Codechange: Make all NWidgetPart arrays constexpr.

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

Codechange: Use CompanyMask to pass Companies to PopupMainCompanyToolbMenu().

It's like the type was designed for it.

Codechange: Use company group statistics to test for vehicles for drop down list state.

This avoids iterating full the vehicle pool to find out if a company has any vehicles of a particular type.

Codechange: Use vector/unique_ptr inside widget containers.

This replaces a C-style double-linked-list which required all widgets
to have next/prev pointers, and removes the need for manual pointer management.

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: Use std::map to provide indexed widget access.

This removes the need to determine the biggest widget index and replaces C-style memory handling.

Codechange: Remove deferred nested_array initialization path. (#11640)

Having two ways (`FillNestedArray` and `SetupSmallestSize`) to initialize
`Window::nested_array` introduces confusion.

Instead, make `FillNestedArray` the canonical way, always call it, and remove
init_array from `SetupSmallestSize`.

Change: Use CRTP-mixins to compose dropdown list items.

This allows list items to built from component parts as required, and additional
functionality is added:

* Icons and text can be positioned at the start or end of the space (templated.)
* Font size of text can be changed (templated.)
* Palette of sprites can be set (runtime.)

Codechange: List toolbar menu items and dividers explicitly.

This makes it clearer what items will be shown in the list, allows for non-consecutive
string IDs, and means unused enum values are not necessary.

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: Add base() method to StrongType to allow access to the base type without casting. (#11445)

This removes the ability to explicitly cast to the base type, but the requirement
to use .base() means the conversion is still explicit.

Codechange: Add __FILE__/__LINE__ of WindowDesc to WindowDesc.

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

Codechange: Assign/StoreSizePosition x/y can be negative. (#11416)

AssignSizePosition is used with negative values when an NWidgetMatrix is
scrolled, but they were passed as unsigned and then stored as signed.

Widget pos_x/pos_y were already made signed.

Add: Debug tool to draw widget outlines. (#11401)

This is considered a developer tool and is controlled from the help menu (or default hotkey Ctrl-O).

This draws a white dashed outline around widgets. NWidgetSpacer and (unused) WWT_EMPTY widgets are also filled with check pattern to highlight them, as they usually indicate a design issue.

Codechange: Remove unused parameter for Height()

DropDownListItem::Height does not need to take an argument so remove it

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

Codechange: Use unified NWidgetContainer methods instead of duplicating.

Most NWidgetContainer derivatives implemented Draw() and GetWidgetFromPos()
the same way. Move this these to NWidgetContainer itself to avoid repeating.

Codechange: Hide toolbar buttons by setting width to zero.

Zero-width is how widgets are hidden elsewhere.
This removes the need for an extra array to lookup if a button is hidden.

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.

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: 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.

Change: Add window description flag to disallow interactive window closing. (#11008)

This replaces/simplifies testing for a closebox to allow closing a window with right-click, and testing for specific window classes when closing all windows by hotkey.

This allows right-click closing of dropdowns and the high-score window.

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: migrate all Window-related timers to the new framework

This means we also say goodbye to GUITimers.

Change: Make all dropdown lists extend width if necessary.

This removes the auto_width parameter from ShowDropDown(At).

Codechange: introduce GetMainWindow() to properly account for nullptr checks

Some nullptr checks have been removed as they were not triggered with nullptr
with the null video driver and in dedicated server mode.

Change: Use Rect helpers for widget drawing.

This replaces repetitive and sometimes unwieldy use of constants.

Cleanup: Text widgets are capable of drawing text without assistance.

Remove custom text drawing of some widgets in favour of standard text
widgets.

Fix: Open scenario editor date query once. (#10050)

Clearing `_left_button_clicked` causes the button callback to be fired
constantly while the mouse button is held.

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.

Fix: add back 'Spectate' option to company toolbar menu (#9556)

This was removed in ce7406f88b, but people used this to quickly
mark themselves as away.

Co-authored-by: dP <dp@dpointer.org>

Feature: rework in-game Online Players GUI

The GUI now more clearly shows some basic information about the
server you joined, your client name (and the ability to change it),
and what players are in which company.

It also contains useful buttons to press to join companies, chat
with other people, and for admins to kick/ban people.

Additionally, renamed "advertised" to "visibility"; this has to
do with future additions, but also because it is more clear in
wording.

Add: settings to limit your fast-forward game speed

By default this setting is set to 2500% normal game speed.

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.

Codechange: Spell 'Viewport' consistently

Some places in the codebase misspell 'Viewport' as 'ViewPort' or 'view_port'.
This patch makes everything consistent.

Add: Hotkey for Land Info in normal mode
- added a hotkey for land_info in normal mode
- no default key is set

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.

Codechange: Use override specifer for overriding member declarations

This is a C++11 feature that allows the compiler to check that a virtual
member declaration overrides a base-class member with the same signature.

Also src/blitter/32bpp_anim_sse4.hpp +38 is no longer erroneously marked
as virtual despite being a template.

Remove: ENABLE_NETWORK switch

This switch has been a pain for years. Often disabling broke
compilation, as no developer compiles OpenTTD without, neither do
any of our official binaries.

Additionaly, it has grown so hugely in our codebase, that it
clearly shows that the current solution was a poor one. 350+
instances of "#ifdef ENABLE_NETWORK" were in the code, of which
only ~30 in the networking code itself. The rest were all around
the code to do the right thing, from GUI to NewGRF.

A more proper solution would be to stub all the functions, and
make sure the rest of the code can simply assume network is
available. This was also partially done, and most variables were
correct if networking was disabled. Despite that, often the #ifdefs
were still used.

With the recent removal of DOS, there is also no platform anymore
which we support where networking isn't working out-of-the-box.

All in all, it is time to remove the ENABLE_NETWORK switch. No
replacement is planned, but if you feel we really need this option,
we welcome any Pull Request which implements this in a way that
doesn't crawl through the code like this diff shows we used to.