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[xmenu] / xmenu.c

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>

/* macros */
#define LEN(x) (sizeof (x) / sizeof (x[0]))
#define MAX(x,y) ((x)>(y)?(x):(y))
#define MIN(x,y) ((x)<(y)?(x):(y))

/* color enum */
enum {ColorFG, ColorBG, ColorLast};

/* draw context structure */
struct DC {
       unsigned long unpressed[ColorLast];
       unsigned long pressed[ColorLast];
       unsigned long decoration[ColorLast];

       Drawable d;
       GC gc;
       XFontStruct *font;
       int fonth;
};

/* menu geometry structure */
struct Geometry {
       int itemb;      /* item border */
       int itemw;      /* item width */
       int itemh;      /* item height */
       int border;     /* window border width */
       int separator;  /* menu separator width */
};

/* screen geometry structure */
struct ScreenGeometry {
       int cursx, cursy;       /* cursor position */
       int screenw, screenh;   /* screen width and height */
};

/* menu item structure */
struct Item {
       char *label;            /* string to be drawed on menu */
       char *output;           /* string to be outputed when item is clicked */
       int y;                  /* item y position relative to menu */
       int h;                  /* item height */
       size_t labellen;        /* strlen(label) */
       struct Item *next;      /* next item */
       struct Menu *submenu;   /* submenu spawned by clicking on item */
};

/* menu structure */
struct Menu {
       struct Menu *parent;    /* parent menu */
       struct Item *caller;    /* item that spawned the menu */
       struct Item *list;      /* list of items contained by the menu */
       struct Item *selected;  /* item currently selected in the menu */
       int x, y, w, h;         /* menu geometry */
       unsigned level;         /* menu level relative to root */
       Drawable pixmap;        /* pixmap to draw the menu on */
       Window win;             /* menu window to map on the screen */
};

/* function declarations */
static unsigned long getcolor(const char *s);
static void setupdc(void);
static void setupgeom(void);
static void setupgrab(void);
static struct Item *allocitem(const char *label, const char *output);
static struct Menu *allocmenu(struct Menu *parent, struct Item *list, unsigned level);
static void getmenuitem(Window win, int y, struct Menu **menu_ret, struct Item **item_ret);
static void drawmenu(void);
static void calcscreengeom(void);
static void calcmenu(struct Menu *menu);
static void setcurrmenu(struct Menu *currmenu_new);
static void parsestdin(void);
static void run(void);
static void freewindow(struct Menu *menu);
static void cleanup(void);
static void usage(void);

/* X variables */
static Colormap colormap;
static Display *dpy;
static Window rootwin;
static int screen;
static struct DC dc;

/* menu variables */
static struct Menu *rootmenu = NULL;
static struct Menu *currmenu = NULL;

/* geometry variables */
static struct Geometry geom;
static struct ScreenGeometry screengeom;

/* flag variables */
static Bool override_redirect = True;

#include "config.h"

int
main(int argc, char *argv[])
{
       int ch;

       while ((ch = getopt(argc, argv, "w")) != -1) {
               switch (ch) {
               case 'w':
                       override_redirect = False;
                       break;
               default:
                       usage();
                       break;
               }
       }
       argc -= optind;
       argv += optind;

       /* open connection to server and set X variables */
       if ((dpy = XOpenDisplay(NULL)) == NULL)
               errx(1, "cannot open display");
       screen = DefaultScreen(dpy);
       rootwin = RootWindow(dpy, screen);
       colormap = DefaultColormap(dpy, screen);

       /* setup */
       setupdc();
       setupgeom();
       setupgrab();

       /* generate menus and recalculate them */
       parsestdin();
       if (rootmenu == NULL)
               errx(1, "no menu generated");
       calcscreengeom();
       calcmenu(rootmenu);

       /* map root menu */
       currmenu = rootmenu;
       XMapWindow(dpy, rootmenu->win);

       /* run event loop */
       run();

       cleanup();

       return 0;
}

/* get color from color string */
static unsigned long
getcolor(const char *s)
{
       XColor color;

       if(!XAllocNamedColor(dpy, colormap, s, &color, &color))
               errx(1, "cannot allocate color: %s", s);
       return color.pixel;
}

/* init draw context */
static void
setupdc(void)
{
       /* get color pixels */
       dc.unpressed[ColorBG] = getcolor(UNPRESSEDBG);
       dc.unpressed[ColorFG] = getcolor(UNPRESSEDFG);
       dc.pressed[ColorBG] = getcolor(PRESSEDBG);
       dc.pressed[ColorFG] = getcolor(PRESSEDFG);
       dc.decoration[ColorBG] = getcolor(DECORATIONBG);
       dc.decoration[ColorFG] = getcolor(DECORATIONFG);

       /* try to get font */
       if ((dc.font = XLoadQueryFont(dpy, FONT)) == NULL)
               errx(1, "cannot load font");
       dc.fonth = dc.font->ascent + dc.font->descent;

       /* create GC and set its font */
       dc.gc = XCreateGC(dpy, rootwin, 0, NULL);
       XSetFont(dpy, dc.gc, dc.font->fid);
}

/* init menu geometry values */
static void
setupgeom(void)
{
       geom.itemb = ITEMB;
       geom.itemh = dc.fonth + ITEMB * 2;
       geom.itemw = ITEMW;
       geom.border = BORDER;
       geom.separator = SEPARATOR;
}

/* grab pointer */
static void
setupgrab(void)
{
       XGrabPointer(dpy, rootwin, True, ButtonPressMask | ButtonReleaseMask,
                    GrabModeAsync, GrabModeAsync, None, None, CurrentTime);
}

/* allocate an item */
static struct Item *
allocitem(const char *label, const char *output)
{
       struct Item *item;

       if ((item = malloc(sizeof *item)) == NULL)
               err(1, "malloc");
       if (*label == '\0') {
               item->label = NULL;
               item->output = NULL;
       } else {
               if ((item->label = strdup(label)) == NULL)
                       err(1, "strdup");
               if ((item->output = strdup(output)) == NULL)
                       err(1, "strdup");
       }
       item->y = 0;
       item->h = item->label ? geom.itemh : geom.separator;
       if (item->label == NULL)
               item->labellen = 0;
       else
               item->labellen = strlen(item->label);
       item->next = NULL;
       item->submenu = NULL;

       return item;
}

/* allocate a menu */
static struct Menu *
allocmenu(struct Menu *parent, struct Item *list, unsigned level)
{
       XSetWindowAttributes swa;
       struct Menu *menu;

       if ((menu = malloc(sizeof *menu)) == NULL)
               err(1, "malloc");
       menu->parent = parent;
       menu->list = list;
       menu->caller = NULL;
       menu->selected = NULL;
       menu->w = geom.itemw;
       menu->h = 0;    /* calculated by calcmenu() */
       menu->x = 0;    /* calculated by calcmenu() */
       menu->y = 0;    /* calculated by calcmenu() */
       menu->level = level;

       swa.override_redirect = override_redirect;
       swa.background_pixel = dc.decoration[ColorBG];
       swa.border_pixel = dc.decoration[ColorFG];
       swa.event_mask = ExposureMask | KeyPressMask | ButtonPressMask | ButtonReleaseMask
                      | PointerMotionMask | LeaveWindowMask;
       menu->win = XCreateWindow(dpy, rootwin, 0, 0, geom.itemw, geom.itemh, geom.border,
                                 CopyFromParent, CopyFromParent, CopyFromParent,
                                 CWOverrideRedirect | CWBackPixel | CWBorderPixel | CWEventMask,
                                 &swa);

       return menu;
}

/* create menus and items from the stdin */
static void
parsestdin(void)
{
       char *s, buf[BUFSIZ];
       char *label, *output;
       unsigned level = 0;
       unsigned i;
       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 for loops */
       struct Menu *menu;              /* dummy menu for for loops */
       size_t count = 0;   /* number of items in the current menu */

       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';

               curritem = allocitem(label, output);

               if (prevmenu == NULL) {                 /* there is no menu yet */
                        menu = allocmenu(NULL, curritem, level);
                        rootmenu = menu;
                        prevmenu = menu;
                        count = 1;
               } else if (level < prevmenu->level) {   /* item is continuation of a parent menu*/
                       for (menu = prevmenu, i = level;
                             menu != NULL && i < prevmenu->level;
                             menu = menu->parent, i++)
                               ;

                       if (menu == NULL)
                               errx(1, "reached NULL menu");

                       for (item = menu->list; item->next != NULL; item = item->next)
                               ;

                       item->next = curritem;
                       prevmenu = menu;
               } else if (level == prevmenu->level) {  /* item is a continuation of current menu */
                       for (item = prevmenu->list; item->next != NULL; item = item->next)
                               ;
                       item->next = curritem;
               } else if (level > prevmenu->level) {   /* item begins a new menu */
                       menu = allocmenu(prevmenu, curritem, level);

                       for (item = prevmenu->list; item->next != NULL; item = item->next)
                               ;

                       item->submenu = menu;
                       menu->caller = item;

                       prevmenu = menu;
               }
               count++;
       }
}

/* calculate screen geometry */
static void
calcscreengeom(void)
{
       Window w1, w2;  /* unused variables */
       int a, b;       /* unused variables */
       unsigned mask;  /* unused variable */

       XQueryPointer(dpy, rootwin, &w1, &w2, &screengeom.cursx, &screengeom.cursy, &a, &b, &mask);
       screengeom.screenw = DisplayWidth(dpy, screen);
       screengeom.screenh = DisplayHeight(dpy, screen);
}

/* recursivelly calculate height and position of the menus */
static void
calcmenu(struct Menu *menu)
{
       XWindowChanges changes;
       XSizeHints sizeh;
       struct Item *item;
       int labelwidth;

       /* calculate items positions and menu width and height */
       menu->w = geom.itemw;
       for (item = menu->list; item != NULL; item = item->next) {
               item->y = menu->h;
               if (item->label == NULL)   /* height for separator item */
                       menu->h += geom.separator;
               else
                       menu->h += geom.itemh;

               labelwidth = XTextWidth(dc.font, item->label, item->labellen) + dc.fonth * 2;
               menu->w = MAX(menu->w, labelwidth);
       }

       /* calculate menu's x and y positions */
       if (menu->parent == NULL) { /* if root menu, calculate in respect to cursor */
               if (screengeom.screenw - screengeom.cursx >= menu->w)
                       menu->x = screengeom.cursx;
               else if (screengeom.cursx > menu->w)
                       menu->x = screengeom.cursx - menu->w;

               if (screengeom.screenh - screengeom.cursy >= menu->h)
                       menu->y = screengeom.cursy;
               else if (screengeom.screenh > menu->h)
                       menu->y = screengeom.screenh - menu->h;
       } else {                    /* else, calculate in respect to parent menu */

               /* search for the item in parent menu that generates this menu */
               for (item = menu->parent->list; item->submenu != menu; item = item->next)
                       ;

               if (screengeom.screenw - (menu->parent->x + menu->parent->w) >= menu->w)
                       menu->x = menu->parent->x + menu->parent->w;
               else if (menu->parent->x > menu->w)
                       menu->x = menu->parent->x - menu->w;

               if (screengeom.screenh - (item->y + menu->parent->y) > menu->h)
                       menu->y = item->y + menu->parent->y;
               else if (screengeom.screenh - menu->parent->y > menu->h)
                       menu->y = menu->parent->y;
               else if (screengeom.screenh > menu->h)
                       menu->y = screengeom.screenh - menu->h;
       }

       /* update menu geometry */
       changes.height = menu->h;
       changes.width = menu->w;
       changes.x = menu->x;
       changes.y = menu->y;
       XConfigureWindow(dpy, menu->win, CWWidth | CWHeight | CWX | CWY, &changes);

       /* set window manager size hints */
       sizeh.flags = PMaxSize | PMinSize;
       sizeh.min_width = sizeh.max_width = menu->w;
       sizeh.min_height = sizeh.max_height = menu->h;
       XSetWMNormalHints(dpy, menu->win, &sizeh);

       /* create pixmap */
       menu->pixmap = XCreatePixmap(dpy, menu->win, menu->w, menu->h,
                                    DefaultDepth(dpy, screen));

       /* calculate positions of submenus */
       for (item = menu->list; item != NULL; item = item->next) {
               if (item->submenu != NULL)
                       calcmenu(item->submenu);
       }
}

/* get menu and item of given window and position */
static void
getmenuitem(Window win, int y,
           struct Menu **menu_ret, struct Item **item_ret)
{
       struct Menu *menu = NULL;
       struct Item *item = NULL;

       for (menu = currmenu; menu != NULL; menu = menu->parent) {
               if (menu->win == win) {
                       for (item = menu->list; item != NULL; item = item->next) {
                               if (y >= item->y && y <= item->y + item->h) {
                                       goto done;
                               }
                       }
               }
       }


done:
       *menu_ret = menu;
       *item_ret = item;
}

/* set currentmenu to menu, umap previous menus and map current menu and its parents */
static void
setcurrmenu(struct Menu *currmenu_new)
{
       struct Menu *menu, *menu_;
       struct Item *item;
       struct Menu *lcamenu;   /* lowest common ancestor menu */
       unsigned minlevel;      /* level of the closest to root menu */
       unsigned maxlevel;      /* level of the closest to root menu */

       if (currmenu_new == currmenu)
               return;

       /* find lowest common ancestor menu */
       lcamenu = rootmenu;
       if (currmenu != NULL) {
               minlevel = MIN(currmenu_new->level, currmenu->level);
               maxlevel = MAX(currmenu_new->level, currmenu->level);
               if (currmenu_new->level == maxlevel) {
                       menu = currmenu_new;
                       menu_ = currmenu;
               } else {
                       menu = currmenu;
                       menu_ = currmenu_new;
               }
               while (menu->level > minlevel)
                       menu = menu->parent;

               while (menu != menu_) {
                       menu = menu->parent;
                       menu_ = menu_->parent;
               }
               lcamenu = menu;
       }

       /* unmap menus from currmenu (inclusive) until lcamenu (exclusive) */
       for (menu = currmenu; menu != lcamenu; menu = menu->parent) {
               XUnmapWindow(dpy, menu->win);
       }

       currmenu = currmenu_new;

       /* map menus from currmenu (inclusive) until lcamenu (exclusive) */
       item = NULL;
       for (menu = currmenu; menu != lcamenu; menu = menu->parent) {
               XMapWindow(dpy, menu->win);
               if (item != NULL)
                       menu->selected = item;
               item = menu->caller;
       }
}

/* draw items of the current menu and of its ancestors */
static void
drawmenu(void)
{
       struct Menu *menu;
       struct Item *item;

       for (menu = currmenu; menu != NULL; menu = menu->parent) {
               for (item = menu->list; item != NULL; item = item->next) {
                       unsigned long *color;
                       int labelx, labely;

                       /* determine item color */
                       if (item->label == NULL)
                               color = dc.decoration;
                       else if (item == menu->selected)
                               color = dc.pressed;
                       else
                               color = dc.unpressed;

                       /* draw item box */
                       XSetForeground(dpy, dc.gc, color[ColorBG]);
                       XDrawRectangle(dpy, menu->pixmap, dc.gc, 0, item->y,
                                      menu->w, item->h);
                       XFillRectangle(dpy, menu->pixmap, dc.gc, 0, item->y,
                                      menu->w, item->h);

                       /* continue if item is a separator */
                       if (item->label == NULL)
                               continue;

                       /* draw item label */
                       labelx = 0 + dc.fonth;
                       labely = item->y + dc.fonth + geom.itemb;
                       XSetForeground(dpy, dc.gc, color[ColorFG]);
                       XDrawString(dpy, menu->pixmap, dc.gc, labelx, labely,
                                   item->label, item->labellen);

                       /* draw triangle, if item contains a submenu */
                       if (item->submenu != NULL) {
                               int trianglex = menu->w - dc.fonth + geom.itemb - 1;
                               int triangley = item->y + (3 * item->h)/8 -1;

                               XPoint triangle[] = {
                                       {trianglex, triangley},
                                       {trianglex + item->h/8 + 1, item->y + item->h/2},
                                       {trianglex, triangley + item->h/4 + 2},
                                       {trianglex, triangley}
                               };

                               XFillPolygon(dpy, menu->pixmap, dc.gc, triangle, LEN(triangle),
                                            Convex, CoordModeOrigin);
                       }

                       XCopyArea(dpy, menu->pixmap, menu->win, dc.gc, 0, item->y,
                                 menu->w, item->h, 0, item->y);
               }
       }
}

/* run event loop */
static void
run(void)
{
       struct Menu *menu;
       struct Item *item;
       struct Item *previtem = NULL;
       XEvent ev;

       while (!XNextEvent(dpy, &ev)) {
               switch(ev.type) {
               case Expose:
                       drawmenu();
                       break;
               case MotionNotify:
                       getmenuitem(ev.xbutton.window, ev.xbutton.y, &menu, &item);
                       if (menu != NULL && item != NULL) {
                               if (previtem != item) {
                                       if (item->submenu != NULL)
                                               setcurrmenu(item->submenu);
                                       else
                                               setcurrmenu(menu);
                                       previtem = item;
                                       drawmenu();
                               } else if (menu->selected != item) {
                                       menu->selected = item;
                                       drawmenu();
                               }
                       }
                       break;
               case ButtonRelease:
                       getmenuitem(ev.xbutton.window, ev.xbutton.y, &menu, &item);
                       if (menu != NULL && item != NULL) {
                               if (item->label == NULL)
                                       break;  /* ignore separators */
                               if (item->submenu != NULL) {
                                       setcurrmenu(item->submenu);
                               } else {
                                       printf("%s\n", item->output);
                                       return;
                               }
                               drawmenu();
                       } else {
                               return;
                       }
                       break;
               case LeaveNotify:
                       currmenu->selected = NULL;
                       drawmenu();
                       break;
               }
       }
}

/* recursivelly free a pixmap */
static void
freewindow(struct Menu *menu)
{
       struct Item *item;

       for (item = menu->list; item != NULL; item = item->next)
               if (item->submenu != NULL)
                       freewindow(item->submenu);

       XFreePixmap(dpy, menu->pixmap);
       XDestroyWindow(dpy, menu->win);
}

/* cleanup and exit */
static void
cleanup(void)
{
       freewindow(rootmenu);
       XFreeFont(dpy, dc.font);
       XFreeGC(dpy, dc.gc);
       XCloseDisplay(dpy);
}

/* show usage */
static void
usage(void)
{
       (void)fprintf(stderr, "usage: xmenu [-w]\n");
       exit(1);
}