From a42ea8a19ab40a02c0c46b2d60ced87c5da1f7eb Mon Sep 17 00:00:00 2001
From: P. J. McDermott <pj@pehjota.net>
Date: Thu, 05 Aug 2021 20:23:50 -0400
Subject: tk: Add text widget (without event handling)

---
(limited to 'src/tk/text.c')

diff --git a/src/tk/text.c b/src/tk/text.c
new file mode 100644
index 0000000..205c8e3
--- /dev/null
+++ b/src/tk/text.c
@@ -0,0 +1,204 @@
+/*
+ * Copyright (C) 2021  P. J. McDermott
+ *
+ * This file is part of Maze Fight
+ *
+ * Maze Fight 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Maze Fight 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 Maze Fight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <SDL.h>
+#include <SDL_ttf.h>
+#include <errno.h>
+#include <string.h>
+#include "../tk.h"
+#include "../util.h"
+#include "widget.h"
+
+struct mftk_text {
+	struct mftk_widget  parent;
+	char                min_char;
+	char                max_char;
+	size_t              len;
+	size_t              cur;
+	int                 y;
+	int                 w;
+	int                 h;
+	char               *val;
+	TTF_Font           *font;
+	int                 line_skip;
+	int                 ascent;
+	SDL_Color          *color;
+	SDL_Texture        *texture;
+};
+
+static void
+_mftk_text_layout(struct mftk_widget *w __attribute__((__unused__)))
+{
+	/* Size set in constructor */
+}
+
+static int
+_mftk_text_event(struct mftk_widget *w, SDL_Event *e,
+		int x __attribute__((__unused__)),
+		int y __attribute__((__unused__)))
+{
+	struct mftk_text *t = (struct mftk_text *) w;
+
+	/* TODO */
+	t->texture = NULL;
+	return 0;
+}
+
+static int
+_mftk_text_render_val(struct mftk_text *t, SDL_Renderer *renderer)
+{
+	SDL_Surface *surface;
+	int          max_y;
+	const char  *c;
+	int          glyph_max_y;
+
+	surface = TTF_RenderUTF8_Blended(t->font, t->val, *t->color);
+	if (surface == NULL) {
+		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+				"Couldn't create surface: %s",
+				TTF_GetError());
+		return -1;
+	}
+
+	t->texture = SDL_CreateTextureFromSurface(renderer, surface);
+	if (t->texture == NULL) {
+		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+				"Couldn't create texture: %s",
+				SDL_GetError());
+		SDL_FreeSurface(surface);
+		return -1;
+	}
+
+	max_y = 0;
+	for (c = t->val; *c != '\0'; ++c) {
+		if (TTF_GlyphMetrics(t->font, *c, NULL, NULL, NULL,
+					&glyph_max_y, NULL) < 0) {
+			SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+					"Couldn't get glyph metrics: %s",
+					TTF_GetError());
+			continue;
+		}
+		if (glyph_max_y > max_y) {
+			max_y = glyph_max_y;
+		}
+	}
+	t->y = (t->line_skip - t->ascent) / 2 + (t->ascent - max_y);
+	t->w = surface->w;
+	t->h = surface->h;
+
+	SDL_FreeSurface(surface);
+
+	return 0;
+}
+
+static int
+_mftk_text_render(struct mftk_widget *w, SDL_Renderer *renderer, int x, int y)
+{
+	struct mftk_text *t = (struct mftk_text *) w;
+	SDL_Rect          rect;
+	char             *val;
+	int               cur_x;
+
+	if (t->texture == NULL && _mftk_text_render_val(t, renderer) < 0) {
+		return -1;
+	}
+
+	rect.x =        x;
+	rect.y = t->y + y;
+	rect.w = t->w;
+	rect.h = t->h;
+
+	val = mf_strdup(t->val);
+	if (val == NULL) {
+		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+				"Couldn't render widget: %s",
+				strerror(errno));
+		return -1;
+	}
+	val[t->cur] = '\0';
+	TTF_SizeUTF8(t->font, val, &cur_x, NULL);
+
+	if (SDL_RenderCopy(renderer, t->texture, NULL, &rect) < 0 ||
+			SDL_SetRenderDrawColor(renderer,
+				t->color->r, t->color->g,
+				t->color->b, t->color->a) < 0 ||
+			SDL_RenderDrawLine(renderer,
+				x + cur_x, y + t->y, x + cur_x, y + t->h) < 0 ||
+			SDL_RenderDrawLine(renderer,
+				x, y + w->h, x + w->w, y + w->h) < 0) {
+		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+				"Couldn't render widget: %s",
+				SDL_GetError());
+		free(val);
+		return -1;
+	}
+
+	free(val);
+	return 0;
+}
+
+static void
+_mftk_text_destroy(struct mftk_widget *w)
+{
+	struct mftk_text *t = (struct mftk_text *) w;
+
+	free(t->val);
+	SDL_DestroyTexture(t->texture);
+}
+
+struct mftk_widget *
+mftk_text_new(char min_char, char max_char, size_t len, const char *val,
+		TTF_Font *font, SDL_Color *color)
+{
+	struct mftk_widget *w;
+	struct mftk_text   *t;
+	int                 advance;
+	char                ch;
+
+	mftk_widget_init(w, t, text);
+
+	t->min_char  = min_char;
+	t->max_char  = max_char;
+	t->len       = len;
+	t->cur       = strlen(val);
+	t->val       = mf_strdup(val);
+	t->font      = font;
+	t->line_skip = TTF_FontLineSkip(font);
+	t->ascent    = TTF_FontAscent  (font);
+	t->color     = color;
+	t->texture   = NULL;
+
+	w->w = 0;
+	for (ch = min_char; ch <= max_char; ++ch) {
+		if (TTF_GlyphMetrics(font, ch, NULL, NULL, NULL, NULL, &advance)
+				< 0) {
+			SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+					"Couldn't get glyph metrics: %s",
+					TTF_GetError());
+			continue;
+		}
+		advance *= len;
+		if (advance > w->w) {
+			w->w = advance;
+		}
+	}
+	w->h = t->line_skip + 1;
+
+	return w;
+}
--
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