From 6fc073ffa74cf9be3f354212032052ac6ae9f3fb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Rydg=C3=A5rd?= <hrydgard@gmail.com>
Date: Sun, 8 Mar 2020 16:41:31 +0100
Subject: [PATCH] UI: Simple joystick navigation. Fixes #10996.

---
 UI/ChatScreen.cpp      |  3 +--
 ext/native/ui/root.cpp | 59 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/UI/ChatScreen.cpp b/UI/ChatScreen.cpp
index bf82b6a3ac..21d4dfba5c 100644
--- a/UI/ChatScreen.cpp
+++ b/UI/ChatScreen.cpp
@@ -25,8 +25,7 @@ void ChatMenu::CreatePopupContents(UI::ViewGroup *parent) {
 	chatEdit_ = bottom->Add(new TextEdit("", n->T("Chat Here"), new LinearLayoutParams(1.0)));
 #if defined(USING_WIN_UI)
 	//freeze  the ui when using ctrl + C hotkey need workaround
-	if (g_Config.bBypassOSKWithKeyboard && !g_Config.bFullScreen)
-	{
+	if (g_Config.bBypassOSKWithKeyboard && !g_Config.bFullScreen) {
 		std::wstring titleText = ConvertUTF8ToWString(n->T("Chat"));
 		std::wstring defaultText = ConvertUTF8ToWString(n->T("Chat Here"));
 		std::wstring inputChars;
diff --git a/ext/native/ui/root.cpp b/ext/native/ui/root.cpp
index 1419d05c9e..b379511d6b 100644
--- a/ext/native/ui/root.cpp
+++ b/ext/native/ui/root.cpp
@@ -246,6 +246,65 @@ bool TouchEvent(const TouchInput &touch, ViewGroup *root) {
 }
 
 bool AxisEvent(const AxisInput &axis, ViewGroup *root) {
+	enum {
+		DIR_POS = 1,
+		DIR_NEG = 2,
+	};
+
+	static uint32_t x_state = 0;
+	static uint32_t y_state = 0;
+
+	const float THRESHOLD = 0.75;
+
+	// Cannot use the remapper since this is for the menu, so we provide our own
+	// axis->button emulation here.
+	auto GenerateKeyFromAxis = [&](uint32_t old, uint32_t cur, keycode_t neg_key, keycode_t pos_key) {
+		if (old == cur)
+			return;
+		if (old == DIR_POS) {
+			KeyEvent(KeyInput{ DEVICE_ID_KEYBOARD, pos_key, KEY_UP }, root);
+		} else if (old == DIR_NEG) {
+			KeyEvent(KeyInput{ DEVICE_ID_KEYBOARD, neg_key, KEY_UP }, root);
+		}
+		if (cur == DIR_POS) {
+			KeyEvent(KeyInput{ DEVICE_ID_KEYBOARD, pos_key, KEY_DOWN }, root);
+		} else if (cur == DIR_NEG) {
+			KeyEvent(KeyInput{ DEVICE_ID_KEYBOARD, neg_key, KEY_DOWN }, root);
+		}
+	};
+
+	switch (axis.deviceId) {
+	case DEVICE_ID_PAD_0:
+	case DEVICE_ID_PAD_1:
+	case DEVICE_ID_PAD_2:
+	case DEVICE_ID_PAD_3:
+	case DEVICE_ID_X360_0:
+	case DEVICE_ID_X360_1:
+	case DEVICE_ID_X360_2:
+	case DEVICE_ID_X360_3:
+	{
+		uint32_t dir = 0;
+		if (axis.axisId == JOYSTICK_AXIS_X) {
+			if (axis.value < -THRESHOLD)
+				dir = DIR_NEG;
+			else if (axis.value > THRESHOLD)
+				dir = DIR_POS;
+			GenerateKeyFromAxis(x_state, dir, NKCODE_DPAD_LEFT, NKCODE_DPAD_RIGHT);
+			x_state = dir;
+		}
+		if (axis.axisId == JOYSTICK_AXIS_Y) {
+			if (axis.value < -THRESHOLD)
+				dir = DIR_NEG;
+			else if (axis.value > THRESHOLD)
+				dir = DIR_POS;
+			// TODO: What do we do with devices that are reversed... ?
+			GenerateKeyFromAxis(y_state, dir, NKCODE_DPAD_DOWN, NKCODE_DPAD_UP);
+			y_state = dir;
+		}
+		break;
+	}
+	}
+
 	root->Axis(axis);
 	return true;
 }