Extract desktop-first decision factors into methods

This CL extracts the desktop-first decision factors into dedicated
methods.
This is a refactor and no functional change is expected.

Flag: com.android.window.flags.enable_display_windowing_mode_switching
Bug: 397557203
Test: DesktopDisplayModeControllerTest

Change-Id: Id13447c55cc11e80cc13b6c64423115c01d58829

2 files changed, 30 insertions, 29 deletions

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopDisplayModeController.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopDisplayModeController.kt
index 78c377bc1234..e89aafe267ed 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopDisplayModeController.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopDisplayModeController.kt
@@ -48,30 +48,8 @@ class DesktopDisplayModeController(
 
     fun refreshDisplayWindowingMode() {
         if (!DesktopExperienceFlags.ENABLE_DISPLAY_WINDOWING_MODE_SWITCHING.isTrue) return
-        // TODO: b/375319538 - Replace the check with a DisplayManager API once it's available.
-        val isExtendedDisplayEnabled =
-            0 !=
-                Settings.Global.getInt(
-                    context.contentResolver,
-                    DEVELOPMENT_FORCE_DESKTOP_MODE_ON_EXTERNAL_DISPLAYS,
-                    0,
-                )
-        if (!isExtendedDisplayEnabled) {
-            // No action needed in mirror or projected mode.
-            return
-        }
 
-        val hasNonDefaultDisplay =
-            rootTaskDisplayAreaOrganizer.getDisplayIds().any { displayId ->
-                displayId != DEFAULT_DISPLAY
-            }
-        val targetDisplayWindowingMode =
-            if (hasNonDefaultDisplay) {
-                WINDOWING_MODE_FREEFORM
-            } else {
-                // Use the default display windowing mode when no non-default display.
-                windowManager.getWindowingMode(DEFAULT_DISPLAY)
-            }
+        val targetDisplayWindowingMode = getTargetWindowingModeForDefaultDisplay()
         val tdaInfo = rootTaskDisplayAreaOrganizer.getDisplayAreaInfo(DEFAULT_DISPLAY)
         requireNotNull(tdaInfo) { "DisplayAreaInfo of DEFAULT_DISPLAY must be non-null." }
         val currentDisplayWindowingMode = tdaInfo.configuration.windowConfiguration.windowingMode
@@ -111,6 +89,25 @@ class DesktopDisplayModeController(
         transitions.startTransition(TRANSIT_CHANGE, wct, /* handler= */ null)
     }
 
+    private fun getTargetWindowingModeForDefaultDisplay(): Int {
+        if (isExtendedDisplayEnabled() && hasExternalDisplay()) {
+            return WINDOWING_MODE_FREEFORM
+        }
+        return windowManager.getWindowingMode(DEFAULT_DISPLAY)
+    }
+
+    // TODO: b/375319538 - Replace the check with a DisplayManager API once it's available.
+    private fun isExtendedDisplayEnabled() =
+        0 !=
+            Settings.Global.getInt(
+                context.contentResolver,
+                DEVELOPMENT_FORCE_DESKTOP_MODE_ON_EXTERNAL_DISPLAYS,
+                0,
+            )
+
+    private fun hasExternalDisplay() =
+        rootTaskDisplayAreaOrganizer.getDisplayIds().any { it != DEFAULT_DISPLAY }
+
     private fun logV(msg: String, vararg arguments: Any?) {
         ProtoLog.v(WM_SHELL_DESKTOP_MODE, "%s: $msg", TAG, *arguments)
     }
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopDisplayModeControllerTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopDisplayModeControllerTest.kt
index 0ff7230f6e0c..f0c97d359a16 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopDisplayModeControllerTest.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopDisplayModeControllerTest.kt
@@ -101,7 +101,7 @@ class DesktopDisplayModeControllerTest : ShellTestCase() {
     private fun testDisplayWindowingModeSwitch(
         defaultWindowingMode: Int,
         extendedDisplayEnabled: Boolean,
-        expectTransition: Boolean,
+        expectToSwitch: Boolean,
     ) {
         defaultTDA.configuration.windowConfiguration.windowingMode = defaultWindowingMode
         whenever(mockWindowManager.getWindowingMode(anyInt())).thenReturn(defaultWindowingMode)
@@ -113,10 +113,14 @@ class DesktopDisplayModeControllerTest : ShellTestCase() {
 
         settingsSession.use {
             connectExternalDisplay()
-            defaultTDA.configuration.windowConfiguration.windowingMode = WINDOWING_MODE_FREEFORM
+            if (expectToSwitch) {
+                // Assumes [connectExternalDisplay] properly triggered the switching transition.
+                // Will verify the transition later along with [disconnectExternalDisplay].
+                defaultTDA.configuration.windowConfiguration.windowingMode = WINDOWING_MODE_FREEFORM
+            }
             disconnectExternalDisplay()
 
-            if (expectTransition) {
+            if (expectToSwitch) {
                 val arg = argumentCaptor<WindowContainerTransaction>()
                 verify(transitions, times(2))
                     .startTransition(eq(TRANSIT_CHANGE), arg.capture(), isNull())
@@ -139,7 +143,7 @@ class DesktopDisplayModeControllerTest : ShellTestCase() {
         testDisplayWindowingModeSwitch(
             defaultWindowingMode = WINDOWING_MODE_FULLSCREEN,
             extendedDisplayEnabled = false,
-            expectTransition = false,
+            expectToSwitch = false,
         )
     }
 
@@ -148,7 +152,7 @@ class DesktopDisplayModeControllerTest : ShellTestCase() {
         testDisplayWindowingModeSwitch(
             defaultWindowingMode = WINDOWING_MODE_FULLSCREEN,
             extendedDisplayEnabled = true,
-            expectTransition = true,
+            expectToSwitch = true,
         )
     }
 
@@ -157,7 +161,7 @@ class DesktopDisplayModeControllerTest : ShellTestCase() {
         testDisplayWindowingModeSwitch(
             defaultWindowingMode = WINDOWING_MODE_FREEFORM,
             extendedDisplayEnabled = true,
-            expectTransition = false,
+            expectToSwitch = false,
         )
     }