This lets windows know when they are dropping a mouse event because their
hit test reported something other than SDL_HITTEST_NORMAL. It lets them know
exactly where in the event queue this happened.
This patch is based on work in Unreal Engine 4's fork of SDL,
compliments of Epic Games.
This allows an app to know when a set of drops are coming in a grouping of
some sort (for example, a user selected multiple files and dropped them all
on the window with a single drag), and when that set is complete.
This also adds a window ID to the drop events, so the app can determine to
which window a given drop was delivered. For application-level drops (for
example, you launched an app by dropping a file on its icon), the window ID
will be zero.
Elise Maurer
When inputting text, dead-keys are currently not handled correctly on Windows with the latest SDL2 tip as well as the 2.0.3 release.
Using a French AZERTY keyboard, when I type the `^` key followed by `e` key to compose the `` character, I erroneously get two SDL_TEXTINPUT events, one with the `^` character and one with the `e` character.
I've looked at the history for SDL_windowsevents.c and there's been some back-and-forth with several methods for handling text input:
* r8142 removed any handling of WM_CHAR because keyboard input was being handled through WM_KEYDOWN along with ToUnicode since r7645.
* But using ToUnicode actually breaks dead-keys (googling for "ToUnicode dead keys" reports many horror stories of people trying to work around that and failing).
* It seems like r7645 introduced a double-fix: it fixed WM_CHAR to properly handle Unicode, and also (unnecessarily?) added text input handling to WM_KEYDOWN. Later, r8142 removed the WM_CHAR stuff instead of the WM_KEYDOWN stuff.
The attached patch restores handling of text input through WM_CHAR and removes it from WM_KEYDOWN. I've tested it with French, English and Russian layouts and it seems to do its job. Obviously, with such matters, it's still a risky change.
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().
