Add an API to allow for creating private virtual displays.

This change enables applications to create a private virtual
display that renders its content to a surface of its own creation.
The display is private in the sense that only the application
that owns the display is allowed to place windows upon it.
Mirroring and blanking is also disabled for these displays.

Bug: 9192512
Change-Id: I852ea07f0c7df1d244e354e3daca3a6960285ca0

1 files changed, 204 insertions, 61 deletions

diff --git a/services/java/com/android/server/display/DisplayManagerService.java b/services/java/com/android/server/display/DisplayManagerService.java
index ca85e427fc18..c339c26e51e5 100644
--- a/services/java/com/android/server/display/DisplayManagerService.java
+++ b/services/java/com/android/server/display/DisplayManagerService.java
@@ -33,15 +33,19 @@ import android.os.Message;
 import android.os.RemoteException;
 import android.os.SystemClock;
 import android.os.SystemProperties;
+import android.text.TextUtils;
 import android.util.Slog;
 import android.util.SparseArray;
 import android.view.Display;
 import android.view.DisplayInfo;
+import android.view.Surface;
+
 import com.android.server.UiThread;
 
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.concurrent.CopyOnWriteArrayList;
 
 /**
@@ -171,6 +175,9 @@ public final class DisplayManagerService extends IDisplayManager.Stub {
     // The Wifi display adapter, or null if not registered.
     private WifiDisplayAdapter mWifiDisplayAdapter;
 
+    // The virtual display adapter, or null if not registered.
+    private VirtualDisplayAdapter mVirtualDisplayAdapter;
+
     // Viewports of the default display and the display that should receive touch
     // input from an external source.  Used by the input system.
     private final DisplayViewport mDefaultViewport = new DisplayViewport();
@@ -363,13 +370,7 @@ public final class DisplayManagerService extends IDisplayManager.Stub {
         synchronized (mSyncRoot) {
             if (mAllDisplayBlankStateFromPowerManager != DISPLAY_BLANK_STATE_BLANKED) {
                 mAllDisplayBlankStateFromPowerManager = DISPLAY_BLANK_STATE_BLANKED;
-
-                final int count = mDisplayDevices.size();
-                for (int i = 0; i < count; i++) {
-                    DisplayDevice device = mDisplayDevices.get(i);
-                    device.blankLocked();
-                }
-
+                updateAllDisplayBlankingLocked();
                 scheduleTraversalLocked(false);
             }
         }
@@ -382,13 +383,7 @@ public final class DisplayManagerService extends IDisplayManager.Stub {
         synchronized (mSyncRoot) {
             if (mAllDisplayBlankStateFromPowerManager != DISPLAY_BLANK_STATE_UNBLANKED) {
                 mAllDisplayBlankStateFromPowerManager = DISPLAY_BLANK_STATE_UNBLANKED;
-
-                final int count = mDisplayDevices.size();
-                for (int i = 0; i < count; i++) {
-                    DisplayDevice device = mDisplayDevices.get(i);
-                    device.unblankLocked();
-                }
-
+                updateAllDisplayBlankingLocked();
                 scheduleTraversalLocked(false);
             }
         }
@@ -403,12 +398,21 @@ public final class DisplayManagerService extends IDisplayManager.Stub {
      */
     @Override // Binder call
     public DisplayInfo getDisplayInfo(int displayId) {
-        synchronized (mSyncRoot) {
-            LogicalDisplay display = mLogicalDisplays.get(displayId);
-            if (display != null) {
-                return display.getDisplayInfoLocked();
+        final int callingUid = Binder.getCallingUid();
+        final long token = Binder.clearCallingIdentity();
+        try {
+            synchronized (mSyncRoot) {
+                LogicalDisplay display = mLogicalDisplays.get(displayId);
+                if (display != null) {
+                    DisplayInfo info = display.getDisplayInfoLocked();
+                    if (info.hasAccess(callingUid)) {
+                        return info;
+                    }
+                }
+                return null;
             }
-            return null;
+        } finally {
+            Binder.restoreCallingIdentity(token);
         }
     }
 
@@ -417,13 +421,27 @@ public final class DisplayManagerService extends IDisplayManager.Stub {
      */
     @Override // Binder call
     public int[] getDisplayIds() {
-        synchronized (mSyncRoot) {
-            final int count = mLogicalDisplays.size();
-            int[] displayIds = new int[count];
-            for (int i = 0; i < count; i++) {
-                displayIds[i] = mLogicalDisplays.keyAt(i);
+        final int callingUid = Binder.getCallingUid();
+        final long token = Binder.clearCallingIdentity();
+        try {
+            synchronized (mSyncRoot) {
+                final int count = mLogicalDisplays.size();
+                int[] displayIds = new int[count];
+                int n = 0;
+                for (int i = 0; i < count; i++) {
+                    LogicalDisplay display = mLogicalDisplays.valueAt(i);
+                    DisplayInfo info = display.getDisplayInfoLocked();
+                    if (info.hasAccess(callingUid)) {
+                        displayIds[n++] = mLogicalDisplays.keyAt(i);
+                    }
+                }
+                if (n != count) {
+                    displayIds = Arrays.copyOfRange(displayIds, 0, n);
+                }
+                return displayIds;
             }
-            return displayIds;
+        } finally {
+            Binder.restoreCallingIdentity(token);
         }
     }
 
@@ -570,6 +588,95 @@ public final class DisplayManagerService extends IDisplayManager.Stub {
                 == PackageManager.PERMISSION_GRANTED;
     }
 
+    @Override // Binder call
+    public int createPrivateVirtualDisplay(IBinder appToken, String packageName,
+            String name, int width, int height, int densityDpi, Surface surface) {
+        final int callingUid = Binder.getCallingUid();
+        if (!validatePackageName(callingUid, packageName)) {
+            throw new SecurityException("packageName must match the calling uid");
+        }
+        if (appToken == null) {
+            throw new IllegalArgumentException("appToken must not be null");
+        }
+        if (TextUtils.isEmpty(name)) {
+            throw new IllegalArgumentException("name must be non-null and non-empty");
+        }
+        if (width <= 0 || height <= 0 || densityDpi <= 0) {
+            throw new IllegalArgumentException("width, height, and densityDpi must be "
+                    + "greater than 0");
+        }
+        if (surface == null) {
+            throw new IllegalArgumentException("surface must not be null");
+        }
+
+        final long token = Binder.clearCallingIdentity();
+        try {
+            synchronized (mSyncRoot) {
+                if (mVirtualDisplayAdapter == null) {
+                    Slog.w(TAG, "Rejecting request to create private virtual display "
+                            + "because the virtual display adapter is not available.");
+                    return -1;
+                }
+
+                DisplayDevice device = mVirtualDisplayAdapter.createPrivateVirtualDisplayLocked(
+                        appToken, callingUid, packageName, name, width, height, densityDpi,
+                        surface);
+                if (device == null) {
+                    return -1;
+                }
+
+                handleDisplayDeviceAddedLocked(device);
+                LogicalDisplay display = findLogicalDisplayForDeviceLocked(device);
+                if (display != null) {
+                    return display.getDisplayIdLocked();
+                }
+
+                // Something weird happened and the logical display was not created.
+                Slog.w(TAG, "Rejecting request to create private virtual display "
+                        + "because the logical display was not created.");
+                mVirtualDisplayAdapter.releaseVirtualDisplayLocked(appToken);
+                handleDisplayDeviceRemovedLocked(device);
+            }
+        } finally {
+            Binder.restoreCallingIdentity(token);
+        }
+        return -1;
+    }
+
+    @Override // Binder call
+    public void releaseVirtualDisplay(IBinder appToken) {
+        final long token = Binder.clearCallingIdentity();
+        try {
+            synchronized (mSyncRoot) {
+                if (mVirtualDisplayAdapter == null) {
+                    return;
+                }
+
+                DisplayDevice device =
+                        mVirtualDisplayAdapter.releaseVirtualDisplayLocked(appToken);
+                if (device != null) {
+                    handleDisplayDeviceRemovedLocked(device);
+                }
+            }
+        } finally {
+            Binder.restoreCallingIdentity(token);
+        }
+    }
+
+    private boolean validatePackageName(int uid, String packageName) {
+        if (packageName != null) {
+            String[] packageNames = mContext.getPackageManager().getPackagesForUid(uid);
+            if (packageNames != null) {
+                for (String n : packageNames) {
+                    if (n.equals(packageName)) {
+                        return true;
+                    }
+                }
+            }
+        }
+        return false;
+    }
+
     private void registerDefaultDisplayAdapter() {
         // Register default display adapter.
         synchronized (mSyncRoot) {
@@ -588,6 +695,7 @@ public final class DisplayManagerService extends IDisplayManager.Stub {
             if (shouldRegisterNonEssentialDisplayAdaptersLocked()) {
                 registerOverlayDisplayAdapterLocked();
                 registerWifiDisplayAdapterLocked();
+                registerVirtualDisplayAdapterLocked();
             }
         }
     }
@@ -608,6 +716,12 @@ public final class DisplayManagerService extends IDisplayManager.Stub {
         }
     }
 
+    private void registerVirtualDisplayAdapterLocked() {
+        mVirtualDisplayAdapter = new VirtualDisplayAdapter(
+                mSyncRoot, mContext, mHandler, mDisplayAdapterListener);
+        registerDisplayAdapterLocked(mVirtualDisplayAdapter);
+    }
+
     private boolean shouldRegisterNonEssentialDisplayAdaptersLocked() {
         // In safe mode, we disable non-essential display adapters to give the user
         // an opportunity to fix broken settings or other problems that might affect
@@ -625,29 +739,23 @@ public final class DisplayManagerService extends IDisplayManager.Stub {
 
     private void handleDisplayDeviceAdded(DisplayDevice device) {
         synchronized (mSyncRoot) {
-            if (mDisplayDevices.contains(device)) {
-                Slog.w(TAG, "Attempted to add already added display device: "
-                        + device.getDisplayDeviceInfoLocked());
-                return;
-            }
+            handleDisplayDeviceAddedLocked(device);
+        }
+    }
 
-            Slog.i(TAG, "Display device added: " + device.getDisplayDeviceInfoLocked());
+    private void handleDisplayDeviceAddedLocked(DisplayDevice device) {
+        if (mDisplayDevices.contains(device)) {
+            Slog.w(TAG, "Attempted to add already added display device: "
+                    + device.getDisplayDeviceInfoLocked());
+            return;
+        }
 
-            mDisplayDevices.add(device);
-            addLogicalDisplayLocked(device);
-            scheduleTraversalLocked(false);
+        Slog.i(TAG, "Display device added: " + device.getDisplayDeviceInfoLocked());
 
-            // Blank or unblank the display immediately to match the state requested
-            // by the power manager (if known).
-            switch (mAllDisplayBlankStateFromPowerManager) {
-                case DISPLAY_BLANK_STATE_BLANKED:
-                    device.blankLocked();
-                    break;
-                case DISPLAY_BLANK_STATE_UNBLANKED:
-                    device.unblankLocked();
-                    break;
-            }
-        }
+        mDisplayDevices.add(device);
+        addLogicalDisplayLocked(device);
+        updateDisplayBlankingLocked(device);
+        scheduleTraversalLocked(false);
     }
 
     private void handleDisplayDeviceChanged(DisplayDevice device) {
@@ -669,17 +777,44 @@ public final class DisplayManagerService extends IDisplayManager.Stub {
 
     private void handleDisplayDeviceRemoved(DisplayDevice device) {
         synchronized (mSyncRoot) {
-            if (!mDisplayDevices.remove(device)) {
-                Slog.w(TAG, "Attempted to remove non-existent display device: "
-                        + device.getDisplayDeviceInfoLocked());
-                return;
-            }
+            handleDisplayDeviceRemovedLocked(device);
+        }
+    }
+    private void handleDisplayDeviceRemovedLocked(DisplayDevice device) {
+        if (!mDisplayDevices.remove(device)) {
+            Slog.w(TAG, "Attempted to remove non-existent display device: "
+                    + device.getDisplayDeviceInfoLocked());
+            return;
+        }
 
-            Slog.i(TAG, "Display device removed: " + device.getDisplayDeviceInfoLocked());
+        Slog.i(TAG, "Display device removed: " + device.getDisplayDeviceInfoLocked());
 
-            mRemovedDisplayDevices.add(device);
-            updateLogicalDisplaysLocked();
-            scheduleTraversalLocked(false);
+        mRemovedDisplayDevices.add(device);
+        updateLogicalDisplaysLocked();
+        scheduleTraversalLocked(false);
+    }
+
+    private void updateAllDisplayBlankingLocked() {
+        final int count = mDisplayDevices.size();
+        for (int i = 0; i < count; i++) {
+            DisplayDevice device = mDisplayDevices.get(i);
+            updateDisplayBlankingLocked(device);
+        }
+    }
+
+    private void updateDisplayBlankingLocked(DisplayDevice device) {
+        // Blank or unblank the display immediately to match the state requested
+        // by the power manager (if known).
+        DisplayDeviceInfo info = device.getDisplayDeviceInfoLocked();
+        if ((info.flags & DisplayDeviceInfo.FLAG_NEVER_BLANK) == 0) {
+            switch (mAllDisplayBlankStateFromPowerManager) {
+                case DISPLAY_BLANK_STATE_BLANKED:
+                    device.blankLocked();
+                    break;
+                case DISPLAY_BLANK_STATE_UNBLANKED:
+                    device.unblankLocked();
+                    break;
+            }
         }
     }
 
@@ -812,13 +947,21 @@ public final class DisplayManagerService extends IDisplayManager.Stub {
     }
 
     private void configureDisplayInTransactionLocked(DisplayDevice device) {
+        DisplayDeviceInfo info = device.getDisplayDeviceInfoLocked();
+        boolean isPrivate = (info.flags & DisplayDeviceInfo.FLAG_PRIVATE) != 0;
+
         // Find the logical display that the display device is showing.
+        // Private displays never mirror other displays.
         LogicalDisplay display = findLogicalDisplayForDeviceLocked(device);
-        if (display != null && !display.hasContentLocked()) {
-            display = null;
-        }
-        if (display == null) {
-            display = mLogicalDisplays.get(Display.DEFAULT_DISPLAY);
+        if (!isPrivate) {
+            if (display != null && !display.hasContentLocked()) {
+                // If the display does not have any content of its own, then
+                // automatically mirror the default logical display contents.
+                display = null;
+            }
+            if (display == null) {
+                display = mLogicalDisplays.get(Display.DEFAULT_DISPLAY);
+            }
         }
 
         // Apply the logical display configuration to the display device.
@@ -828,11 +971,11 @@ public final class DisplayManagerService extends IDisplayManager.Stub {
                     + device.getDisplayDeviceInfoLocked());
             return;
         }
-        boolean isBlanked = (mAllDisplayBlankStateFromPowerManager == DISPLAY_BLANK_STATE_BLANKED);
+        boolean isBlanked = (mAllDisplayBlankStateFromPowerManager == DISPLAY_BLANK_STATE_BLANKED)
+                && (info.flags & DisplayDeviceInfo.FLAG_NEVER_BLANK) == 0;
         display.configureDisplayInTransactionLocked(device, isBlanked);
 
         // Update the viewports if needed.
-        DisplayDeviceInfo info = device.getDisplayDeviceInfoLocked();
         if (!mDefaultViewport.valid
                 && (info.flags & DisplayDeviceInfo.FLAG_DEFAULT_DISPLAY) != 0) {
             setViewportLocked(mDefaultViewport, display, device);