mraber/xmenu
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Simplifying parsing and data structure building

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• Parsing of stdin was simplified by using conventional stdlib functions
  rather than parsing the stdin byte-by-byte.
• Splited parsing of textual input and building of internal data
  structures into two different functions.
This commit is contained in:
phillbush 2020-05-29 23:48:49 -03:00
parent 15dfafdfb1
commit a5ddd2cd22
1 changed files with 76 additions and 79 deletions
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105
xmenu.c
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@ -73,6 +73,7 @@ static void setupdc(void);
static void calcgeom(void);
static struct Item *allocitem(const char *label, const char *output);
static struct Menu *allocmenu(struct Menu *parent, struct Item *list, unsigned level);
static struct Menu * buildmenutree(unsigned level, const char *label, const char *output);
static struct Menu *parsestdin(void);
static void calcmenu(struct Menu *menu);
static void grabpointer(void);
@ -251,7 +252,7 @@ allocitem(const char *label, const char *output)
if ((item = malloc(sizeof *item)) == NULL)
err(1, "malloc");
if (*label == '\0') {
if (label == NULL) {
item->label = NULL;
item->output = NULL;
} else {
@ -310,96 +311,92 @@ allocmenu(struct Menu *parent, struct Item *list, unsigned level)
return menu;
}
/* create menus and items from the stdin */
/* build the menu tree */
static struct Menu *
parsestdin(void)
buildmenutree(unsigned level, const char *label, const char *output)
{
char *s, buf[BUFSIZ];
char *label, *output;
unsigned level = 0;
unsigned i;
static struct Menu *prevmenu = NULL; /* menu the previous item was added to */
static struct Menu *rootmenu = NULL; /* menu to be returned */
struct Item *curritem = NULL; /* item currently being read */
struct Menu *prevmenu = NULL; /* menu the previous item was added to */
struct Item *item; /* dummy item for loops */
struct Menu *menu; /* dummy menu for loops */
struct Menu *rootmenu; /* menu to be returned */
rootmenu = NULL;
while (fgets(buf, BUFSIZ, stdin) != NULL) {
level = 0;
s = buf;
while (*s == '\t') {
level++;
s++;
}
label = output = s;
while (*s != '\0' && *s != '\t' && *s != '\n')
s++;
while (*s == '\t')
*s++ = '\0';
if (*s != '\0' && *s != '\n')
output = s;
while (*s != '\0' && *s != '\n')
s++;
if (*s == '\n')
*s = '\0';
unsigned i;
/* create the item */
curritem = allocitem(label, output);
/* put the item in the menu tree */
if (prevmenu == NULL) { /* there is no menu yet */
menu = allocmenu(NULL, curritem, level);
rootmenu = menu;
prevmenu = menu;
curritem->prev = NULL;
curritem->next = NULL;
} else if (level < prevmenu->level) { /* item is continuation of a parent menu */
/* go up the menu tree until find the menu this item continues */
for (menu = prevmenu, i = level;
menu != NULL && i < prevmenu->level;
menu != NULL && i != prevmenu->level;
menu = menu->parent, i++)
;
if (menu == NULL)
errx(1, "reached NULL menu");
/* find last item in the new menu */
for (item = menu->list; item->next != NULL; item = item->next)
;
item->next = curritem;
curritem->prev = item;
curritem->next = NULL;
prevmenu = menu;
item->next = curritem;
curritem->prev = item;
} else if (level == prevmenu->level) { /* item is a continuation of current menu */
/* find last item in the previous menu */
for (item = prevmenu->list; item->next != NULL; item = item->next)
;
item->next = curritem;
curritem->prev = item;
curritem->next = NULL;
} else if (level > prevmenu->level) { /* item begins a new menu */
menu = allocmenu(prevmenu, curritem, level);
/* find last item in the previous menu */
for (item = prevmenu->list; item->next != NULL; item = item->next)
;
item->submenu = menu;
menu->caller = item;
curritem->prev = NULL;
curritem->next = NULL;
prevmenu = menu;
menu->caller = item;
item->submenu = menu;
curritem->prev = NULL;
}
return rootmenu;
}
/* create menus and items from the stdin */
static struct Menu *
parsestdin(void)
{
struct Menu *rootmenu;
char *s, buf[BUFSIZ];
char *label, *output;
unsigned level = 0;
while (fgets(buf, BUFSIZ, stdin) != NULL) {
/* get the indentation level */
level = strspn(buf, "\t");
/* get the label */
s = level + buf;
label = strtok(s, "\t\n");
/* get the output */
output = strtok(NULL, "\n");
if (output == NULL) {
output = label;
} else {
while (*output == '\t')
output++;
}
rootmenu = buildmenutree(level, label, output);
}
return rootmenu;