large refactor

.gitignore

@@ -3,3 +3,4 @@
 .vscode/c_cpp_properties.json
 .vscode/launch.json
 .vscode/ipch
+.vscode/settings.json

platformio.ini

@@ -17,6 +17,7 @@ lib_deps =
   https://github.com/m5stack/M5EPD
   https://github.com/arduino-libraries/NTPClient
   https://github.com/tobozo/YAMLDuino
+  https://github.com/josephlarralde/ArduinoEventEmitter
   LovyanGFX
   bblanchon/ArduinoJson
   knolleary/PubSubClient

src/button.hpp

@@ -0,0 +1,142 @@
+#ifndef _KEYPADBUTTON_H_
+#define _KEYPADBUTTON_H_
+
+#define LGFX_AUTODETECT
+#include <LovyanGFX.hpp>
+
+class Keypad;
+
+typedef void (*BUTTON_ON_PRESSED_CALLBACK)(void *, int);
+
+class KeypadButton
+{
+public:
+    KeypadButton(String label, int value, bool enabled, BUTTON_ON_PRESSED_CALLBACK on_pressed) : label{label}, value{value}, enabled{enabled}, on_pressed{on_pressed} {}
+    KeypadButton(String label, int value, bool enabled, float x, float y, BUTTON_ON_PRESSED_CALLBACK on_pressed) : label{label}, value{value}, enabled{enabled}, x{x}, y{y}, on_pressed{on_pressed} {}
+    KeypadButton(String label, int value, bool enabled, float x, float y, int width, int height, BUTTON_ON_PRESSED_CALLBACK on_pressed) : label{label}, value{value}, enabled{enabled}, x{x}, y{y}, width{width}, height{height}, on_pressed{on_pressed} {}
+
+    void draw(LGFX *canvas)
+    {
+        if (!dirty)
+        {
+            return;
+        }
+        dirty = false;
+
+        float MARGIN = 10.0;
+        float HALF_MARGIN = MARGIN / 2.0;
+
+        float new_x = x + HALF_MARGIN;
+        float new_y = y + HALF_MARGIN;
+
+        float new_width = width - MARGIN;
+        float new_height = height - MARGIN;
+
+        int bg_color = enabled ? TFT_WHITE : TFT_DARKGRAY;
+        int fg_color = enabled ? TFT_BLACK : TFT_WHITE;
+
+        canvas->setEpdMode(epd_fastest);
+        canvas->setColor(bg_color);
+        canvas->fillRect(new_x + 1, new_y + 1, new_width - 2, new_height - 2);
+
+        canvas->setTextSize(4.0);
+        canvas->setBaseColor(bg_color);
+        canvas->setTextColor(fg_color);
+        canvas->setCursor(x + (width / 2) - (canvas->fontWidth() / 2), y + (height / 2) - (canvas->fontHeight() / 2));
+        canvas->print(label);
+
+        canvas->setColor(TFT_BLACK);
+        canvas->drawFastHLine(new_x, new_y, new_width);
+        canvas->drawFastHLine(new_x, new_y + new_height, new_width);
+        canvas->drawFastVLine(new_x, new_y, new_height);
+        canvas->drawFastVLine(new_x + new_width, new_y, new_height);
+    }
+
+    ~KeypadButton() = default;
+
+    String get_label()
+    {
+        return label;
+    }
+    void set_label(String value)
+    {
+        label = value;
+    }
+
+    int get_value()
+    {
+        return value;
+    }
+    void set_value(int value)
+    {
+        this->value = value;
+    }
+
+    int get_width()
+    {
+        return width;
+    }
+    void set_width(int value)
+    {
+        width = value;
+    }
+
+    int get_x()
+    {
+        return x;
+    }
+    void set_x(int value)
+    {
+        x = value;
+    }
+
+    int get_y()
+    {
+        return y;
+    }
+    void set_y(int value)
+    {
+        y = value;
+    }
+
+    void disable()
+    {
+        if (!enabled)
+            return;
+
+        enabled = false;
+        dirty = true;
+    }
+    void enable()
+    {
+        if (enabled)
+            return;
+
+        enabled = true;
+        dirty = true;
+    }
+
+    void update(Keypad *keypad, uint16_t touch_x, uint16_t touch_y)
+    {
+        if (enabled && touch_x > x && touch_x < x + width && touch_y > y && touch_y < y + height)
+        {
+            on_pressed(keypad, value);
+        }
+    }
+
+private:
+    String label;
+    BUTTON_ON_PRESSED_CALLBACK on_pressed = NULL;
+    bool enabled = true;
+    bool dirty = true;
+
+    int value = 0;
+
+    int width = 0;
+    int height = 0;
+
+    float x = 0;
+    float y = 0;
+};
+
+#endif

src/display.hpp

@@ -0,0 +1,28 @@
+#ifndef _DISPLAY_H_
+#define _DISPLAY_H_
+
+#define LGFX_M5PAPER
+#define LGFX_USE_V1
+#define LGFX_AUTODETECT
+
+#include <LovyanGFX.hpp>
+
+class Display : public LGFX
+{
+public:
+    void init()
+    {
+        LGFX::init();
+        setRotation(1);
+
+        setEpdMode(epd_mode_t::epd_quality);
+        fillScreen(TFT_WHITE);
+        waitDisplay();
+        fillScreen(TFT_WHITE);
+        setEpdMode(epd_mode_t::epd_fast);
+
+        setColor(TFT_BLACK);
+    }
+};
+
+#endif

src/input.hpp

@@ -0,0 +1,132 @@
+#ifndef _INPUT_H_
+#define _INPUT_H_
+
+#define LGFX_AUTODETECT
+#include <LovyanGFX.hpp>
+
+class Input
+{
+public:
+    Input(String value) : value{value}, old_value{value} {}
+    Input(String value, float x, float y) : value{value}, x{x}, y{y} {}
+    Input(String value, float x, float y, int width, int height) : value{value}, x{x}, y{y}, width{width}, height{height} {}
+
+    ~Input() = default;
+
+    String get_value()
+    {
+        return value;
+    }
+    void set_value(String value)
+    {
+        this->value = value;
+        dirty = true;
+    }
+
+    void append(String value)
+    {
+        this->value += value;
+        dirty = true;
+    }
+
+    void append(int value)
+    {
+        this->append(String(value));
+    }
+
+    void clear()
+    {
+        this->value = "";
+        dirty = true;
+    }
+
+    inline unsigned int length()
+    {
+        return this->value.length();
+    }
+
+    int get_width()
+    {
+        return width;
+    }
+    void set_width(int value)
+    {
+        width = value;
+    }
+
+    int get_x()
+    {
+        return x;
+    }
+    void set_x(int value)
+    {
+        x = value;
+    }
+
+    int get_y()
+    {
+        return y;
+    }
+    void set_y(int value)
+    {
+        y = value;
+    }
+
+    void draw(LGFX *canvas)
+    {
+        if (!dirty)
+        {
+            return;
+        }
+        dirty = false;
+
+        float MARGIN = 10.0;
+        float HALF_MARGIN = MARGIN / 2.0;
+
+        float new_x = x + HALF_MARGIN;
+        float new_y = y + HALF_MARGIN;
+
+        float new_width = width - MARGIN;
+        float new_height = height - MARGIN;
+
+        int bg_color = TFT_WHITE;
+        int fg_color = TFT_BLACK;
+
+        canvas->setTextSize(8.0);
+
+        canvas->setEpdMode(epd_fastest);
+        canvas->setColor(bg_color);
+        canvas->fillRect(new_x + 1, new_y + 1, new_width - 2, new_height - 2);
+
+        canvas->setBaseColor(bg_color);
+        canvas->setTextColor(fg_color);
+        canvas->setCursor(x + (width / 2) - ((canvas->fontWidth() * value.length()) / 2), y + (height / 2) - (canvas->fontHeight() / 2));
+        canvas->setEpdMode(epd_text);
+        canvas->print(value);
+
+        if (length() == 0)
+        {
+            canvas->setEpdMode(epd_fastest);
+            canvas->setColor(TFT_BLACK);
+            canvas->drawFastHLine(new_x, new_y, new_width);
+            canvas->drawFastHLine(new_x, new_y + new_height, new_width);
+            canvas->drawFastVLine(new_x, new_y, new_height);
+            canvas->drawFastVLine(new_x + new_width, new_y, new_height);
+        }
+    }
+
+private:
+    LGFX *canvas;
+    String value;
+    String old_value;
+
+    bool dirty = true;
+
+    int width = 0;
+    int height = 0;
+
+    float x = 0;
+    float y = 0;
+};
+
+#endif

src/keypad.cpp

@@ -1,198 +0,0 @@
-#define LGFX_M5PAPER
-#define LGFX_USE_V1
-#define LGFX_AUTODETECT
-
-#include "keypad.hpp"
-#include <M5EPD.h>
-#include <LovyanGFX.hpp>
-
-static LGFX gfx;
-
-static const float_t BUTTON_WIDTH = 115;
-static const float_t BUTTON_HEIGHT = 115;
-
-int Keypad::get_button_index_from_touch(int x, int y)
-{
-    for (int index = 0; index <= 11; index++)
-    {
-        float_t cx = (125 * (index % 3)) + 15;
-        float_t cy = (125 * (index / 3)) + 20;
-
-        if (x > cx && x < cx + BUTTON_WIDTH && y > cy && y < cy + BUTTON_HEIGHT)
-        {
-            return index;
-        }
-    }
-
-    return -1;
-}
-
-void Keypad::draw_button(int i)
-{
-    gfx.setTextSize(FONT_SIZE_NORMAL);
-
-    String label = String(i + 1);
-    if (i == 9)
-    {
-        label = String("<");
-    }
-    if (i == 10)
-    {
-        label = String("0");
-    }
-    if (i == 11)
-    {
-        label = String(">");
-    }
-
-    float_t x = (125 * (i % 3)) + 15;
-    float_t y = (125 * (i / 3)) + 20;
-
-    gfx.setCursor(x + (115 / 2) - (gfx.fontWidth() / 2), y + (115 / 2) - (gfx.fontHeight() / 2));
-    gfx.print(label);
-
-    gfx.setColor(TFT_BLACK);
-    gfx.drawFastHLine(x, y, BUTTON_WIDTH);
-    gfx.drawFastHLine(x, y + BUTTON_HEIGHT, BUTTON_WIDTH);
-    gfx.drawFastVLine(x, y, BUTTON_HEIGHT);
-    gfx.drawFastVLine(x + BUTTON_WIDTH, y, BUTTON_HEIGHT);
-}
-
-void Keypad::draw_input_field()
-{
-    int x = 405;
-    int y = 20;
-
-    gfx.setColor(TFT_BLACK);
-    gfx.drawFastHLine(x, y, 520);
-    gfx.drawFastHLine(x, y + 115, 520);
-    gfx.drawFastVLine(x, y, 115);
-    gfx.drawFastVLine(x + 520, y, 115);
-}
-
-void Keypad::draw_input()
-{
-    int x = 405;
-    int y = 20;
-
-    gfx.setEpdMode(epd_mode_t::epd_text);
-    gfx.setColor(TFT_BLACK);
-    gfx.setTextSize(FONT_SIZE_LARGE);
-
-    if (input.length() < oldinput.length())
-    {
-        gfx.setColor(TFT_WHITE);
-        gfx.fillRect(x + 1, y + 1, 519, 114);
-        gfx.setColor(TFT_BLACK);
-    }
-
-    gfx.setCursor(x + (520 / 2) - ((gfx.fontWidth() * input.length()) / 2), y + (115 / 2) - (gfx.fontHeight() / 2));
-    String keypad = "";
-    for (int i = 0; i < input.length(); i++)
-    {
-        keypad += "*";
-    }
-    gfx.print(keypad);
-    gfx.setEpdMode(epd_mode_t::epd_fast);
-}
-
-void Keypad::draw()
-{
-    gfx.setEpdMode(epd_mode_t::epd_quality);
-    gfx.fillScreen(TFT_WHITE);
-    gfx.waitDisplay();
-    gfx.fillScreen(TFT_WHITE);
-    gfx.setEpdMode(epd_mode_t::epd_fast);
-
-    gfx.setColor(TFT_BLACK);
-    gfx.waitDisplay();
-
-    for (int i = 0; i <= 11; i++)
-    {
-        this->draw_button(i);
-    }
-
-    draw_input_field();
-    draw_input();
-}
-
-Keypad::Keypad()
-{
-    gfx.init();
-    gfx.setRotation(1);
-
-    draw();
-}
-
-void Keypad::write(String payload)
-{
-    payload.replace("_", " ");
-
-    gfx.setTextSize(FONT_SIZE_NORMAL);
-
-    gfx.setColor(TFT_WHITE);
-    gfx.fillRect(405, 155, gfx.fontWidth() * 10, gfx.fontHeight());
-    gfx.setColor(TFT_BLACK);
-
-    gfx.setCursor(405, 155);
-    payload[0] = toupper(payload[0]);
-    gfx.printf("%s", payload);
-}
-
-std::optional<String> Keypad::check_input()
-{
-    if (M5.TP.available())
-    {
-        M5.TP.update();
-        if (M5.TP.isFingerUp())
-        {
-            last_index = -1;
-            return std::nullopt;
-        }
-
-        tp_finger_t fingerItem = M5.TP.readFinger(0);
-
-        int i = get_button_index_from_touch(fingerItem.x, fingerItem.y);
-        if (last_index != i)
-        {
-            last_index = i;
-            if (i == 9)
-            {
-                // revert
-                input = "";
-            }
-            else if (i == 10)
-            {
-                if (input.length() >= 6)
-                    return std::nullopt;
-                input += String(0);
-            }
-            else if (i == 11)
-            {
-                // submit
-                String retval = input;
-                input = "";
-                return retval;
-            }
-            else
-            {
-                if (input.length() >= 6)
-                    return std::nullopt;
-                input += String(i + 1);
-            }
-        }
-    }
-    return std::nullopt;
-}
-
-std::optional<String> Keypad::get_input()
-{
-    auto value = check_input();
-    if (oldinput != input)
-    {
-        draw_input();
-        oldinput = input;
-    }
-
-    return value;
-}

src/keypad.hpp

@@ -1,31 +1,104 @@
 #ifndef _KEYPAD_H_
 #define _KEYPAD_H_
 
-#include <WString.h>
-#include <optional>
+#include <EventEmitter.h>
+#include "button.hpp"
 
-constexpr float FONT_SIZE_NORMAL = 4.0;
-constexpr float FONT_SIZE_LARGE = 8.0;
+constexpr int BUTTON_ROWS = 4;
+constexpr int BUTTON_COLS = 3;
+constexpr int BUTTON_COUNT = BUTTON_ROWS * BUTTON_COLS;
 
-class Keypad
+class Keypad : public EventEmitter<int>
 {
 public:
-    Keypad();
-    int get_button_index_from_touch(int x, int y);
-    void draw();
-    void write(String);
-    std::optional<String> get_input();
+    Keypad(LGFX *canvas) : EventEmitter<int>(), canvas{canvas}
+    {
+        int BUTTON_SIZE = canvas->height() / BUTTON_ROWS;
+        width = BUTTON_SIZE * BUTTON_COLS;
+
+        for (int i = 0; i < BUTTON_COUNT; i++)
+        {
+            float x = BUTTON_SIZE * (i % BUTTON_COLS);
+            float y = BUTTON_SIZE * (i / BUTTON_COLS);
+
+            String lbl = String(i + 1);
+            bool enabled = true;
+
+            if (i == 9)
+            {
+                lbl = String("<");
+            }
+            if (i == 10)
+            {
+                lbl = String("0");
+            }
+            if (i == 11)
+            {
+                lbl = String(">");
+                enabled = false;
+            }
+
+            buttons.push_back(new KeypadButton(lbl, i, enabled, x, y, BUTTON_SIZE, BUTTON_SIZE, Keypad::on_button_pressed));
+        }
+    }
+
+    ~Keypad() = default;
+
+    inline unsigned int get_width()
+    {
+        return width;
+    }
+
+    void update(tp_finger_t touch)
+    {
+        for (int i = 0; i < BUTTON_COUNT; i++)
+        {
+            buttons[i]->update(this, touch.x, touch.y);
+        }
+    }
+
+    void draw()
+    {
+        for (int i = 0; i < BUTTON_COUNT; i++)
+        {
+            buttons[i]->draw(canvas);
+        }
+    }
+
+    void disable(int index)
+    {
+        if (index >= 0 && index < BUTTON_COUNT)
+        {
+            buttons[index]->disable();
+        }
+    }
+
+    void set_enabled(int index, bool enabled)
+    {
+        if (index >= 0 && index < BUTTON_COUNT)
+        {
+            if (enabled)
+            {
+                buttons[index]->enable();
+            }
+            else
+            {
+                buttons[index]->disable();
+            }
+        }
+    }
 
 private:
-    int last_index = -1;
-    String oldinput = "";
-    String input = "";
+    LGFX *canvas;
+    std::vector<KeypadButton *> buttons;
+    bool touching = false;
+    unsigned int width = 0;
 
-    void draw_button(int index);
-    void draw_input_field();
-    void draw_input();
-
-    std::optional<String> check_input();
+    static void on_button_pressed(void *context, int value)
+    {
+        auto c = static_cast<Keypad *>(context);
+        c->emit("pressed", c->buttons[value]->get_value());
+    }
 };
 
 #endif

src/main.cpp

@@ -3,21 +3,42 @@
 
 #define YAML_DISABLE_CJSON
 
-#include <WiFi.h>
+#define LGFX_M5PAPER
+#define LGFX_USE_V1
+#define LGFX_AUTODETECT
+
 #include <M5EPD.h>
+#include <WiFi.h>
 #include <NTPClient.h>
 #include <HTTPClient.h>
-
 #include <totp.hpp>
 
+#include "display.hpp"
+#include "keypad.hpp"
+#include "input.hpp"
+#include "status.hpp"
+#include "touch.hpp"
 #include "settings.hpp"
 #include "mqtt.hpp"
-#include "keypad.hpp"
 
 static WiFiUDP ntpUDP;
 static NTPClient timeClient(ntpUDP);
 static MQTT *mqtt;
+
+static Display display;
 static Keypad *keypad;
+static Status *status;
+static Input *input;
+static Touch *touch;
+
+void keypad_state(bool enabled)
+{
+    for (int i = 0; i < 11; i++)
+    {
+        keypad->set_enabled(i, enabled);
+    }
+    keypad->set_enabled(11, !enabled);
+}
 
 static bool is_disarmed = false;
 
@@ -29,13 +50,13 @@ void mqtt_callback(char *topic, byte *payload, unsigned int length)
     String state((const char *)payload);
     is_disarmed = state == "disarmed";
 
-    if (state == "armed_away")
-    {
-        keypad->draw();
-    }
-
+    state.replace("_", " ");
+    state[0] = toupper(state[0]);
     Serial.println(state);
-    keypad->write(state);
+    status->set(state);
+    status->draw(&display);
+
+    keypad_state(!is_disarmed);
 }
 
 void lock()
@@ -51,23 +72,37 @@ void unlock()
     mqtt->send("DISARM");
 }
 
+void submit(String code)
+{
+    uint32_t newCode = getCodeFromTimestamp(timeClient.getEpochTime());
+    uint32_t input = code.toInt();
+
+    if (newCode != input)
+    {
+        status->set("Invalid");
+        return;
+    }
+
+    unlock();
+}
+
 bool isConnecting = false;
 void initWifi(Settings *settings)
 {
     if (!settings)
     {
-        keypad->write("no settings");
+        status->set("No settings");
         return;
     }
 
     if (isConnecting)
     {
-        keypad->write("already connecting");
+        status->set("Already connecting");
         return;
     }
 
     isConnecting = true;
-    keypad->write("connecting");
+    status->set("Connecting");
 
     WiFi.begin(settings->gettext("wifi:ssid"), settings->gettext("wifi:password"));
 
@@ -89,11 +124,11 @@ void initWifi(Settings *settings)
         Serial.print("Local IP: ");
         Serial.println(WiFi.localIP());
         isConnecting = false;
-        keypad->write("connected");
+        status->set("Connected");
     }
     else
     {
-        keypad->write("failed to connect");
+        status->set("Failed to connect");
         isConnecting = false;
         return;
     }
@@ -112,49 +147,116 @@ void initTOTP(Settings *settings)
     TOTP(base32_key, 20, 30);
 }
 
+void p(int v)
+{
+    switch (v)
+    {
+    case 9:
+        input->clear();
+        break;
+    case 10:
+        input->append("0");
+        break;
+    case 11:
+        lock();
+        break;
+    default:
+        input->append(v + 1);
+        break;
+    }
+
+    if (input->length() >= 6)
+    {
+        // verify
+        input->draw(&display); // force one more redraw for the last character
+        submit(input->get_value());
+        input->clear();
+    }
+}
+
 void setup()
 {
     M5.begin();
-
-    keypad = new Keypad();
-    keypad->write("loading");
+    display.init();
+    touch = new Touch(M5.TP);
+    status = new Status("Loading");
+    keypad = new Keypad(&display);
+    keypad->addListener("pressed", p);
+    input = new Input("", keypad->get_width(), 0, display.width() - keypad->get_width(), 115);
 
     auto settings = new Settings();
 
     if (!settings)
     {
-        keypad->write("unable to load settings");
+        status->set("Settings Error");
         return;
     }
-
     mqtt = new MQTT(settings, mqtt_callback);
-
     initWifi(settings);
     mqtt->connect();
     timeClient.begin();
     initTOTP(settings);
 }
 
-void submit(String code)
-{
-    uint32_t newCode = getCodeFromTimestamp(timeClient.getEpochTime());
-    uint32_t input = code.toInt();
-
-    if (newCode == input)
-    {
-        unlock();
-        return;
-    }
-
-    lock();
-}
-
 void loop()
 {
     timeClient.update();
     mqtt->loop();
 
-    auto value = keypad->get_input();
-    if (value.has_value())
-        submit(value.value());
+    auto tap = touch->tap();
+    if (tap.has_value())
+        keypad->update(tap.value());
+
+    keypad->draw();
+    input->draw(&display);
+    status->draw(&display);
 }
+
+// static Keypad *keypad;
+
+// void setup()
+// {
+//     M5.begin();
+
+//     keypad = new Keypad();
+//     status->set("loading");
+
+//     auto settings = new Settings();
+
+//     if (!settings)
+//     {
+//         status->set("unable to load settings");
+//         return;
+//     }
+
+//     mqtt = new MQTT(settings, mqtt_callback);
+
+//     initWifi(settings);
+//     mqtt->connect();
+//     timeClient.begin();
+//     initTOTP(settings);
+// }
+
+// void submit(String code)
+// {
+//     uint32_t newCode = getCodeFromTimestamp(timeClient.getEpochTime());
+//     uint32_t input = code.toInt();
+
+//     if (newCode == input)
+//     {
+//         unlock();
+//         return;
+//     }
+
+//     lock();
+// }
+
+// void loop()
+// {
+//     timeClient.update();
+//     mqtt->loop();
+
+//     auto value = keypad->get_input();
+//     if (value.has_value())
+//         submit(value.value());
+// }

src/status.hpp

@@ -0,0 +1,65 @@
+#ifndef _STATUS_H_
+#define _STATUS_H_
+
+#define LGFX_AUTODETECT
+#include <LovyanGFX.hpp>
+
+class Status
+{
+public:
+    Status(String value) : value{value}
+    {
+        old_length = value.length();
+    }
+
+    ~Status() = default;
+
+    void set(String value)
+    {
+        old_length = this->value.length();
+        this->value = value;
+        dirty = true;
+    }
+
+    void draw(LGFX *canvas)
+    {
+        if (!dirty)
+        {
+            return;
+        }
+        dirty = false;
+
+        float MARGIN = 10.0;
+
+        canvas->setTextSize(3.0);
+
+        int bg_color = TFT_WHITE;
+        int fg_color = TFT_BLACK;
+
+        float old_x = canvas->width() - (canvas->fontWidth() * old_length) - MARGIN;
+        float new_x = canvas->width() - (canvas->fontWidth() * value.length()) - MARGIN;
+        float new_y = canvas->height() - canvas->fontHeight() - MARGIN;
+
+        canvas->setEpdMode(epd_fastest);
+        canvas->setColor(bg_color);
+
+        canvas->fillRect(old_x, new_y, canvas->width() - old_x, canvas->height() - new_y);
+        canvas->waitDisplay();
+        canvas->setColor(fg_color);
+
+        canvas->setEpdMode(epd_text);
+        canvas->setBaseColor(bg_color);
+        canvas->setTextColor(fg_color);
+        canvas->setCursor(new_x, new_y);
+        canvas->print(value);
+    }
+
+private:
+    LGFX *canvas;
+    String value;
+    int old_length = 0;
+
+    bool dirty = true;
+};
+
+#endif

src/touch.hpp

@@ -0,0 +1,42 @@
+#include <utility/GT911.h>
+#ifndef _TOUCH_H_
+#define _TOUCH_H_
+
+#include <optional>
+
+class Touch
+{
+public:
+    Touch(GT911 TP) : TP{TP} {}
+
+    std::optional<tp_finger_t> tap()
+    {
+        if (!TP.available())
+        {
+            return std::nullopt;
+        }
+
+        TP.update();
+
+        if (TP.isFingerUp())
+        {
+            touching = false;
+            return std::nullopt;
+        }
+
+        if (touching)
+        {
+            return std::nullopt;
+        }
+
+        touching = true;
+        return TP.readFinger(0);
+    }
+
+private:
+    GT911 TP;
+    tp_finger_t finger;
+    bool touching;
+};
+
+#endif