Add setFocusedWindow function stub

This function, once implemented, will set focus on the specified
window. This is the first step in changing focus selection from
setInputWindows and using explicit call which will help us more
easily decouple z-order from focus selection and support focus
for SurfaceViewHost surfaces.

Bug: 151179149
Test: presubmit
Test: go/wm-smoke
Test: atest inputflinger_tests

Change-Id: Ib2254b4ab3ba8d579dfe49ddf3286f8ce2eecf9e
diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index 4a4510e..686e274 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -92,6 +92,7 @@
 
     export_shared_lib_headers: [
         "libbinder",
+        "libinput",
     ],
 
     // bufferhub is not used when building libgui for vendors
diff --git a/libs/gui/LayerState.cpp b/libs/gui/LayerState.cpp
index 1030b82..117ce58 100644
--- a/libs/gui/LayerState.cpp
+++ b/libs/gui/LayerState.cpp
@@ -448,19 +448,36 @@
 
 // ------------------------------- InputWindowCommands ----------------------------------------
 
-void InputWindowCommands::merge(const InputWindowCommands& other) {
+bool InputWindowCommands::merge(const InputWindowCommands& other) {
+    bool changes = false;
+#ifndef NO_INPUT
+    changes |= !other.focusRequests.empty();
+    focusRequests.insert(focusRequests.end(), std::make_move_iterator(other.focusRequests.begin()),
+                         std::make_move_iterator(other.focusRequests.end()));
+#endif
+    changes |= other.syncInputWindows && !syncInputWindows;
     syncInputWindows |= other.syncInputWindows;
+    return changes;
 }
 
 void InputWindowCommands::clear() {
+#ifndef NO_INPUT
+    focusRequests.clear();
+#endif
     syncInputWindows = false;
 }
 
 void InputWindowCommands::write(Parcel& output) const {
+#ifndef NO_INPUT
+    output.writeParcelableVector(focusRequests);
+#endif
     output.writeBool(syncInputWindows);
 }
 
 void InputWindowCommands::read(const Parcel& input) {
+#ifndef NO_INPUT
+    input.readParcelableVector(&focusRequests);
+#endif
     syncInputWindows = input.readBool();
 }
 
diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index d797a35..229a5c2 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -1364,6 +1364,21 @@
     return *this;
 }
 
+SurfaceComposerClient::Transaction& SurfaceComposerClient::Transaction::setFocusedWindow(
+        const sp<IBinder>& token, const sp<IBinder>& focusedToken, nsecs_t timestampNanos) {
+    FocusRequest request;
+    request.token = token;
+    request.focusedToken = focusedToken;
+    request.timestamp = timestampNanos;
+    return setFocusedWindow(request);
+}
+
+SurfaceComposerClient::Transaction& SurfaceComposerClient::Transaction::setFocusedWindow(
+        const FocusRequest& request) {
+    mInputWindowCommands.focusRequests.push_back(request);
+    return *this;
+}
+
 SurfaceComposerClient::Transaction& SurfaceComposerClient::Transaction::syncInputWindows() {
     mInputWindowCommands.syncInputWindows = true;
     return *this;
diff --git a/libs/gui/include/gui/LayerState.h b/libs/gui/include/gui/LayerState.h
index 00ae220..41aad0d 100644
--- a/libs/gui/include/gui/LayerState.h
+++ b/libs/gui/include/gui/LayerState.h
@@ -26,6 +26,7 @@
 #include <math/mat4.h>
 
 #ifndef NO_INPUT
+#include <android/FocusRequest.h>
 #include <input/InputWindow.h>
 #endif
 
@@ -283,9 +284,13 @@
 };
 
 struct InputWindowCommands {
+#ifndef NO_INPUT
+    std::vector<FocusRequest> focusRequests;
+#endif
     bool syncInputWindows{false};
 
-    void merge(const InputWindowCommands& other);
+    // Merges the passed in commands and returns true if there were any changes.
+    bool merge(const InputWindowCommands& other);
     void clear();
     void write(Parcel& output) const;
     void read(const Parcel& input);
diff --git a/libs/gui/include/gui/SurfaceComposerClient.h b/libs/gui/include/gui/SurfaceComposerClient.h
index eb757ba..d5ca0f6 100644
--- a/libs/gui/include/gui/SurfaceComposerClient.h
+++ b/libs/gui/include/gui/SurfaceComposerClient.h
@@ -507,6 +507,9 @@
 
 #ifndef NO_INPUT
         Transaction& setInputWindowInfo(const sp<SurfaceControl>& sc, const InputWindowInfo& info);
+        Transaction& setFocusedWindow(const sp<IBinder>& token, const sp<IBinder>& focusedToken,
+                                      nsecs_t timestampNanos);
+        Transaction& setFocusedWindow(const FocusRequest& request);
         Transaction& syncInputWindows();
 #endif