imgui_impl_android_ext.cpp

// dear imgui: Platform Binding for Android native app
// This needs to be used along with the OpenGL 3 Renderer (imgui_impl_opengl3)

// Implemented features:
//  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy AKEYCODE_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
//  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen/Pen.
// Missing features:
//  [ ] Platform: Clipboard support.
//  [ ] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
//  [ ] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'. FIXME: Check if this is even possible with Android.
// Important:
//  - Consider using SDL or GLFW backend on Android, which will be more full-featured than this.
//  - FIXME: On-screen keyboard currently needs to be enabled by the application (see examples/ and issue #3446)
//  - FIXME: Unicode character inputs needs to be passed by Dear ImGui by the application (see examples/ and issue #3446)

// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
// Read online: https://github.com/ocornut/imgui/tree/master/docs

// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
//  2022-09-26: Inputs: Renamed ImGuiKey_ModXXX introduced in 1.87 to ImGuiMod_XXX (old names still supported).
//  2022-01-26: Inputs: replaced short-lived io.AddKeyModsEvent() (added two weeks ago) with io.AddKeyEvent() using ImGuiKey_ModXXX flags. Sorry for the confusion.
//  2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
//  2022-01-10: Inputs: calling new io.AddKeyEvent(), io.AddKeyModsEvent() + io.SetKeyEventNativeData() API (1.87+). Support for full ImGuiKey range.
//  2021-03-04: Initial version.


// [Bruno]
// 2023-07-25: Stylus, text input, softkeyboard show/hide
//             (right mouse button and mouse wheel in gui/user_callbacks_android.cpp)
// NOTE: default Samsung keyboard does not work well (too smart, does not send event before ortho correction),
//        it is the same thing when phys kbd is plugged (phys kbd is re-routed through soft kbd, for a phys kbd,
//        one needs to specify language for each soft kbd


#ifdef __ANDROID__

#include "imgui.h"
#ifndef IMGUI_DISABLE
#include "imgui_impl_android_ext.h"
#include <time.h>
#include <android/native_window.h>
#include <android_native_app_glue.h>
#include <android/input.h>
#include <android/keycodes.h>
#include <android/log.h>


#include <geogram/basic/string.h>
#include <geogram/basic/android_utils.h>

// Android data
static double                                   g_Time = 0.0;
static android_app*                             g_app = nullptr; // [Bruno]
static ANativeWindow*                           g_Window = nullptr;
static bool                                     g_soft_keyboard_visible = false;
static bool                                     g_events_fingers_or_stylus = false; // [Bruno] true if a finger or stylus event occured during last frame
// static char                                  g_LogTag[] = "ImGuiExample";

static ImGuiKey ImGui_ImplAndroid_KeyCodeToImGuiKey(int32_t key_code)
{
    switch (key_code)
    {
    case AKEYCODE_TAB:                  return ImGuiKey_Tab;
    case AKEYCODE_DPAD_LEFT:            return ImGuiKey_LeftArrow;
    case AKEYCODE_DPAD_RIGHT:           return ImGuiKey_RightArrow;
    case AKEYCODE_DPAD_UP:              return ImGuiKey_UpArrow;
    case AKEYCODE_DPAD_DOWN:            return ImGuiKey_DownArrow;
    case AKEYCODE_PAGE_UP:              return ImGuiKey_PageUp;
    case AKEYCODE_PAGE_DOWN:            return ImGuiKey_PageDown;
    case AKEYCODE_MOVE_HOME:            return ImGuiKey_Home;
    case AKEYCODE_MOVE_END:             return ImGuiKey_End;
    case AKEYCODE_INSERT:               return ImGuiKey_Insert;
    case AKEYCODE_FORWARD_DEL:          return ImGuiKey_Delete;
    case AKEYCODE_DEL:                  return ImGuiKey_Backspace;
    case AKEYCODE_SPACE:                return ImGuiKey_Space;
    case AKEYCODE_ENTER:                return ImGuiKey_Enter;
    case AKEYCODE_ESCAPE:               return ImGuiKey_Escape;
    case AKEYCODE_APOSTROPHE:           return ImGuiKey_Apostrophe;
    case AKEYCODE_COMMA:                return ImGuiKey_Comma;
    case AKEYCODE_MINUS:                return ImGuiKey_Minus;
    case AKEYCODE_PERIOD:               return ImGuiKey_Period;
    case AKEYCODE_SLASH:                return ImGuiKey_Slash;
    case AKEYCODE_SEMICOLON:            return ImGuiKey_Semicolon;
    case AKEYCODE_EQUALS:               return ImGuiKey_Equal;
    case AKEYCODE_LEFT_BRACKET:         return ImGuiKey_LeftBracket;
    case AKEYCODE_BACKSLASH:            return ImGuiKey_Backslash;
    case AKEYCODE_RIGHT_BRACKET:        return ImGuiKey_RightBracket;
    case AKEYCODE_GRAVE:                return ImGuiKey_GraveAccent;
    case AKEYCODE_CAPS_LOCK:            return ImGuiKey_CapsLock;
    case AKEYCODE_SCROLL_LOCK:          return ImGuiKey_ScrollLock;
    case AKEYCODE_NUM_LOCK:             return ImGuiKey_NumLock;
    case AKEYCODE_SYSRQ:                return ImGuiKey_PrintScreen;
    case AKEYCODE_BREAK:                return ImGuiKey_Pause;
    case AKEYCODE_NUMPAD_0:             return ImGuiKey_Keypad0;
    case AKEYCODE_NUMPAD_1:             return ImGuiKey_Keypad1;
    case AKEYCODE_NUMPAD_2:             return ImGuiKey_Keypad2;
    case AKEYCODE_NUMPAD_3:             return ImGuiKey_Keypad3;
    case AKEYCODE_NUMPAD_4:             return ImGuiKey_Keypad4;
    case AKEYCODE_NUMPAD_5:             return ImGuiKey_Keypad5;
    case AKEYCODE_NUMPAD_6:             return ImGuiKey_Keypad6;
    case AKEYCODE_NUMPAD_7:             return ImGuiKey_Keypad7;
    case AKEYCODE_NUMPAD_8:             return ImGuiKey_Keypad8;
    case AKEYCODE_NUMPAD_9:             return ImGuiKey_Keypad9;
    case AKEYCODE_NUMPAD_DOT:           return ImGuiKey_KeypadDecimal;
    case AKEYCODE_NUMPAD_DIVIDE:        return ImGuiKey_KeypadDivide;
    case AKEYCODE_NUMPAD_MULTIPLY:      return ImGuiKey_KeypadMultiply;
    case AKEYCODE_NUMPAD_SUBTRACT:      return ImGuiKey_KeypadSubtract;
    case AKEYCODE_NUMPAD_ADD:           return ImGuiKey_KeypadAdd;
    case AKEYCODE_NUMPAD_ENTER:         return ImGuiKey_KeypadEnter;
    case AKEYCODE_NUMPAD_EQUALS:        return ImGuiKey_KeypadEqual;
    case AKEYCODE_CTRL_LEFT:            return ImGuiKey_LeftCtrl;
    case AKEYCODE_SHIFT_LEFT:           return ImGuiKey_LeftShift;
    case AKEYCODE_ALT_LEFT:             return ImGuiKey_LeftAlt;
    case AKEYCODE_META_LEFT:            return ImGuiKey_LeftSuper;
    case AKEYCODE_CTRL_RIGHT:           return ImGuiKey_RightCtrl;
    case AKEYCODE_SHIFT_RIGHT:          return ImGuiKey_RightShift;
    case AKEYCODE_ALT_RIGHT:            return ImGuiKey_RightAlt;
    case AKEYCODE_META_RIGHT:           return ImGuiKey_RightSuper;
    case AKEYCODE_MENU:                 return ImGuiKey_Menu;
    case AKEYCODE_0:                    return ImGuiKey_0;
    case AKEYCODE_1:                    return ImGuiKey_1;
    case AKEYCODE_2:                    return ImGuiKey_2;
    case AKEYCODE_3:                    return ImGuiKey_3;
    case AKEYCODE_4:                    return ImGuiKey_4;
    case AKEYCODE_5:                    return ImGuiKey_5;
    case AKEYCODE_6:                    return ImGuiKey_6;
    case AKEYCODE_7:                    return ImGuiKey_7;
    case AKEYCODE_8:                    return ImGuiKey_8;
    case AKEYCODE_9:                    return ImGuiKey_9;
    case AKEYCODE_A:                    return ImGuiKey_A;
    case AKEYCODE_B:                    return ImGuiKey_B;
    case AKEYCODE_C:                    return ImGuiKey_C;
    case AKEYCODE_D:                    return ImGuiKey_D;
    case AKEYCODE_E:                    return ImGuiKey_E;
    case AKEYCODE_F:                    return ImGuiKey_F;
    case AKEYCODE_G:                    return ImGuiKey_G;
    case AKEYCODE_H:                    return ImGuiKey_H;
    case AKEYCODE_I:                    return ImGuiKey_I;
    case AKEYCODE_J:                    return ImGuiKey_J;
    case AKEYCODE_K:                    return ImGuiKey_K;
    case AKEYCODE_L:                    return ImGuiKey_L;
    case AKEYCODE_M:                    return ImGuiKey_M;
    case AKEYCODE_N:                    return ImGuiKey_N;
    case AKEYCODE_O:                    return ImGuiKey_O;
    case AKEYCODE_P:                    return ImGuiKey_P;
    case AKEYCODE_Q:                    return ImGuiKey_Q;
    case AKEYCODE_R:                    return ImGuiKey_R;
    case AKEYCODE_S:                    return ImGuiKey_S;
    case AKEYCODE_T:                    return ImGuiKey_T;
    case AKEYCODE_U:                    return ImGuiKey_U;
    case AKEYCODE_V:                    return ImGuiKey_V;
    case AKEYCODE_W:                    return ImGuiKey_W;
    case AKEYCODE_X:                    return ImGuiKey_X;
    case AKEYCODE_Y:                    return ImGuiKey_Y;
    case AKEYCODE_Z:                    return ImGuiKey_Z;
    case AKEYCODE_F1:                   return ImGuiKey_F1;
    case AKEYCODE_F2:                   return ImGuiKey_F2;
    case AKEYCODE_F3:                   return ImGuiKey_F3;
    case AKEYCODE_F4:                   return ImGuiKey_F4;
    case AKEYCODE_F5:                   return ImGuiKey_F5;
    case AKEYCODE_F6:                   return ImGuiKey_F6;
    case AKEYCODE_F7:                   return ImGuiKey_F7;
    case AKEYCODE_F8:                   return ImGuiKey_F8;
    case AKEYCODE_F9:                   return ImGuiKey_F9;
    case AKEYCODE_F10:                  return ImGuiKey_F10;
    case AKEYCODE_F11:                  return ImGuiKey_F11;
    case AKEYCODE_F12:                  return ImGuiKey_F12;
    default:                            return ImGuiKey_None;
    }
}

int32_t ImGui_ImplAndroidExt_HandleInputEvent(AInputEvent* input_event)
{
    ::GEO::AndroidUtils::debug_show_event(input_event);
    ImGuiIO& io = ImGui::GetIO();
    int32_t event_type = AInputEvent_getType(input_event);
    switch (event_type)
    {
    case AINPUT_EVENT_TYPE_KEY:
    {
        int32_t event_key_code = AKeyEvent_getKeyCode(input_event);
        int32_t event_scan_code = AKeyEvent_getScanCode(input_event);
        int32_t event_action = AKeyEvent_getAction(input_event);
        int32_t event_meta_state = AKeyEvent_getMetaState(input_event);

        // [Bruno] handle right mouse button
        if(event_key_code == AKEYCODE_BACK && AInputEvent_getSource(input_event) == AINPUT_SOURCE_MOUSE)
        {
            ::GEO::AndroidUtils::debug_log("right mouse button event");
            return 1;
        }
        else
        {
            io.AddKeyEvent(ImGuiMod_Ctrl,  (event_meta_state & AMETA_CTRL_ON)  != 0);
            io.AddKeyEvent(ImGuiMod_Shift, (event_meta_state & AMETA_SHIFT_ON) != 0);
            io.AddKeyEvent(ImGuiMod_Alt,   (event_meta_state & AMETA_ALT_ON)   != 0);
            io.AddKeyEvent(ImGuiMod_Super, (event_meta_state & AMETA_META_ON)  != 0);

            switch (event_action)
            {
                // FIXME: AKEY_EVENT_ACTION_DOWN and AKEY_EVENT_ACTION_UP occur at once as soon as a touch pointer
                // goes up from a key. We use a simple key event queue/ and process one event per key per frame in
                // ImGui_ImplAndroid_NewFrame()...or consider using IO queue, if suitable: https://github.com/ocornut/imgui/issues/2787
            case AKEY_EVENT_ACTION_DOWN:
            case AKEY_EVENT_ACTION_UP:
            {
                ImGuiKey key = ImGui_ImplAndroid_KeyCodeToImGuiKey(event_key_code);
                if (key != ImGuiKey_None && (event_action == AKEY_EVENT_ACTION_DOWN || event_action == AKEY_EVENT_ACTION_UP))
                {
                    io.AddKeyEvent(key, event_action == AKEY_EVENT_ACTION_DOWN);
                    io.SetKeyEventNativeData(key, event_key_code, event_scan_code);
                }

                // [Bruno]
                if(event_action == AKEY_EVENT_ACTION_DOWN)
                {
                    jint unicode = GEO::AndroidUtils::keycode_to_unicode(g_app, AInputEvent_getDeviceId(input_event), event_key_code, event_meta_state);
                    io.AddInputCharacterUTF16(unicode);
                }

                break;
            }
            default:
                break;
            }
            break;
        }
    }
    case AINPUT_EVENT_TYPE_MOTION:
    {
        int32_t event_action = AMotionEvent_getAction(input_event);
        int32_t event_pointer_index = (event_action & AMOTION_EVENT_ACTION_POINTER_INDEX_MASK) >> AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT;
        event_action &= AMOTION_EVENT_ACTION_MASK;

        switch (AMotionEvent_getToolType(input_event, event_pointer_index))
        {
        case AMOTION_EVENT_TOOL_TYPE_MOUSE:
            io.AddMouseSourceEvent(ImGuiMouseSource_Mouse);
            break;
        case AMOTION_EVENT_TOOL_TYPE_STYLUS:
        case AMOTION_EVENT_TOOL_TYPE_ERASER:
            io.AddMouseSourceEvent(ImGuiMouseSource_Pen);
            g_events_fingers_or_stylus = true;
            break;
        case AMOTION_EVENT_TOOL_TYPE_FINGER:
            g_events_fingers_or_stylus = true;
        default:
            io.AddMouseSourceEvent(ImGuiMouseSource_TouchScreen);
            break;
        }

        switch (event_action)
        {
        case AMOTION_EVENT_ACTION_DOWN:
        case AMOTION_EVENT_ACTION_UP:
            // Physical mouse buttons (and probably other physical devices) also invoke the actions AMOTION_EVENT_ACTION_DOWN/_UP,
            // but we have to process them separately to identify the actual button pressed. This is done below via
            // AMOTION_EVENT_ACTION_BUTTON_PRESS/_RELEASE. Here, we only process "FINGER" input (and "UNKNOWN", as a fallback).
            if((AMotionEvent_getToolType(input_event, event_pointer_index) == AMOTION_EVENT_TOOL_TYPE_FINGER)
               || (AMotionEvent_getToolType(input_event, event_pointer_index) == AMOTION_EVENT_TOOL_TYPE_UNKNOWN))
            {
                io.AddMousePosEvent(AMotionEvent_getX(input_event, event_pointer_index), AMotionEvent_getY(input_event, event_pointer_index));
                io.AddMouseButtonEvent(0, event_action == AMOTION_EVENT_ACTION_DOWN);
            }

            // [Bruno] synthesize button press / button release for stylus UP / DOWN
            if(AMotionEvent_getToolType(input_event, event_pointer_index) == AMOTION_EVENT_TOOL_TYPE_STYLUS) {
                // "No button" mapped to button 0, all other buttons mapped to button 1
                int btn = int((AMotionEvent_getButtonState(input_event) & AMOTION_EVENT_BUTTON_STYLUS_PRIMARY) != 0);
                if(btn == 0) {
                    io.AddMouseButtonEvent(0, (event_action == AMOTION_EVENT_ACTION_DOWN));
                }
            }

            // [Bruno]
            // Mark the soft keyboard as hidden on finger touch if text input is required, so that if the user re-touches a text entry zone
            // after having hidden the soft keyboard, it will be re-opened.
            if(
                event_action == AMOTION_EVENT_ACTION_DOWN &&
                (AMotionEvent_getToolType(input_event, event_pointer_index) == AMOTION_EVENT_TOOL_TYPE_FINGER ||
                 AMotionEvent_getToolType(input_event, event_pointer_index) == AMOTION_EVENT_TOOL_TYPE_STYLUS)
            )
            {
                g_soft_keyboard_visible = false;
            }

            break;
        case AMOTION_EVENT_ACTION_BUTTON_PRESS:
        case AMOTION_EVENT_ACTION_BUTTON_RELEASE:
        {
            int32_t button_state = AMotionEvent_getButtonState(input_event);
            io.AddMouseButtonEvent(0, (button_state & AMOTION_EVENT_BUTTON_PRIMARY) != 0);
            io.AddMouseButtonEvent(1, (button_state & AMOTION_EVENT_BUTTON_SECONDARY) != 0);
            io.AddMouseButtonEvent(2, (button_state & AMOTION_EVENT_BUTTON_TERTIARY) != 0);
        }
        break;
        case AMOTION_EVENT_ACTION_HOVER_MOVE: // Hovering: Tool moves while NOT pressed (such as a physical mouse)
        case AMOTION_EVENT_ACTION_MOVE:       // Touch pointer moves while DOWN
            io.AddMousePosEvent(AMotionEvent_getX(input_event, event_pointer_index), AMotionEvent_getY(input_event, event_pointer_index));
            break;
        case AMOTION_EVENT_ACTION_SCROLL:
            io.AddMouseWheelEvent(AMotionEvent_getAxisValue(input_event, AMOTION_EVENT_AXIS_HSCROLL, event_pointer_index), AMotionEvent_getAxisValue(input_event, AMOTION_EVENT_AXIS_VSCROLL, event_pointer_index));
            break;
        default:
            break;
        }
    }
    return 1;
    default:
        break;
    }

    return 0;
}

// [Bruno] pass app instead of window
bool ImGui_ImplAndroidExt_Init(android_app* app)
{
    g_app = app;
    g_Window = app->window;
    g_Time = 0.0;

    // Setup backend capabilities flags
    ImGuiIO& io = ImGui::GetIO();
    io.BackendPlatformName = "imgui_impl_android";

    return true;
}

void ImGui_ImplAndroidExt_Shutdown()
{
    ImGuiIO& io = ImGui::GetIO();
    io.BackendPlatformName = nullptr;
}

void ImGui_ImplAndroidExt_NewFrame()
{
    ImGuiIO& io = ImGui::GetIO();

    // Setup display size (every frame to accommodate for window resizing)
    int32_t window_width = ANativeWindow_getWidth(g_Window);
    int32_t window_height = ANativeWindow_getHeight(g_Window);
    int display_width = window_width;
    int display_height = window_height;

    io.DisplaySize = ImVec2((float)window_width, (float)window_height);
    if (window_width > 0 && window_height > 0)
        io.DisplayFramebufferScale = ImVec2((float)display_width / window_width, (float)display_height / window_height);

    // Setup time step
    struct timespec current_timespec;
    clock_gettime(CLOCK_MONOTONIC, &current_timespec);
    double current_time = (double)(current_timespec.tv_sec) + (current_timespec.tv_nsec / 1000000000.0);
    io.DeltaTime = g_Time > 0.0 ? (float)(current_time - g_Time) : (float)(1.0f / 60.0f);
    g_Time = current_time;

    // [Bruno]
    {
        // Would be good to test that no USB or bluetooth kbd is attached.
        // https://stackoverflow.com/questions/2415558/how-to-detect-hardware-keyboard-presence
        // Seems non-trivial: there is a function to test whether a phys kbd is included in the device,
        // but it does not report connected BT kbds, and the only way to detect BT kbds seems to be
        // tracking BT connect/disconnect events.

        // Only show soft kbd if a finger or stylus event occured during last frame
        if(ImGui::GetIO().WantTextInput && g_events_fingers_or_stylus) {
            if(!g_soft_keyboard_visible) {
                GEO::AndroidUtils::show_soft_keyboard(g_app);
                g_soft_keyboard_visible = true;
            }
        }

        if(!ImGui::GetIO().WantTextInput && g_soft_keyboard_visible) {
            GEO::AndroidUtils::hide_soft_keyboard(g_app);
            g_soft_keyboard_visible = false;
        }

        g_events_fingers_or_stylus = false;
    }
}

//-----------------------------------------------------------------------------

#endif // #ifndef IMGUI_DISABLE

#endif