Codechange: Add method to replace the content of a dropdown menu.

If necessary the dropdown list window will be resized and scrollbar enabled/disabled.

Codechange: Add parameter to persist dropdown menus.

If a dropdown menu is set to persist, it will not close when an item is selected. It will close as normal if the window loses focus.

Closing the list is the responsibility of the caller.

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: Move dropdown list size and position calculation to window.

This simplifies initialization of DropdownWindow, as instead of both the caller code and the class needing to know about list sizes and available space, only the DropdownWindow needs to know.

Codechange: Add specific WidgetDimension for dropdown list window. (#11554)

This avoids contorting fullbevel dimensions.

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: 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.

Codechange: Call Widget::SetDirty/SetLowered directly. (#11417)

In these instances we already have the widget to hand, so don't need to look it up by index again.

Fix d42a78f: Some raw drop down list strings may need token processing. (#11400)

Storing the raw string without processing though GetString() caused token
processing to be skipped.

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: 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 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.

Fix #11043: Don't choose toolbar dropdown option if focus is lost. (#11044)

Since dropdown menus now get closed if they lose focus, 'instant close' dropdowns (i.e. the toolbar dropdowns) should no longer execute their action to avoid unintended actions.

Fix #10987: Double-close of dropdown stopped land-info tool working as default. (#11000)

Clicking and releasing on the query toolbar icon is meant to select the land-info tool.

This did not work as during closing a window, OnFocusLost() is called, which then closes the window again. These two calls toggled the land-info tool one and off in the same action.

Resolve by not calling Window::Close in OnFocusLost() if the window is already closing.

Fix dec7ff6b0c: Dropdowns couldn't be closed by pressing the parent button. (#10954)

Since dropdowns self-close, the detection of re-clicking a dropdown
button no longer worked, as the dropdown is already closed.

Instead set (and then test) a flag on the parent widget to indicate that
the dropdown closed. This method avoids looping windows on every click.

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: Scrollbar methods now accept size_t.

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

Codechange: Scrollbar::UpdatePosition() will tell if the position changed. (#10777)

So we don't need to check this manually.

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).

Fix: Incorrect available height for dropdowns due to unsigned promotion. (#10264)

Dropdowns which are taller than the main window should automatically have
a scrollbar added. This did not work for toolbar dropdown as the location
near the top of the window resulted in an unsigned underflow.

Change: Use Rect helpers for widget drawing.

This replaces repetitive and sometimes unwieldy use of constants.

Codechange: use IterateFromBack/Front only if the order is important.

Use Iterate if the order does not matter.

Codechange: Make GetCurrentRect() conform to usual Rect bounds, and reuse it.

Similar code is already repeated in other locations.

Fix: Incorrect vertical alignment of icon and text in DropDownListIconItem. (#9133)

This happens if the bounding dimensions are changed so that each item is the same size, as happens on the railtype/roadtype dropdown lists, as the vertical offset was calculated before this dimension is changed.

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.

Fix #6060: When opening a scrollable dropdown above a widget, scroll it to its very bottom.
This "prevents" the fast movement towards the bottom when holding down the mouse button.

(svn r23525) -Codechange: make Window::flags4 WindowFlags instead of uint16, with only values known in WindowFlags (and move out 2 timers to their own variable)
-Codechange: rename Window::flags4 to Window::flags
-Codechange: move some non-inline functions from .hpp to .cpp