Alignment improvements for PCBNew

[Leandro Heck]

Align in the middle/center use something like the reference point. Right now, I don't know which object is being used for that. I think that, maybe, it is using the object from the right.

I propose to change this behavior to use the "first selected" or the "last selected" object for that purpose.

Inkscape has this and it is good because let the user choose which object will remain in its place. I prefer to use the "first selected" for that.

Also, "middle" and "center" are not clear to me. Which one is vertical, which one is horizontal? I never know the difference. I propose to change it to:
- Align middle -> Align center Vertically
- Align center -> Align center Horizontally

Application: kicad
Version: 5.0.0-fee4fd1~66~ubuntu18.04.1, release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.58.0 OpenSSL/1.1.0g zlib/1.2.11 libidn2/2.0.4 libpsl/0.19.1 (+libidn2/2.0.4) nghttp2/1.30.0 librtmp/2.3
Platform: Linux 4.15.0-34-generic x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 2.24
    Boost: 1.65.1
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.58.0
    Compiler: GCC 7.3.0 with C++ ABI 1011

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=OFF
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_WXPYTHON=OFF
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON

[Seth Hillbrand (sethh)]

You are right. The middle-alignment, center-alignment issue was a quick-fix in the last days of 5.0-rc. I recall the decision at the time was to make it deterministic (left-most and center-most) instead of picking the middle of the group. But the plan is to eventually update that to align to the element you right-click on. In the case of keyboard shortcut, we would use the first element selected.