From d63c61e27cfdff0625618527b39d6469fca722e2 Mon Sep 17 00:00:00 2001
From: rsn8887 <rsn8887@users.noreply.github.com>
Date: Thu, 11 Jul 2019 11:32:00 -0500
Subject: [PATCH] Add virtual keyboard support on Switch

---
 CMakeLists.txt                       |  1 +
 SourceX/DiabloUI/diabloui.cpp        |  8 +++
 SourceX/platform/switch/keyboard.cpp | 79 ++++++++++++++++++++++++++++
 SourceX/platform/switch/keyboard.h   |  3 ++
 4 files changed, 91 insertions(+)
 create mode 100644 SourceX/platform/switch/keyboard.cpp
 create mode 100644 SourceX/platform/switch/keyboard.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index fd947e1ba..9dd3c29fd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -283,6 +283,7 @@ set(BIN_TARGET devilutionx)
 
 if(SWITCH)
   list(APPEND devilutionx_SRCS
+    SourceX/platform/switch/keyboard.cpp
     SourceX/platform/switch/docking.cpp)
   set(BIN_TARGET devilutionx.elf)
 endif()
diff --git a/SourceX/DiabloUI/diabloui.cpp b/SourceX/DiabloUI/diabloui.cpp
index f53649f41..e6d72c348 100644
--- a/SourceX/DiabloUI/diabloui.cpp
+++ b/SourceX/DiabloUI/diabloui.cpp
@@ -16,6 +16,11 @@
 #include "DiabloUI/button.h"
 #include "DiabloUI/dialogs.h"
 
+#ifdef __SWITCH__
+// for virtual keyboard on Switch
+#include "platform/switch/keyboard.h"
+#endif
+
 namespace dvl {
 
 int SelectedItemMin = 1;
@@ -80,6 +85,9 @@ void UiInitList(int min, int max, void (*fnFocus)(int value), void (*fnSelect)(i
 	SDL_StopTextInput(); // input is enabled by default
 	for (int i = 0; i < itemCnt; i++) {
 		if (items[i].type == UI_EDIT) {
+#ifdef __SWITCH__
+			switch_start_text_input(items[i - 1].art_text.text, items[i].edit.value, /*multiline=*/0);
+#endif
 			SDL_StartTextInput();
 			UiTextInput = items[i].edit.value;
 			UiTextInputLen = items[i].edit.max_length;
diff --git a/SourceX/platform/switch/keyboard.cpp b/SourceX/platform/switch/keyboard.cpp
new file mode 100644
index 000000000..e4e33e0ca
--- /dev/null
+++ b/SourceX/platform/switch/keyboard.cpp
@@ -0,0 +1,79 @@
+#include <string.h>
+#include <stdbool.h>
+
+#include <switch.h>
+#include <SDL.h>
+#include "platform/switch/keyboard.h"
+
+static void switch_keyboard_get(const char *guide_text, char *initial_text, int max_len, int multiline, char *buf)
+{
+    Result rc = 0;
+
+    SwkbdConfig kbd;
+
+    rc = swkbdCreate(&kbd, 0);
+
+    if (R_SUCCEEDED(rc)) {
+        swkbdConfigMakePresetDefault(&kbd);
+        swkbdConfigSetGuideText(&kbd, guide_text);
+        swkbdConfigSetInitialText(&kbd, initial_text);
+        swkbdConfigSetStringLenMax(&kbd, max_len);
+        rc = swkbdShow(&kbd, buf, max_len);
+        swkbdClose(&kbd);
+    }
+}
+
+static int get_utf8_character_bytes(const uint8_t *uc)
+{
+    if (uc[0] < 0x80) {
+        return 1;
+    } else if ((uc[0] & 0xe0) == 0xc0 && (uc[1] & 0xc0) == 0x80) {
+        return 2;
+    } else if ((uc[0] & 0xf0) == 0xe0 && (uc[1] & 0xc0) == 0x80 && (uc[2] & 0xc0) == 0x80) {
+        return 3;
+    } else if ((uc[0] & 0xf8) == 0xf0 && (uc[1] & 0xc0) == 0x80 && (uc[2] & 0xc0) == 0x80 && (uc[3] & 0xc0) == 0x80) {
+        return 4;
+    } else {
+        return 1;
+    }
+}
+
+static void switch_create_and_push_sdlkey_event(uint32_t event_type, SDL_Scancode scan, SDL_Keycode key)
+{
+    SDL_Event event;
+    event.type = event_type;
+    event.key.keysym.scancode = scan;
+    event.key.keysym.sym = key;
+    event.key.keysym.mod = 0;
+    SDL_PushEvent(&event);
+}
+
+void switch_start_text_input(const char *guide_text, char *initial_text, int multiline)
+{
+    char text[65] = {'\0'};
+    switch_keyboard_get(guide_text, initial_text, 64, multiline, text);
+    for (int i = 0; i < 600; i++) {
+        switch_create_and_push_sdlkey_event(SDL_KEYDOWN, SDL_SCANCODE_BACKSPACE, SDLK_BACKSPACE);
+        switch_create_and_push_sdlkey_event(SDL_KEYUP, SDL_SCANCODE_BACKSPACE, SDLK_BACKSPACE);
+    }
+    for (int i = 0; i < 600; i++) {
+        switch_create_and_push_sdlkey_event(SDL_KEYDOWN, SDL_SCANCODE_DELETE, SDLK_DELETE);
+        switch_create_and_push_sdlkey_event(SDL_KEYUP, SDL_SCANCODE_DELETE, SDLK_DELETE);
+    }
+    if (text[0] == '\0') {
+        strncpy(text, initial_text, 63);
+        text[64] = {'\0'};
+    }
+    const uint8_t *utf8_text = (uint8_t*) text;
+    for (int i = 0; i < 599 && utf8_text[i];) {
+        int bytes_in_char = get_utf8_character_bytes(&utf8_text[i]);
+        SDL_Event textinput_event;
+        textinput_event.type = SDL_TEXTINPUT;
+        for (int n = 0; n < bytes_in_char; n++) {
+            textinput_event.text.text[n] = text[i + n];
+        }
+        textinput_event.text.text[bytes_in_char] = 0;
+        SDL_PushEvent(&textinput_event);
+        i += bytes_in_char;
+    }
+}
diff --git a/SourceX/platform/switch/keyboard.h b/SourceX/platform/switch/keyboard.h
new file mode 100644
index 000000000..5ab737913
--- /dev/null
+++ b/SourceX/platform/switch/keyboard.h
@@ -0,0 +1,3 @@
+#pragma once
+
+void switch_start_text_input(const char *guide_text, char *initial_text, int multiline);