Configuration flags

Debug-Tools.md

@@ -1,5 +1,26 @@
 (work in progress) Also see [[Tips]].
 
+### Debug Configuration Flags
+
+Runtime flags available in `ImGuiIO` (and exposed in Demo->Configuration):
+```cpp
+// Tools to test correct Begin/End and BeginChild/EndChild behaviors.
+// 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 provide tools to facilitate checking user-code behavior.
+bool ConfigDebugBeginReturnValueOnce; // 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; // 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;      // Ignore io.AddFocusEvent(false), consequently not calling io.ClearInputKeys() in input processing.
+
+// Options to audit .ini data
+bool ConfigDebugIniSettings;          // Save .ini data with extra comments (particularly helpful for Docking, but makes saving slower)
+```
+
+
 ### Metrics/Debugger window
 
 Many internal state and tools are exposed in the Metrics window. To access the Metrics window: