Debug Tools: Added 'io.ConfigDebugIgnoreFocusLoss' option. (#4388, #4921)

docs/CHANGELOG.txt

@@ -64,6 +64,9 @@ Other changes:
 - Misc: Added ImVec2 unary minus operator. (#6368) [@Koostosh]
 - Debug Tools: Debug Log: Fixed not parsing 0xXXXXXXXX values for geo-locating on mouse
   hover hover when the identifier is at the end of the line. (#5855)
+- Debug Tools: Added 'io.ConfigDebugIgnoreFocusLoss' option to disable 'io.AddFocusEvent(false)'
+  handling. May facilitate interactions with a debugger when focus loss leads to clearing
+  inputs data. (#4388, #4921)
 - Backends: Clear bits sets io.BackendFlags on backend Shutdown(). (#6334, #6335] [@GereonV]
   Potentially this would facilitate switching runtime backend mid-session.
 - Backends: Win32: Added ImGui_ImplWin32_InitForOpenGL() to facilitate combining raw

imgui.cpp

@@ -1540,7 +1540,7 @@ void ImGuiIO::AddFocusEvent(bool focused)
     // Filter duplicate
     const ImGuiInputEvent* latest_event = FindLatestInputEvent(&g, ImGuiInputEventType_Focus);
     const bool latest_focused = latest_event ? latest_event->AppFocused.Focused : !g.IO.AppFocusLost;
-    if (latest_focused == focused)
+    if (latest_focused == focused || (ConfigDebugIgnoreFocusLoss && !focused))
         return;
 
     ImGuiInputEvent e;

imgui.h

@@ -1952,11 +1952,15 @@ struct ImGuiIO
 
     // Debug options
     // - tools to test correct Begin/End and BeginChild/EndChild behaviors.
-    // - presently Begn()/End() and BeginChild()EndChild() needs to ALWAYS be called in tandem, regardless of return value of BeginXXX()
+    // - presently Begin()/End() and BeginChild()/EndChild() needs to ALWAYS be called in tandem, regardless of return value of BeginXXX()
     //   this is inconsistent with other BeginXXX functions and create confusion for many users.
-    // - we expect to update the API eventually. In the meanwhile we provided tools to facilitate checking user-code behavior.
+    // - we expect to update the API eventually. In the meanwhile we provide tools to facilitate checking user-code behavior.
     bool        ConfigDebugBeginReturnValueOnce;// = false          // First-time calls to Begin()/BeginChild() will return false. NEEDS TO BE SET AT APPLICATION BOOT TIME if you don't want to miss windows.
     bool        ConfigDebugBeginReturnValueLoop;// = false          // Some calls to Begin()/BeginChild() will return false. Will cycle through window depths then repeat. Suggested use: add "io.ConfigDebugBeginReturnValue = io.KeyShift" in your main loop then occasionally press SHIFT. Windows should be flickering while running.
+    // - option to deactivate io.AddFocusEvent(false) handling. May facilitate interactions with a debugger when focus loss leads to clearing inputs data.
+    // - backends may have other side-effects on focus loss, so this will reduce side-effects but not necessary remove all of them.
+    // - consider using e.g. Win32's IsDebuggerPresent() as an additional filter (or see ImOsIsDebuggerPresent() in imgui_test_engine/imgui_te_utils.cpp for a Unix compatible version).
+    bool        ConfigDebugIgnoreFocusLoss;     // = false          // Ignore io.AddFocusEvent(false), consequently not calling io.ClearInputKeys() in input processing.
 
     //------------------------------------------------------------------
     // Platform Functions

imgui_demo.cpp

@@ -471,6 +471,8 @@ void ImGui::ShowDemoWindow(bool* p_open)
             ImGui::SameLine(); HelpMarker("First calls to Begin()/BeginChild() will return false.\n\nTHIS OPTION IS DISABLED because it needs to be set at application boot-time to make sense. Showing the disabled option is a way to make this feature easier to discover");
             ImGui::Checkbox("io.ConfigDebugBeginReturnValueLoop", &io.ConfigDebugBeginReturnValueLoop);
             ImGui::SameLine(); HelpMarker("Some calls to Begin()/BeginChild() will return false.\n\nWill cycle through window depths then repeat. Windows should be flickering while running.");
+            ImGui::Checkbox("io.ConfigDebugIgnoreFocusLoss", &io.ConfigDebugIgnoreFocusLoss);
+            ImGui::SameLine(); HelpMarker("Option to deactivate io.AddFocusEvent(false) handling. May facilitate interactions with a debugger when focus loss leads to clearing inputs data.");
 
             ImGui::TreePop();
             ImGui::Spacing();