Platform IME: add ImGuiPlatformImeData::InputLineHeight (unused by win32). (#3113)

docs/CHANGELOG.txt

@@ -62,6 +62,7 @@ Other Changes:
   now taking a ImGuiPlatformImeData structure which we can more easily extend in the future.
 - Platform IME: moved io.ImeWindowHandle to GetMainViewport()->PlatformHandleRaw.
 - Platform IME: add ImGuiPlatformImeData::WantVisible, hide IME composition window when not used. (#2589) [@actboy168]
+- Platform IME: add ImGuiPlatformImeData::InputLineHeight. (#3113) [@liuliu]
 - Platform IME: [windows] call ImmSetCandidateWindow() to position candidate window.
 - Backends: OpenGL3: Fixed a buffer overflow in imgui_impl_opengl3_loader.h init (added in 1.86). (#4468, #4830) [@dymk]
   It would generally not have noticeable side-effect at runtime but would be detected by runtime checkers.

imgui.h

@@ -2834,6 +2834,7 @@ struct ImGuiPlatformImeData
 {
     bool    WantVisible;        // A widget wants the IME to be visible
     ImVec2  InputPos;           // Position of the input cursor
+    float   InputLineHeight;    // Line height
 
     ImGuiPlatformImeData() { memset(this, 0, sizeof(*this)); }
 };

imgui_widgets.cpp

@@ -4763,6 +4763,7 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             {
                 g.PlatformImeData.WantVisible = true;
                 g.PlatformImeData.InputPos = ImVec2(cursor_screen_pos.x - 1.0f, cursor_screen_pos.y - g.FontSize);
+                g.PlatformImeData.InputLineHeight = g.FontSize;
             }
         }
     }