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keyboard.c contains the source code for the bitmap font keyboard exam…

…ple.
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Holmes Futrell committed Aug 2, 2008
1 parent d58a3e9 commit 515f34214cb3445d95aa7d59940a740747539c53
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  1. +279 −0 XCodeiPhoneOS/Demos/src/keyboard.c
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/*
* keyboard.c
* written by Holmes Futrell
* use however you want
*/

#import "SDL.h"
#import "common.h"

#define GLYPH_SIZE_IMAGE 16 /* size of glyphs (characters) in the bitmap font file */
#define GLYPH_SIZE_SCREEN 32 /* size of glyphs (characters) as shown on the screen */

static SDL_TextureID textureID; /* texture where we'll hold our font */

/* iPhone SDL addition keyboard related function definitions */
extern DECLSPEC int SDLCALL SDL_iPhoneKeyboardShow(SDL_WindowID windowID);
extern DECLSPEC int SDLCALL SDL_iPhoneKeyboardHide(SDL_WindowID windowID);
extern DECLSPEC SDL_bool SDLCALL SDL_iPhoneKeyboardIsShown(SDL_WindowID windowID);
extern DECLSPEC int SDLCALL SDL_iPhoneKeyboardToggle(SDL_WindowID windowID);

/* function declarations */
void cleanup(void);
void drawBlank(int x, int y);

static int numChars = 0; /* number of characters we've typed so far */
static SDL_bool lastCharWasColon = 0; /* we use this to detect sequences such as :) */
static SDL_Color bg_color = { 50, 50, 100, 255 }; /* color of background */

/* this structure maps a scancode to an index in our bitmap font.
it also contains data about under which modifiers the mapping is valid
(for example, we don't want shift + 1 to produce the character '1',
but rather the character '!')
*/
typedef struct {
SDL_scancode scancode; /* scancode of the key we want to map */
int allow_no_mod; /* is the map valid if the key has no modifiers? */
SDLMod mod; /* what modifiers are allowed for the mapping */
int index; /* what index in the font does the scancode map to */
} fontMapping;

#define TABLE_SIZE 51 /* size of our table which maps keys and modifiers to font indices */

/* Below is the table that defines the mapping between scancodes and modifiers to indices in the
bitmap font. As an example, then line '{ SDL_SCANCODE_A, 1, KMOD_SHIFT, 33 }' means, map
the key A (which has scancode SDL_SCANCODE_A) to index 33 in the font (which is a picture of an A),
The '1' means that the mapping is valid even if there are no modifiers, and KMOD_SHIFT means the
mapping is also valid if the user is holding shift.
*/
fontMapping map[TABLE_SIZE] = {

{ SDL_SCANCODE_A, 1, KMOD_SHIFT, 33 }, /* A */
{ SDL_SCANCODE_B, 1, KMOD_SHIFT, 34 }, /* B */
{ SDL_SCANCODE_C, 1, KMOD_SHIFT, 35 }, /* C */
{ SDL_SCANCODE_D, 1, KMOD_SHIFT, 36 }, /* D */
{ SDL_SCANCODE_E, 1, KMOD_SHIFT, 37 }, /* E */
{ SDL_SCANCODE_F, 1, KMOD_SHIFT, 38 }, /* F */
{ SDL_SCANCODE_G, 1, KMOD_SHIFT, 39 }, /* G */
{ SDL_SCANCODE_H, 1, KMOD_SHIFT, 40 }, /* H */
{ SDL_SCANCODE_I, 1, KMOD_SHIFT, 41 }, /* I */
{ SDL_SCANCODE_J, 1, KMOD_SHIFT, 42 }, /* J */
{ SDL_SCANCODE_K, 1, KMOD_SHIFT, 43 }, /* K */
{ SDL_SCANCODE_L, 1, KMOD_SHIFT, 44 }, /* L */
{ SDL_SCANCODE_M, 1, KMOD_SHIFT, 45 }, /* M */
{ SDL_SCANCODE_N, 1, KMOD_SHIFT, 46 }, /* N */
{ SDL_SCANCODE_O, 1, KMOD_SHIFT, 47 }, /* O */
{ SDL_SCANCODE_P, 1, KMOD_SHIFT, 48 }, /* P */
{ SDL_SCANCODE_Q, 1, KMOD_SHIFT, 49 }, /* Q */
{ SDL_SCANCODE_R, 1, KMOD_SHIFT, 50 }, /* R */
{ SDL_SCANCODE_S, 1, KMOD_SHIFT, 51 }, /* S */
{ SDL_SCANCODE_T, 1, KMOD_SHIFT, 52 }, /* T */
{ SDL_SCANCODE_U, 1, KMOD_SHIFT, 53 }, /* U */
{ SDL_SCANCODE_V, 1, KMOD_SHIFT, 54 }, /* V */
{ SDL_SCANCODE_W, 1, KMOD_SHIFT, 55 }, /* W */
{ SDL_SCANCODE_X, 1, KMOD_SHIFT, 56 }, /* X */
{ SDL_SCANCODE_Y, 1, KMOD_SHIFT, 57 }, /* Y */
{ SDL_SCANCODE_Z, 1, KMOD_SHIFT, 58 }, /* Z */
{ SDL_SCANCODE_0, 1, 0, 16 }, /* 0 */
{ SDL_SCANCODE_1, 1, 0, 17 }, /* 1 */
{ SDL_SCANCODE_2, 1, 0, 18 }, /* 2 */
{ SDL_SCANCODE_3, 1, 0, 19 }, /* 3 */
{ SDL_SCANCODE_4, 1, 0, 20 }, /* 4 */
{ SDL_SCANCODE_5, 1, 0, 21 }, /* 5 */
{ SDL_SCANCODE_6, 1, 0, 22 }, /* 6 */
{ SDL_SCANCODE_7, 1, 0, 23 }, /* 7 */
{ SDL_SCANCODE_8, 1, 0, 24 }, /* 8 */
{ SDL_SCANCODE_9, 1, 0, 25 }, /* 9 */
{ SDL_SCANCODE_SPACE, 1, 0, 0 }, /*' '*/
{ SDL_SCANCODE_1, 0, KMOD_SHIFT, 1 }, /* ! */
{ SDL_SCANCODE_SLASH, 0, KMOD_SHIFT, 31}, /* ? */
{ SDL_SCANCODE_SLASH, 1, 0, 15}, /* / */
{ SDL_SCANCODE_COMMA, 1, 0, 12}, /* , */
{ SDL_SCANCODE_SEMICOLON, 1, 0, 27}, /* ; */
{ SDL_SCANCODE_SEMICOLON, 0, KMOD_SHIFT, 26}, /* : */
{ SDL_SCANCODE_PERIOD, 1, 0, 14}, /* . */
{ SDL_SCANCODE_MINUS, 1, 0, 13}, /* - */
{ SDL_SCANCODE_EQUALS, 0, KMOD_SHIFT, 11}, /* = */
{ SDL_SCANCODE_APOSTROPHE, 1, 0, 7}, /* ' */
{ SDL_SCANCODE_APOSTROPHE, 0, KMOD_SHIFT, 2}, /* " */
{ SDL_SCANCODE_5, 0, KMOD_SHIFT, 5}, /* % */

};

/*
This function maps an SDL_keysym to an index in the bitmap font.
It does so by scanning through the font mapping table one entry
at a time.
If a match is found (scancode and allowed modifiers), the proper
index is returned.
If there is no entry for the key, -1 is returned
*/
int keyToIndex(SDL_keysym key) {
int i, index = -1;
for (i=0; i<TABLE_SIZE; i++) {
fontMapping compare = map[i];
if (key.scancode == compare.scancode) {
/* if this entry is valid with no key mod and we have no keymod, or if
the key's modifiers are allowed modifiers for that mapping */
if ((compare.allow_no_mod && key.mod == 0) || ( key.mod & compare.mod ) ) {
index = compare.index;
break;
}
}
}
return index;
}
/*
This function returns and x,y position for a given character number.
It is used for positioning each character of text
*/
void getPositionForCharNumber(int n, int *x, int *y) {
int x_padding = 16; /* padding space on left and right side of screen */
int y_padding = 32; /* padding space at top of screen */
/* figure out the number of characters that can fit horizontally across the screen */
int max_x_chars = (SCREEN_WIDTH - 2 * x_padding) / GLYPH_SIZE_SCREEN;
int line_separation = 5; /* pixels between each line */
*x = (n % max_x_chars) * GLYPH_SIZE_SCREEN + x_padding;
*y = (n / max_x_chars) * (GLYPH_SIZE_SCREEN + line_separation) + y_padding;
}
void drawIndex(int index) {
int x, y;
getPositionForCharNumber(numChars, &x, &y);
SDL_Rect srcRect = { GLYPH_SIZE_IMAGE * index, 0, GLYPH_SIZE_IMAGE, GLYPH_SIZE_IMAGE };
SDL_Rect dstRect = { x, y, GLYPH_SIZE_SCREEN, GLYPH_SIZE_SCREEN };
drawBlank(x, y);
SDL_RenderCopy(textureID, &srcRect, &dstRect);
}
/* draws the cursor icon at the current end position of the text */
void drawCursor(void) {
drawIndex(29); /* cursor is at index 29 in the bitmap font */
}
/* paints over a glyph sized region with the background color
in effect it erases the area
*/
void drawBlank(int x, int y) {
SDL_Rect rect = { x, y, GLYPH_SIZE_SCREEN, GLYPH_SIZE_SCREEN };
SDL_RenderFill(bg_color.r, bg_color.g, bg_color.b, bg_color.unused, &rect);
}
/* moves backwards one character, erasing the last one put down */
void backspace(void) {
int x, y;
if (numChars > 0) {
getPositionForCharNumber(numChars, &x, &y);
drawBlank(x, y);
numChars--;
getPositionForCharNumber(numChars, &x, &y);
drawBlank(x, y);
drawCursor();
}
}
/* this function loads our font into an SDL_Texture and returns the SDL_TextureID */
SDL_TextureID loadFont(void) {

SDL_Surface *surface = SDL_LoadBMP("kromasky_16x16.bmp");

if (!surface) {
printf("Error loading bitmap: %s\n", SDL_GetError());
return 0;
}
else {
/* set the transparent color for the bitmap font (hot pink) */
SDL_SetColorKey(surface, 1, SDL_MapRGB(surface->format, 238, 0, 252 ));
/* now we convert the surface to our desired pixel format */
int format = SDL_PIXELFORMAT_ABGR8888; /* desired texture format */
Uint32 Rmask, Gmask, Bmask, Amask; /* masks for desired format */
int bpp; /* bits per pixel for desired format */
SDL_PixelFormatEnumToMasks(format, &bpp, &Rmask, &Gmask, &Bmask, &Amask);
SDL_Surface *converted = SDL_CreateRGBSurface(0, surface->w, surface->h, bpp, Rmask, Gmask, Bmask, Amask);
SDL_BlitSurface(surface, NULL, converted, NULL);
/* create our texture */
textureID = SDL_CreateTextureFromSurface(SDL_PIXELFORMAT_ABGR8888, converted);
if (textureID == 0) {
printf("texture creation failed: %s\n", SDL_GetError());
}
else {
/* set blend mode for our texture */
SDL_SetTextureBlendMode(textureID, SDL_TEXTUREBLENDMODE_BLEND);
}
SDL_FreeSurface(surface);
SDL_FreeSurface(converted);
return textureID;
}
}

int main(int argc, char *argv[]) {

int index; /* index of last key we pushed in the bitmap font */
SDL_Event event; /* last event received */
SDLMod mod; /* key modifiers of last key we pushed */
SDL_scancode scancode; /* scancode of last key we pushed */

if (SDL_Init(SDL_INIT_VIDEO) < 0) {
printf("Error initializing SDL: %s", SDL_GetError());
}
/* create window */
SDL_WindowID windowID = SDL_CreateWindow("iPhone keyboard test", 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT, 0);
/* create renderer */
SDL_CreateRenderer(windowID, 0, 0);

/* load up our font */
loadFont();

/* draw the background, we'll just paint over it */
SDL_RenderFill(bg_color.r, bg_color.g, bg_color.b, bg_color.unused, NULL);
SDL_RenderPresent();

int done = 0;
/* loop till we get SDL_Quit */
while (SDL_WaitEvent(&event)) {
switch (event.type) {
case SDL_QUIT:
done = 1;
break;
case SDL_KEYDOWN:
index = keyToIndex(event.key.keysym);
scancode = event.key.keysym.scancode;
mod = event.key.keysym.mod;
if (scancode == SDL_SCANCODE_DELETE) {
/* if user hit delete, delete the last character */
backspace();
lastCharWasColon = 0;
}
else if (lastCharWasColon && scancode == SDL_SCANCODE_0 && (mod & KMOD_SHIFT)) {
/* if our last key was a colon and this one is a close paren, the make a hoppy face */
backspace();
drawIndex(32); /* index for happy face */
numChars++;
drawCursor();
lastCharWasColon = 0;
}
else if (index != -1) {
/* if we aren't doing a happy face, then just draw the normal character */
drawIndex(index);
numChars++;
drawCursor();
lastCharWasColon = (event.key.keysym.scancode == SDL_SCANCODE_SEMICOLON\
&& (event.key.keysym.mod & KMOD_SHIFT));
}
/* check if the key was a colon */
/* draw our updates to the screen */
SDL_RenderPresent();
break;
case SDL_MOUSEBUTTONUP:
/* mouse up toggles keyboard */
SDL_iPhoneKeyboardToggle(windowID);
break;
}
}
cleanup();
return 0;
}

/* clean up after ourselves like a good kiddy */
void cleanup(void) {
SDL_DestroyTexture(textureID);
SDL_Quit();
}

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