UI: experimental keypad to replace android keypad

Author: chrisws

CMakeLists.txt

@@ -185,7 +185,7 @@ set(SOURCES
   ${UI_DIR}/textedit.cpp
   ${UI_DIR}/keypad.cpp
   ${UI_DIR}/image.cpp
-  ${UI_DIR}/lodepng_codec.cpp
+  ${UI_DIR}/image_codec.cpp
   ${UI_DIR}/strlib.cpp
   ${UI_DIR}/audio.cpp
   ${SDL_DIR}/main.cpp

images/keypad/build.sh

@@ -9,12 +9,16 @@ declare -a IMAGE_FILES=(\
  "proicons-book-info-2.png"\
  "proicons-backspace.png"\
  "proicons-arrow-enter.png"\
+ "proicons-search.png"\
 )
 
-echo "#pragma once" > keypad-icons.h
-echo "// https://procode-software.github.io/proicons/icons" >> keypad-icons.h
+echo "#pragma once" > keypad_icons.h
+echo "// https://procode-software.github.io/proicons/icons" >> keypad_icons.h
 for imageFile in "${IMAGE_FILES[@]}"
 do
     name=`ls -1 ${imageFile} | sed -e 's/proicons-/img-/' | sed -e 's/\.png//'`
-    xxd -n ${name} -i ${imageFile}  >> keypad-icons.h
+    xxd -n ${name} -i ${imageFile}  >> keypad_icons.h
 done
+
+cp keypad_icons.h ../../src/ui
+

src/ui/image_codec.cpp

@@ -0,0 +1,99 @@
+// This file is part of SmallBASIC
+//
+// Image handling
+//
+// This program is distributed under the terms of the GPL v2.0 or later
+// Download the GNU Public License (GPL) from www.gnu.org
+//
+// Copyright(C) 2002-2025 Chris Warren-Smith.
+
+#include "image_codec.h"
+#include "lib/lodepng/lodepng.h"
+#include <cstdlib>
+#include <cstring>
+
+static char g_last_error[256] = {0};
+
+static float lerp(float a, float b, float t) {
+  return a + t * (b - a);
+}
+
+ImageCodec::ImageCodec(const uint8_t *data, size_t size) :
+  _width(0),
+  _height(0),
+  _pixels(nullptr) {
+  auto error = lodepng_decode32(&_pixels, &_width, &_height, data, size);
+  if (error) {
+    snprintf(g_last_error, sizeof(g_last_error), "%s", lodepng_error_text(error));
+  }
+}
+
+ImageCodec::~ImageCodec() {
+  free(_pixels);
+  _pixels = nullptr;
+}
+
+const char *ImageCodec::getLastError(void) {
+  return g_last_error;
+}
+
+bool ImageCodec::encode(uint8_t **data, size_t *size) const {
+  bool result;
+  if (!data || !size) {
+    sprintf(g_last_error, "Invalid args");
+    result = false;
+  } else {
+    uint8_t *img = nullptr;
+    size_t img_size = 0;
+    auto error = lodepng_encode32(&img, &img_size, _pixels, _width, _height);
+    if (error) {
+      snprintf(g_last_error, sizeof(g_last_error), "%s", lodepng_error_text(error));
+    } else {
+      *data = img;
+      *size = img_size;
+    }
+    result = !error;
+  }
+  return result;
+}
+
+void ImageCodec::resize(unsigned width, unsigned height) {
+  uint8_t *pixels = new uint8_t[width * height * 4];
+
+  for (int y = 0; y < height; y++) {
+    float gy = ((float)y + 0.5f) * _height / height - 0.5f;
+    int y0 = (int)gy, y1 = y0 + 1;
+    float fy = gy - y0;
+    y0 = y0 < 0 ? 0 : (y0 >= _height ? _height - 1 : y0);
+    y1 = y1 < 0 ? 0 : (y1 >= _height ? _height - 1 : y1);
+
+    for (int x = 0; x < width; x++) {
+      float gx = ((float)x + 0.5f) * _width / width - 0.5f;
+      int x0 = (int)gx, x1 = x0 + 1;
+      float fx = gx - x0;
+      x0 = x0 < 0 ? 0 : (x0 >= _width ? _width - 1 : x0);
+      x1 = x1 < 0 ? 0 : (x1 >= _width ? _width - 1 : x1);
+
+      int offset = 4 * (y * width + x);
+      for (int c = 0; c < 4; c++) {
+        // A, R, G, B
+        float tl = _pixels[4 * (y0 * _width + x0) + c];
+        float tr = _pixels[4 * (y0 * _width + x1) + c];
+        float bl = _pixels[4 * (y1 * _width + x0) + c];
+        float br = _pixels[4 * (y1 * _width + x1) + c];
+
+        float top = lerp(tl, tr, fx);
+        float bottom = lerp(bl, br, fx);
+        float value = lerp(top, bottom, fy);
+
+        pixels[offset + c] = (uint8_t)(value + 0.5f);
+      }
+    }
+  }
+
+  free(_pixels);
+  _pixels = pixels;
+  _width = width;
+  _height = height;
+}
+

src/ui/image_codec.h

@@ -6,47 +6,53 @@
 // Download the GNU Public License (GPL) from www.gnu.org
 //
 
-#ifndef IMG_CODEC_H
-#define IMG_CODEC_H
+#pragma once
 
 #include "config.h"
 #include <cstddef>
 #include <cstdint>
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-struct ImageData {
-  ImageData();
-  ~ImageData();
-
+class ImageCodec {
+public:
+  //
+  // Decode IMG to raw RGBA image
+  //
+  ImageCodec(const uint8_t *data, size_t size);
+  virtual ~ImageCodec();
+
+  // Prevent copy and move
+  ImageCodec(const ImageCodec &) = delete;
+  ImageCodec& operator=(const ImageCodec &) = delete;
+
+  //
+  // Encode the raw image RGBA data to png
+  // The function allocates *data which must be freed.
+  //
+  bool encode(uint8_t **data, size_t *size) const;
+
+  //
+  // resize the image to the given dimensions
+  //
+  void resize(unsigned width, unsigned height);
+
+  //
+  // Returns the last error
+  //
+  static const char *getLastError(void);
+
+  //
+  // Returns the image width
+  //
+  int getWidth() const { return _width; }
+
+  //
+  // Returns the image height
+  //
+  int getHeight() const { return _height; }
+
+protected:
   unsigned _width;
   unsigned _height;
   uint8_t *_pixels;
 };
 
-//
-// Decode IMG to raw RGBA image
-// Caller allocates and passes in imgData and its size.
-// The function allocates ImageData.pixels (must be freed with img_free).
-//
-int img_decode(const uint8_t *imgData, size_t imgSize, ImageData *outImage);
-
-//
-// Encode raw RGBA image to IMG
-// Caller allocates and passes in image.
-// The function allocates *outImgData which must be freed.
-//
-int img_encode(const ImageData *image, uint8_t **outImgData, size_t *outImgSize);
-
-//
-// Get last error string
-//
-const char *img_get_last_error(void);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif // IMG_CODEC_H

src/ui/keycode.h

@@ -0,0 +1,95 @@
+// This file is part of SmallBASIC
+//
+// Copyright(C) 2001-2025 Chris Warren-Smith.
+//
+// This program is distributed under the terms of the GPL v2.0 or later
+// Download the GNU Public License (GPL) from www.gnu.org
+//
+
+#pragma once
+
+enum KeyCode : char {
+  K_UP       = -1,
+  K_DOWN     = -2,
+  K_LEFT     = -3,
+  K_RIGHT    = -4,
+  K_HOME     = -5,
+  K_END      = -6,
+  K_PAGE_UP  = -7,
+  K_PAGE_DOWN = -8,
+  K_INSERT   = -9,
+  K_DELETE   = -10,
+  K_CUT      = -11,
+  K_COPY     = -12,
+  K_PASTE    = -13,
+  K_SAVE     = -14,
+  K_HELP     = -15,
+  K_SEARCH   = -16,
+  K_RUN      = -17,
+  K_TOGGLE   = -18,
+  K_SHIFT    = -19,
+  K_FIND     = -20,
+  K_NULL     = 0,
+  K_BACKSPACE = 8,
+  K_TAB      = 9,
+  K_NEWLINE  = 10,
+  K_ENTER    = 13,
+  K_ESCAPE   = 27,
+  K_SPACE    = 32,
+  K_EXCLAIM  = 33,  // !
+  K_QUOTE    = 34,  // "
+  K_HASH     = 35,  // #
+  K_DOLLAR   = 36,  // $
+  K_PERCENT  = 37,  // %
+  K_AMPERSAND = 38, // &
+  K_APOSTROPHE = 39, // '
+  K_LPAREN   = 40,  // (
+  K_RPAREN   = 41,  // )
+  K_ASTERISK = 42,  // *
+  K_PLUS     = 43,  // +
+  K_COMMA    = 44,  // ,
+  K_MINUS    = 45,  // -
+  K_PERIOD   = 46,  // .
+  K_SLASH    = 47,  // /
+  K_0 = 48, K_1 = 49, K_2 = 50, K_3 = 51, K_4 = 52,
+  K_5 = 53, K_6 = 54, K_7 = 55, K_8 = 56, K_9 = 57,
+  K_COLON    = 58,  // :
+  K_SEMICOLON = 59, // ;
+  K_LESS     = 60,  // <
+  K_EQUALS   = 61,  // =
+  K_GREATER  = 62,  // >
+  K_QUESTION = 63,  // ?
+  K_AT       = 64,  // @
+  K_A = 65, K_B = 66, K_C = 67, K_D = 68, K_E = 69,
+  K_F = 70, K_G = 71, K_H = 72, K_I = 73, K_J = 74,
+  K_K = 75, K_L = 76, K_M = 77, K_N = 78, K_O = 79,
+  K_P = 80, K_Q = 81, K_R = 82, K_S = 83, K_T = 84,
+  K_U = 85, K_V = 86, K_W = 87, K_X = 88, K_Y = 89,
+  K_Z = 90,
+  K_LBRACKET = 91,  // [
+  K_BACKSLASH = 92, //
+  K_RBRACKET = 93,  // ]
+  K_CARET    = 94,  // ^
+  K_UNDERSCORE = 95, // _
+  K_BACKTICK = 96,  // `
+  K_a = 97,  K_b = 98,  K_c = 99,  K_d = 100, K_e = 101,
+  K_f = 102, K_g = 103, K_h = 104, K_i = 105, K_j = 106,
+  K_k = 107, K_l = 108, K_m = 109, K_n = 110, K_o = 111,
+  K_p = 112, K_q = 113, K_r = 114, K_s = 115, K_t = 116,
+  K_u = 117, K_v = 118, K_w = 119, K_x = 120, K_y = 121,
+  K_z = 122,
+  K_LBRACE   = 123, // {
+  K_PIPE     = 124, // |
+  K_RBRACE   = 125, // }
+  K_TILDE    = 126, // ~
+  K_DEL      = 127  // DEL
+};
+
+inline bool isPrintable(KeyCode key) {
+  return key >= K_SPACE && key <= K_TILDE;
+}
+
+inline bool isNumber(KeyCode key) {
+  return key >= K_0 && key <= K_9;
+}
+