Change: Show 6 or 2 orientation buttons in NewGRF road stop picker as appropriate.

This replaces the normal method of masking unusable buttons.

Codechange: allow certain enumeration to be added

Otherwise C++20 doesn't like it.

Codechange: Make all NWidgetPart arrays constexpr.

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

Fix #11655: Crash due to NWidgetMatrix modifying widget->index. (#11657)

NWidgetMatrix modifies its child widget's index to indicate which element
is to be drawn, which now causes issues with code that does not know about
stuffing extra data into the index.

Instead, let NWidgetMatrix store the currently processing element, and
retrieve this information from the matrix widget while child widgets are
being drawn.

This means only widgets that are children of NWidgetMatrix need to know
anything about their extra data.

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.

Fix: Draw unavailable mask over picker sprite instead of behind it.

This makes these disabled picker buttons consistent with other disabled buttons.

Codechange: Add Rect version of FillDrawPixelInfo().

This simplifies most callers as they longer have to split out a rect.

Codechange: Optionally allow passing state to GUIList sorter function.

GUIList sorter functions can currently only use global state, which makes per-window-instance sorting difficult.

Codechange: Add DropDownIcon constructor to override dimension.

This avoids the need to construct a DropDownIcon and set the dimension after.

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: Remove now-unnecessary containers in picker layouts. (#11473)

These are no longer necessary as the issue they work around was resolved by #11471

Codechange: Add __FILE__/__LINE__ of WindowDesc to WindowDesc.

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

Codechange: Avoid emplace_back(new()) into a unique_ptr. (#11384)

This could theoretically leave an unmanaged pointer in certain circumstances, and directly using
make_unique shows intent.

Add: data parameter in Window::Close method.

This allows passing data when closing a window, e.g. to indicate how it was closed.

Codechange: use better location for the "invalid" action sentinel value

It used to be a random sentinel for end-of-(widget-)list that was used to tell
that no action has taken place yet. Since the last action is practically the
widget that was pressed, add the sentinel to that enumeration.

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

Fix: Build road/tram stop windows did not set WindowDesc::ini_key (#11126)

Saved default window sizes were not persisted in the configuration file

Codechange: Make DropDownListStringItem preformat and remove other implementations. (#11063)

Having to choose between DropDownListStringItem, DropDownListCharStringItem, and DropDownListParamStringItem depending on whether to draw a StringID, a raw string, or a StringID with extra parameters was needlessly complex.

Instead, allow passing a StringID or raw string to DropDownListStringItem. This will preformat the StringID into a raw string, and can therefore accept parameters via the normal SetDParam mechanism.

This also means that strings no longer need to be formatted on every draw.

Codechange: Reorganise hotkey initialisation. (#10951)

Hotkeys are now initialized inline, and use std::vector instead of
separate static C-arrays and std::string instead of char *. The list end
marker is no longer required.

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.

Fix: Support more than 256 stations/waypoints/roadstops per class. (#10793)

It was already possible to define more than 256 per class, but not possible
to use them as the index used in GUI and passed through commands was limited
to a byte.

Codechange: Scrollbar methods now accept size_t.

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

Feature: Separate rail/road and sea/air velocity units, and add knots. (#10594)

This is achieved by packing vehicle type along with the velocity so that
the string system can decode and pick the appropriate unit.

Change: Use power-of-2 scaling for some dimensions in GUI.

These are related to drawing sprites that are normally drawn on the
landscape, and should therefore still follow power-of-2 scaling to fit
correctly.

Change: Tidy up coverage area label widget layout.

Label is now centered properly and uses standard spacing.

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: Template DoCommand 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.

Change: always allow to click on the toolbar icons for road/rail/dock/airport

This change allows a user to see what is available and what will become
available before it is available, instead of only disabling the button
with no further explanation. It also always allows building roads and
canals, even if no vehicles are available for road / water.

For rail/road/tram, a dropdown with available types is shown. If
none are available, it reads "None". If the type is not yet available,
it is greyed out.

For dock/airport, this always open the toolbar, but building airports,
docks, and depots buttons are disabled till vehicles are available
for those.

Road is the only exception, with the primary road always being
available. Here too, stations and depots are disabled till vehicles
become available. It does mean you can now always build roads to
for example help towns grow.

Fix #6659: Bus stations can be demolished when not in demolish mode (#6815)

For Bus and Road stations only, if you are in demolish mode and click on the station
without releasing the button. Then you cancel demolish mode with R key.
Finally you release the mouse button. The station was demolished, instead of being built.

The demolish mode was not checked when mouse up event occured.