Method onWebTouchCallback

core/platform/RenderViewImpl.cpp:1176–1220

#if defined(__EMSCRIPTEN__)
void RenderViewImpl::onWebTouchCallback(int eventType, const EmscriptenTouchEvent* touchEvent)
{
    float boundingX = EM_ASM_INT(return canvas.getBoundingClientRect().left);
    float boundingY = EM_ASM_INT(return canvas.getBoundingClientRect().top);
    int canvasWidth, canvasHeight;
    emscripten_get_canvas_element_size("#canvas", &canvasWidth, &canvasHeight);
    double cssWidth, cssHeight;
    emscripten_get_element_css_size("#canvas", &cssWidth, &cssHeight);
    const auto zoomX = canvasWidth / cssWidth;
    const auto zommY = canvasHeight / cssHeight;

    int numTouches = touchEvent->numTouches;
    _touchesId.resize(numTouches);
    _touchesX.resize(numTouches);
    _touchesY.resize(numTouches);
    for (int i = 0; i < numTouches; i++)
    {
        _touchesId[i] = (touchEvent->touches[i].identifier);
        // convert coords screen(origin:left-top) to canvas
        _touchesX[i] = ((touchEvent->touches[i].targetX - boundingX) * zoomX);
        _touchesY[i] = ((touchEvent->touches[i].targetY - boundingY) * zommY);
    }
    if (numTouches)
    {
        switch (eventType)
        {
        case EMSCRIPTEN_EVENT_TOUCHSTART:
            _captured = true;
            handleTouchesBegin(numTouches, _touchesId.data(), _touchesX.data(), _touchesY.data());
            break;
        case EMSCRIPTEN_EVENT_TOUCHEND:
            handleTouchesEnd(numTouches, _touchesId.data(), _touchesX.data(), _touchesY.data());
            _captured = false;
            break;
        case EMSCRIPTEN_EVENT_TOUCHMOVE:
            if (_captured)
                handleTouchesMove(numTouches, _touchesId.data(), _touchesX.data(), _touchesY.data());
            break;
        case EMSCRIPTEN_EVENT_TOUCHCANCEL:
            handleTouchesCancel(numTouches, _touchesId.data(), _touchesX.data(), _touchesY.data());
            _captured = false;
            break;
        }
    }
}

void RenderViewImpl::onWebClickCallback()
{