IO: added AddKeyAnalogEvent() and support for ImGuiKey_GamepadXXXX. (#4858, #787)

docs/CHANGELOG.txt

@@ -76,6 +76,10 @@ Breaking Changes:
      - Access to full key ranges will allow us to develop a proper keyboard shortcut system. (#456)
      - io.AddKeyEvent() will later be turned into a trickling IO queue (for all inputs) to handle very low framerate better. (#2525, #2787, #3383)
      - io.SetKeyEventNativeData() include native keycode/scancode which will later be exposed. (#3141, #2959)
+- Reworked IO nav/gamepad input API and unifying inputs sources: (#4858, #787)
+  - Added full range of ImGuiKey_GamepadXXXX enums (e.g. ImGuiKey_GamepadDpadUp, ImGuiKey_GamepadR2) to use with
+    io.AddKeyEvent(), io.AddKeyAnalogEvent().
+  - Added io.AddKeyAnalogEvent() function, obsoleting writing directly to io.NavInputs[] arrays.
 - Renamed ImGuiKey_KeyPadEnter to ImGuiKey_KeypadEnter to align with new symbols. Kept redirection enum. (#2625)
 - Backends: GLFW: backend now uses glfwSetCursorPosCallback().
   - If calling ImGui_ImplGlfw_InitXXX with install_callbacks=true: nothing to do. is already done for you.
@@ -101,6 +105,8 @@ Other Changes:
 - IO: Added event based input queue API, which now trickles events to support low framerates. [@thedmd, @ocornut]
   Previously the most common issue case (button presses in low framerates) was handled by backend. This is now
   handled by core automatically for all kind of inputs. (#4858, #2787, #1992, #3383, #2525, #1320)
+  - New IO functions for keyboard/gamepad: AddKeyEvent(), AddKeyAnalogEvent(), AddKeyModsEvent().
+  - New IO functions for mouse: AddMousePosEvent(), AddMouseButtonEvent(), AddMouseWheelEvent().
 - Fixed a situation where CTRL+Tab or Modal can occasionally lead to the creation of ImDrawCmd with zero triangles,
   which would makes the draw operation of some backends assert (e.g. Metal with debugging). (#4857)
 - Popups: Fixed a regression crash when a new window is created after a modal on the same frame. (#4920) [@rokups]