
| /** |
| * Gets all currently valid logical displays. |
| * |
| * @return An array containing all displays. |
| */ |
| public Display[] getDisplays() { |
| int[] displayIds = mGlobal.getDisplayIds(); |
| int expectedCount = displayIds.length; |
| Display[] displays = new Display[expectedCount]; |
| synchronized (mLock) { |
| int actualCount = 0; |
| for (int i = 0; i < expectedCount; i++) { |
| Display display = getOrCreateDisplayLocked(displayIds[i], true /*assumeValid*/); |
| if (display != null) { |
| displays[actualCount++] = display; |
| } |
| } |
| if (actualCount != expectedCount) { |
| Display[] oldDisplays = displays; |
| displays = new Display[actualCount]; |
| System.arraycopy(oldDisplays, 0, displays, 0, actualCount); |
| } |
| } |
| return displays; |
| } |
| |
| private Display getOrCreateDisplayLocked(int displayId, boolean assumeValid) { |
| Display display = mDisplays.get(displayId); |
| if (display == null) { |
| display = mGlobal.getCompatibleDisplay(displayId, |
| mContext.getCompatibilityInfo(displayId)); |
| if (display != null) { |
| mDisplays.put(displayId, display); |
| } |
| } else if (!assumeValid && !display.isValid()) { |
| display = null; |
| } |
| return display; |
| } |
| |
| /** |
| * Registers an display listener to receive notifications about when |
| * displays are added, removed or changed. |
| * |
| * @param listener The listener to register. |
| * @param handler The handler on which the listener should be invoked, or null |
| * if the listener should be invoked on the calling thread's looper. |
| * |
| * @see #unregisterDisplayListener |
| */ |
| public void registerDisplayListener(DisplayListener listener, Handler handler) { |
| mGlobal.registerDisplayListener(listener, handler); |
| } |
| |
| /** |
| * Unregisters an input device listener. |
| * |
| * @param listener The listener to unregister. |
| * |
| * @see #registerDisplayListener |
| */ |
| public void unregisterDisplayListener(DisplayListener listener) { |
| mGlobal.unregisterDisplayListener(listener); |
| } |
| |
| /** |
| * Listens for changes in available display devices. |
| */ |
| public interface DisplayListener { |
| /** |
| * Called whenever a logical display has been added to the system. |
| * Use {@link DisplayManager#getDisplay} to get more information about |
| * the display. |
| * |
| * @param displayId The id of the logical display that was added. |
| */ |
| void onDisplayAdded(int displayId); |
| |
| /** |
| * Called whenever a logical display has been removed from the system. |
| * |
| * @param displayId The id of the logical display that was removed. |
| */ |
| void onDisplayRemoved(int displayId); |
| |
| /** |
| * Called whenever the properties of a logical display have changed. |
| * |
| * @param displayId The id of the logical display that changed. |
| */ |
| void onDisplayChanged(int displayId); |
| } |
| } |