Tests: Reworking hook prototypes for imgui-test to be faster and multi-context friendly.

Fixed animated window titles from being updated when displayed in the CTRL+Tab list. + Adding overkill helpers for reusing buffers. (#787)

Renamed ImFont::GlyphRangesBuilder to ImFontGlyphRangesBuilder. Keep redirection typedef (will obsolete).

IO: Renamed InputCharacters[], marked internal as was always intended. AddInputCharacter() goes into a queue which can receive as many characters as needed during the frame. This is useful for automation to not have an upper limit on typing speed. Will later transition key/mouse to use the event queue later.

Nav: Fixed an keyboard issue where holding Activate/Space for longer than two frames on a button would unnecessary keep the focus on the parent window, which could steal it from newly appearing windows. (#787)

Added bindings in Readme. Added internal IMGUI_DEBUG_LOG() helper. Comments, missing breaking changes note relative to imgui_impl_xxxx changes, not really part of core but worth adding in the imgui.cpp breaking change section.

Added sanity check to debug parent/child ordering issues (they would generally manifest with an assert/crash in EndFrame bu tthis assert will catch some earlier).

Internals: Extracted code out of EndFrame() into UpdateMouseMovingWindowEndFrame()

Alternative fix for bug introduced in d845135 (#1651), fix CTRL+Tab and fallback tooltip.

Revert "Fixes crash/assert bug introduced in d845135 (#1651): would assert when showing the CTRL+Tab list and or fallback "...." tooltip." ...

This reverts commit 1b0e38d.

Fixes crash/assert bug introduced in d845135 (#1651): would assert when showing the CTRL+Tab list and or fallback "...." tooltip.

Happy new year! & comments

Comments: fixed missing line in the "how a simple rendering function may look like" section (#2258)

Error recovery: Extraneous/undesired calls to End() are now being caught by an assert in the End() function itself at the call site (instead of being reported in EndFrame). Past the assert, they don't lead to crashes any more. Missing calls to End(), pass the assert, should not lead to crashes any more, nor to the fallback/debug window appearing on screen. (#1651).

Tweaked asserts

Made it illegal to call Begin("") with an empty string. This somehow accidentally worked before but had various undesirable side-effect as the window would have ID zero. In particular it is causing problems in viewport/docking branches.

IO: Added BackendPlatformUserData, BackendRendererUserData, BackendLanguageUserData void* for storage use by back-ends. (#2004 + for cimgui)

Fixed using SetNextWindowPos() on a child window (which wasn't really documented) position the cursor as expected in the parent window, so there is no mismatch between the layout in parent and the position of the child window. Demo tweak and adding some child window stuff

Various user-facing comments

Tidying up README, moved entries to FAQ, updated screenshots, removed comma in title.

Fix merge issue on master.

Window, Focus, Popup: Fixed an issue where closing a popup by clicking another window with the _NoMove flag would refocus the parent window of the popup instead of the newly clicked window.

Moved setting up NavHideHighlightOneFrame from lower-level ClosePopupToLevel() to CloseCurrentPopup() with an explanation. (Followup on 68d3e13)

Internals: Popups: Renamed CurrentPopupStack to BeginPopupStack which is much less ambiguous.

Internals: Popup related comments. Renamed the misleading internal ClosePopup() function. Added bool* test to BeginPopupModal in demo.

Tests: Changed prototype of ImGuiTestEngineHook_ItemAdd to match functions called in same spot. Made ButtonBehavior submit fallback item info if ItemAdd() was not called (for resize grips, resize borders, scrollbar, columns, etc.)

Comments, minor tweaks.

Internals: Windows hidden with HiddenFramesRegular (but NOT HiddenFramesForResize) preserve their SizeContents, so restoring a auto-resize window after it's been hidden by tabs won't reset its size for a frame. Arguable. Let's see how it goes. (Followup to b48e295)

Contents size is preserved while a window collapsed. Fix auto-resizing window losing their size for one frame when uncollapsed.

Added BETA api for Tab Bar/Tabs widgets. (#261, #351) (merged this feature from the from Docking branch so it can be used earlier as as standalone feature) ...

- Added BeginTabBar(), EndTabBar(), BeginTabItem(), EndTabItem(), SetTabItemClosed() API.
- Added ImGuiTabBarFlags flags for BeginTabBar().
- Added ImGuiTabItemFlags flags for BeginTabItem().
- Style: Added ImGuiCol_Tab, ImGuiCol_TabHovered, ImGuiCol_TabActive, ImGuiCol_TabUnfocused, ImGuiCol_TabUnfocusedActive colors.
- Demo: Added Layout->Tabs demo code.
- Demo: Added "Documents" example app showcasing possible use for tabs.