Switch to input buffering on Android

Key, touch and joystick events will be passed directly from the UI thread to Godot, so they can benefit from agile input flushing.

As another consequence of this new way of passing events, less Java object are created at runtime (`Runnable`), which is good since the garbage collector needs to run less.

`AndroidInputHandler` is introduced to have a smaller cross-thread surface. `main_loop_request_go_back()` is removed in favor just inline calling `send_window_event()` at the most caller's convenience (i.e., leveraging the new `p_deferred`` parameter as appropriate).

Lastly, `get_mouse_position()` and `get_mouse_button_state()` now just call through `Input` to avoid the need of sync of mouse data tracked on the UI thread.

1 files changed, 11 insertions, 366 deletions

diff --git a/platform/android/display_server_android.cpp b/platform/android/display_server_android.cpp
index 7be4235876..720752d28f 100644
--- a/platform/android/display_server_android.cpp
+++ b/platform/android/display_server_android.cpp
@@ -30,7 +30,6 @@
 
 #include "display_server_android.h"
 
-#include "android_keys_utils.h"
 #include "core/config/project_settings.h"
 #include "java_godot_io_wrapper.h"
 #include "java_godot_wrapper.h"
@@ -203,17 +202,21 @@ void DisplayServerAndroid::window_set_drop_files_callback(const Callable &p_call
 	// Not supported on Android.
 }
 
-void DisplayServerAndroid::_window_callback(const Callable &p_callable, const Variant &p_arg) const {
+void DisplayServerAndroid::_window_callback(const Callable &p_callable, const Variant &p_arg, bool p_deferred) const {
 	if (!p_callable.is_null()) {
 		const Variant *argp = &p_arg;
 		Variant ret;
 		Callable::CallError ce;
-		p_callable.call((const Variant **)&argp, 1, ret, ce);
+		if (p_deferred) {
+			p_callable.call((const Variant **)&argp, 1, ret, ce);
+		} else {
+			p_callable.call_deferred((const Variant **)&argp, 1);
+		}
 	}
 }
 
-void DisplayServerAndroid::send_window_event(DisplayServer::WindowEvent p_event) const {
-	_window_callback(window_event_callback, int(p_event));
+void DisplayServerAndroid::send_window_event(DisplayServer::WindowEvent p_event, bool p_deferred) const {
+	_window_callback(window_event_callback, int(p_event), p_deferred);
 }
 
 void DisplayServerAndroid::send_input_event(const Ref<InputEvent> &p_event) const {
@@ -454,6 +457,7 @@ DisplayServerAndroid::DisplayServerAndroid(const String &p_rendering_driver, Dis
 #endif
 
 	Input::get_singleton()->set_event_dispatch_function(_dispatch_input_events);
+	Input::get_singleton()->set_use_input_buffering(true); // Needed because events will come directly from the UI thread
 
 	r_error = OK;
 }
@@ -473,344 +477,6 @@ DisplayServerAndroid::~DisplayServerAndroid() {
 #endif
 }
 
-void DisplayServerAndroid::process_joy_event(DisplayServerAndroid::JoypadEvent p_event) {
-	switch (p_event.type) {
-		case JOY_EVENT_BUTTON:
-			Input::get_singleton()->joy_button(p_event.device, (JoyButton)p_event.index, p_event.pressed);
-			break;
-		case JOY_EVENT_AXIS:
-			Input::JoyAxisValue value;
-			value.min = -1;
-			value.value = p_event.value;
-			Input::get_singleton()->joy_axis(p_event.device, (JoyAxis)p_event.index, value);
-			break;
-		case JOY_EVENT_HAT:
-			Input::get_singleton()->joy_hat(p_event.device, (HatMask)p_event.hat);
-			break;
-		default:
-			return;
-	}
-}
-
-void DisplayServerAndroid::_set_key_modifier_state(Ref<InputEventWithModifiers> ev) {
-	ev->set_shift_pressed(shift_mem);
-	ev->set_alt_pressed(alt_mem);
-	ev->set_meta_pressed(meta_mem);
-	ev->set_ctrl_pressed(control_mem);
-}
-
-void DisplayServerAndroid::process_key_event(int p_keycode, int p_scancode, int p_unicode_char, bool p_pressed) {
-	static char32_t prev_wc = 0;
-	char32_t unicode = p_unicode_char;
-	if ((p_unicode_char & 0xfffffc00) == 0xd800) {
-		if (prev_wc != 0) {
-			ERR_PRINT("invalid utf16 surrogate input");
-		}
-		prev_wc = unicode;
-		return; // Skip surrogate.
-	} else if ((unicode & 0xfffffc00) == 0xdc00) {
-		if (prev_wc == 0) {
-			ERR_PRINT("invalid utf16 surrogate input");
-			return; // Skip invalid surrogate.
-		}
-		unicode = (prev_wc << 10UL) + unicode - ((0xd800 << 10UL) + 0xdc00 - 0x10000);
-		prev_wc = 0;
-	} else {
-		prev_wc = 0;
-	}
-
-	Ref<InputEventKey> ev;
-	ev.instantiate();
-	int val = unicode;
-	int keycode = android_get_keysym(p_keycode);
-	int phy_keycode = android_get_keysym(p_scancode);
-
-	if (keycode == KEY_SHIFT) {
-		shift_mem = p_pressed;
-	}
-	if (keycode == KEY_ALT) {
-		alt_mem = p_pressed;
-	}
-	if (keycode == KEY_CTRL) {
-		control_mem = p_pressed;
-	}
-	if (keycode == KEY_META) {
-		meta_mem = p_pressed;
-	}
-
-	ev->set_keycode((Key)keycode);
-	ev->set_physical_keycode((Key)phy_keycode);
-	ev->set_unicode(val);
-	ev->set_pressed(p_pressed);
-
-	_set_key_modifier_state(ev);
-
-	if (val == '\n') {
-		ev->set_keycode(KEY_ENTER);
-	} else if (val == 61448) {
-		ev->set_keycode(KEY_BACKSPACE);
-		ev->set_unicode(KEY_BACKSPACE);
-	} else if (val == 61453) {
-		ev->set_keycode(KEY_ENTER);
-		ev->set_unicode(KEY_ENTER);
-	} else if (p_keycode == 4) {
-		OS_Android::get_singleton()->main_loop_request_go_back();
-	}
-
-	Input::get_singleton()->parse_input_event(ev);
-}
-
-void DisplayServerAndroid::process_touch(int p_event, int p_pointer, const Vector<DisplayServerAndroid::TouchPos> &p_points) {
-	switch (p_event) {
-		case AMOTION_EVENT_ACTION_DOWN: { //gesture begin
-			if (touch.size()) {
-				//end all if exist
-				for (int i = 0; i < touch.size(); i++) {
-					Ref<InputEventScreenTouch> ev;
-					ev.instantiate();
-					ev->set_index(touch[i].id);
-					ev->set_pressed(false);
-					ev->set_position(touch[i].pos);
-					Input::get_singleton()->parse_input_event(ev);
-				}
-			}
-
-			touch.resize(p_points.size());
-			for (int i = 0; i < p_points.size(); i++) {
-				touch.write[i].id = p_points[i].id;
-				touch.write[i].pos = p_points[i].pos;
-			}
-
-			//send touch
-			for (int i = 0; i < touch.size(); i++) {
-				Ref<InputEventScreenTouch> ev;
-				ev.instantiate();
-				ev->set_index(touch[i].id);
-				ev->set_pressed(true);
-				ev->set_position(touch[i].pos);
-				Input::get_singleton()->parse_input_event(ev);
-			}
-
-		} break;
-		case AMOTION_EVENT_ACTION_MOVE: { //motion
-			ERR_FAIL_COND(touch.size() != p_points.size());
-
-			for (int i = 0; i < touch.size(); i++) {
-				int idx = -1;
-				for (int j = 0; j < p_points.size(); j++) {
-					if (touch[i].id == p_points[j].id) {
-						idx = j;
-						break;
-					}
-				}
-
-				ERR_CONTINUE(idx == -1);
-
-				if (touch[i].pos == p_points[idx].pos)
-					continue; //no move unncesearily
-
-				Ref<InputEventScreenDrag> ev;
-				ev.instantiate();
-				ev->set_index(touch[i].id);
-				ev->set_position(p_points[idx].pos);
-				ev->set_relative(p_points[idx].pos - touch[i].pos);
-				Input::get_singleton()->parse_input_event(ev);
-				touch.write[i].pos = p_points[idx].pos;
-			}
-
-		} break;
-		case AMOTION_EVENT_ACTION_CANCEL:
-		case AMOTION_EVENT_ACTION_UP: { //release
-			if (touch.size()) {
-				//end all if exist
-				for (int i = 0; i < touch.size(); i++) {
-					Ref<InputEventScreenTouch> ev;
-					ev.instantiate();
-					ev->set_index(touch[i].id);
-					ev->set_pressed(false);
-					ev->set_position(touch[i].pos);
-					Input::get_singleton()->parse_input_event(ev);
-				}
-				touch.clear();
-			}
-		} break;
-		case AMOTION_EVENT_ACTION_POINTER_DOWN: { // add touch
-			for (int i = 0; i < p_points.size(); i++) {
-				if (p_points[i].id == p_pointer) {
-					TouchPos tp = p_points[i];
-					touch.push_back(tp);
-
-					Ref<InputEventScreenTouch> ev;
-					ev.instantiate();
-
-					ev->set_index(tp.id);
-					ev->set_pressed(true);
-					ev->set_position(tp.pos);
-					Input::get_singleton()->parse_input_event(ev);
-
-					break;
-				}
-			}
-		} break;
-		case AMOTION_EVENT_ACTION_POINTER_UP: { // remove touch
-			for (int i = 0; i < touch.size(); i++) {
-				if (touch[i].id == p_pointer) {
-					Ref<InputEventScreenTouch> ev;
-					ev.instantiate();
-					ev->set_index(touch[i].id);
-					ev->set_pressed(false);
-					ev->set_position(touch[i].pos);
-					Input::get_singleton()->parse_input_event(ev);
-					touch.remove(i);
-
-					break;
-				}
-			}
-		} break;
-	}
-}
-
-void DisplayServerAndroid::process_hover(int p_type, Point2 p_pos) {
-	// https://developer.android.com/reference/android/view/MotionEvent.html#ACTION_HOVER_ENTER
-	switch (p_type) {
-		case AMOTION_EVENT_ACTION_HOVER_MOVE: // hover move
-		case AMOTION_EVENT_ACTION_HOVER_ENTER: // hover enter
-		case AMOTION_EVENT_ACTION_HOVER_EXIT: { // hover exit
-			Ref<InputEventMouseMotion> ev;
-			ev.instantiate();
-			_set_key_modifier_state(ev);
-			ev->set_position(p_pos);
-			ev->set_global_position(p_pos);
-			ev->set_relative(p_pos - hover_prev_pos);
-			Input::get_singleton()->parse_input_event(ev);
-			hover_prev_pos = p_pos;
-		} break;
-	}
-}
-
-void DisplayServerAndroid::process_mouse_event(int input_device, int event_action, int event_android_buttons_mask, Point2 event_pos, float event_vertical_factor, float event_horizontal_factor) {
-	MouseButton event_buttons_mask = _android_button_mask_to_godot_button_mask(event_android_buttons_mask);
-	switch (event_action) {
-		case AMOTION_EVENT_ACTION_BUTTON_PRESS:
-		case AMOTION_EVENT_ACTION_BUTTON_RELEASE: {
-			Ref<InputEventMouseButton> ev;
-			ev.instantiate();
-			_set_key_modifier_state(ev);
-			if ((input_device & AINPUT_SOURCE_MOUSE) == AINPUT_SOURCE_MOUSE) {
-				ev->set_position(event_pos);
-				ev->set_global_position(event_pos);
-			} else {
-				ev->set_position(hover_prev_pos);
-				ev->set_global_position(hover_prev_pos);
-			}
-			ev->set_pressed(event_action == AMOTION_EVENT_ACTION_BUTTON_PRESS);
-			MouseButton changed_button_mask = MouseButton(buttons_state ^ event_buttons_mask);
-
-			buttons_state = event_buttons_mask;
-
-			ev->set_button_index(_button_index_from_mask(changed_button_mask));
-			ev->set_button_mask(event_buttons_mask);
-			Input::get_singleton()->parse_input_event(ev);
-		} break;
-
-		case AMOTION_EVENT_ACTION_MOVE: {
-			Ref<InputEventMouseMotion> ev;
-			ev.instantiate();
-			_set_key_modifier_state(ev);
-			if ((input_device & AINPUT_SOURCE_MOUSE) == AINPUT_SOURCE_MOUSE) {
-				ev->set_position(event_pos);
-				ev->set_global_position(event_pos);
-				ev->set_relative(event_pos - hover_prev_pos);
-				hover_prev_pos = event_pos;
-			} else {
-				ev->set_position(hover_prev_pos);
-				ev->set_global_position(hover_prev_pos);
-				ev->set_relative(event_pos);
-			}
-			ev->set_button_mask(event_buttons_mask);
-			Input::get_singleton()->parse_input_event(ev);
-		} break;
-		case AMOTION_EVENT_ACTION_SCROLL: {
-			Ref<InputEventMouseButton> ev;
-			ev.instantiate();
-			if ((input_device & AINPUT_SOURCE_MOUSE) == AINPUT_SOURCE_MOUSE) {
-				ev->set_position(event_pos);
-				ev->set_global_position(event_pos);
-			} else {
-				ev->set_position(hover_prev_pos);
-				ev->set_global_position(hover_prev_pos);
-			}
-			ev->set_pressed(true);
-			buttons_state = event_buttons_mask;
-			if (event_vertical_factor > 0) {
-				_wheel_button_click(event_buttons_mask, ev, MOUSE_BUTTON_WHEEL_UP, event_vertical_factor);
-			} else if (event_vertical_factor < 0) {
-				_wheel_button_click(event_buttons_mask, ev, MOUSE_BUTTON_WHEEL_DOWN, -event_vertical_factor);
-			}
-
-			if (event_horizontal_factor > 0) {
-				_wheel_button_click(event_buttons_mask, ev, MOUSE_BUTTON_WHEEL_RIGHT, event_horizontal_factor);
-			} else if (event_horizontal_factor < 0) {
-				_wheel_button_click(event_buttons_mask, ev, MOUSE_BUTTON_WHEEL_LEFT, -event_horizontal_factor);
-			}
-		} break;
-	}
-}
-
-void DisplayServerAndroid::_wheel_button_click(MouseButton event_buttons_mask, const Ref<InputEventMouseButton> &ev, MouseButton wheel_button, float factor) {
-	Ref<InputEventMouseButton> evd = ev->duplicate();
-	_set_key_modifier_state(evd);
-	evd->set_button_index(wheel_button);
-	evd->set_button_mask(MouseButton(event_buttons_mask ^ (1 << (wheel_button - 1))));
-	evd->set_factor(factor);
-	Input::get_singleton()->parse_input_event(evd);
-	Ref<InputEventMouseButton> evdd = evd->duplicate();
-	evdd->set_pressed(false);
-	evdd->set_button_mask(event_buttons_mask);
-	Input::get_singleton()->parse_input_event(evdd);
-}
-
-void DisplayServerAndroid::process_double_tap(int event_android_button_mask, Point2 p_pos) {
-	MouseButton event_button_mask = _android_button_mask_to_godot_button_mask(event_android_button_mask);
-	Ref<InputEventMouseButton> ev;
-	ev.instantiate();
-	_set_key_modifier_state(ev);
-	ev->set_position(p_pos);
-	ev->set_global_position(p_pos);
-	ev->set_pressed(event_button_mask != 0);
-	ev->set_button_index(_button_index_from_mask(event_button_mask));
-	ev->set_button_mask(event_button_mask);
-	ev->set_double_click(true);
-	Input::get_singleton()->parse_input_event(ev);
-}
-
-MouseButton DisplayServerAndroid::_button_index_from_mask(MouseButton button_mask) {
-	switch (button_mask) {
-		case MOUSE_BUTTON_MASK_LEFT:
-			return MOUSE_BUTTON_LEFT;
-		case MOUSE_BUTTON_MASK_RIGHT:
-			return MOUSE_BUTTON_RIGHT;
-		case MOUSE_BUTTON_MASK_MIDDLE:
-			return MOUSE_BUTTON_MIDDLE;
-		case MOUSE_BUTTON_MASK_XBUTTON1:
-			return MOUSE_BUTTON_XBUTTON1;
-		case MOUSE_BUTTON_MASK_XBUTTON2:
-			return MOUSE_BUTTON_XBUTTON2;
-		default:
-			return MOUSE_BUTTON_NONE;
-	}
-}
-
-void DisplayServerAndroid::process_scroll(Point2 p_pos) {
-	Ref<InputEventPanGesture> ev;
-	ev.instantiate();
-	_set_key_modifier_state(ev);
-	ev->set_position(p_pos);
-	ev->set_delta(p_pos - scroll_prev_pos);
-	Input::get_singleton()->parse_input_event(ev);
-	scroll_prev_pos = p_pos;
-}
-
 void DisplayServerAndroid::process_accelerometer(const Vector3 &p_accelerometer) {
 	Input::get_singleton()->set_accelerometer(p_accelerometer);
 }
@@ -852,32 +518,11 @@ DisplayServer::MouseMode DisplayServerAndroid::mouse_get_mode() const {
 }
 
 Point2i DisplayServerAndroid::mouse_get_position() const {
-	return hover_prev_pos;
+	return Input::get_singleton()->get_mouse_position();
 }
 
 MouseButton DisplayServerAndroid::mouse_get_button_state() const {
-	return buttons_state;
-}
-
-MouseButton DisplayServerAndroid::_android_button_mask_to_godot_button_mask(int android_button_mask) {
-	MouseButton godot_button_mask = MOUSE_BUTTON_NONE;
-	if (android_button_mask & AMOTION_EVENT_BUTTON_PRIMARY) {
-		godot_button_mask |= MOUSE_BUTTON_MASK_LEFT;
-	}
-	if (android_button_mask & AMOTION_EVENT_BUTTON_SECONDARY) {
-		godot_button_mask |= MOUSE_BUTTON_MASK_RIGHT;
-	}
-	if (android_button_mask & AMOTION_EVENT_BUTTON_TERTIARY) {
-		godot_button_mask |= MOUSE_BUTTON_MASK_MIDDLE;
-	}
-	if (android_button_mask & AMOTION_EVENT_BUTTON_BACK) {
-		godot_button_mask |= MOUSE_BUTTON_MASK_XBUTTON1;
-	}
-	if (android_button_mask & AMOTION_EVENT_BUTTON_SECONDARY) {
-		godot_button_mask |= MOUSE_BUTTON_MASK_XBUTTON2;
-	}
-
-	return godot_button_mask;
+	return (MouseButton)Input::get_singleton()->get_mouse_button_mask();
 }
 
 void DisplayServerAndroid::cursor_set_shape(DisplayServer::CursorShape p_shape) {