[20/n Dispatcher refactor] Allow access to all TouchedWindowHandles

In this CL we introduce following methods to allow iterating over all
touchedWindowHandles.
1. forAllTouchedWindows
2. forAllTouchedWindowsOnDisplay

Bug: 367661487
Bug: 245989146
Test: atest inputflinger_tests
Flag: EXEMPT refactor
Change-Id: I65b2b48d73e11c068d208339931b919e419e2893

Author: Arpit Singh

services/inputflinger/dispatcher/InputDispatcher.cpp

@@ -4072,13 +4072,17 @@ void InputDispatcher::synthesizeCancelationEventsForAllConnectionsLocked(
     // Generate cancellations for touched windows first. This is to avoid generating cancellations
     // through a non-touched window if there are more than one window for an input channel.
     if (cancelPointers) {
-        for (const auto& [displayId, touchState] : mTouchStates.mTouchStatesByDisplay) {
-            if (options.displayId.has_value() && options.displayId != displayId) {
-                continue;
-            }
-            for (const auto& touchedWindow : touchState.windows) {
-                synthesizeCancelationEventsForWindowLocked(touchedWindow.windowHandle, options);
-            }
+        if (options.displayId.has_value()) {
+            mTouchStates.forAllTouchedWindowsOnDisplay(
+                    options.displayId.value(), [&](const sp<gui::WindowInfoHandle>& windowHandle) {
+                        base::ScopedLockAssertion assumeLocked(mLock);
+                        synthesizeCancelationEventsForWindowLocked(windowHandle, options);
+                    });
+        } else {
+            mTouchStates.forAllTouchedWindows([&](const sp<gui::WindowInfoHandle>& windowHandle) {
+                base::ScopedLockAssertion assumeLocked(mLock);
+                synthesizeCancelationEventsForWindowLocked(windowHandle, options);
+            });
         }
     }
     // Follow up by generating cancellations for all windows, because we don't explicitly track
@@ -7475,6 +7479,27 @@ InputDispatcher::DispatcherTouchState::findTouchedWindowHandleAndDisplay(
     return std::nullopt;
 }
 
+void InputDispatcher::DispatcherTouchState::forAllTouchedWindows(
+        std::function<void(const sp<gui::WindowInfoHandle>&)> f) const {
+    for (const auto& [_, state] : mTouchStatesByDisplay) {
+        for (const TouchedWindow& window : state.windows) {
+            f(window.windowHandle);
+        }
+    }
+}
+
+void InputDispatcher::DispatcherTouchState::forAllTouchedWindowsOnDisplay(
+        ui::LogicalDisplayId displayId,
+        std::function<void(const sp<gui::WindowInfoHandle>&)> f) const {
+    const auto touchStateIt = mTouchStatesByDisplay.find(displayId);
+    if (touchStateIt == mTouchStatesByDisplay.end()) {
+        return;
+    }
+    for (const TouchedWindow& window : touchStateIt->second.windows) {
+        f(window.windowHandle);
+    }
+}
+
 std::string InputDispatcher::DispatcherTouchState::dump() const {
     std::string dump;
     if (!mTouchStatesByDisplay.empty()) {

services/inputflinger/dispatcher/InputDispatcher.h

@@ -396,6 +396,12 @@ class InputDispatcher : public android::InputDispatcherInterface {
         std::optional<std::tuple<const sp<gui::WindowInfoHandle>&, ui::LogicalDisplayId>>
         findTouchedWindowHandleAndDisplay(const sp<IBinder>& token) const;
 
+        void forAllTouchedWindows(std::function<void(const sp<gui::WindowInfoHandle>&)> f) const;
+
+        void forAllTouchedWindowsOnDisplay(
+                ui::LogicalDisplayId displayId,
+                std::function<void(const sp<gui::WindowInfoHandle>&)> f) const;
+
         std::string dump() const;
 
         // Updates the touchState for display from WindowInfo,