Add test view for touch-input-test (#36879)

This PR adds a touch-input-view for use in the touch-input-test to validate touch input. The view will be attached to the test, and a touch event will be injected. The test asserts that a correct response is sent back from the view (the location of the touch as well as the name of the view).

Author: lin-erik

shell/platform/fuchsia/flutter/tests/integration/touch-input/BUILD.gn

@@ -34,18 +34,19 @@ executable("touch-input-test-bin") {
     "$fuchsia_sdk_root/fidl:fuchsia.tracing.provider",
     "$fuchsia_sdk_root/fidl:fuchsia.ui.app",
     "$fuchsia_sdk_root/fidl:fuchsia.ui.input",
+    "$fuchsia_sdk_root/fidl:fuchsia.ui.pointerinjector",
     "$fuchsia_sdk_root/fidl:fuchsia.ui.policy",
     "$fuchsia_sdk_root/fidl:fuchsia.ui.scenic",
     "$fuchsia_sdk_root/fidl:fuchsia.ui.test.input",
     "$fuchsia_sdk_root/fidl:fuchsia.ui.test.scene",
-    "$fuchsia_sdk_root/fidl:fuchsia.ui.test.scene",
     "$fuchsia_sdk_root/fidl:fuchsia.web",
     "$fuchsia_sdk_root/pkg:async",
     "$fuchsia_sdk_root/pkg:async-loop-testing",
     "$fuchsia_sdk_root/pkg:fidl_cpp",
     "$fuchsia_sdk_root/pkg:scenic_cpp",
     "$fuchsia_sdk_root/pkg:sys_component_cpp_testing",
     "$fuchsia_sdk_root/pkg:zx",
+    "touch-input-view:package",
     "//build/fuchsia/fidl:fuchsia.ui.gfx",
     "//flutter/fml",
     "//flutter/shell/platform/fuchsia/flutter/tests/integration/utils:portable_ui_test",
@@ -58,7 +59,6 @@ fuchsia_test_archive("touch-input-test") {
   testonly = true
   deps = [
     ":touch-input-test-bin",
-    "one-flutter:package",
 
     # "OOT" copies of the runners used by tests, to avoid conflicting with the
     # runners in the base fuchsia image.

shell/platform/fuchsia/flutter/tests/integration/touch-input/README.md

@@ -0,0 +1,76 @@
+# touch-input
+
+`touch-input-test` exercises touch through a child view (in this case, the `touch-input-view` Dart component) and asserting
+the precise location of the touch event. We do this by attaching the child view, injecting touch, and validating that the view
+reports the touch event back with the correct coordinates.
+
+```shell
+Injecting the tap event
+[touch-input-test.cm] INFO: [portable_ui_test.cc(193)] Injecting tap at (-500, -500)
+
+View receives the event
+[flutter_jit_runner] INFO: touch-input-view.cm(flutter): touch-input-view received tap: PointerData(embedderId: 0, timeStamp: 0:01:03.623259,
+change: PointerChange.add, kind: PointerDeviceKind.touch, signalKind: PointerSignalKind.none, device: -4294967295, pointerIdentifier: 0,
+physicalX: 319.99998331069946, physicalY: 199.99999284744263, physicalDeltaX: 0.0, physicalDeltaY: 0.0, buttons: 0, synthesized: false,
+pressure: 0.0, pressureMin: 0.0, pressureMax: 0.0, distance: 0.0, distanceMax: 0.0, size: 0.0, radiusMajor: 0.0, radiusMinor: 0.0,
+radiusMin: 0.0, radiusMax: 0.0, orientation: 0.0, tilt: 0.0, platformData: 0, scrollDeltaX: 0.0, scrollDeltaY: 0.0, panX: 0.0, panY: 0.0,
+panDeltaX: 0.0, panDeltaY: 0.0, scale: 0.0, rotation: 0.0)
+
+Successfully received response from view
+[touch-input-test.cm] INFO: [touch-input-test.cc(162)] Received ReportTouchInput event
+[touch-input-test.cm] INFO: [touch-input-test.cc(255)] Expecting event for component touch-input-view at (320, 200)
+[touch-input-test.cm] INFO: [touch-input-test.cc(257)] Received event for component touch-input-view at (320, 200), accounting for pixel scale of 1
+```
+
+Some interesting details (thanks to abrusher@):
+
+There exists two coordinate spaces within our testing realm. The first is `touch-input-view`'s "logical" coordinate space. This
+is determined based on `touch-input-view`'s size and is the space in which it sees incoming events. The second is the "injector"
+coordinate space, which spans [-1000, 1000] on both axes.
+
+The size/position of a view doesn't always match the bounds of a display exactly. As a result, Scenic has a separate coordinate space
+to specify the location at which to inject a touch event. This is always fixed to the display bounds. Scenic knows how to map this
+coordinate space onto the client view's space.
+
+For example, if we inject at (-500, -500) `touch-input-view` will see a touch event at the middle of the upper-left quadrant of the screen.
+
+## Running the Test
+
+Reference the Flutter integration test [documentation](https://github.com/flutter/engine/blob/main/shell/platform/fuchsia/flutter/tests/integration/README.md) at //flutter/shell/platform/fuchsia/flutter/tests/integration/README.md
+
+## Playing around with `touch-input-view`
+
+Build Fuchsia with `workstation_eng.qemu-x64`
+```shell
+fx set workstation_eng.qemu-x64 --with-base=//src/session/bin/session_manager && fx build
+```
+
+Build flutter/engine
+```shell
+$ENGINE_DIR/flutter/tools/gn --fuchsia --no-lto && ninja -C $ENGINE_DIR/out/fuchsia_debug_x64 flutter/shell/platform/fuchsia/flutter/tests/
+integration/touch_input:tests
+```
+
+Start a Fuchsia package server
+```shell
+cd "$FUCHSIA_DIR"
+fx serve
+```
+
+Publish `touch-input-view`
+```shell
+$FUCHSIA_DIR/.jiri_root/bin/fx pm publish -a -repo $FUCHSIA_DIR/$(cat $FUCHSIA_DIR/.fx-build-dir)/amber-files -f $ENGINE_DIR/out/
+fuchsia_debug_x64/gen/flutter/shell/platform/fuchsia/flutter/tests/integration/touch-input/touch-input-view/touch-input-view/touch-input-view.far
+```
+
+Launch Fuchsia emulator in a graphical environment
+```shell
+ffx emu start
+```
+
+**Before proceeding, make sure you have successfully completed the "Set a Password" screen**
+
+Add `touch-input-view`
+```shell
+ffx session add fuchsia-pkg://fuchsia.com/touch-input-view#meta/touch-input-view.cm
+```

shell/platform/fuchsia/flutter/tests/integration/touch-input/meta/touch-input-test.cml

@@ -6,21 +6,24 @@
         "gtest_runner.shard.cml",
         "sys/component/realm_builder_absolute.shard.cml",
 
-        "syslog/client.shard.cml",
-        "vulkan/client.shard.cml",
-
         // This test needs both the vulkan facet and the hermetic-tier-2 facet,
         // so we are forced to make it a system test.
         "sys/testing/system-test.shard.cml",
     ],
     program: {
         binary: "bin/app",
     },
+    use: [
+        {
+            protocol: [
+                "fuchsia.ui.test.input.TouchInputListener",
+            ]
+        }
+    ],
     offer: [
         {
             // Offer capabilities needed by components in this test realm.
             // Keep it minimal, describe only what's actually needed.
-            // TODO(fxbug.dev/81446): Remove this list.
             protocol: [
                 "fuchsia.kernel.RootJobForInspect",
                 "fuchsia.kernel.Stats",
@@ -30,9 +33,21 @@
                 "fuchsia.tracing.provider.Registry",
                 "fuchsia.ui.input.ImeService",
                 "fuchsia.vulkan.loader.Loader",
+                "fuchsia.ui.scenic.Scenic",
+                "fuchsia.ui.test.input.TouchInputListener",
+                "fuchsia.intl.PropertyProvider",
+                "fuchsia.posix.socket.Provider",
+                "fuchsia.ui.pointerinjector.Registry",
             ],
             from: "parent",
             to: "#realm_builder",
         },
+        {
+            directory: "pkg",
+            subdir: "config",
+            as: "config-data",
+            from: "framework",
+            to: "#realm_builder",
+        },
     ],
 }