/*

MIT/X11 License

Copyright (c) 2012 Sean Pringle <sean.pringle@gmail.com>

Permission is hereby granted, free of charge, to any person obtaining

a copy of this software and associated documentation files (the

"Software"), to deal in the Software without restriction, including

without limitation the rights to use, copy, modify, merge, publish,

distribute, sublicense, and/or sell copies of the Software, and to

permit persons to whom the Software is furnished to do so, subject to

the following conditions:

The above copyright notice and this permission notice shall be

included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.

IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY

CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,

TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE

SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

*/

#define TB_AUTOHEIGHT 1<<0

#define TB_AUTOWIDTH 1<<1

#define TB_LEFT 1<<16

#define TB_RIGHT 1<<17

#define TB_CENTER 1<<18

#define TB_EDITABLE 1<<19

typedef struct {

unsigned long flags;

Window window, parent;

short x, y, w, h, cursor;

XftFont *font;

XftColor color_fg, color_bg;

char *text, *prompt;

XIM xim;

XIC xic;

XGlyphInfo extents;

} textbox;

void textbox_font(textbox *tb, char *font, char *fg, char *bg);

void textbox_text(textbox *tb, char *text);

void textbox_moveresize(textbox *tb, int x, int y, int w, int h);

// Xft text box, optionally editable

textbox* textbox_create(Window parent, unsigned long flags, short x, short y, short w, short h, char *font, char *fg, char *bg, char *text, char *prompt)

{

textbox *tb = calloc(1, sizeof(textbox));

tb->flags = flags;

tb->parent = parent;

tb->x = x; tb->y = y; tb->w = MAX(1, w); tb->h = MAX(1, h);

XColor color; Colormap map = DefaultColormap(display, DefaultScreen(display));

unsigned int cp = XAllocNamedColor(display, map, bg, &color, &color) ? color.pixel: None;

tb->window = XCreateSimpleWindow(display, tb->parent, tb->x, tb->y, tb->w, tb->h, 0, None, cp);

// need to preload the font to calc line height

textbox_font(tb, font, fg, bg);

tb->prompt = strdup(prompt ? prompt: "");

textbox_text(tb, text ? text: "");

// auto height/width modes get handled here

textbox_moveresize(tb, tb->x, tb->y, tb->w, tb->h);

// edit mode controls

if (tb->flags & TB_EDITABLE)

{

tb->xim = XOpenIM(display, NULL, NULL, NULL);

tb->xic = XCreateIC(tb->xim, XNInputStyle, XIMPreeditNothing | XIMStatusNothing, XNClientWindow, tb->window, XNFocusWindow, tb->window, NULL);

}

return tb;

}

// set an Xft font by name

void textbox_font(textbox *tb, char *font, char *fg, char *bg)

{

if (tb->font) XftFontClose(display, tb->font);

tb->font = XftFontOpenName(display, DefaultScreen(display), font);

XftColorAllocName(display, DefaultVisual(display, DefaultScreen(display)), DefaultColormap(display, DefaultScreen(display)), fg, &tb->color_fg);

XftColorAllocName(display, DefaultVisual(display, DefaultScreen(display)), DefaultColormap(display, DefaultScreen(display)), bg, &tb->color_bg);

}

// outer code may need line height, width, etc

void textbox_extents(textbox *tb)

{

int length = strlen(tb->text) + strlen(tb->prompt);

char line[length + 1];

sprintf(line, "%s%s", tb->prompt, tb->text);

XftTextExtents8(display, tb->font, (unsigned char*)line, length, &tb->extents);

}

// set the default text to display

void textbox_text(textbox *tb, char *text)

{

if (tb->text) free(tb->text);

tb->text = strdup(text ? text: "");

tb->cursor = MAX(0, MIN(strlen(tb->text), tb->cursor));

textbox_extents(tb);

}

// set an input prompt for edit mode

void textbox_prompt(textbox *tb, char *text)

{

if (tb->prompt) free(tb->prompt);

tb->prompt = strdup(text);

textbox_extents(tb);

}

// within the parent. handled auto width/height modes

void textbox_moveresize(textbox *tb, int x, int y, int w, int h)

{

if (tb->flags & TB_AUTOHEIGHT)

h = tb->font->ascent + tb->font->descent;

if (tb->flags & TB_AUTOWIDTH)

w = tb->extents.width;

if (x != tb->x || y != tb->y || w != tb->w || h != tb->h)

{

tb->x = x; tb->y = y; tb->w = MAX(1, w); tb->h = MAX(1, h);

XMoveResizeWindow(display, tb->window, tb->x, tb->y, tb->w, tb->h);

}

}

void textbox_show(textbox *tb)

{

XMapWindow(display, tb->window);

}

void textbox_hide(textbox *tb)

{

XUnmapWindow(display, tb->window);

}

// will also unmap the window if still displayed

void textbox_free(textbox *tb)

{

if (tb->flags & TB_EDITABLE)

{

XDestroyIC(tb->xic);

XCloseIM(tb->xim);

}

if (tb->text) free(tb->text);

if (tb->prompt) free(tb->prompt);

if (tb->font) XftFontClose(display, tb->font);

XDestroyWindow(display, tb->window);

free(tb);

}

void textbox_draw(textbox *tb)

{

int i;

XGlyphInfo extents;

GC context = XCreateGC(display, tb->window, 0, 0);

Pixmap canvas = XCreatePixmap(display, tb->window, tb->w, tb->h, DefaultDepth(display, DefaultScreen(display)));

XftDraw *draw = XftDrawCreate(display, canvas, DefaultVisual(display, DefaultScreen(display)), DefaultColormap(display, DefaultScreen(display)));

// clear canvas

XftDrawRect(draw, &tb->color_bg, 0, 0, tb->w, tb->h);

char *line = tb->text,

*text = tb->text ? tb->text: "",

*prompt = tb->prompt ? tb->prompt: "";

int text_len = strlen(text);

int length = text_len;

int line_height = tb->font->ascent + tb->font->descent;

int cursor_x = 0;

int cursor_offset = 0;

int cursor_width = MAX(2, line_height/10);

if (tb->flags & TB_EDITABLE)

{

int prompt_len = strlen(prompt);

length = text_len + prompt_len;

cursor_offset = MIN(tb->cursor + prompt_len, length);

char eline[length + 10]; line = eline;

sprintf(line, "%s%s", prompt, text);

// replace spaces so XftTextExtents8 includes their width

for (i = 0; i < length; i++) if (isspace(line[i])) line[i] = '_';

// calc cursor position

XftTextExtents8(display, tb->font, (unsigned char*)line, cursor_offset, &extents);

cursor_x = extents.width;

// restore correct text string with spaces

sprintf(line, "%s%s", prompt, text);

}

// calc full input text width

XftTextExtents8(display, tb->font, (unsigned char*)line, length, &extents);

int line_width = extents.width;

int x = 0, y = tb->font->ascent;

if (tb->flags & TB_RIGHT) x = tb->w - line_width;

if (tb->flags & TB_CENTER) x = MAX(0, (tb->w - line_width) / 2);

// draw the text, including any prompt in edit mode

XftDrawString8(draw, &tb->color_fg, tb->font, x, y, (unsigned char*)line, length);

// draw the cursor

if (tb->flags & TB_EDITABLE)

XftDrawRect(draw, &tb->color_fg, cursor_x, 2, cursor_width, line_height-4);

// flip canvas to window

XCopyArea(display, canvas, tb->window, context, 0, 0, tb->w, tb->h, 0, 0);

XFreeGC(display, context);

XftDrawDestroy(draw);

XFreePixmap(display, canvas);

}

// cursor handling for edit mode

void textbox_cursor(textbox *tb, int pos)

{

tb->cursor = MAX(0, MIN(strlen(tb->text), pos));

}

// move right

void textbox_cursor_inc(textbox *tb)

{

textbox_cursor(tb, tb->cursor+1);

}

// move left

void textbox_cursor_dec(textbox *tb)

{

textbox_cursor(tb, tb->cursor-1);

}

// beginning of line

void textbox_cursor_home(textbox *tb)

{

tb->cursor = 0;

}

// end of line

void textbox_cursor_end(textbox *tb)

{

tb->cursor = strlen(tb->text);

}

// insert text

void textbox_insert(textbox *tb, int pos, char *str)

{

int len = strlen(tb->text), slen = strlen(str);

pos = MAX(0, MIN(len, pos));

// expand buffer

tb->text = realloc(tb->text, len + slen + 1);

// move everything after cursor upward

char *at = tb->text + pos;

memmove(at + slen, at, len - pos + 1);

// insert new str

memmove(at, str, slen);

textbox_extents(tb);

}

// remove text

void textbox_delete(textbox *tb, int pos, int dlen)

{

int len = strlen(tb->text);

pos = MAX(0, MIN(len, pos));

// move everything after pos+dlen down

char *at = tb->text + pos;

memmove(at, at + dlen, len - pos);

textbox_extents(tb);

}

// insert one character

void textbox_cursor_ins(textbox *tb, char c)

{

char tmp[2] = { c, 0 };

textbox_insert(tb, tb->cursor, tmp);

textbox_cursor_inc(tb);

}

// delete on character

void textbox_cursor_del(textbox *tb)

{

textbox_delete(tb, tb->cursor, 1);

}

// back up and delete one character

void textbox_cursor_bkspc(textbox *tb)

{

if (tb->cursor > 0)

{

textbox_cursor_dec(tb);

textbox_cursor_del(tb);

}

}

// handle a keypress in edit mode

// 0 = unhandled

// 1 = handled

// -1 = handled and return pressed (finished)

int textbox_keypress(textbox *tb, XEvent *ev)

{

if (!(tb->flags & TB_EDITABLE)) return 0;

KeySym key; Status stat; char pad[32];

int len = XmbLookupString(tb->xic, &ev->xkey, pad, sizeof(pad), &key, &stat);

pad[len] = 0;

switch (key)

{

case XK_Left : textbox_cursor_dec(tb); return 1;

case XK_Right : textbox_cursor_inc(tb); return 1;

case XK_Home : textbox_cursor_home(tb); return 1;

case XK_End : textbox_cursor_end(tb); return 1;

case XK_Delete : textbox_cursor_del(tb); return 1;

case XK_BackSpace : textbox_cursor_bkspc(tb); return 1;

case XK_Return : return -1;

default:

if (!iscntrl(*pad))

{

textbox_insert(tb, tb->cursor, pad);

textbox_cursor_inc(tb);

return 1;

}

}

return 0;

}