Android: Pass touch events through as mouse events

This is probably not the best way of handling touch events, but at least
it allows the user to actually interact with the page!

Ladybird/Android/src/main/cpp/WebViewImplementationNative.cpp

@@ -103,6 +103,25 @@ void WebViewImplementationNative::set_device_pixel_ratio(float f)
     client().async_set_device_pixels_per_css_pixel(0, m_device_pixel_ratio);
 }
 
+void WebViewImplementationNative::mouse_event(Web::MouseEvent::Type event_type, float x, float y, float raw_x, float raw_y)
+{
+    Gfx::IntPoint position = { x, y };
+    Gfx::IntPoint screen_position = { raw_x, raw_y };
+    auto event = Web::MouseEvent {
+        event_type,
+        position.to_type<Web::DevicePixels>(),
+        screen_position.to_type<Web::DevicePixels>(),
+        Web::UIEvents::MouseButton::Primary,
+        Web::UIEvents::MouseButton::Primary,
+        Web::UIEvents::KeyModifier::Mod_None,
+        0,
+        0,
+        nullptr
+    };
+
+    enqueue_input_event(move(event));
+}
+
 NonnullRefPtr<WebView::WebContentClient> WebViewImplementationNative::bind_web_content_client()
 {
     JavaEnvironment env(global_vm);

Ladybird/Android/src/main/cpp/WebViewImplementationNative.h

@@ -29,6 +29,8 @@ public:
     void set_viewport_geometry(int w, int h);
     void set_device_pixel_ratio(float f);
 
+    void mouse_event(Web::MouseEvent::Type event_type, float x, float y, float raw_x, float raw_y);
+
     static jclass global_class_reference;
     static jmethodID bind_webcontent_method;
     static jmethodID invalidate_layout_method;

Ladybird/Android/src/main/cpp/WebViewImplementationNativeJNI.cpp

@@ -93,3 +93,29 @@ Java_org_serenityos_ladybird_WebViewImplementation_nativeSetDevicePixelRatio(JNI
     auto* impl = reinterpret_cast<WebViewImplementationNative*>(instance);
     impl->set_device_pixel_ratio(ratio);
 }
+
+extern "C" JNIEXPORT void JNICALL
+Java_org_serenityos_ladybird_WebViewImplementation_nativeMouseEvent(JNIEnv*, jobject /* thiz */, jlong instance, jint event_type, jfloat x, jfloat y, jfloat raw_x, jfloat raw_y)
+{
+    auto* impl = reinterpret_cast<WebViewImplementationNative*>(instance);
+
+    Web::MouseEvent::Type web_event_type;
+
+    // These integers are defined in Android's MotionEvent.
+    // See https://developer.android.com/reference/android/view/MotionEvent#constants_1
+    if (event_type == 0) {
+        // MotionEvent.ACTION_DOWN
+        web_event_type = Web::MouseEvent::Type::MouseDown;
+    } else if (event_type == 1) {
+        // MotionEvent.ACTION_UP
+        web_event_type = Web::MouseEvent::Type::MouseUp;
+    } else if (event_type == 2) {
+        // MotionEvent.ACTION_MOVE
+        web_event_type = Web::MouseEvent::Type::MouseMove;
+    } else {
+        // Unknown event type, default to MouseUp
+        web_event_type = Web::MouseEvent::Type::MouseUp;
+    }
+
+    impl->mouse_event(web_event_type, x, y, raw_x, raw_y);
+}

Ladybird/Android/src/main/java/org/serenityos/ladybird/WebView.kt

@@ -10,6 +10,7 @@ import android.content.Context
 import android.graphics.Bitmap
 import android.graphics.Canvas
 import android.util.AttributeSet
+import android.view.MotionEvent
 import android.view.View
 
 // FIXME: This should (eventually) implement NestedScrollingChild3 and ScrollingView
@@ -30,6 +31,23 @@ class WebView(context: Context, attributeSet: AttributeSet) : View(context, attr
         viewImpl.loadURL(url)
     }
 
+    override fun onTouchEvent(event: MotionEvent): Boolean {
+        // The native side only supports down, move, and up events.
+        // So, ignore any other MotionEvents.
+        if (event.action != MotionEvent.ACTION_DOWN &&
+            event.action != MotionEvent.ACTION_MOVE &&
+            event.action != MotionEvent.ACTION_UP) {
+            return super.onTouchEvent(event);
+        }
+
+        // FIXME: We are passing these through as mouse events.
+        // We should really be handling them as touch events.
+        // (And we should handle scrolling - right now you have tap and drag the scrollbar!)
+        viewImpl.mouseEvent(event.action, event.x, event.y, event.rawX, event.rawY)
+
+        return true
+    }
+
     override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
         super.onSizeChanged(w, h, oldw, oldh)
         contentBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888)

Ladybird/Android/src/main/java/org/serenityos/ladybird/WebViewImplementation.kt

@@ -11,6 +11,7 @@ import android.content.Intent
 import android.content.ServiceConnection
 import android.graphics.Bitmap
 import android.util.Log
+import android.view.MotionEvent
 import android.view.View
 import java.net.URL
 
@@ -49,6 +50,10 @@ class WebViewImplementation(private val view: WebView) {
         nativeSetDevicePixelRatio(nativeInstance, ratio)
     }
 
+    fun mouseEvent(eventType: Int, x: Float, y: Float, rawX: Float, rawY: Float) {
+        nativeMouseEvent(nativeInstance, eventType, x, y, rawX, rawY)
+    }
+
     // Functions called from native code
     fun bindWebContentService(ipcFd: Int) {
         val connector = LadybirdServiceConnection(ipcFd, resourceDir)
@@ -82,6 +87,7 @@ class WebViewImplementation(private val view: WebView) {
     private external fun nativeSetViewportGeometry(instance: Long, w: Int, h: Int)
     private external fun nativeSetDevicePixelRatio(instance: Long, ratio: Float)
     private external fun nativeLoadURL(instance: Long, url: String)
+    private external fun nativeMouseEvent(instance: Long, eventType: Int, x: Float, y: Float, rawX: Float, rawY: Float)
 
     companion object {
         /*