Simplify cursor checking

Additional tweaks and docs improvements

Signed-off-by: Tin <tin.svagelj@live.com>

doc/config_settings.yaml

@@ -369,7 +369,7 @@ values:
   - name: overwrite_file
     desc: Overwrite the file given as argument.
   - name: own_window
-    desc: Boolean, create own window to draw.
+    desc: Boolean, draw conky in own window instead of drawing on root window.
   - name: own_window_argb_value
     desc: |-
       When ARGB visuals are enabled, this use this to modify the
@@ -388,7 +388,7 @@ values:
     desc: |-
       If own_window_transparent no, set a specified background
       colour. Takes either a hex value (e.g. '#ffffff'),
-      a shorthand hex value (e.g. '#fff'), or a valid RGB nam 
+      a shorthand hex value (e.g. '#fff'), or a valid RGB name
       (see `/usr/lib/X11/rgb.txt`).
     default: black
     args:

src/display-x11.cc

@@ -382,13 +382,12 @@ bool display_output_x11::main_loop_wait(double t) {
 
     XNextEvent(display, &ev);
     
-#ifdef BUILD_XINPUT
+#if defined(BUILD_MOUSE_EVENTS) && defined(BUILD_XINPUT)
       if (ev.type == GenericEvent && ev.xcookie.extension == window.xi_opcode) {
         XGetEventData(display, &ev.xcookie);
         if (ev.xcookie.evtype == XI_Motion) {
           auto *data = reinterpret_cast<XIDeviceEvent*>(ev.xcookie.data);
 
-          // XQueryPointer returns wrong results because conky is a weird window
           Window query_result = query_x11_window_at_pos(display, data->root_x, data->root_y);
 
           static bool cursor_inside = false;
@@ -415,7 +414,7 @@ bool display_output_x11::main_loop_wait(double t) {
         XFreeEventData(display, &ev.xcookie);
         continue;
       }
-#endif /* BUILD_XINPUT */
+#endif /* BUILD_MOUSE_EVENTS && BUILD_XINPUT */
 
     // Any of the remaining events apply to conky window
     if (ev.xany.window != window.window) continue;

src/x11.cc

@@ -1381,7 +1381,9 @@ void propagate_x11_event(XEvent &ev) {
 }
 
 #ifdef BUILD_MOUSE_EVENTS
-Window last_descendant(Display* display, Window parent) {
+// Assuming parent has a simple linear stack of descendants, this function
+// returns the last leaf on the graph.
+inline Window last_descendant(Display* display, Window parent) {
   Window ignored, *children;
   uint32_t count;
 
@@ -1398,26 +1400,19 @@ Window last_descendant(Display* display, Window parent) {
 Window query_x11_window_at_pos(Display* display, int x, int y) {
   Window root = DefaultRootWindow(display);
 
-  Window root_return, parent_return, *windows;
-  unsigned int count;
-    
+  // these values are ignored but NULL can't be passed
+  Window root_return;
+  int root_x_return, root_y_return, win_x_return, win_y_return;
+  unsigned int mask_return;
+
   Window last = None;
+  XQueryPointer(display, window.root, &root_return, &last,
+    &root_x_return, &root_y_return, &win_x_return, &win_y_return, &mask_return
+  );
 
-  XWindowAttributes attrs;
-  if (XQueryTree(display, root, &root_return, &parent_return, &windows, &count) != 0) {
-    for (unsigned int i = 0; i < count; i++) {
-      if (XGetWindowAttributes(display, windows[i], &attrs)) {
-        if (attrs.map_state == IsViewable && x >= attrs.x && x < (attrs.x + attrs.width) && y >= attrs.y && y < (attrs.y + attrs.height)) {
-          last = windows[i];
-        }
-      }
-    }
-
-    if (count != 0) {
-      XFree(windows);
-    }
-  }
-  
+  // X11 correctly returns a window which covers conky area, but returned window
+  // is not window.window, but instead a parent node in some cases and the
+  // window.window we want to check for is a 1x1 child of that window.
   return last_descendant(display, last);
 }
 

src/x11.h

@@ -150,7 +150,6 @@ InputEvent *xev_as_input_event(XEvent &ev);
 void propagate_x11_event(XEvent &ev);
 
 #ifdef BUILD_MOUSE_EVENTS
-
 Window query_x11_window_at_pos(Display* display, int x, int y);
 #endif /* BUILD_MOUSE_EVENTS */