EmojiHistory: Maintain a history of emojis

Serialize/deserialize a list of recently used emojis and provide a
method to record usage.

src/bin/xmoji/emojihistory.c

@@ -0,0 +1,140 @@
+#include "emojihistory.h"
+
+#include "emoji.h"
+#include "unistr.h"
+#include "unistrbuilder.h"
+
+#include <poser/core.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct EmojiHistory
+{
+    PSC_Event *changed;
+    size_t size;
+    const Emoji *history[];
+};
+
+EmojiHistory *EmojiHistory_create(size_t size)
+{
+    EmojiHistory *self = PSC_malloc(sizeof *self +
+	    (size * sizeof *self->history));
+    self->changed = PSC_Event_create(self);
+    self->size = size;
+    memset(self->history, 0, size * sizeof *self->history);
+    return self;
+}
+
+PSC_Event *EmojiHistory_changed(EmojiHistory *self)
+{
+    return self->changed;
+}
+
+const Emoji *EmojiHistory_at(const EmojiHistory *self, size_t i)
+{
+    if (i >= self->size) return 0;
+    return self->history[i];
+}
+
+static const Emoji *emojiById(const UniStr *str)
+{
+    for (size_t i = 0; i < Emoji_numEmojis(); ++i)
+    {
+	const Emoji *tmp = Emoji_at(i);
+	if (UniStr_equals(str, Emoji_str(tmp))) return tmp;
+    }
+    return 0;
+}
+
+void EmojiHistory_record(EmojiHistory *self, const UniStr *str)
+{
+    const Emoji *emoji = emojiById(str);
+    if (!emoji) return;
+
+    size_t i;
+    for (i = 0; i < self->size; ++i)
+    {
+	if (!self->history[i] || self->history[i] == emoji) break;
+    }
+    if (!i)
+    {
+	if (*self->history) return;
+    }
+    else
+    {
+	if (i == self->size) --i;
+	memmove(self->history+1, self->history, i * sizeof *self->history);
+    }
+
+    *self->history = emoji;
+    PSC_Event_raise(self->changed, 0, 0);
+}
+
+char *EmojiHistory_serialize(const EmojiHistory *self)
+{
+    UniStrBuilder *builder = UniStrBuilder_create();
+    for (size_t i = 0; i < self->size; ++i)
+    {
+	if (!self->history[i]) break;
+	if (i) UniStrBuilder_appendChar(builder, U' ');
+	UniStrBuilder_appendStr(builder,
+		UniStr_str(Emoji_str(self->history[i])));
+    }
+    char *serialized = UniStr_toUtf8(UniStrBuilder_stringView(builder), 0);
+    UniStrBuilder_destroy(builder);
+    return serialized;
+}
+
+static const Emoji *findEmoji(char **str)
+{
+    while (**str == ' ' || **str == '\t') ++(*str);
+    if (!**str) return 0;
+    const char *utf8 = *str;
+    while (**str && **str != ' ' && **str != '\t') ++(*str);
+    if (**str)
+    {
+	**str = 0;
+	++(*str);
+	while (**str && (**str == ' ' || **str == '\t')) ++(*str);
+    }
+    if (!**str) *str = 0;
+
+    UniStr *estr = UniStr_create(utf8);
+    const Emoji *emoji = emojiById(estr);
+    UniStr_destroy(estr);
+    return emoji;
+}
+
+void EmojiHistory_deserialize(EmojiHistory *self, const char *str)
+{
+    char *cstr = PSC_copystr(str);
+    char *tmp = cstr;
+    size_t pos = 0;
+    int havechanges = 0;
+    while (pos < self->size && tmp)
+    {
+	const Emoji *emoji = findEmoji(&tmp);
+	for (size_t i = 0; emoji && i < pos; ++i)
+	{
+	    if (self->history[i] == emoji) emoji = 0;
+	}
+	if (!emoji) continue;
+	if (self->history[pos] != emoji) havechanges = 1;
+	self->history[pos++] = emoji;
+    }
+    free(cstr);
+    if (pos < self->size && self->history[pos])
+    {
+	havechanges = 1;
+	memset(self->history + pos, 0, self->size - pos);
+    }
+    if (havechanges) PSC_Event_raise(self->changed, 0, 0);
+}
+
+void EmojiHistory_destroy(EmojiHistory *self)
+{
+    if (!self) return;
+    PSC_Event_destroy(self->changed);
+    free(self);
+}
+

src/bin/xmoji/emojihistory.h

@@ -0,0 +1,27 @@
+#ifndef XMOJI_EMOJIHISTORY_H
+#define XMOJI_EMOJIHISTORY_H
+
+#include <poser/decl.h>
+#include <stddef.h>
+
+C_CLASS_DECL(Emoji);
+C_CLASS_DECL(EmojiHistory);
+C_CLASS_DECL(PSC_Event);
+C_CLASS_DECL(UniStr);
+
+EmojiHistory *EmojiHistory_create(size_t size);
+
+PSC_Event *EmojiHistory_changed(EmojiHistory *self)
+    CMETHOD ATTR_RETNONNULL;
+const Emoji *EmojiHistory_at(const EmojiHistory *self, size_t i)
+    CMETHOD;
+void EmojiHistory_record(EmojiHistory *self, const UniStr *str)
+    CMETHOD ATTR_NONNULL((2));
+char *EmojiHistory_serialize(const EmojiHistory *self)
+    CMETHOD;
+void EmojiHistory_deserialize(EmojiHistory *self, const char *str)
+    CMETHOD ATTR_NONNULL((2));
+
+void EmojiHistory_destroy(EmojiHistory *self);
+
+#endif

src/bin/xmoji/xmoji.mk

@@ -9,6 +9,7 @@ xmoji_MODULES=		button \
 			command \
 			emoji \
 			emojibutton \
+			emojihistory \
 			filewatcher \
 			flowgrid \
 			flyout \