Scrolling, Nav: Fixed programmatic scroll leading to a slightly incorrect scroll offset when the window has decorations or a menu-bar (broken in 1.71). This was mostly noticeable when a keyboard/gamepad movement led to scrolling the view, or using e.g. SetScrollHereY() function. Fix/amend a0994d74.

Internal refactor: moved all Scroll related functions in a same spot.

Internal: Moved NavScrollToBringItemIntoView() declaration to imgui_internal.h. Fixed spacing missing in 494d804. Fixed changelog wreck from 1.72.

Internal: Avoid using GImGui multiple times in same function.

Nav: Fixed an issue with NavFlattened window flag where widgets not entirely fitting in child window (often selectable because of their extruded bits) would be not considered to navigate toward the child window. (#787) ...

This creates a little bit of tension because g.NavDisableHighlight tends to makes the reference point not always visible.
Amend c665c15

Version 1.73 WIP

Version 1.72

Internal: Added IsMouseDragPastThreshold(). Tweaks. Todo. ...

Demo: Showing how to use the format parameter of Slider/Drag functions to display the name of an enum value instead of the underlying integer value

Fixed Clang 8.0 warning "empty expression statement has no effect; remove unnecessary ';' to silence this" warning [-Wextra-semi-stmt] ...

+ Comment

Internals: Added IMGUI_DEBUG_INI_SETTINGS. Made IMGUI_DEBUG_LOG redefinable in imconfig.h. Comments. Fix to allow Metrics's NodeWindow() being called with a NULL window.

Internals: Merge in minor noise from wip Tables branch to simplify further merging.

Scrolling: Made mouse-wheel scrolling lock the underlying window until the mouse is moved again or until a short delay expires (2 seconds). This allow uninterrupted scroll even if child windows are passing under the mouse cursor. (#2604)

Scrolling: Made it possible for mouse wheel and navigation-triggered scrolling to override a call to SetScrollX()/SetScrollY(), making it possible to use a simpler stateless pattern for auto-scrolling. ...

Demo: Log, Console: Using a simpler stateless pattern for auto-scrolling.

Internals: Nav: Tweak NavUpdatePageUpPageDown() to make it more readable.

OSX: Disabled default native Mac clipboard copy/paste implementation in core library (added in 1.71), because it needs application to be linked with '-framework ApplicationServices'. It can be explicitly enabled back by using '#define IMGUI_ENABLE_OSX_DEFAULT_CLIPBOARD_FUNCTIONS' in imconfig.h. Re-added equivalent using NSPasteboard api in the imgui_impl_osx.mm experimental back-end. (#2546)

Fixed incorrect application of io.DisplaySafeAreaPadding which would be problematic with multi-viewports when a monitor uses negative coordinates (correct clamping is done right below). (#2674)

Internals: Extracted some code out of the NewFrame() function.

Debug Tools: Added DebugStartItemPicker() in imgui_internal.h to facilitate binding this anywhere in user's tool. Adedd highlight. Added IMGUI_DEBUG_TOOL_ITEM_PICKER_EX to break in ItemAdd().

Internals: Refactor: Moved all Columns code from imgui.cpp to imgui_widgets.cpp (#125) ...

Also moved NextColumn between BeginColumn and NextColumn which makes it easier to work on that code.

Debug, Metrics: Added "Tools->Item Picker" tool which allow clicking on a widget to break in the debugger within the item code. The tool calls IM_DEBUG_BREAK() which can be redefined in imconfig.h if needed.

Style: Added style.ColorButtonButton (left/right, defaults to ImGuiDir_Right) to move the color button of ColorEdit3/ColorEdit4 functions to either side of the inputs.

Removed TreeAdvanceToLabelPos() which is rarely used and only does SetCursorPosX(GetCursorPosX() + GetTreeNodeToLabelSpacing()). Kept redirection function (will obsolete). (#581, #324)

Fixed unnecessary test in UpdateMouseWheel() (thanks PVS). ...

TreeNodeBehavior: avoid computing bg_col for non-framed non-active tree nodes.
Comments, binaries update, minor typos.

Settings: Minor optimization to reduce calls in SettingsHandlerWindow_WriteAll.

Renamed ImFontAtlas::CustomRect to ImFontAtlasCustomRect. Keep redirection typedef (will obsolete).

Prefixed internal structs exposed in imgui.h with a fully qualified name to facilitate auto-generation with cimgui.

Window: Mouse wheel scrolling while hovering a child window is automatically forwarded to parent window if ScrollMax is zero on the scrolling axis. Also still case if ImGuiWindowFlags_NoScrollWithMouse is set (not new), but previously the forwarding ...

would be disabled if ImGuiWindowFlags_NoScrollbar was set on the child window, which is not the case any more (amend #1502, #1380).

Misc: Added IMGUI_DISABLE_METRICS_WINDOW imconfig.h setting to explicitly compile out ShowMetricsWindow(). + Internals: Minor renaming.

Added SetScrollXHere, SetScrollFromPosX: Changelog, demo, comments (#1580).

Added 'SetScrollHereX' and 'SetScrollFromPosX' (#1580)