geometry.c

// Copyright 2020, Alisa Bedard
#include "geometry.h"
#include "JBWMClient.h"
#include "JBWMScreen.h"
#include "JBWMSize.h"
#include "log.h"
#include "macros.h"
#include <X11/Xutil.h>
struct GeometryData {
  Display * display;
  union JBWMRectangle * attribute;
  union JBWMRectangle * geometry;
  Window window;
};
static long handle_wm_normal_hints(struct GeometryData * g)
{
  /* Though these statements may be combined, writing the following
   * assignment this way ensures the conditional is only evaluated once.
   * */
  XSizeHints h;
  if (XGetWMNormalHints(g->display, g->window, &h, &(long){0})
    && (h.flags & USSize)) {
    // if size hints provided, use them
    g->geometry->width = JB_MAX(h.width, h.min_width);
    g->geometry->height = JB_MAX(h.height, h.min_height);
  } else // use existing window attributes
    *g->geometry = *g->attribute;
  return h.flags;
}
static void check_dimensions(union JBWMRectangle * g,
  const struct JBWMSize screen)
{
  g->width = JB_MIN(g->width, screen.width);
  g->height = JB_MIN(g->height, screen.height);
}
__attribute__((const))
static int16_t get_center(const int16_t window_size,
  const int16_t screen_size)
{
  return (screen_size - window_size) >> 1;
}
static void center(union JBWMRectangle * g,
  const struct JBWMSize s)
{
  g->x = get_center(g->width, s.width);
  g->y = get_center(g->height, s.height);
}
// returns true if window is viewable
static bool get_window_attributes(struct JBWMClient * c,
  union JBWMRectangle * geometry_attribute)
{
  XWindowAttributes a;
  Display * d = c->screen->xlib->display;
  XGetWindowAttributes(d, c->window, &a);
  JBWM_LOG("XGetWindowAttributes() win: 0x%x,"
    "x: %d, y: %d, w: %d, h: %d",
    (int)c->window, a.x, a.y, a.width, a.height);
  c->cmap = a.colormap;
  *geometry_attribute = (union JBWMRectangle){.x = a.x, .y = a.y,
    .width = a.width, .height = a.height};
  return a.map_state == IsViewable;
}
static void init_geometry_for_screen(struct JBWMClient * c,
  union JBWMRectangle * geometry_attribute)
{
  struct JBWMScreen *s=c->screen;
  Display * d = c->screen->xlib->display;
  struct JBWMSize screen_size={s->xlib->width,s->xlib->height};
  struct GeometryData g={ .display=d, .attribute = geometry_attribute,
    .geometry = &c->size, .window = c->window};
  check_dimensions(g.geometry, screen_size);
  {
    const long flags = handle_wm_normal_hints(&g);
    const bool user_specified_position = flags & USPosition;
    const bool nonzero_position = g.attribute->x ||
    g.attribute->y;
    if (user_specified_position && nonzero_position) {
      JBWM_LOG("\t\tPosition is set by hints.");
      g.geometry->x = g.attribute->x;
      g.geometry->y = g.attribute->y;
    } else // Position not specified
      center(g.geometry, screen_size);
  }
}
void jbwm_set_client_geometry(struct JBWMClient * c)
{
  union JBWMRectangle geometry_attribute;
  if (get_window_attributes(c, &geometry_attribute)) { // viewable
    /* Increment unmap event counter for the reparent event.  */
    ++c->ignore_unmap;
    /* If the window is already on screen before the window
       manager starts, simply save its geometry then return. */
    c->size = geometry_attribute;
  } else // not viewable yet
    init_geometry_for_screen(c, &geometry_attribute);
}