input focus: calculate areas of intersection

1 files changed, 22 insertions, 12 deletions

diff --git a/dmenu.c b/dmenu.c
index 671095e..841af4a 100644
--- a/dmenu.c
+++ b/dmenu.c
@@ -13,9 +13,10 @@
 #endif
 #include "draw.h"
 
-#define INRECT(x,y,rx,ry,rw,rh) ((x) >= (rx) && (x) < (rx)+(rw) && (y) >= (ry) && (y) < (ry)+(rh))
-#define MIN(a,b)                ((a) < (b) ? (a) : (b))
-#define MAX(a,b)                ((a) > (b) ? (a) : (b))
+#define INTERSECT(x,y,w,h,r)  (MAX(0, MIN((x)+(w),(r).x_org+(r).width)  - MAX((x),(r).x_org)) \
+                             * MAX(0, MIN((y)+(h),(r).y_org+(r).height) - MAX((y),(r).y_org)))
+#define MIN(a,b)              ((a) < (b) ? (a) : (b))
+#define MAX(a,b)              ((a) > (b) ? (a) : (b))
 
 typedef struct Item Item;
 struct Item {
@@ -513,19 +514,28 @@ setup(void) {
         mh = (lines + 1) * bh;
 #ifdef XINERAMA
         if((info = XineramaQueryScreens(dc->dpy, &n))) {
-                int i, di;
+                int a, j, di, i = 0, area = 0;
                 unsigned int du;
-                Window w, dw;
+                Window w, pw, dw, *dws;
                 XWindowAttributes wa;
 
                 XGetInputFocus(dc->dpy, &w, &di);
-                if(w != root && w != PointerRoot && w != None && XGetWindowAttributes(dc->dpy, w, &wa))
-                        XTranslateCoordinates(dc->dpy, w, root, wa.x, wa.y, &x, &y, &dw);
-                else
-                        XQueryPointer(dc->dpy, root, &dw, &dw, &x, &y, &di, &di, &du);
-                for(i = 0; i < n-1; i++)
-                        if(INRECT(x, y, info[i].x_org, info[i].y_org, info[i].width, info[i].height))
-                                break;
+                if(w != root && w != PointerRoot && w != None) {
+                        do {
+                                if(XQueryTree(dc->dpy, (pw = w), &dw, &w, &dws, &du) && dws)
+                                        XFree(dws);
+                        } while(w != root && w != pw);
+                        if(XGetWindowAttributes(dc->dpy, pw, &wa))
+                                for(j = 0; j < n; j++)
+                                        if((a = INTERSECT(wa.x, wa.y, wa.width, wa.height, info[j])) > area) {
+                                                area = a;
+                                                i = j;
+                                        }
+                }
+                if(!area && XQueryPointer(dc->dpy, root, &dw, &dw, &x, &y, &di, &di, &du))
+                        for(i = 0; i < n; i++)
+                                if(INTERSECT(x, y, 1, 1, info[i]))
+                                        break;
                 x = info[i].x_org;
                 y = info[i].y_org + (topbar ? 0 : info[i].height - mh);
                 mw = info[i].width;