--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libmlk-ui/mlk/ui/button.c	Sat Oct 15 21:19:25 2022 +0200
@@ -0,0 +1,115 @@
+/*
+ * button.c -- GUI button
+ *
+ * Copyright (c) 2020-2022 David Demelier <markand@malikania.fr>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <assert.h>
+#include <string.h>
+
+#include <mlk/core/event.h>
+#include <mlk/core/maths.h>
+#include <mlk/core/painter.h>
+#include <mlk/core/trace.h>
+
+#include "align.h"
+#include "button.h"
+#include "label.h"
+#include "theme.h"
+
+static int
+is_boxed(const struct button *button, const struct event_click *click)
+{
+	assert(button);
+	assert(click);
+	assert(click->type == EVENT_CLICKDOWN || click->type == EVENT_CLICKUP);
+
+	return maths_is_boxed(button->x, button->y, button->w, button->h,
+	    click->x, click->y);
+}
+
+void
+button_draw_default(const struct theme *t, const struct button *button)
+{
+	assert(t);
+	assert(button);
+
+	(void)t;
+
+	struct label label = {
+		.text = button->text,
+	};
+	unsigned int lw, lh;
+
+	label_query(&label, &lw, &lh);
+
+	if (lw > button->w)
+		tracef("button width is too small for text: %u < %u", button->w, lw);
+	if (lh > button->h)
+		tracef("button height is too small for text: %u < %u", button->h, lh);
+
+	align(ALIGN_CENTER, &label.x, &label.y, lw, lh,
+	    button->x, button->y, button->w, button->h);
+
+	painter_set_color(0x577277ff);
+	painter_draw_rectangle(button->x, button->y, button->w, button->h);
+
+	label_draw(&label);
+}
+
+int
+button_handle(struct button *button, const union event *ev)
+{
+	assert(button);
+	assert(ev);
+
+	switch (ev->type) {
+	case EVENT_CLICKDOWN:
+		if (is_boxed(button, &ev->click))
+			button->state = BUTTON_STATE_PRESSED;
+		break;
+	case EVENT_CLICKUP:
+		/*
+		 * If the button was pressed, indicate that the button is
+		 * finally activated. This let the user to move the cursor
+		 * outside the button to "forget" the press.
+		 */
+		if (!is_boxed(button, &ev->click))
+			button->state = BUTTON_STATE_NONE;
+		else if (button->state == BUTTON_STATE_PRESSED)
+			button->state = BUTTON_STATE_ACTIVATED;
+		break;
+	default:
+		break;
+	}
+
+	return button->state == BUTTON_STATE_ACTIVATED;
+}
+
+void
+button_reset(struct button *button)
+{
+	assert(button);
+
+	button->state = BUTTON_STATE_NONE;
+}
+
+void
+button_draw(const struct button *button)
+{
+	assert(button);
+
+	theme_draw_button(button->theme, button);
+}