X11 has a so-called primary selection, which you can use by marking text and middle-clicking elsewhere to copy the marked text.
There are 3 new API functions in `SDL_clipboard.h`, which work exactly like their clipboard equivalents.
## Test Instructions
* Run the tests (just a copy of the clipboard tests): `$ ./test/testautomation --filter Clipboard`
* Build and run this small application:
<details>
```C
#include <SDL.h>
#include <unistd.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
void print_error(const char *where)
{
const char *errstr = SDL_GetError();
if (errstr == NULL || errstr[0] == '\0')
return;
fprintf(stderr, "SDL Error after '%s': %s\n", where, errstr);
SDL_ClearError();
}
int main()
{
char text_buf[256];
srand(time(NULL));
SDL_Init(SDL_INIT_VIDEO);
print_error("SDL_INIT()");
SDL_Window *window = SDL_CreateWindow("Primary Selection Test", SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED, 400, 400, SDL_WINDOW_SHOWN);
print_error("SDL_CreateWindow()");
SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
print_error("SDL_CreateRenderer()");
bool quit = false;
unsigned int do_render = 0;
while (!quit) {
SDL_Event event;
while (SDL_PollEvent(&event)) {
print_error("SDL_PollEvent()");
switch (event.type) {
case SDL_QUIT: {
quit = true;
break;
} case SDL_KEYDOWN: {
switch (event.key.keysym.sym) {
case SDLK_ESCAPE:
case SDLK_q:
quit = true;
break;
case SDLK_c:
snprintf(text_buf, sizeof(text_buf), "foo%d", rand());
SDL_SetClipboardText(text_buf);
print_error("SDL_SetClipboardText()");
printf("clipboard: set_to=\"%s\"\n", text_buf);
break;
case SDLK_v: {
printf("clipboard: has=%d, ", SDL_HasClipboardText());
print_error("SDL_HasClipboardText()");
char *text = SDL_GetClipboardText();
print_error("SDL_GetClipboardText()");
printf("text=\"%s\"\n", text);
SDL_free(text);
break;
} case SDLK_d:
snprintf(text_buf, sizeof(text_buf), "bar%d", rand());
SDL_SetPrimarySelectionText(text_buf);
print_error("SDL_SetPrimarySelectionText()");
printf("primselec: set_to=\"%s\"\n", text_buf);
break;
case SDLK_f: {
printf("primselec: has=%d, ", SDL_HasPrimarySelectionText());
print_error("SDL_HasPrimarySelectionText()");
char *text = SDL_GetPrimarySelectionText();
print_error("SDL_GetPrimarySelectionText()");
printf("text=\"%s\"\n", text);
SDL_free(text);
break;
} default:
break;
}
break;
} default: {
break;
}}
}
// create less noise with WAYLAND_DEBUG=1
if (do_render == 0) {
SDL_RenderPresent(renderer);
print_error("SDL_RenderPresent()");
}
do_render += 1;
usleep(12000);
}
SDL_DestroyRenderer(renderer);
SDL_DestroyWindow(window);
SDL_Quit();
print_error("quit");
return 0;
}
```
</details>
* Use c,v,d,f to get and set the clipboard and primary selection.
* Mark text and middle-click also in other applications.
* For wayland under x:
* `$ mutter --wayland --no-x11 --nested`
* `$ XDG_SESSION_TYPE=wayland SDL_VIDEODRIVER=wayland ./<path_to_test_appl_binary>`
So if Gnome/KDE/etc have a keyboard shortcut or titlebar decoration to
make any window go fullscreen (with the _NET_WM_FULLSCREEN flag on the
_NET_WM_STATE property), we update the SDL window flag.
Fixes#5390.
If that condition was reachable, the return value should be negative to indicate that waiting for the timeout failed.
Otherwise, SDL_WaitEventTimeout would incorrectly return early.
A racing reader could read from our fd between SDL_IOReady()/X11_Pending()
and our call to XNextEvent() which will cause XNextEvent() to block for
more data. Avoid this by using XCheckIfEvent() which will never block.
This also fixes a bug where we could poll() for data, even when events were
already read and pending in the queue. Unlike the Wayland implementation,
this isn't totally thread-safe because nothing prevents a racing reader
from reading events into the queue between our XCheckIfEvent() and
SDL_IOReady() calls, but I think this is the best we can do with Xlib.
This API and implementation comes from the Unreal Engine branch of SDL, which
originally called this "SDL_ConfineCursor".
Some minor cleanup and changes for consistency with the rest of SDL_video, but
there are two major changes:
1. The coordinate system has been changed so that `rect` is _window_ relative
and not _screen_ relative, making it easier to implement without having
global access to the display.
2. The UE version unset all rects when passing `NULL` as a parameter for
`window`, this has been removed as it was an unused feature anyhow.
Currently this is only implemented for X, but can be supported on Wayland and
Windows at minimum too.
Add a new flag to avoid suppressing EINTR in SDL_IOReady(). Pass the
flag in WaitEventTimeout() to ensure that a SIGINT will wake up
SDL_WaitEvent() without another event coming in.
When possible use native os functions to make a blocking call waiting for
an incoming event. Previous behavior was to continuously poll the event
queue with a small delay between each poll.
The blocking call uses a new optional video driver event,
WaitEventTimeout, if available. It is called only if an window
already shown is available. If present the window is designated
using the variable wakeup_window to receive a wakeup event if
needed.
The WaitEventTimeout function accept a timeout parameter. If
positive the call will wait for an event or return if the timeout
expired without any event. If the timeout is zero it will
implement a polling behavior. If the timeout is negative the
function will block indefinetely waiting for an event.
To let the main thread sees events sent form a different thread
a "wake-up" signal is sent to the main thread if the main thread
is in a blocking state. The wake-up event is sent to the designated
wakeup_window if present.
The wake-up event is sent only if the PushEvent call is coming
from a different thread. Before sending the wake-up event
the ID of the thread making the blocking call is saved using the
variable blocking_thread_id and it is compared to the current
thread's id to decide if the wake-up event should be sent.
Two new optional video device methods are introduced:
WaitEventTimeout
SendWakeupEvent
in addition the mutex
wakeup_lock
which is defined and initialized but only for the drivers supporting the
methods above.
If the methods are not present the system behaves as previously
performing a periodic polling of the events queue.
The blocking call is disabled if a joystick or sensor is detected
and falls back to previous behavior.
GNOME Mutter requires keyboard grab for certain important functionality like
window resizing, interaction with the application context menu, and opening the
Activites view. To allow Mutter to grab the keyboard as needed, we'll ungrab
when the mouse leaves our window.
To be safe, we'll do this for all WMs since forks of Mutter and Matacity (and
possibly others) may have the same behavior, and we don't want to have to keep
track of those.
wcodelyokoyt
The atom name that X11_GetAtomName() returns never gets freed, which result in a minor memory leak (14 bytes?) every time the user drops a file on a window.
You can see the line in question here:
6b6170caf6/src/video/x11/SDL_x11events.c (L1350)
Fix: call XFree on name after the while loop.
UnmapNotify event does not mean that window has been iconified. It
just reports that window changed state from mapped to unmapped.
XReparentWindow can unmap and remap window if it was mapped. This
causes unnecessary events - HIDDEN, MINIMIZED, RESTORED and SHOW.
These events are problematic with Metacity 3.36+ which started to
remove window decorations from fullscreen windows.
- SDL makes decorated window fullscreen
- Metacity removes decorations
- SDL gets UnmapNotify and exits from fullscreen
- Metacity re-adds decorations
As SDL will also get MapNotify event it will try to restore
window state causing above steps to repeat.
https://bugzilla.libsdl.org/show_bug.cgi?id=5314
wengxt
Due to the new major fcitx version is coming close, the existing code need to be ported to use new Fcitx dbus interface.
The new dbus interface is supported by both fcitx 4 and 5, and has a good side effect, which is that it will work with flatpak for free. Also the patch remove the dependency on fcitx header. Instead, it just hardcodes a few enum value in the code so need to handle the different header for fcitx4 or 5.
SDL_SendWindowEvent will only send a RESTORED event if the window has
the minimized or maximized flag set. However, for a SHOWN event, it
will clear the minimized flag. Since the SHOWN event was being sent
first for a MapNotify event, the RESTORED event would never be sent.
Swapping the SendWindowEvent calls around fixes this.
https://bugzilla.libsdl.org/show_bug.cgi?id=4821
Andrei Drexler
For X11 GenericEvents, the associated data is only available between a call to XGetEventData and the matching XFreeEventData, i.e. in X11_HandleGenericEvent. Trying to call XGetEventData a second time on the same event will fail, so an application that wants to inspect XInput2 events (e.g. for stylus pressure) has no way of retrieving its data from queued SYSWM events.
The attached patch (based on SDL-2.0.7-11629) sends SYSWM messages from X11_HandleGenericEvent while the data is still available, allowing client code to register an event filter/watcher and process the event inside the callback.
Martijn Courteaux
I implemented precise scrolling events. I have been through all the folders in /src/video/[platform] to implement where possible. This works on OS X, but I can't speak for others. Build farm will figure that out, I guess. I think this patch should introduce precise scrolling on OS X, Wayland, Mir, Windows, Android, Nacl, Windows RT.
The way I provide precise scrolling events is by adding two float fields to the SDL_MouseWheelScrollEvent datastructure, called "preciseX" and "preciseY". The old integer fields "x" and "y" are still present. The idea is that every platform specific code normalises the scroll amounts and forwards them to the SDL_SendMouseWheel function. It is this function that will now accumulate these (using a static variable, as I have seen how it was implemented in the Windows specific code) and once we hit a unit size, set the traditional integer "x" and "y" fields.
I believe this is pretty solid way of doing it, although I'm not the expert here.
There is also a fix in the patch for a typo recently introduced, that might need to be taken away by the time anybody merges this in. There is also a file in Nacl which I have stripped a horrible amount of trailing whitespaces. (Leave that part out if you want).
manuel.montezelo
Original bug report (note that it was against 2.0.0, it might have been fixed in between): http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=733015
--------------------------------------------------------
Package: libsdl2-2.0-0
Version: 2.0.0+dfsg1-3
Severity: normal
Tags: patch
I have occasional crashes here caused by the X11 backend of SDL2. It seems to
be caused by the X11_Pending function trying to add a high number (> 1024)
file descriptor to a fd_set before doing a select on it to avoid busy waiting
on X11 events. This causes a buffer overflow because the file descriptor is
larger (or equal) than the limit FD_SETSIZE.
Attached is a possible workaround patch.
Please also keep in mind that fd_set are also used in following files which
may have similar problems.
src/audio/bsd/SDL_bsdaudio.c
src/audio/paudio/SDL_paudio.c
src/audio/qsa/SDL_qsa_audio.c
src/audio/sun/SDL_sunaudio.c
src/joystick/linux/SDL_sysjoystick.c
--------------------------------------------------------
On Tuesday 24 December 2013 00:43:13 Sven Eckelmann wrote:
> I have occasional crashes here caused by the X11 backend of SDL2. It seems
> to be caused by the X11_Pending function trying to add a high number (>
> 1024) file descriptor to a fd_set before doing a select on it to avoid busy
> waiting on X11 events. This causes a buffer overflow because the file
> descriptor is larger (or equal) than the limit FD_SETSIZE.
I personally experienced this problem while hacking on the python bindings
package for SDL2 [1] (while doing make runtest). But it easier to reproduce in
a smaller, synthetic testcase.
Now the clipboard isn't lost if you destroy a specific SDL_Window, as it
works on other platforms. You will still lose the clipboard data on
SDL_Quit() or process termination, but that's X11 for you; run a
Clipboard Manager daemon.
Fixes Bugzilla #3222.
Fixes Bugzilla #3718.
Failing to check if a key was known to be pressed by SDL was causing
SDL_SendKeyboardKey to send duplicate key pressed events with the repeat
property set to true.
Fixes Bugzilla #3637.