Internals: Fixed HoveredIdTimer so it is safe to call SetHoveredId() multiple times without altering the timer.

CollapseButton: Added hovering highlight + minor consistency tweaks.

Internals: Drag and Drop: default drop preview use a narrower clipping rectangle (no effect here, but other branches uses a narrow clipping rectangle that was too small so this is a fix for it) + Comments

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp
#	imgui_internal.h

Internals: Changed SplitterBehavior() signature to be consistent with other similar signatures. (#319).

Internals: Extracted part of Begin into UpdateWindowParentAndRootLinks(). Useful to call to keep state updated immediately (namely useful for docking) + small tidying up of imgui_internal.h

Assert that fmt != NULL before calling vsnprintf (#1969) ...

In the case of Visual Studio 15.6 + Windows SDK 10.0, vsnprintf() with NULL format string appears to corrupt the stack...

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp

Internals: Child windows that are clipped or part of a collapsed parent are not marked as collapsed anymore, but just a separate hidden marker set. We distinguish hiding for size measurement vs hiding for other reasons. Cleaned a little the end of Begin.

Nav: Tweaked CTRL+TAB to hide visual noise on fast switch + fading out screen dimming and highlight to make the experience less harsh

Nav: Tweaked CTRL+TAB to hide visual noise on fast switch + fading out screen dimming and highlight to make the experience less harsh

FAQ update

Internals: SplitterBehavior() added hover_visibility_delay parameter which is helpful to reduce visual noise. (#319)

Internals: Exposed NavScoreItemGetQuadrant() as ImGetDirQuadrantFromDelta() in imgui_internal.h

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_sdl.cpp
#	imgui.cpp

Made it possible to move a window by dragging from the Collapse button (past the drag threshold). Extracted some code out to a CollapseButton() function.

Internals: Renamed one of the arrow functions so their name don't collide.

Fixed horizontal mouse wheel not forwarding the request to the parent window if ImGuiWindowFlags_NoScrollWithMouse is set. (#1463, #1380, #1502)

Internals: Extracted part of NewFrame() into a UpdateMouseWheel() function.

Added asserts to catch illegal modifications of the font atlas between NewFrame() and EndFrame()/Render(). (#1958)

Changed ImGui::GetTime() return value from float to double to avoid accumulating floating point imprecisions over time.

Viewport: Fixed a situation when the implicit Debug window can hold on a zombie viewport which platform window is not properly destroyed. (#1542)

ImGuiTextFilter, TextRange: removed cruft from TextRange since it's not a publicly and generic helper at the moment + marked internal stuff + changed a reference to a pointer. (#1879)

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp

Nav: Fixed CTRL+TAB windowing list from always showing the implicit Debug window. (#787)

Fix warning when IMGUI_DEFINE_MATH_OPERATORS is already defined by build system. (#1950)

Viewport: Removed the need for the back-end to fill io.MousePosViewport, it seems unnecessary at this point. (#1542)

Internals: Viewport: Renamed g.MouseRefViewport to g.MouseViewport. (#1542)

Viewport: when moving window we use the moving window viewport unless drag and dropping. This is to fix e.g. IsItemHovered() + Tooltip pattern that may be active while moving a window. (#1542)

Viewport: Revert part of 7abf72e, the viewport ownership stealing is problematic. (#1542). Will rework in the context of docking. (+1 squashed commits) ...

+ Fixed unused prototype warning (left-over from a merge)