Add display manager skeleton.

The purpose of this change is to remove direct reliance on
SurfaceFlinger for describing the size and characteristics of
displays.

This patch also starts to make a distinction between logical displays
and physical display devices.  Currently, the window manager owns
the concept of a logical display whereas the new display
manager owns the concept of a physical display device.

Change-Id: I7e0761f83f033be6c06fd1041280c21500bcabc0

1 files changed, 76 insertions, 0 deletions

diff --git a/core/java/android/hardware/display/DisplayManager.java b/core/java/android/hardware/display/DisplayManager.java
new file mode 100644
index 0000000..13a2db4
--- /dev/null
+++ b/core/java/android/hardware/display/DisplayManager.java
@@ -0,0 +1,76 @@
+/*
+ * 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.IBinder;
+import android.os.RemoteException;
+import android.os.ServiceManager;
+import android.util.Log;
+import android.view.DisplayInfo;
+
+/**
+ * Manages the properties, media routing and power state 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 DisplayManager sInstance;
+
+    private final IDisplayManager mDm;
+
+    private DisplayManager(IDisplayManager dm) {
+        mDm = dm;
+    }
+
+    /**
+     * Gets an instance of the display manager.
+     * @return The display manager instance.
+     * @hide
+     */
+    public static DisplayManager getInstance() {
+        synchronized (DisplayManager.class) {
+            if (sInstance == null) {
+                IBinder b = ServiceManager.getService(Context.DISPLAY_SERVICE);
+                sInstance = new DisplayManager(IDisplayManager.Stub.asInterface(b));
+            }
+            return sInstance;
+        }
+    }
+
+    /**
+     * Get information about a particular logical display.
+     *
+     * @param displayId The logical display id.
+     * @param outInfo A structure to populate with the display info.
+     * @return True if the logical display exists, false otherwise.
+     */
+    public boolean getDisplayInfo(int displayId, DisplayInfo outInfo) {
+        try {
+            return mDm.getDisplayInfo(displayId, outInfo);
+        } catch (RemoteException ex) {
+            Log.e(TAG, "Could not get display information from display manager.", ex);
+            return false;
+        }
+    }
+}