Allow XIM XNArea for client preedit area in OnTheSpot mode.

Author: xorgy

src/frontend/xim/xim.cpp

@@ -303,18 +303,28 @@ class XIMInputContext final : public InputContext {
 
     void updateCursorLocation() {
         // kinds of like notification for position moving
-        bool hasSpotLocation =
-            xcb_im_input_context_get_preedit_attr_mask(xic_) &
-            XCB_XIM_XNSpotLocation_MASK;
-        auto p = xcb_im_input_context_get_preedit_attr(xic_)->spot_location;
+        auto mask = xcb_im_input_context_get_preedit_attr_mask(xic_);
         auto w = xcb_im_input_context_get_focus_window(xic_);
         if (!w) {
             w = xcb_im_input_context_get_client_window(xic_);
         }
         if (!w) {
             return;
         }
-        if (hasSpotLocation) {
+        if (mask & XCB_XIM_XNArea_MASK) {
+            auto a = xcb_im_input_context_get_preedit_attr(xic_)->area;
+            auto trans_cookie = xcb_translate_coordinates(
+                server_->conn(), w, server_->root(), a.x, a.y);
+            auto reply = makeUniqueCPtr(xcb_translate_coordinates_reply(
+                server_->conn(), trans_cookie, nullptr));
+            if (!reply) {
+                return;
+            }
+            setCursorRect(Rect()
+                              .setPosition(reply->dst_x, reply->dst_y)
+                              .setSize(a.width, a.height));
+        } else if (mask & XCB_XIM_XNSpotLocation_MASK) {
+            auto p = xcb_im_input_context_get_preedit_attr(xic_)->spot_location;
             auto trans_cookie = xcb_translate_coordinates(
                 server_->conn(), w, server_->root(), p.x, p.y);
             auto reply = makeUniqueCPtr(xcb_translate_coordinates_reply(

test/testxim.cpp

@@ -52,10 +52,16 @@ class XIMTest {
             1, 1, XCB_WINDOW_CLASS_INPUT_OUTPUT, screen_->root_visual, 0, NULL);
         uint32_t input_style = XCB_IM_PreeditPosition | XCB_IM_StatusArea;
         xcb_point_t spot;
-        spot.x = 0;
-        spot.y = 0;
-        xcb_xim_nested_list nested = xcb_xim_create_nested_list(
-            im.get(), XCB_XIM_XNSpotLocation, &spot, NULL);
+        spot.x = 5;
+        spot.y = 10;
+        xcb_rectangle_t area;
+        area.x = 0;
+        area.y = 0;
+        area.width = 5;
+        area.height = 10;
+        xcb_xim_nested_list nested =
+            xcb_xim_create_nested_list(im.get(), XCB_XIM_XNSpotLocation, &spot,
+                                       XCB_XIM_XNArea, &area, NULL);
         xcb_xim_create_ic(im.get(), create_ic_callback, this,
                           XCB_XIM_XNInputStyle, &input_style,
                           XCB_XIM_XNClientWindow, &w_, XCB_XIM_XNFocusWindow,