SurfaceControl: Add setDropInputMode api

Introduces an API to drop input events on this SurfaceControl. This
policy will be inherited by its children. The caller must hold the
ACCESS_SURFACE_FLINGER permission.

Options include:
ALL: SurfaceControl and its children will not receive any
input regardless of whether it has a valid input channel.
OBSCURED: SurfaceControl and its children will not
receive any input if the layer is obscured, cropped by its parent or
translucent.

These policies are used to enable features that allow for a less trusted
interaction model between apps. See the bug for more details.

Test: atest libgui_test InputDispatcherDropInputFeatureTest
Bug:197364677

Change-Id: I443741d5ab51a45d37fb865f11c433c436d96c1e

1 files changed, 10 insertions, 0 deletions

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 5a881a3dfe..5aa0b87e22 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -4147,6 +4147,16 @@ uint32_t SurfaceFlinger::setClientStateLocked(
             flags |= eTraversalNeeded;
         }
     }
+    if (what & layer_state_t::eDropInputModeChanged) {
+        if (privileged) {
+            if (layer->setDropInputMode(s.dropInputMode)) {
+                flags |= eTraversalNeeded;
+                mInputInfoChanged = true;
+            }
+        } else {
+            ALOGE("Attempt to update DropInputMode without permission ACCESS_SURFACE_FLINGER");
+        }
+    }
     // This has to happen after we reparent children because when we reparent to null we remove
     // child layers from current state and remove its relative z. If the children are reparented in
     // the same transaction, then we have to make sure we reparent the children first so we do not