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

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

Fix: TextfileWindow called virtual methods before constructor completed. (#11889)

SetStringParameters() was called during widget tree init in the constructor.

Calls within a constructor cannot call the derived classes methods. This would result in invalid data being passed to the string system, which could then crash.

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.

Change: Hide bevel for resizeable sparse layout windows. (#11572)

When clicked, the button is still highlighted to show that it is active.

The bevel is controlled with widget_data by RWV_SHOW_BEVEL or RWV_HIDE_BEVEL values.

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: 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 __FILE__/__LINE__ of WindowDesc to WindowDesc.

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

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 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

Feature: opt-in survey when exiting a game

On first start-up, the game will ask if you want to participate
in our automated survey. You have to opt-in, and can easily opt-out
(via the Options) at any time.

When opt-in, whenever you exit a game, a JSON blob will be send
to the survey server hosted by OpenTTD. This JSON blob contains
information that gives a global picture of the game just played:
- What settings were used
- How many humans vs AIs
- How long the game has been played
- Basic information about the OS / CPU

All this information is kept very generic, so there is no
chance we send private information to our survey server.
Nothing in the JSON blob could identify you as a person; it
mostly tells about the game played. At any time you can see
what the JSON blob includes, by pressing the "Preview Survey
Results" button in-game.

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: reset content download progress to zero if falling back to TCP

Otherwise this chain of events can happen:
- You already have a (partial) file downloaded
- You start the download, and HTTP fails
- This resets the download progress to the current size of the file
- The TCP download starts at a very large value (UINT32_MAX - filesize)

It now resets to 0% done when any negative value is being given.
As added bonus, we no longer have to query how much was already
downloaded.

Change: Standardize progress bar layout.

Progress bars are drawn differently depending on when it was added, with
different layouts and sizes.

This change adds a standard padding size to use, and makes all progress
bars visually similar, with scaled padding.

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.

Codechange: [Network] split CloseSocket and CloseConnection more clearly (#9261)

* Codechange: [Network] split CloseSocket and CloseConnection more clearly

- CloseSocket now closes the actual OS socket.
- CloseConnection frees up the resources to just before CloseSocket.
- dtors call CloseSocket / CloseConnection where needed.

Add: make modal windows update more smooth

Basically, modal windows had their own thread-locking for what
drawing was possible. This is a bit nonsense now we have a
game-thread. And it makes much more sense to do things like
NewGRFScan and GenerateWorld in the game-thread, and not in a
thread next to the game-thread.

This commit changes that: it removes the threads for NewGRFScan
and GenerateWorld, and just runs the code in the game-thread.
On regular intervals it allows the draw-thread to do a tick,
which gives a much smoother look and feel.

It does slow down NewGRFScan and GenerateWorld ever so slightly
as it spends more time on drawing. But the slowdown is not
measureable on my machines (with 700+ NewGRFs / 4kx4k map and
a Debug build).

Running without a game-thread means NewGRFScan and GenerateWorld
are now blocking.

Fix: mention our websites with https:// (instead of http://) (#8657)

It is 2021. Nobody should advertise http anymore. Not even us.

Fix #8024: make online content gui more responsive while loading

Previously the internal content list was invalidated and sorted for
every new item added. Now the sorting is delayed until the GUI is
drawn, which means we only sort once per GUI tick.

Since the amount of incoming items per GUI tick is not controlled by
the GUI but rather by network speed, we were previously doing a lot
of duplicate work per tick, causing the mouse cursor to lag while
the list was initialized.

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.