Add automatic detection of number of results.

Tofi will now try to autodetect how many results can be drawn if
--num-results=0 is specified, which is now the default.

8 files changed, 70 insertions, 11 deletions

diff --git a/doc/tofi.5.md b/doc/tofi.5.md
index 55e615f..916fc22 100644
--- a/doc/tofi.5.md
+++ b/doc/tofi.5.md
@@ -83,9 +83,10 @@ options.
 
 **num-results**=*n*
 
-> Maximum number of results to display.
+> Maximum number of results to display. If *n* = 0, tofi will draw as
+> many results as it can fit in the window.
 >
-> Default: 5
+> Default: 0
 
 **selection-color**=*color*
 
diff --git a/doc/tofi.5.scd b/doc/tofi.5.scd
index 41c5fe9..3ad7015 100644
--- a/doc/tofi.5.scd
+++ b/doc/tofi.5.scd
@@ -75,9 +75,10 @@ options.
 	Default: "run: "
 
 *num-results*=_n_
-	Maximum number of results to display.
+	Maximum number of results to display. If _n_ = 0, tofi will draw as
+	many results as it can fit in the window.
 
-	Default: 5
+	Default: 0
 
 *selection-color*=_color_
 	Color of selected result. See *COLORS* for more information.
diff --git a/src/drun.c b/src/drun.c
index bc755fb..8e1e0b4 100644
--- a/src/drun.c
+++ b/src/drun.c
@@ -122,6 +122,11 @@ static void parse_desktop_file(gpointer key, gpointer value, void *data)
 
 struct desktop_vec drun_generate(void)
 {
+	/*
+	 * Note for the future: this custom logic could be replaced with
+	 * g_app_info_get_all(), but that's slower. Worth remembering
+	 * though if this runs into issues.
+	 */
 	log_debug("Retrieving application dirs.\n");
 	struct string_vec paths = get_application_paths();
  	struct string_vec desktop_files = string_vec_create();
diff --git a/src/entry.c b/src/entry.c
index 89f274f..e308a3c 100644
--- a/src/entry.c
+++ b/src/entry.c
@@ -131,6 +131,14 @@ void entry_init(struct entry *entry, uint8_t *restrict buffer, uint32_t width, u
 		entry_backend_harfbuzz_init(entry, &width, &height);
 	}
 
+	/* Store the clip rectangle width and height. */
+	cairo_matrix_t mat;
+	cairo_get_matrix(cr, &mat);
+	entry->clip_x = mat.x0;
+	entry->clip_y = mat.y0;
+	entry->clip_width = width;
+	entry->clip_height = height;
+
 	/*
 	 * Perform an initial render of the text.
 	 * This is done here rather than by calling entry_update to avoid the
@@ -159,8 +167,6 @@ void entry_init(struct entry *entry, uint8_t *restrict buffer, uint32_t width, u
 	 * frame has been displayed on screen (and while the user is unlikely
 	 * to press another key for the <10ms it takes to memcpy).
 	 */
-	cairo_matrix_t mat;
-	cairo_get_matrix(cr, &mat);
 	cairo_set_matrix(entry->cairo[1].cr, &mat);
 	cairo_rectangle(entry->cairo[1].cr, 0, 0, width, height);
 	cairo_clip(entry->cairo[1].cr);
diff --git a/src/entry.h b/src/entry.h
index 63aad8a..c45bb85 100644
--- a/src/entry.h
+++ b/src/entry.h
@@ -40,10 +40,16 @@ struct entry {
 	struct history history;
 	bool use_pango;
 
+	uint32_t clip_x;
+	uint32_t clip_y;
+	uint32_t clip_width;
+	uint32_t clip_height;
+
 	/* Options */
 	bool drun;
 	bool horizontal;
 	uint32_t num_results;
+	uint32_t num_results_drawn;
 	int32_t result_spacing;
 	uint32_t font_size;
 	char font_name[MAX_FONT_NAME_LENGTH];
diff --git a/src/entry_backend/harfbuzz.c b/src/entry_backend/harfbuzz.c
index bb4429c..ed2a5aa 100644
--- a/src/entry_backend/harfbuzz.c
+++ b/src/entry_backend/harfbuzz.c
@@ -218,13 +218,32 @@ void entry_backend_harfbuzz_update(struct entry *entry)
 	cairo_font_extents_t font_extents;
 	cairo_font_extents(cr, &font_extents);
 
+	cairo_matrix_t mat;
 	/* Render our results entry text */
-	for (size_t i = 0; i < entry->num_results && i < entry->results.count; i++) {
+	for (size_t i = 0; i < entry->results.count; i++) {
 		if (entry->horizontal) {
 			cairo_translate(cr, width + entry->result_spacing, 0);
 		} else {
 			cairo_translate(cr, 0, font_extents.height + entry->result_spacing);
 		}
+		if (entry->num_results == 0) {
+			cairo_get_matrix(cr, &mat);
+			if (entry->horizontal) {
+				if (mat.x0 > entry->clip_x + entry->clip_width) {
+					entry->num_results_drawn = i;
+					log_debug("Drew %zu results.\n", i);
+					break;
+				}
+			} else {
+				if (mat.y0 > entry->clip_y + entry->clip_height) {
+					entry->num_results_drawn = i;
+					log_debug("Drew %zu results.\n", i);
+					break;
+				}
+			}
+		} else if (i >= entry->num_results) {
+			break;
+		}
 
 		hb_buffer_clear_contents(buffer);
 		setup_hb_buffer(buffer);
diff --git a/src/entry_backend/pango.c b/src/entry_backend/pango.c
index 34bb05e..13e21ee 100644
--- a/src/entry_backend/pango.c
+++ b/src/entry_backend/pango.c
@@ -72,12 +72,31 @@ void entry_backend_pango_update(struct entry *entry)
 	pango_layout_get_size(layout, &width, &height);
 	width = MAX(width, (int)entry->input_width * PANGO_SCALE);
 
-	for (size_t i = 0; i < entry->num_results && i < entry->results.count; i++) {
+	cairo_matrix_t mat;
+	for (size_t i = 0; i < entry->results.count; i++) {
 		if (entry->horizontal) {
 			cairo_translate(cr, (int)(width / PANGO_SCALE) + entry->result_spacing, 0);
 		} else {
 			cairo_translate(cr, 0, (int)(height / PANGO_SCALE) + entry->result_spacing);
 		}
+		if (entry->num_results == 0) {
+			cairo_get_matrix(cr, &mat);
+			if (entry->horizontal) {
+				if (mat.x0 > entry->clip_x + entry->clip_width) {
+					entry->num_results_drawn = i;
+					log_debug("Drew %zu results.\n", i);
+					break;
+				}
+			} else {
+				if (mat.y0 > entry->clip_y + entry->clip_height) {
+					entry->num_results_drawn = i;
+					log_debug("Drew %zu results.\n", i);
+					break;
+				}
+			}
+		} else if (i >= entry->num_results) {
+			break;
+		}
 		const char *str;
 		if (i < entry->results.count) {
 			str = entry->results.buf[i].string;
diff --git a/src/main.c b/src/main.c
index ef0dc48..9429408 100644
--- a/src/main.c
+++ b/src/main.c
@@ -201,6 +201,11 @@ static void wl_keyboard_key(
 		return;
 	}
 
+	uint32_t num_results = tofi->window.entry.num_results;
+	if (num_results == 0) {
+		num_results = tofi->window.entry.num_results_drawn;
+	}
+	uint32_t nsel = MAX(MIN(num_results, tofi->window.entry.results.count), 1);
 	if (sym == XKB_KEY_Up || sym == XKB_KEY_Left
 			|| (sym == XKB_KEY_k
 				&& xkb_state_mod_name_is_active(
@@ -209,7 +214,6 @@ static void wl_keyboard_key(
 					XKB_STATE_MODS_EFFECTIVE)
 			   )
 			) {
-		uint32_t nsel = MAX(MIN(tofi->window.entry.num_results, tofi->window.entry.results.count), 1);
 		tofi->window.entry.selection += nsel;
 		tofi->window.entry.selection--;
 		tofi->window.entry.selection %= nsel;
@@ -221,7 +225,6 @@ static void wl_keyboard_key(
 					XKB_STATE_MODS_EFFECTIVE)
 			   )
 			) {
-		uint32_t nsel = MAX(MIN(tofi->window.entry.num_results, tofi->window.entry.results.count), 1);
 		tofi->window.entry.selection++;
 		tofi->window.entry.selection %= nsel;
 	} else {
@@ -839,7 +842,6 @@ int main(int argc, char *argv[])
 				.font_name = "Sans",
 				.font_size = 24,
 				.prompt_text = "run: ",
-				.num_results = 5,
 				.padding_top = 8,
 				.padding_bottom = 8,
 				.padding_left = 8,