fix: make router socket non-blocking to prevent poll loop stalls

sketch/ArduinoGraphics.h

@@ -0,0 +1,115 @@
+/*
+  This file is part of the ArduinoGraphics library.
+  Copyright (c) 2025 Arduino SA. All rights reserved.
+*/
+
+#ifndef _ARDUINO_GRAPHICS_H
+#define _ARDUINO_GRAPHICS_H
+
+#include <Arduino.h>
+
+#include "Font.h"
+#include "Image.h"
+
+enum {
+  NO_SCROLL,
+  SCROLL_LEFT,
+  SCROLL_RIGHT,
+  SCROLL_UP,
+  SCROLL_DOWN
+};
+
+class ArduinoGraphics : public Print {
+public:
+  ArduinoGraphics(int width, int height);
+  virtual ~ArduinoGraphics();
+
+  virtual int begin();
+  virtual void end();
+
+  int width();
+  int height();
+  uint32_t background();
+
+  virtual void beginDraw();
+  virtual void endDraw();
+
+  void background(uint8_t r, uint8_t g, uint8_t b);
+  void background(uint32_t color);
+  void clear();
+  void clear(int x, int y);
+  void fill(uint8_t r, uint8_t g, uint8_t b);
+  void fill(uint32_t color);
+  void noFill();
+  void stroke(uint8_t r, uint8_t g, uint8_t b);
+  void stroke(uint32_t color);
+  void noStroke();
+
+  //virtual void arc(int x, int y, int width, int height, int start, int stop);
+  virtual void circle(int x, int y, int diameter);
+  virtual void ellipse(int x, int y, int width, int height);
+  virtual void line(int x1, int y1, int x2, int y2);
+  virtual void point(int x, int y);
+  //virtual void quad(int x1, int y1, int x2, int y2, int x3, int y3, int x4, int y4);
+  //virtual void triangle(int x1, int y1, int x2, int y2, int x3, int y3);
+  virtual void rect(int x, int y, int width, int height);
+
+  virtual void text(const char* str, int x = 0, int y = 0);
+  virtual void text(const String& str, int x = 0, int y = 0) { text(str.c_str(), x, y); }
+  virtual void textFont(const Font& which);
+  virtual void textSize(uint8_t s) {textSize(s, s);}
+  virtual void textSize(uint8_t sx, uint8_t sy);
+
+  virtual int textFontWidth() const;
+  virtual int textFontHeight() const;
+
+  virtual void image(const Image& img, int x, int y);
+  virtual void image(const Image& img, int x, int y, int width, int height);
+
+  virtual void set(int x, int y, uint8_t r, uint8_t g, uint8_t b) = 0;
+  virtual void set(int x, int y, uint32_t color);
+
+  // from Print
+  virtual size_t write(uint8_t);
+  virtual void flush();
+
+  virtual void beginText(int x = 0, int y = 0);
+  virtual void beginText(int x, int y, uint8_t r, uint8_t g, uint8_t b);
+  virtual void beginText(int x, int y, uint32_t color);
+  virtual void endText(int scroll = NO_SCROLL);
+  virtual void textScrollSpeed(unsigned long speed = 150);
+
+protected:
+  virtual void bitmap(const uint8_t* data, int x, int y, int w, int h, uint8_t scale_x = 1, 
+                      uint8_t scale_y = 1);
+  virtual void imageRGB(const Image& img, int x, int y, int width, int height);
+  virtual void imageRGB24(const Image& img, int x, int y, int width, int height);
+  virtual void imageRGB16(const Image& img, int x, int y, int width, int height);
+
+private:
+  void lineLow(int x1, int y1, int x2, int y2);
+  void lineHigh(int x1, int y1, int x2, int y2);
+
+private:
+  int _width;
+  int _height;
+  const Font* _font;
+
+  bool _fill, _stroke;
+  uint8_t _backgroundR, _backgroundG, _backgroundB;
+  uint8_t _fillR, _fillG, _fillB;
+  uint8_t _strokeR, _strokeG, _strokeB;
+
+  String _textBuffer;
+  uint8_t _textR, _textG, _textB;
+  int _textX;
+  int _textY;
+  uint8_t _textSizeX;
+  uint8_t _textSizeY;
+  unsigned long _textScrollSpeed;
+};
+
+extern const struct Font Font_4x6;
+extern const struct Font Font_5x7;
+
+#endif