Remove non-split touch from input code

The behaviour  was changed to permanently split since 24Q4. Therefore,
all of the existing complexity around supporting non-split can now be
removed.

Bug: 239934827
Test: TEST=inputflinger_tests; m $TEST && $ANDROID_HOST_OUT/nativetest64/$TEST/$TEST
Flag: NONE removing flag
Change-Id: I8ca23d502a4c23de2dfafbd7653318b8909912ce

4 files changed, 5 insertions, 18 deletions

diff --git a/libs/gui/WindowInfo.cpp b/libs/gui/WindowInfo.cpp
index 82d2554340..e1a7ac9b18 100644
--- a/libs/gui/WindowInfo.cpp
+++ b/libs/gui/WindowInfo.cpp
@@ -73,10 +73,6 @@ void WindowInfo::addTouchableRegion(const Rect& region) {
     touchableRegion.orSelf(region);
 }
 
-bool WindowInfo::supportsSplitTouch() const {
-    return !inputConfig.test(InputConfig::PREVENT_SPLITTING);
-}
-
 bool WindowInfo::isSpy() const {
     return inputConfig.test(InputConfig::SPY);
 }
diff --git a/libs/gui/include/gui/WindowInfo.h b/libs/gui/include/gui/WindowInfo.h
index eb3be5588a..f7e6084eef 100644
--- a/libs/gui/include/gui/WindowInfo.h
+++ b/libs/gui/include/gui/WindowInfo.h
@@ -150,8 +150,6 @@ struct WindowInfo : public Parcelable {
                 static_cast<uint32_t>(os::InputConfig::NOT_FOCUSABLE),
         NOT_TOUCHABLE =
                 static_cast<uint32_t>(os::InputConfig::NOT_TOUCHABLE),
-        PREVENT_SPLITTING =
-                static_cast<uint32_t>(os::InputConfig::PREVENT_SPLITTING),
         DUPLICATE_TOUCH_TO_WALLPAPER =
                 static_cast<uint32_t>(os::InputConfig::DUPLICATE_TOUCH_TO_WALLPAPER),
         IS_WALLPAPER =
diff --git a/libs/input/android/os/InputConfig.aidl b/libs/input/android/os/InputConfig.aidl
index da62e03821..e5f7b56561 100644
--- a/libs/input/android/os/InputConfig.aidl
+++ b/libs/input/android/os/InputConfig.aidl
@@ -57,16 +57,9 @@ enum InputConfig {
     NOT_TOUCHABLE                = 1 << 3,
 
     /**
-     * Indicates that this window will not accept a touch event that is split between
-     * more than one window. When set:
-     *  - If this window receives a DOWN event with the first pointer, all successive
-     *    pointers that go down, regardless of their location on the screen, will be
-     *    directed to this window;
-     *  - If the DOWN event lands outside the touchable bounds of this window, no
-     *    successive pointers that go down, regardless of their location on the screen,
-     *    will be directed to this window.
-     */
-    PREVENT_SPLITTING            = 1 << 4,
+     * This flag is now deprecated and should not be used.
+     */
+    DEPRECATED_PREVENT_SPLITTING = 1 << 4,
 
     /**
      * Indicates that this window shows the wallpaper behind it, so all touch events
diff --git a/libs/input/input_flags.aconfig b/libs/input/input_flags.aconfig
index 6cdd249b9e..feff096720 100644
--- a/libs/input/input_flags.aconfig
+++ b/libs/input/input_flags.aconfig
@@ -37,9 +37,9 @@ flag {
 }
 
 flag {
-  name: "split_all_touches"
+  name: "deprecate_split_touch_apis"
   namespace: "input"
-  description: "Set FLAG_SPLIT_TOUCHES to true for all windows, regardless of what they specify. This is essentially deprecating this flag by forcefully enabling the split functionality"
+  description: "Deprecate all public APIs related to split touch because now all windows behave as if split touch is permanently enabled and there's no way for a window to disable split touch."
   bug: "239934827"
 }