Use right click as previous and enable scrolling to switch slides

In load() we allocated slides before checking if we actually read
anything from the FILE fp and then continue with an allocated but
“empty” space wich would lead to errors.

README.md

@@ -1,70 +1,50 @@
-sent
-====
-
-A simple plaintext presentation tool.
+sent is a simple plaintext presentation tool.
 
 sent does not need latex, libreoffice or any other fancy file format, it uses
-plaintext files and png images. Every line represents a slide in the
-presentation. This may limit the use, but for presentations using the [Takahashi
-method](https://en.wikipedia.org/wiki/Takahashi_method) this is very nice and
-allows you to write down the presentation for a quick lightning talk within a
-few minutes.
+plaintext files and png images. Every paragraph represents a slide in the
+presentation.
+
+The presentation is displayed in a simple X11 window. The content of each slide
+is automatically scaled to fit the window and centered so you also don't have to
+worry about alignment. Instead you can really concentrate on the content.
 
-The presentation is displayed in a simple X11 window colored black on white for
-maximum contrast even if the sun shines directly onto the projected image. The
-content of each slide is automatically scaled to fit the window so you don't
-have to worry about alignment. Instead you can really concentrate on the
-content.
 
 Demo
-----
 
 To get a little demo, just type
 
 	make && ./sent example
 
-You can navigate with the arrow keys and quit with `q`. If you get
+You can navigate with the arrow keys and quit with `q`.
 
-	sent: could not find a scalable font matching -*-dejavu sans condensed-bold-r-*-*-0-0-*-*-*-0-*-*
-
-you should add the dejavu fonts dir (customize path to fit your distribution)
-with:
-
-	xset fp+ /usr/share/fonts/dejavu
-
-Configuration
--------------
-
-Edit config.h to fit your needs. The font has to be in the X servers font path,
-see `man xset` for how to add it.
 
 Usage
------
 
-	sent [-f FONTSTRING] FILE1 [FILE2 ...]
+	sent FILE1 [FILE2 ...]
 
-If one FILE equals `-`, stdin will be read. Use png images by prepending a `@`
-before the filename. Lines starting with `#` will be ignored. A presentation
-file could look like this:
+If one FILE equals `-`, stdin will be read. Produce image slides by prepending a
+`@` in front of the filename as a single paragraph. Lines starting with `#` will
+be ignored. A `\` at the beginning of the line escapes `@` and `#`. A
+presentation file could look like this:
 
 	sent
-	why?
+	
 	@nyan.png
-	easy to use
-	depends on Xlib, libpng
-	no bloat
-	how?
+	
+	depends on
+	- Xlib
+	- libpng
+	
 	sent FILENAME
-	one slide per line
+	one slide per paragraph
 	# This is a comment and will not be part of the presentation
-	# The next line starts with a whitespace, it will not produce an image slide
-	 @FILE.png
+	\# This and the next line start with backslashes
+	
+	\@FILE.png
+	
 	thanks / questions?
 
-future features
----------------
 
-* multiple lines per slide?
-* light colored background and table of contents
-* second window for speakers laptop (progress, time, notes?)
-* markdown?
+Development
+
+sent is developed at http://tools.suckless.org/sent

config.def.h

@@ -1,11 +1,11 @@
 /* See LICENSE file for copyright and license details. */
 
 static char *fontfallbacks[] = {
-	"dejavu",
+	"dejavu sans",
 	"roboto",
 	"ubuntu",
 };
-#define NUMFONTSCALES 30
+#define NUMFONTSCALES 42
 #define FONTSZ(x) ((int)(10.0 * powf(1.1288, (x)))) /* x in [0, NUMFONTSCALES-1] */
 
 static const char *fgcol = "#000000";
@@ -20,15 +20,19 @@ static const float usableheight = 0.75;
 static Mousekey mshortcuts[] = {
 	/* button         function        argument */
 	{ Button1,        advance,        {.i = +1} },
-	{ Button2,        advance,        {.i = -1} },
+	{ Button3,        advance,        {.i = -1} },
+	{ Button4,        advance,        {.i = -1} },
+	{ Button5,        advance,        {.i = +1} },
 };
 
 static Shortcut shortcuts[] = {
 	/* keysym         function        argument */
+	{ XK_Escape,      quit,           {0} },
 	{ XK_q,           quit,           {0} },
 	{ XK_Right,       advance,        {.i = +1} },
 	{ XK_Left,        advance,        {.i = -1} },
 	{ XK_Return,      advance,        {.i = +1} },
+	{ XK_space,       advance,        {.i = +1} },
 	{ XK_BackSpace,   advance,        {.i = -1} },
 	{ XK_l,           advance,        {.i = +1} },
 	{ XK_h,           advance,        {.i = -1} },

config.mk

@@ -1,5 +1,5 @@
 # sent version
-VERSION = 0.1
+VERSION = 0.2
 
 # Customize below to fit your system
 

drw.c

@@ -396,9 +396,9 @@ drw_font_getexts(Fnt *font, const char *text, unsigned int len, unsigned int *w,
 
 Cur *
 drw_cur_create(Drw *drw, int shape) {
-	Cur *cur = (Cur *)calloc(1, sizeof(Cur));
+	Cur *cur;
 
-	if(!drw || !cur)
+	if(!drw || !(cur = (Cur *)calloc(1, sizeof(Cur))))
 		return NULL;
 	cur->cursor = XCreateFontCursor(drw->dpy, shape);
 	return cur;

example

@@ -29,8 +29,8 @@ $ sent FILE1 [FILE2 …]
 
 ▸ one slide per paragraph
 ▸ lines starting with # are ignored
-▸ paragraphs starting with a @ line are png images
-▸ for an empty slide just use a \ as a paragraph
+▸ image slide: paragraph containing @FILE.png
+▸ empty slide: just use a \ as a paragraph
 
 # This is a comment and will not be part of the presentation
 

sent.c

@@ -318,7 +318,7 @@ void pngdraw(Image *img)
 
 void getfontsize(Slide *s, unsigned int *width, unsigned int *height)
 {
-	size_t i, j;
+	int i, j;
 	unsigned int curw, imax;
 	float lfac = linespacing * (s->linecount - 1) + 1;
 
@@ -326,6 +326,7 @@ void getfontsize(Slide *s, unsigned int *width, unsigned int *height)
 	for (j = NUMFONTSCALES - 1; j >= 0; j--)
 		if (fonts[j]->h * lfac <= xw.uh)
 			break;
+	LIMIT(j, 0, NUMFONTSCALES - 1);
 	drw_setfontset(d, fonts[j]);
 
 	/* fit width */
@@ -334,7 +335,7 @@ void getfontsize(Slide *s, unsigned int *width, unsigned int *height)
 		curw = drw_fontset_getwidth(d, s->lines[i]);
 		if (curw >= *width)
 			imax = i;
-		while (j >= 0 && curw > xw.uw) {
+		while (j > 0 && curw > xw.uw) {
 			drw_setfontset(d, fonts[--j]);
 			curw = drw_fontset_getwidth(d, s->lines[i]);
 		}
@@ -412,10 +413,6 @@ void load(FILE *fp)
 
 	/* read each line from fp and add it to the item list */
 	while (1) {
-		if ((slidecount+1) * sizeof(*slides) >= size)
-			if (!(slides = realloc(slides, (size += BUFSIZ))))
-				die("cannot realloc %u bytes:", size);
-
 		/* eat consecutive empty lines */
 		while ((p = fgets(buf, sizeof(buf), fp)))
 			if (strcmp(buf, "\n") != 0 && buf[0] != '#')
@@ -423,6 +420,10 @@ void load(FILE *fp)
 		if (!p)
 			break;
 
+		if ((slidecount+1) * sizeof(*slides) >= size)
+			if (!(slides = realloc(slides, (size += BUFSIZ))))
+				die("cannot realloc %u bytes:", size);
+
 		/* read one slide */
 		maxlines = 0;
 		memset((s = &slides[slidecount]), 0, sizeof(Slide));
@@ -571,14 +572,13 @@ void xinit()
 	xw.vis = XDefaultVisual(xw.dpy, xw.scr);
 	resize(DisplayWidth(xw.dpy, xw.scr), DisplayHeight(xw.dpy, xw.scr));
 
-	xw.attrs.background_pixel = WhitePixel(xw.dpy, xw.scr);
 	xw.attrs.bit_gravity = CenterGravity;
 	xw.attrs.event_mask = KeyPressMask | ExposureMask | StructureNotifyMask
 		| ButtonMotionMask | ButtonPressMask;
 
 	xw.win = XCreateWindow(xw.dpy, XRootWindow(xw.dpy, xw.scr), 0, 0,
 			xw.w, xw.h, 0, XDefaultDepth(xw.dpy, xw.scr), InputOutput, xw.vis,
-			CWBackPixel | CWBitGravity | CWEventMask, &xw.attrs);
+			CWBitGravity | CWEventMask, &xw.attrs);
 
 	xw.wmdeletewin = XInternAtom(xw.dpy, "WM_DELETE_WINDOW", False);
 	xw.netwmname = XInternAtom(xw.dpy, "_NET_WM_NAME", False);
@@ -588,6 +588,7 @@ void xinit()
 		die("Can't create drawing context.");
 	sc = drw_scm_create(d, fgcol, bgcol);
 	drw_setscheme(d, sc);
+	XSetWindowBackground(xw.dpy, xw.win, sc->bg.pix);
 
 	xloadfonts();
 
@@ -615,7 +616,8 @@ void xloadfonts()
 			if (MAXFONTSTRLEN < snprintf(fstrs[j], MAXFONTSTRLEN, "%s:size=%d", fontfallbacks[j], FONTSZ(i)))
 				die("font string too long");
 		}
-		fonts[i] = drw_fontset_create(d, (const char**)fstrs, LEN(fstrs));
+		if (!(fonts[i] = drw_fontset_create(d, (const char**)fstrs, LEN(fstrs))))
+			die("unable to load any font for size %d", FONTSZ(i));
 	}
 
 	for (j = 0; j < LEN(fontfallbacks); j++)
@@ -683,7 +685,7 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	if (!slides || !slides[0].lines)
+	if (!slidecount)
 		usage();
 
 	xinit();