widgets.c

一个很好的SDL建立应用程序界面的例子

	y += 4;
	closebtn->x = x;
	closebtn->y = y;
	addWList(closebtn);
}

// Display a TextBox

void showTextBox(TEXTBOX *t)
{
	int		i, j, x, y, xlim, ylim, fg, bg, xoffset, pos;
	BUTTON	*btn;
	BLIST		*bl;
	TLIST		*tl;
	char		*str, chr;

	makeBar(t->x + 1, t->y + 1, t->w - 2, t->h - 2, t->bg);	// body of window
	makeBar(t->x, t->y, t->w, 1, t->hi);							// top border
	makeBar(t->x + 1, t->y + t->h - 1, t->w - 1, 1, t->lo);	// bottom border
	makeBar(t->x, t->y, 1, t->h, t->hi);							// left border
	makeBar(t->x + t->w - 1, t->y + 1, 1, t->h - 1, t->lo);	// right border

	x = t->x + 4;
	y = t->y + 1;
	xlim = t->w - (2 + FONT_WIDTH);
	ylim = t->y + 1 + t->h - FONT_HEIGHT;
	fg = t->fg;
	bg = t->bg;
	bl = t->list;

	while (bl)
	{
		btn = bl->thislist.button;

		if (btn)
			showWidget(btn);

		bl = bl->next;
	}

	tl = t->text;
	i = t->line;

	while (i && tl && tl->next)
	{
		tl = tl->next;
		--i;
	}

	while (tl && y < ylim)
	{
		str = tl->str;
		fg = tl->fg;
		bg = tl->bg;
		i = 0;
		j = x;
		pos = 0;

		if (t->xoffset)
		{
			xoffset = t->xoffset;

			while (*str && xoffset)
			{
				str++;
				--xoffset;
			}
		}

		while (str && *str && i < xlim)
		{
			chr = *str++;

			if ((chr & 0x7f) == '\n')
				break;

			if ((chr & 0x7f) == '\t')
			{
				drawChar(j, y, fg, bg, ' ');
				pos++;
				i += FONT_WIDTH;
				j += FONT_WIDTH;

				if (i >= xlim)
					break;

				while (pos & 7)
				{
					drawChar(j, y, fg, bg, ' ');
					pos++;
					i += FONT_WIDTH;
					j += FONT_WIDTH;

					if (i >= xlim)
						break;
				}
			}
			else
			{
				if (chr & 0x80)
					drawChar(j, y, bg, fg, chr & 0x7f);
				else
					drawChar(j, y, fg, bg, chr);

				i += FONT_WIDTH;
				j += FONT_WIDTH;
				pos++;
			}
		}

		y += FONT_HEIGHT;
		tl = tl->next;
	}
}

// Display an InputBox

void showInputBox(INPUTBOX *ib)
{
	int		i, j, x, y, xlim, ylim, fg, bg, xc, yc, line;
	BUTTON	*btn;
	BLIST		*bl;
	SLIST		*sl;
	char		*str, chr;

	makeBar(ib->x + 1, ib->y + 1, ib->w - 2, ib->h - 2, ib->bg);	// body of window
	makeBar(ib->x, ib->y, ib->w, 1, ib->hi);								// top border
	makeBar(ib->x + 1, ib->y + ib->h - 1, ib->w - 1, 1, ib->lo);	// bottom border
	makeBar(ib->x, ib->y, 1, ib->h, ib->hi);								// left border
	makeBar(ib->x + ib->w - 1, ib->y + 1, 1, ib->h - 1, ib->lo);	// right border

	x = ib->x + 4;
	y = ib->y + 1;
	yc = y;
	xlim = ib->w - (2 + FONT_WIDTH);
	ylim = ib->y + 1 + ib->h - FONT_HEIGHT;
	fg = ib->fg;
	bg = ib->bg;
	bl = ib->list;

	while (bl)
	{
		btn = bl->thislist.button;

		if (btn)
		{
			showWidget(btn);

			if (childInParent(ib, btn))
			{
				y += btn->h;
				yc += btn->h;
			}
		}
		bl = bl->next;
	}

	sl = ib->text;
	i = ib->line;
	line = i;

	while (i && sl && sl->next)
	{
		sl = sl->next;
		--i;
		line++;
	}

	while (sl && y < ylim)
	{
		str = sl->str;
		i = 0;
		j = x;

		while (*str && i < xlim)
		{
			chr = *str++;

			if (chr == '\n')
				break;

			drawChar(j, y, fg, bg, chr);
			i += FONT_WIDTH;
			j += FONT_WIDTH;
		}

		y += FONT_HEIGHT;
		line++;
		sl = sl->next;
	}

	xc = ib->cursorx * FONT_WIDTH;
	y = ib->cursory;

	if (y >= line)
	{
		y = line - 1;
		ib->line++;
	}
}

// Display a Button

void showButton(BUTTON *b)
{
	int		x, y;
	char		*text;
	WINDOW	*w = b->parent;

	if (b->border)
		y = b->y;
	else
		y = b->y + 1;

	makeBar(b->x + 1, y, b->w - 2, b->h - 1, b->bg);	// body of button
	x = b->x + 4;
	text = b->text;

	if (text)
	{
		if (b->y < w->y || b->y > w->y + w->h ||
			 b->x < w->x || b->x > w->x + w->w)			// button outside the parent box
		{
			printString(b->x + 4, b->y, b->fg, b->bg, text);
		}
		else														// button inside the parent box
		{
			printString(x, b->y, b->fg, b->bg, text);
			x += strlen(text) * FONT_WIDTH + 8;
		}

		if (b->border)
		{
			makeBar(b->x, b->y - 1, b->w, 1, b->hi);						// top
			makeBar(b->x + 1, b->y + b->h - 1, b->w - 1, 1, b->lo);	// bottom
			makeBar(b->x, b->y, 1, b->h, b->hi);							// left
			makeBar(b->x + b->w - 1, b->y, 1, b->h - 1, b->lo);		// right
		}
	}
}

// Display a CheckBox

void showCheckBox(CHECKBOX *cb)
{
	int		x;
	char		*text;

	makeBar(cb->x + 1, cb->y + 1, cb->w - 2, cb->h - 1, cb->bg);		// body of checkbox
	x = cb->x + 4;
	text = cb->text;

	if (text)
	{
		drawChar(x, cb->y, cb->fg, cb->bg, '[');

		if (*cb->value)
			drawChar(x + FONT_WIDTH, cb->y, cb->fg, cb->bg, CHECK_MARK);
		else
			drawChar(x + FONT_WIDTH, cb->y, cb->fg, cb->bg, ' ');

		drawChar(x + FONT_WIDTH * 2, cb->y, cb->fg, cb->bg, ']');
		printString(x + FONT_WIDTH * 4, cb->y, cb->fg, cb->bg, text);

		if (cb->border)
		{
			makeBar(cb->x, cb->y, 1, cb->h, cb->hi);		// left
			makeBar(cb->x + cb->w - 1, cb->y + 1, 1, cb->h - 1, cb->lo);	// right
		}

		x += (strlen(text) + 4) * FONT_WIDTH + 8;
	}
}

// Display a Label

void showLabel(LABEL *lab)
{
	int	y, len, max;
	char	*cptr;

	if (lab->border)
		y = lab->y;
	else
		y = lab->y + 1;

	makeBar(lab->x + 1, y, lab->w - 2, lab->h - 1, lab->bg);	// body of label

	if (lab->border)
	{
		makeBar(lab->x, lab->y - 1, lab->w, 1, lab->hi);						// top
		makeBar(lab->x + 1, lab->y + lab->h - 1, lab->w - 1, 1, lab->lo);	// bottom
		makeBar(lab->x, lab->y, 1, lab->h, lab->hi);								// left
		makeBar(lab->x + lab->w - 1, lab->y, 1, lab->h - 1, lab->lo);		// right
	}

	cptr = lab->text;

	if (cptr)
	{
		len = strlen(cptr);
		max = lab->w / FONT_WIDTH - 1;

// Since label names may change, usually because it's a directory or
// file name, adjust the text pointer to show the tail end of the text.

		if (len >= max)
			cptr = (char *) ((int) cptr + len - max);

		printString(lab->x + 4, lab->y, lab->fg, lab->bg, cptr);
	}
}

// Display a Highlighted Label

void showHLabel(HLABEL *lab)
{
	int	y, len, max;
	char	*cptr;

	if (lab->border)
		y = lab->y;
	else
		y = lab->y + 1;

	makeBar(lab->x + 1, y, lab->w - 2, lab->h - 1, lab->bg);	// body of label

	if (lab->border)
	{
		makeBar(lab->x, lab->y - 1, lab->w, 1, lab->hi);						// top
		makeBar(lab->x + 1, lab->y + lab->h - 1, lab->w - 1, 1, lab->lo);	// bottom
		makeBar(lab->x, lab->y, 1, lab->h, lab->hi);								// left
		makeBar(lab->x + lab->w - 1, lab->y, 1, lab->h - 1, lab->lo);		// right
	}

	cptr = lab->text;

	if (cptr)
	{
		len = strlen(cptr);
		max = lab->w / FONT_WIDTH - 1;

// Since label names may change, usually because it's a directory or
// file name, adjust the text pointer to show the tail end of the text.

		if (len >= max)
			cptr = (char *) ((int) cptr + len - max);

		if (lab->hlflag)
			printHLString(lab->x + 4, lab->y, lab->fg, lab->bg, cptr);
		else
			printString(lab->x + 4, lab->y, lab->fg, lab->bg, cptr);
	}
}

// Display a left pointing arrowhead

void showLeftArrow(int x, int y)
{
	int	i;

	setPixel(x, y, black);

	for (i = -1; i < 2; i++)
		setPixel(x + 1, y + i, black);

	for (i = -2; i < 3; i++)
		setPixel(x + 2, y + i, black);

	for (i = -3; i < 4; i++)
		setPixel(x + 3, y + i, black);
}

// Display a right pointing arrowhead

void showRightArrow(int x, int y)
{
	int	i;

	setPixel(x, y, black);

	for (i = -1; i < 2; i++)
		setPixel(x - 1, y + i, black);

	for (i = -2; i < 3; i++)
		setPixel(x - 2, y + i, black);

	for (i = -3; i < 4; i++)
		setPixel(x - 3, y + i, black);
}

// Display an upward pointing arrowhead

void showUpArrow(int x, int y)
{
	int	i;

	setPixel(x, y, black);

	for (i = -1; i < 2; i++)
		setPixel(x + i, y + 1, black);

	for (i = -2; i < 3; i++)
		setPixel(x + i, y + 2, black);

	for (i = -3; i < 4; i++)
		setPixel(x + i, y + 3, black);
}

// Display a downward pointing arrowhead

void showDownArrow(int x, int y)
{
	int	i;

	setPixel(x, y, black);

	for (i = -1; i < 2; i++)
		setPixel(x + i, y - 1, black);

	for (i = -2; i < 3; i++)
		setPixel(x + i, y - 2, black);

	for (i = -3; i < 4; i++)
		setPixel(x + i, y - 3, black);
}

// Display a Vertical Slider

void showVSlider(VSLIDER *vs)
{
	int	x, y, w, h, p;
	int	sstart, sstop, size;
	BUTTON	*btn;
	BLIST		*bl;

	x = vs->x;
	y = vs->y;
	w = vs->w;
	h = vs->h;
	p = vs->position;

	if (p < 0)
		vs->position = p = 0;

	bl = vs->list;

	while (bl)
	{
		btn = bl->thislist.button;

		if (btn)
			showWidget(btn);

		bl = bl->next;
	}

	makeBar(x, y, w + 1, 1, vs->hi);				// top border
	makeBar(x + 1, y + h, w, 1, vs->lo);		// bottom
	makeBar(x, y, 1, h + 1, vs->hi);				// left
	makeBar(x + w, y + 1, 1, h - 1, vs->lo);	// right

	size = vs->size;
	sstart = p + SLIDERBUTTONSIZE;

	if (sstart > h - size - SLIDERBUTTONSIZE)	// at bottom of slider
		sstart = h - size - SLIDERBUTTONSIZE;

	sstop = sstart + size;

	if (sstart)														// slider not at top,
		makeBar(x + 1, y + 1, w - 1, sstart, vs->bg);	// show area preceeding slider

	makeBar(x + 1, y + sstart, w - 1, size, lgray);		// show the slider

	if (sstop < h)
		makeBar(x + 1, y + sstop, w - 1, h - sstop, vs->bg);	// show area following slider

// do marker border

	makeBar(x + 1, y + sstart, w - 1, 1, white);				// top
	makeBar(x + 1, y + sstart + size, w - 1, 1, black);	// bottom
	makeBar(x + 1, y + sstart, 1, size, white);				// left
	makeBar(x + w - 1, y + sstart, 1, size, black);			// right

	makeBar(x, y + SLIDERBUTTONSIZE - 2, w + 1, 1, black);			// top divider
	showUpArrow(x + vs->w / 2, y + 2);
	makeBar(x, y + vs->h - SLIDERBUTTONSIZE + 1, w + 1, 1, white);	// bottom divider
	showDownArrow(x + vs->w / 2, y + vs->h - 2);
}

// Display a Horizontal Slider

void showHSlider(HSLIDER *hs)
{
	int	x, y, w, h, p;
	int	sstart, sstop, size;
	BUTTON	*btn;
	BLIST		*bl;

	x = hs->x;
	y = hs->y;
	w = hs->w;
	h = hs->h;
	p = hs->position;

	if (p < 0)
		hs->position = p = 0;

	bl = hs->list;

	while (bl)
	{
		btn = bl->thislist.button;

		if (btn)
			showWidget(btn);

		bl = bl->next;
	}

	makeBar(x, y, w, 1, hs->hi);			// top border
	makeBar(x, y + h, w, 1, hs->lo);		// bottom
	makeBar(x, y, 1, h, hs->hi);			// left
	makeBar(x + w, y, 1, h, hs->lo);		// right

	size = hs->size;
	sstart = p + SLIDERBUTTONSIZE;

	if (sstart > w - size - SLIDERBUTTONSIZE)	// at right end of slider
		sstart = w - size - SLIDERBUTTONSIZE;

	sstop = sstart + size;

	if (sstart)														// slider not at left end,
		makeBar(x + 1, y + 1, sstart, h - 1, hs->bg);	// show area preceeding slider

	makeBar(x + sstart, y + 1, size, h - 1, lgray);		// show the slider

	if (sstop < w)
		makeBar(x + sstop, y + 1, w - sstop, h - 1, hs->bg);	// show area following slider

// do marker border

	makeBar(x + sstart, y + 1, size, 1, white);			// top
	makeBar(x + sstart, y + h - 1, size, 1, black);		// bottom
	makeBar(x + sstart, y + 1, 1, h - 1, white);			// left
	makeBar(x + sstop, y + 1, 1, h - 1, black);			// right

	makeBar(x + SLIDERBUTTONSIZE - 1, y, 1, h + 1, black);			// left divider
	showLeftArrow(x + 2, y + h / 2);
	makeBar(x + hs->w - SLIDERBUTTONSIZE + 2, y, 1, h + 1, white);	// right divider
	showRightArrow(x + hs->w - 2, y + h / 2);
}

// Return code for where the mouse is within the slider.
// Input mx & my are the current mouse coordinates.

int whereInSlider(void *slider, int mx, int my)
{
	int		top, bottom, loc, pos;
	int		left, right, e;
	VSLIDER	*sp;

	sp = (VSLIDER *) slider;
	pos = sp->position;

	if (sp->type == VSliderType)
	{
		top = sp->y;
		bottom = top + sp->h;
		left = sp->x;
		right = left + sp->w;
		loc = my;
		e = mx;
	}
	else if (sp->type == HSliderType)
	{
		top = sp->x;
		bottom = top + sp->w;
		left = sp->y;
		right = left + sp->h;
		loc = mx;
		e = my;
	}
	else
		return MOUSE_NOT_IN_SLIDER;

	pos += (top + SLIDERBUTTONSIZE);

	if (loc < top || loc > bottom)
		return MOUSE_NOT_IN_SLIDER;

	if (loc < top + SLIDERBUTTONSIZE)
	{
		if (e >= left && e <= right)
			return MOUSE_IN_SLIDER_UPBUTTON;

		return MOUSE_NOT_IN_SLIDER;
	}

	if (loc < pos)
		return MOUSE_IN_UPPER_SLIDER;

	if (loc < pos + sp->size)
		return MOUSE_ON_SLIDER;

	if (loc < bottom - SLIDERBUTTONSIZE)
		return MOUSE_IN_LOWER_SLIDER;

	if (e >= left && e <= right)
		return MOUSE_IN_SLIDER_DOWNBUTTON;

	return MOUSE_NOT_IN_SLIDER;
}

// Adjust slider position and return TRUE if position change caused a state change

bool tweakSlider(VSLIDER *sp, int x, int y, int where)
{
	int	state, pos, len, pc;
	bool	change;

	change = FALSE;
	state = whereInSlider(sp, x, y);

	if (state != where)						// if adjustment caused a state change...
	{
		if (sp->type == VSliderType)
		{
			pos = y - sp->y;
			len = sp->h;
		}
		else
		{
			pos = x - sp->x;
			len = sp->w;
		}

		len -= (sp->size + 2 * SLIDERBUTTONSIZE);
		pos -= (SLIDERBUTTONSIZE + SLIDERBUTTONSIZE/ 2);

		if (pos < 0)
			pos = 0;

		if (pos > len)
			pos = len;

		sp->position = pos;
		pc = (pos * 100) / len;
		sp->pc = pc;
		sp->offset = (sp->range * pc) / 100;
		change = TRUE;
	}

	return change;
}

// Adjust slider position by some amount

void adjustSlider(void *slider, int amount)
{
	int		pos, pc, loc, count, len;
	int		offset;
	VSLIDER	*sp;

	if (!topWidget)
		return;

	if ((((WIDGET *) topWidget)->p.type == AlertType) ||
			(((WIDGET *) topWidget)->p.type == NoticeType))
		return;

	sp = (VSLIDER *) slider;

	if (sp->type == VSliderType)
		len = sp->h;
	else if (sp->type == HSliderType)
		len = sp->w;
	else
		return;

	len -= (sp->size + 2 * SLIDERBUTTONSIZE);
	offset = sp->offset;
	count = sp->range;

	if (!count)
		count = 1;

	loc = offset + amount;

	if (loc < 0)
		loc = 0;
	else if (loc > count)
		loc = count;

	sp->offset = loc;
	pc = (loc * 100) / count;
	pos = (pc * len) / 100;
	sp->position = pos;
	sp->pc = pc;
}

// Update slider parameters

void updateSlider(SDL_Event *ev, void *slider)
{
	int		x, y, pos, pc, len, size;
	VSLIDER	*sp;
	int		where;

	sp = (VSLIDER *) slider;
	size = sp->size;
	x = ev->button.x;