From a8fe3dfdfdaed3c7eb31c48f63cfe6f3961e4d40 Mon Sep 17 00:00:00 2001
From: Andrii Kulian <akulian@google.com>
Date: Fri, 16 Jun 2017 15:29:26 -0700
Subject: [PATCH] Look on all displays if can't launch on a source secondary
 one

If an activity is launched from a secondary display but is not
allowed to land on it, then look for a topmost valid launch stack
across all displays.

Bug: 62544886
Test: go/wm-smoke
Test: android.server.cts.ActivityManagerDisplayTests
Test: #testLaunchNonResizeableActivityFromSecondaryDisplaySameTask
Test: #testLaunchNonResizeableActivityFromSecondaryDisplayNewTask
Change-Id: I57470e9ede317f7d492e2b7641a5cb02db13f1b0
---
 .../server/am/ActivityStackSupervisor.java    | 25 +++++++++++++++++++
 .../android/server/am/ActivityStarter.java    | 15 ++++++++---
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/services/core/java/com/android/server/am/ActivityStackSupervisor.java b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
index 7de56fa17877f..f37979179eaed 100644
--- a/services/core/java/com/android/server/am/ActivityStackSupervisor.java
+++ b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
@@ -2257,6 +2257,31 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
         return null;
     }
 
+    /**
+     * Get next valid stack for launching provided activity in the system. This will search across
+     * displays and stacks in last-focused order for a focusable and visible stack, except those
+     * that are on a currently focused display.
+     *
+     * @param r The activity that is being launched.
+     * @param currentFocus The display that previously had focus and thus needs to be ignored when
+     *                     searching for the next candidate.
+     * @return Next valid {@link ActivityStack}, null if not found.
+     */
+    ActivityStack getNextValidLaunchStackLocked(@NonNull ActivityRecord r, int currentFocus) {
+        mWindowManager.getDisplaysInFocusOrder(mTmpOrderedDisplayIds);
+        for (int i = mTmpOrderedDisplayIds.size() - 1; i >= 0; --i) {
+            final int displayId = mTmpOrderedDisplayIds.get(i);
+            if (displayId == currentFocus) {
+                continue;
+            }
+            final ActivityStack stack = getValidLaunchStackOnDisplay(displayId, r);
+            if (stack != null) {
+                return stack;
+            }
+        }
+        return null;
+    }
+
     ActivityRecord getHomeActivity() {
         return getHomeActivityForUser(mCurrentUser);
     }
diff --git a/services/core/java/com/android/server/am/ActivityStarter.java b/services/core/java/com/android/server/am/ActivityStarter.java
index d74d1d6dc9542..c7ee149a9727b 100644
--- a/services/core/java/com/android/server/am/ActivityStarter.java
+++ b/services/core/java/com/android/server/am/ActivityStarter.java
@@ -2027,7 +2027,18 @@ class ActivityStarter {
             return mSupervisor.mFocusedStack;
         }
 
-        if (mSourceDisplayId == DEFAULT_DISPLAY) {
+        if (mSourceDisplayId != DEFAULT_DISPLAY) {
+            // Try to put the activity in a stack on a secondary display.
+            stack = mSupervisor.getValidLaunchStackOnDisplay(mSourceDisplayId, r);
+            if (stack == null) {
+                // If source display is not suitable - look for topmost valid stack in the system.
+                if (DEBUG_FOCUS || DEBUG_STACK) Slog.d(TAG_FOCUS,
+                        "computeStackFocus: Can't launch on mSourceDisplayId=" + mSourceDisplayId
+                                + ", looking on all displays.");
+                stack = mSupervisor.getNextValidLaunchStackLocked(r, mSourceDisplayId);
+            }
+        }
+        if (stack == null) {
             // We first try to put the task in the first dynamic stack on home display.
             final ArrayList<ActivityStack> homeDisplayStacks = mSupervisor.mHomeStack.mStacks;
             for (int stackNdx = homeDisplayStacks.size() - 1; stackNdx >= 0; --stackNdx) {
@@ -2043,8 +2054,6 @@ class ActivityStarter {
                     bounds != null ? FREEFORM_WORKSPACE_STACK_ID :
                             FULLSCREEN_WORKSPACE_STACK_ID;
             stack = mSupervisor.getStack(stackId, CREATE_IF_NEEDED, ON_TOP);
-        } else {
-            stack = mSupervisor.getValidLaunchStackOnDisplay(mSourceDisplayId, r);
         }
         if (DEBUG_FOCUS || DEBUG_STACK) Slog.d(TAG_FOCUS, "computeStackFocus: New stack r="
                 + r + " stackId=" + stack.mStackId);