entry.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

#include <u.h>
#include <libc.h>
#include <draw.h>
#include <thread.h>
#include <mouse.h>
#include <keyboard.h>
#include <control.h>

typedef struct Entry Entry;

struct Entry
{
	Control;
	int		border;
	CFont	*font;
	CImage	*image;
	CImage	*textcolor;
	CImage	*bordercolor;
	Rune		*text;
	int		ntext;
	int		cursor;
	int		align;
	int		hasfocus;
	int		lastbut;
};

enum{
	EAlign,
	EBorder,
	EBordercolor,
	EData,
	EFocus,
	EFont,
	EFormat,
	EHide,
	EImage,
	ERect,
	EReveal,
	EShow,
	ESize,
	ETextcolor,
	EValue,
};

static char *cmds[] = {
	[EAlign] =			"align",
	[EBorder] =		"border",
	[EBordercolor] =	"bordercolor",
	[EData] = 			"data",
	[EFocus] = 		"focus",
	[EFont] =			"font",
	[EFormat] = 		"format",
	[EHide] =			"hide",
	[EImage] =		"image",
	[ERect] =			"rect",
	[EReveal] =		"reveal",
	[EShow] =			"show",
	[ESize] =			"size",
	[ETextcolor] =		"textcolor",
	[EValue] =			"value",
	nil
};

static void
entryfree(Control *c)
{
	Entry *e;

	e = (Entry *)c;
	_putctlfont(e->font);
	_putctlimage(e->image);
	_putctlimage(e->textcolor);
	_putctlimage(e->bordercolor);
	free(e->text);
}

static Point
entrypoint(Entry *e, int c)
{
	Point p;
	Rectangle r;

	r = e->rect;
	if(e->border > 0)
		r = insetrect(r, e->border);
	p = _ctlalignpoint(r,
		runestringnwidth(e->font->font, e->text, e->ntext),
		e->font->font->height, e->align);
	if(c > e->ntext)
		c = e->ntext;
	p.x += runestringnwidth(e->font->font, e->text, c);
	return p;
}

static void
entryshow(Entry *e)
{
	Rectangle r, dr;
	Point p;

	if (e->hidden)
		return;
	r = e->rect;
	draw(e->screen, r, e->image->image, nil, e->image->image->r.min);
	if(e->border > 0){
		border(e->screen, r, e->border, e->bordercolor->image, e->bordercolor->image->r.min);
		dr = insetrect(r, e->border);
	}else
		dr = r;
	p = entrypoint(e, 0);
	_string(e->screen, p, e->textcolor->image,
		ZP, e->font->font, nil, e->text, e->ntext,
		dr, nil, ZP, SoverD);
	if(e->hasfocus){
		p = entrypoint(e, e->cursor);
		r.min = p;
		r.max.x = p.x+1;
		r.max.y = p.y+e->font->font->height;
		if(rectclip(&r, dr))
			draw(e->screen, r, e->textcolor->image, nil, ZP);
	}
	flushimage(display, 1);
}

static void
entrysetpoint(Entry *e, Point cp)
{
	Point p;
	int i;

	if(!ptinrect(cp, insetrect(e->rect, e->border)))
		return;
	p = entrypoint(e, 0);
	for(i=0; i<e->ntext; i++){
		p.x += runestringnwidth(e->font->font, e->text+i, 1);
		if(p.x > cp.x)
			break;
	}
	e->cursor = i;
	entryshow(e);
}

static void
entrymouse(Control *c, Mouse *m)
{
	Entry *e;

	e = (Entry*)c;
	if(m->buttons==1 && e->lastbut==0)
		entrysetpoint(e, m->xy);
	e->lastbut = m->buttons;
}

static void
entryctl(Control *c, CParse *cp)
{
	int cmd;
	Rectangle r;
	Entry *e;
	Rune *rp;

	e = (Entry*)c;
	cmd = _ctllookup(cp->args[0], cmds, nelem(cmds));
	switch(cmd){
	default:
		ctlerror("%q: unrecognized message '%s'", e->name, cp->str);
		break;
	case EAlign:
		_ctlargcount(e, cp, 2);
		e->align = _ctlalignment(cp->args[1]);
		break;
	case EBorder:
		_ctlargcount(e, cp, 2);
		if(cp->iargs[1] < 0)
			ctlerror("%q: bad border: %c", e->name, cp->str);
		e->border = cp->iargs[1];
		break;
	case EBordercolor:
		_ctlargcount(e, cp, 2);
		_setctlimage(e, &e->bordercolor, cp->args[1]);
		break;
	case EData:
		_ctlargcount(e, cp, 1);
		chanprint(e->data, "%S", e->text);
		break;
	case EFocus:
		_ctlargcount(e, cp, 2);
		e->hasfocus = cp->iargs[1];
		e->lastbut = 0;
		entryshow(e);
		break;
	case EFont:
		_ctlargcount(e, cp, 2);
		_setctlfont(e, &e->font, cp->args[1]);
		break;
	case EFormat:
		_ctlargcount(e, cp, 2);
		e->format = ctlstrdup(cp->args[1]);
		break;
	case EHide:
		_ctlargcount(e, cp, 1);
		e->hidden = 1;
		break;
	case EImage:
		_ctlargcount(e, cp, 2);
		_setctlimage(e, &e->image, cp->args[1]);
		break;
	case ERect:
		_ctlargcount(e, cp, 5);
		r.min.x = cp->iargs[1];
		r.min.y = cp->iargs[2];
		r.max.x = cp->iargs[3];
		r.max.y = cp->iargs[4];
		if(Dx(r)<=0 || Dy(r)<=0)
			ctlerror("%q: bad rectangle: %s", e->name, cp->str);
		e->rect = r;
		break;
	case EReveal:
		_ctlargcount(e, cp, 1);
		e->hidden = 0;
		entryshow(e);
		break;
	case EShow:
		_ctlargcount(e, cp, 1);
		entryshow(e);
		break;
	case ESize:
		if (cp->nargs == 3)
			r.max = Pt(0x7fffffff, 0x7fffffff);
		else{
			_ctlargcount(e, cp, 5);
			r.max.x = cp->iargs[3];
			r.max.y = cp->iargs[4];
		}
		r.min.x = cp->iargs[1];
		r.min.y = cp->iargs[2];
		if(r.min.x<=0 || r.min.y<=0 || r.max.x<=0 || r.max.y<=0 || r.max.x < r.min.x || r.max.y < r.min.y)
			ctlerror("%q: bad sizes: %s", e->name, cp->str);
		e->size.min = r.min;
		e->size.max = r.max;
		break;
	case ETextcolor:
		_ctlargcount(e, cp, 2);
		_setctlimage(e, &e->textcolor, cp->args[1]);
		break;
	case EValue:
		_ctlargcount(e, cp, 2);
		rp = _ctlrunestr(cp->args[1]);
		if(runestrcmp(rp, e->text) != 0){
			free(e->text);
			e->text = rp;
			e->ntext = runestrlen(e->text);
			e->cursor = e->ntext;
			entryshow(e);
		}else
			free(rp);
		break;
	}
}

static void
entrykey(Entry *e, Rune r)
{
	Rune *s;
	int n;
	char *p;

	switch(r){
	default:
		e->text = ctlrealloc(e->text, (e->ntext+1+1)*sizeof(Rune));
		memmove(e->text+e->cursor+1, e->text+e->cursor,
			(e->ntext+1-e->cursor)*sizeof(Rune));
		e->text[e->cursor++] = r;
		e->ntext++;
		break;
	case L'\n':	/* newline: return value */
		p = _ctlstrrune(e->text);
		chanprint(e->event, e->format, e->name, p);
		free(p);
		return;
	case L'\b':
		if(e->cursor > 0){
			memmove(e->text+e->cursor-1, e->text+e->cursor,
				(e->ntext+1-e->cursor)*sizeof(Rune));
			e->cursor--;
			e->ntext--;
		}
		break;
	case 0x15:	/* control U: kill line */
		e->cursor = 0;
		e->ntext = 0;
		break;
	case 0x16:	/* control V: paste (append snarf buffer) */
		s = _ctlgetsnarf();
		if(s != nil){
			n = runestrlen(s);
			e->text = ctlrealloc(e->text, (e->ntext+n+1)*sizeof(Rune));
			memmove(e->text+e->cursor+n, e->text+e->cursor,
				(e->ntext+1-e->cursor)*sizeof(Rune));
			memmove(e->text+e->cursor, s, n*sizeof(Rune));
			e->cursor += n;
			e->ntext += n;
		}
		break;
	}
	e->text[e->ntext] = L'\0';
}

static void
entrykeys(Control *c, Rune *rp)
{
	Entry *e;
	int i;

	e = (Entry *)c;
	for(i=0; rp[i]!=L'\0'; i++)
		entrykey(e, rp[i]);
	entryshow(e);
}

Control*
createentry(Controlset *cs, char *name)
{
	Entry *e;

	e = (Entry*) _createctl(cs, "entry", sizeof(Entry), name);
	e->text = ctlmalloc(sizeof(Rune));
	e->ntext = 0;
	e->image = _getctlimage("white");
	e->textcolor = _getctlimage("black");
	e->bordercolor = _getctlimage("black");
	e->font = _getctlfont("font");
	e->format = ctlstrdup("%q: value %q");
	e->border = 0;
	e->ctl = entryctl;
	e->mouse = entrymouse;
	e->key = entrykeys;
	e->exit = entryfree;
	return (Control *)e;
}