Codechange: Use `GetVisibleRangeIterators()` in more places. (#12190)

This replaces more first/last index calculation, along with indexed array/vector access, with iterator access instead.

Codechange: Remove direct access to _colour_gradient.

Access is now through GetColourGradient, which ensures parameters are in range.

Codechange: Make all NWidgetPart arrays constexpr.

This ensures that the arrays are not created at runtime and prevents using non-constexpr values.

Codechange: Replace mishmash of types for widget index with WidgetID.

Indices were stored as int, but often passed around as uint/uint8_t and casts.

Now they should all use WidgetID.

Codechange: Cargo filters no longer take an index. (#11582)

Update naming of functions to reflect that parameter is now a cargoid.

Change: Hide unused cargos from vehicle cargo filter. (#11533)

The list of used cargo types is updated when the list is invalidated.

Codechange: Remove FONT_HEIGHT_... macros. (#11481)

These make it look like we're dealing with a constant, but actually each is a call to `GetCharacterHeight(...)`.

Codechange: Simplify cargo filter lists, building only when required.

Some cargo filter lists were built in advance, and used as lookups to test which cargo type to filter.

Instead, use the Cargo ID directly as the filter parameter, and build the lists only when the drop down list is used.

Codechange: Add __FILE__/__LINE__ of WindowDesc to WindowDesc.

This is to allow unit-tests to produce more useful output.

Codechange: Don't access cargo filter before it is initialized. (#11321)

The cargo filter list is initialized during window OnInit, but the first
build of the filtered list occurred before this.

Codechange: Use begin/end of nwidget parts of begin/length.

This simplifies processing nwidget parts as, unlike the remaining length, the pointer to the end of the list never changes. This is the same principle as we use(d) for tracking end instead of length for C-style strings.

And this removes 160~ instances of the lengthof() macro.

Codechange: automatic adding of _t to (u)int types, and WChar to char32_t

for i in `find src -type f|grep -v 3rdparty/fmt|grep -v 3rdparty/catch2|grep -v 3rdparty/opengl|grep -v stdafx.h`; do sed 's/uint16& /uint16 \&/g;s/int8\([ >*),;[]\)/int8_t\1/g;s/int16\([ >*),;[]\)/int16_t\1/g;s/int32\([ >*),;[]\)/int32_t\1/g;s/int64\([ >*),;[]\)/int64_t\1/g;s/ uint32(/ uint32_t(/g;s/_uint8_t/_uint8/;s/Uint8_t/Uint8/;s/ft_int64_t/ft_int64/g;s/uint64$/uint64_t/;s/WChar/char32_t/g;s/char32_t char32_t/char32_t WChar/' -i $i; done

Codechange: Use window parent association for dropdowns.

This replaces the separate window class and number properties, and
allows the window system to close dropdowns automatically.

Codechange: Use std::any_of() (#10830)

When the result of std::find_if is compared only with end()
then '!= end()' is replaced with any_of().

Just... there's only one.

Codechange: Pass reference instead of pointer to GUI*Lists. (#10822)

Pointer-avoidance.

Codechange: Add and use GetScrolledItemFromWidget to get a list item.

This function returns an iterator, either to the selected item or the
container's end.

This makes handling the result more robust as indices are not used.

Codechange: Scrollbar methods now accept size_t.

This clears up a lot of casts from size_t to int.

Fix 3c047b1: AIGroup.GetProfitLastYear could get values different than those displayed in GUI (#10227)

* Change: Store "all time" and "since minimum age" last year profits on groups

* Fix: Update last year profit for groups when copying vehicle statistics on autoreplace

* Codechange: Refactor profit last year

* Change: Rename some group related items for clarity

* Change: Reorder the fields in GroupStatistics

That way less memory gets wasted.

Change: Use Rect helpers for widget drawing.

This replaces repetitive and sometimes unwieldy use of constants.

Change: Use NC_BIGFIRST in group window.

This means we no longer need to manually calculate the size of other
widgets in the window to determine how much space we need, as the widget
system will automatically fill as much as possible.

Codechange: Template DoCommandP to automagically reflect the parameters of the command proc.

When finished, this will allow each command handler to take individually
different parameters, obliviating the need for bit-packing.

Codechange: Make TileIndex a "strong" typedef to give it a distinct type.

This is accomplished by changing it to a single member struct with the
appropriate operator overloads to make it all work with not too much
source modifications.

Cleanup: Remove unnecessary parameter of GetScrolledRowFromWidget()

Line height defaults to the resize height of the relevant widget, which is
set in all cases. Therefore it is not necessary to specify this value every time.

Additionally fixes scrolled padding for the framerate window.

Change: Improve layout and spacing of vehicle group widgets. (#9041)

Existing layout included a blank widget above the group list to align with the vehicle list, however since then an additional sort-by row was added.
Group list size tweaks to match normal row size (at least with normal gui and text size.)
Removed reduction of 2 rows in the group list <- main culprit of odd sizing.
Removed fill attribute on buttons which gave strange sizes, and put it on the group info widget instead.
Tweaked various soft-padding values to line up (centreing text with a 1px offset does not make centred text.)

Codechange: Apply coding style (#8640)

* Fix: Missing or needed spaces

* Codechange: Remove space

* Codechange: Remove space

* Codechange: More missing spaces

* Codechange: Missing spaces

* Codechange: Remove space

* Codechange: Remove space

Fix #8332: aborting group drag&drop could cause crashes with vehicle drag&drop (#8511)

The selected group was not reset when drag&drop was aborted. When
after that vehicle drag&drop was successful, group drag&drop code
was still executed, causing weird behaviour or even crashes.

Feature: Option to group vehicle lists by shared orders

This applies to all kinds of vehicle lists, as well as the "vehicle groups" window.

Codechange: Make vehicle lists internally support grouping of vehicles

This is in preparation for the new UI feature that allows grouping by shared orders.

Fix: Violation of strict weak ordering in group name sorters

This could be caused by a group being renamed, and the old
name being cached from a previous sort.

See: #7838

Fix: Do not refer to a function in the documentation that was removed years ago (#7844)

The 'DoDrawString' was removed with this commit: f11300d

Codechange: Switch DropDownList to directly use std::vector, thus making AutoDeleteSmallVector obsolete.

DropDownListItem are strongly managed using std::unique_ptr to ensure leak-free handling. Appropriate use
of move-semantics make intent a lot clearer than parameter comments and allows the compiler to generate
copy-free code for most situations.

Feature: Group liveries, and livery window usability enhancements. (#7108)

* Change: Replace checkbox in livery selection window with Default option in drop down selection.

This reduces clutter in the UI and allows for primary/secondary colours to independently follow the default scheme if desired.

* Feature: Add vehicle group liveries.