widgets.c

一个很好的SDL建立应用程序界面的例子

/*
 * widgets.c - SDL widget set in C
 *
 * Copyright 2004 by Jeffery L. Post
 * theposts<AT>pacbell<DOT>net
 * Version 0.0.3 - 11/26/04
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include	<stdio.h>
#include	<stdlib.h>
#include	<string.h>
#include	<ctype.h>
#include	<signal.h>
#include	<sys/time.h>

#include	"widgets.h"

#define	CURSOR_Y_OFFSET	1	// this insures that the cursor is under the character

// We use a system interval timer because SDL timers screw up popen(), exec(), etc.

#define	WIDGET_TIMER_UPDATE_TIME		50
#define	WIDGET_SLIDER_REPEAT_DELAY		3

#define	IBOX_CURSOR_DELAY					5

struct timer_data {
	int		*timeout;
	VSLIDER	*vs;
};

extern SDL_Surface	*screen;

// Local prototypes

void	widgetTimerCB(void);
void	blankScreen(void);
int	printString(int x, int y, int fg, int bg, char *str);
int	printHLString(int x, int y, int fg, int bg, char *str);
void	drawCursor(int x, int y, int fg, char chr);
void	setPixel(int x, int y, int color);
void	shiftStringUp(char *str, int index);
void	shiftStringDown(char *str, int index);
int	whereInSlider(void *slider, int mx, int my);
bool	tweakSlider(VSLIDER *sp, int x, int y, int where);
void	adjustSlider(void *slider, int amount);
void	updateSlider(SDL_Event *ev, void *slider);
void	makeBar(int x, int y, int w, int h, int color);
void	processAlertCallBack(SDL_Event *ev, BUTTON * btn);
void	processNoticeCallBack(SDL_Event *ev, BUTTON * btn);
bool	childInParent(void *parent, void *child);
int	maxWidth(WINDOW *win);
void	updateIBox(SDL_Event *event, INPUTBOX *b);

void	showWindow(WINDOW *w);
void	showVMenu(VMENU *w);
void	showAlertBox(WINDOW *w);
void	showNoticeBox(WINDOW *w);
void	showTextBox(TEXTBOX *w);
void	showInputBox(INPUTBOX *w);
void	showButton(BUTTON *b);
void	showLabel(LABEL *lab);
void	showHLabel(HLABEL *lab);
void	showCheckBox(CHECKBOX *cb);
void	showLeftArrow(int x, int y);
void	showRightArrow(int x, int y);
void	showUpArrow(int x, int y);
void	showDownArrow(int x, int y);
void	showVSlider(VSLIDER *vs);
void	showHSlider(HSLIDER *hs);
void	addWList(void *w);
void	removeWList(void *w);

// Global variables

#ifdef DEBUG

// widget_names MUST match enum WidgetType in widgets.h

char	*widget_names[] = {
	"Window",
	"Menu",
	"VMenu",
	"Button",
	"CheckBox",
	"Label",
	"HLabel",
	"Alert",
	"Notice",
	"TextBox",
	"InputBox",
	"VSlider",
	"HSlider",
	"Invalid Widget",
};

#endif	// DEBUG

int		widgetRepeatDelay = WIDGET_SLIDER_REPEAT_DELAY;

#ifndef WIN32
struct itimerval	vtimer;
#endif

struct timer_data timerData = {
	&widgetRepeatDelay,
	NULL,
};

// Simulated mouse button down event for automatic callbacks

SDL_MouseButtonEvent timerEvent = {
	SDL_MOUSEBUTTONDOWN,		// simulate mouse button down event
	0,								// mouse device index
	0,								// mouse button index
	SDL_PRESSED,				// state
	0,								// x coordinate
	0,								// y coordinate
};

// Timer event for auto callback

SDL_Event	AlarmEvent = {TIMER_EVENT};

int		widget_id = 0;
void		*topWidget = NULL;
int		screen_width;
int		screen_height;
Uint8		bits_per_pixel;
Uint8		bytes_per_pixel;
Uint16	pitch;

// Colors

Uint32	black;		// 0
Uint32	blue;			// 1
Uint32	green;		// 2
Uint32	cyan;			// 3
Uint32	red;			// 4
Uint32	magenta;		// 5
Uint32	brown;		// 6
Uint32	lgray;		// 7
Uint32	gray;			// 8
Uint32	lblue;		// 9
Uint32	lgreen;		// 10
Uint32	lcyan;		// 11
Uint32	lred;			// 12
Uint32	lmagenta;	// 13
Uint32	yellow;		// 14
Uint32	white;		// 15
Uint32	lyellow;		// 16
Uint32	dyellow;		// 17
Uint32	pink;			// 18
Uint32	dblue;		// 19
Uint32	dgreen;		// 20

WLIST		*wlist = NULL;

#ifdef DEBUG

void dump_widget_list(void)
{
	int		i;
	WLIST 	*next;
	WIDGET	*w;
	
	printf("\nWidget List at 0x%x:\n", (int) wlist);
	next = wlist;
	i = 1;

	while (next)
	{
		w = next->w;
		printf("%2d: widget %d at 0x%x, entry 0x%x, %s, parent 0x%x, x %d, y %d, w %d, h %d.",
			i, w->p.id, (int) w, (int) next, widget_names[w->p.type], (int) w->p.parent, w->p.x, w->p.y, w->p.w, w->p.h);
		printf(" Callbacks: 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n",
			(int) w->p.mdfunc, (int) w->p.mufunc, (int) w->p.mmfunc, (int) w->p.kdfunc, (int) w->p.kufunc);
		fflush(stdout);
		next = next->next;
		i++;
	}

	if (topWidget)
		printf("topWidget 0x%x, %s\n", (int) topWidget, widget_names[((WIDGET *) topWidget)->p.type]);
}

#endif

/*
 * Functions
 *
 */

void SigHandler(int sig)
{
#ifndef WIN32
	if (sig == SIGALRM)
		SDL_PushEvent(&AlarmEvent);
#else
	SDL_PushEvent(&AlarmEvent);
#endif
}

// Display a character with given colors at given coordinates

void drawChar(int x, int y, int fg, int bg, char chr)
{
	int	i, j, b;
	int	bpp, neg;
	Uint8	*row;

	b = (int) (Uint8) chr * FONT_WIDTH * FONT_HEIGHT;
	bpp = (int) bytes_per_pixel;
	neg = FONT_WIDTH * bpp;
	row = (Uint8 *) screen->pixels + y * pitch + x * bpp;

	switch (bytes_per_pixel)
	{
		case 1:
			for (i=0; i<FONT_HEIGHT; i++, y++)
			{
				row += pitch;

				for (j=0; j<FONT_WIDTH; j++)
				{
					if (fontdata[b + j])
						*row = (Uint8) fg;
					else
						*row = (Uint8) bg;

					row += bpp;
				}

				b += FONT_WIDTH;
				row -= neg;
			}
			break;

		case 2:
			for (i=0; i<FONT_HEIGHT; i++, y++)
			{
				row += pitch;

				for (j=0; j<FONT_WIDTH; j++)
				{
					if (fontdata[b + j])
						*(Uint16 *)row = (Uint16) fg;
					else
						*(Uint16 *)row = (Uint16) bg;

					row += bpp;
				}

				b += FONT_WIDTH;
				row -= neg;
			}
			break;

		case 4:
			for (i=0; i<FONT_HEIGHT; i++, y++)
			{
				row += pitch;

				for (j=0; j<FONT_WIDTH; j++)
				{
					if (fontdata[b + j])
						*(Uint32 *)row = (Uint32) fg;
					else
						*(Uint32 *)row = (Uint32) bg;

					row += bpp;
				}

				b += FONT_WIDTH;
				row -= neg;
			}
			break;
	}
}

// Display cursor

void drawCursor(int x, int y, int fg, char chr)
{
	int	i, j, b;
	int	bpp, neg;
	Uint8	*row;

	b = (int) (Uint8) chr * FONT_WIDTH * FONT_HEIGHT;
	bpp = (int) bytes_per_pixel;
	neg = FONT_WIDTH * bpp;
	y += CURSOR_Y_OFFSET;
	row = (Uint8 *) screen->pixels + y * pitch + x * bpp;

	switch (bytes_per_pixel)
	{
		case 1:
			for (i=0; i<FONT_HEIGHT; i++, y++)
			{
				row += pitch;

				for (j=0; j<FONT_WIDTH; j++)
				{
					if (fontdata[b + j])
						*row = (Uint8) fg;

					row += bpp;
				}

				b += FONT_WIDTH;
				row -= neg;
			}
			break;

		case 2:
			for (i=0; i<FONT_HEIGHT; i++, y++)
			{
				row += pitch;

				for (j=0; j<FONT_WIDTH; j++)
				{
					if (fontdata[b + j])
						*(Uint16 *)row = (Uint16) fg;

					row += bpp;
				}

				b += FONT_WIDTH;
				row -= neg;
			}
			break;

		case 4:
			for (i=0; i<FONT_HEIGHT; i++, y++)
			{
				row += pitch;

				for (j=0; j<FONT_WIDTH; j++)
				{
					if (fontdata[b + j])
						*(Uint32 *)row = (Uint32) fg;

					row += bpp;
				}

				b += FONT_WIDTH;
				row -= neg;
			}
			break;
	}
}

// Set pixel at given coordinates to the given color

void setPixel(int x, int y, int color)
{
	Uint8		*row8;
	Uint16	*row16;
	Uint32	*row32;

	switch (bytes_per_pixel)
	{
		case 1:
			row8 = (Uint8 *) ((int) screen->pixels + y * pitch + x * bytes_per_pixel);
			*row8 = (Uint8) color;
			break;

		case 2:
			row16 = (Uint16 *) ((int) screen->pixels + y * pitch + x * bytes_per_pixel);
			*row16 = (Uint16) color;
			break;

		case 4:
			row32 = (Uint32 *) ((int) screen->pixels + y * pitch + x * bytes_per_pixel);
			*row32 = (Uint32) color;
			break;
	}
}

// Display a string

int printString(int x, int y, int fg, int bg, char *str)
{
	int	i;
	char	chr;

	i = 0;

	while (*str)
	{
		chr = *str++;
		drawChar(x, y, fg, bg, chr);
		x += FONT_WIDTH;
		i++;
	}

	return i;
}

// Display a highlighted string

int printHLString(int x, int y, int fg, int bg, char *str)
{
	int	i;
	char	chr;

	i = 0;

	while (*str)
	{
		chr = *str++;

		if (chr & 0x80)
			drawChar(x, y, bg, fg, chr & 0x7f);
		else
			drawChar(x, y, fg, bg, chr);

		x += FONT_WIDTH;
		i++;
	}

	return i;
}

void shiftStringUp(char *str, int index)
{
	int	len;

	len = strlen(str);

	while (len > index)
	{
		str[len] = str[len - 1];
		--len;
	}
}

void shiftStringDown(char *str, int index)
{
	do
	{
		str[index] = str[index + 1];
		index++;
	} while (str[index]);
}

// Initialize the video system

void initWidgets(void)
{
	SDL_VideoInfo		*v_info;
	SDL_PixelFormat	*vfmt;

	v_info = (SDL_VideoInfo *) SDL_GetVideoInfo();

	if (!v_info)
	{
		printf("\n\nCan't get video info: %s\n\n", SDL_GetError());
		exit(1);
	}

	screen_width = screen->w;
	screen_height = screen->h;

	vfmt = screen->format;
	bits_per_pixel = vfmt->BitsPerPixel;
	bytes_per_pixel = vfmt->BytesPerPixel;
	pitch = screen->pitch;

	SDL_EnableUNICODE(TRUE);

#ifndef WIN32
	signal(SIGALRM, SigHandler);				// set up a signal handler
	vtimer.it_interval.tv_sec = 0;			// set a 50msec interval timer
	vtimer.it_interval.tv_usec = (WIDGET_TIMER_UPDATE_TIME * 1000);
	vtimer.it_value.tv_sec = 0;
	vtimer.it_value.tv_usec = (WIDGET_TIMER_UPDATE_TIME * 1000);
	setitimer(ITIMER_REAL, &vtimer, NULL);
#else
	SetTimer(NULL, 0, WIDGET_TIMER_UPDATE_TIME, (VOID CALLBACK*) &SigHandler);
#endif

//                                       R             G             B
	black		= SDL_MapRGB(vfmt, (Uint8) 0x00, (Uint8) 0x00, (Uint8) 0x00);	// 0
	blue     = SDL_MapRGB(vfmt, (Uint8) 0x00, (Uint8) 0x00, (Uint8) 0xd0);	// 1
	green    = SDL_MapRGB(vfmt, (Uint8) 0x00, (Uint8) 0xd0, (Uint8) 0x00);	// 2
	cyan     = SDL_MapRGB(vfmt, (Uint8) 0x00, (Uint8) 0xa6, (Uint8) 0xa6);	// 3
	red      = SDL_MapRGB(vfmt, (Uint8) 0xa6, (Uint8) 0x00, (Uint8) 0x00);	// 4
	magenta  = SDL_MapRGB(vfmt, (Uint8) 0xa6, (Uint8) 0x00, (Uint8) 0xa6);	// 5
	brown    = SDL_MapRGB(vfmt, (Uint8) 0xa6, (Uint8) 0x54, (Uint8) 0x00);	// 6
	lgray    = SDL_MapRGB(vfmt, (Uint8) 0xd0, (Uint8) 0xd0, (Uint8) 0xd0);	// 7
	gray     = SDL_MapRGB(vfmt, (Uint8) 0xa6, (Uint8) 0xa6, (Uint8) 0xa6);	// 8
	lblue    = SDL_MapRGB(vfmt, (Uint8) 0x00, (Uint8) 0x00, (Uint8) 0xff);	// 9
	lgreen   = SDL_MapRGB(vfmt, (Uint8) 0x00, (Uint8) 0xff, (Uint8) 0x00);	// 10
	lcyan    = SDL_MapRGB(vfmt, (Uint8) 0x54, (Uint8) 0xff, (Uint8) 0xff);	// 11
	lred     = SDL_MapRGB(vfmt, (Uint8) 0xff, (Uint8) 0x00, (Uint8) 0x00);	// 12
	lmagenta = SDL_MapRGB(vfmt, (Uint8) 0xff, (Uint8) 0x54, (Uint8) 0xff);	// 13
	yellow   = SDL_MapRGB(vfmt, (Uint8) 0xff, (Uint8) 0xff, (Uint8) 0x54);	// 14
	white		= SDL_MapRGB(vfmt, (Uint8) 0xff, (Uint8) 0xff, (Uint8) 0xff);	// 15
	lyellow	= SDL_MapRGB(vfmt, (Uint8) 0xff, (Uint8) 0xff, (Uint8) 0xc0);	// 16
	dyellow	= SDL_MapRGB(vfmt, (Uint8) 0xa6, (Uint8) 0xa6, (Uint8) 0x00);	// 17
	pink		= SDL_MapRGB(vfmt, (Uint8) 0xff, (Uint8) 0xa6, (Uint8) 0xa6);	// 18
	dblue		= SDL_MapRGB(vfmt, (Uint8) 0x00, (Uint8) 0x00, (Uint8) /*0xa6*/0x80);	// 19
	dgreen	= SDL_MapRGB(vfmt, (Uint8) 0x00, (Uint8) 0x80, (Uint8) 0x00);	// 20
}

void widgetQuit(void)
{
	timerData.vs = NULL;
}

// Blank the entire screen to black

void blankScreen(void)
{
	SDL_Rect	blank_area;

	blank_area.x = 0;
	blank_area.y = 0;
	blank_area.w = screen_width;
	blank_area.h = screen_height;
	SDL_FillRect(screen, (SDL_Rect *) &blank_area, 0);
}

// Mouse button down event has occurred on an AlertBox Cancel or OK button.
// Set the response code for the parent widget (the AlertBox), and then
// call its mousebuttondown function.

void processAlertCallBack(SDL_Event *ev, BUTTON * btn)
{
	ALERT	*parent;
	char		*c;
	void		(*fptr)(SDL_Event *, void *);

	parent = btn->parent;
	c = btn->text;

	if (!strcmp(c, " Cancel "))
		parent->response = ALERT_CANCEL;
	else if (!strcmp(c, " OK "))
		parent->response = ALERT_OK;
	else
		parent->response = ALERT_NO_RESPONSE;

	fptr = parent->mdfunc;

	if (fptr)
		(*fptr)(ev, parent);

	updateScreen();
}

// Mouse button down event has occurred on an NoticeBox Close button.

void processNoticeCallBack(SDL_Event *ev, BUTTON * btn)
{
	NOTICE	*parent;
	void		(*fptr)(SDL_Event *, void *);

	parent = btn->parent;
	fptr = parent->mdfunc;

	if (fptr)
		(*fptr)(ev, parent);

	pushDownWidget(parent);
	updateScreen();
}

void attachCallBack(void *w, int type, void *func)
{
	WIDGET	*x;

	x = (WIDGET *) w;

	switch (type)
	{
		case SDL_MOUSEBUTTONDOWN:
			x->p.mdfunc = func;
			break;

		case SDL_MOUSEBUTTONUP:
			x->p.mufunc = func;
			break;

		case SDL_MOUSEMOTION:
			x->p.mmfunc = func;
			break;

		case SDL_KEYDOWN:
			x->p.kdfunc = func;
			break;

		case SDL_KEYUP:
			x->p.kufunc = func;
			break;

		case SLIDER_AUTO_CALLBACK:
			if (x->p.type == VSliderType || x->p.type == HSliderType)
				((VSLIDER *) x)->adjfunc = func;
			break;
	}
}

void removeCallBack(void *w, int type)
{
	WIDGET	*x;

	x = (WIDGET *) w;

	switch (type)
	{
		case SDL_MOUSEBUTTONDOWN:
			x->p.mdfunc = NULL;
			break;

		case SDL_MOUSEBUTTONUP:
			x->p.mufunc = NULL;
			break;

		case SDL_MOUSEMOTION:
			x->p.mmfunc = NULL;
			break;

		case SDL_KEYDOWN:
			x->p.kdfunc = NULL;
			break;

		case SDL_KEYUP:
			x->p.kufunc = NULL;
			break;

		case SLIDER_AUTO_CALLBACK:
			if (x->p.type == VSliderType || x->p.type == HSliderType)
				((VSLIDER *) x)->adjfunc = NULL;
			break;
	}
}

// A dummy callback function which does nothing at all.
// This is available so that users can attach it to a
// Label or other widget when they don't really want to
// do anything except prevent underlying widgets from
// executing their callbacks.

void nullCallBack(void *w, ...)
{
	// do nothing
}

// Return TRUE if child widget displays inside parent widget

bool childInParent(void *parent, void *child)
{
	int		x, y;
	WIDGET	*p, *c;

	p = (WIDGET *) parent;
	c = (WIDGET *) child;
	x = c->p.x;
	y = c->p.y;

	if (x >= p->p.x && x <= p->p.x + p->p.w && y >= p->p.y && y <= p->p.y + p->p.h)
		return TRUE;

	return FALSE;
}

// Allocate a window structure

WINDOW *newWindow(int x, int y, int w, int h, int fg, int bg, int hi, int lo)
{
	WINDOW *win = (WINDOW *) malloc(sizeof(WINDOW));
	win->type = WindowType;
	win->id = widget_id++;
	win->x = x;
	win->y = y;
	win->w = w;
	win->h = h;
	win->fg = fg;
	win->bg = bg;
	win->hi = hi;
	win->lo = lo;
	win->mdfunc = NULL;
	win->mufunc = NULL;
	win->mmfunc = NULL;
	win->kdfunc = NULL;
	win->kufunc = NULL;
	win->parent = NULL;
	win->list = NULL;
	return win;
}

// Allocate a menu structure

MENU *newMenu(int x, int y, int w, int h, int fg, int bg, int hi, int lo)
{
	MENU *menu = (MENU *) malloc(sizeof(MENU));
	menu->type = MenuType;
	menu->id = widget_id++;