Commit cf63af8ae265c99e80ffc93e9930336c939524bc
2022-07-31T22:10:45
events: Don't lose window RESIZED events during SIZED_CHANGED processing. Previously, calling SDL_SendWindowEvent for a SIZED_CHANGED event would filter the queue to remove RESIZED and SIZED_CHANGED events, so you don't overflow the queue with obsolete data, but any RESIZED events would be lost in this process. Now we note if there was a RESIZED pending and replace it with a new event using the same dimensions as the new SIZED_CHANGED event. This fixes cases where an app is only listening for RESIZED events and thus might lose important information in some cases. Fixes #5925.
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diff --git a/src/events/SDL_windowevents.c b/src/events/SDL_windowevents.c
index cc8b891..209295a 100644
--- a/src/events/SDL_windowevents.c
+++ b/src/events/SDL_windowevents.c
@@ -27,15 +27,27 @@
#include "SDL_mouse_c.h"
#include "SDL_hints.h"
+typedef struct RemovePendingSizeChangedAndResizedEvents_Data
+{
+ const SDL_Event *new_event;
+ SDL_bool saw_resized;
+} RemovePendingSizeChangedAndResizedEvents_Data;
+
static int SDLCALL
-RemovePendingSizeChangedAndResizedEvents(void * userdata, SDL_Event *event)
+RemovePendingSizeChangedAndResizedEvents(void *_userdata, SDL_Event *event)
{
- SDL_Event *new_event = (SDL_Event *)userdata;
+ RemovePendingSizeChangedAndResizedEvents_Data *userdata = (RemovePendingSizeChangedAndResizedEvents_Data *) _userdata;
+ const SDL_Event *new_event = userdata->new_event;
if (event->type == SDL_WINDOWEVENT &&
(event->window.event == SDL_WINDOWEVENT_SIZE_CHANGED ||
event->window.event == SDL_WINDOWEVENT_RESIZED) &&
event->window.windowID == new_event->window.windowID) {
+
+ if (event->window.event == SDL_WINDOWEVENT_RESIZED) {
+ userdata->saw_resized = SDL_TRUE;
+ }
+
/* We're about to post a new size event, drop the old one */
return 0;
}
@@ -188,7 +200,18 @@ SDL_SendWindowEvent(SDL_Window * window, Uint8 windowevent, int data1,
/* Fixes queue overflow with resize events that aren't processed */
if (windowevent == SDL_WINDOWEVENT_SIZE_CHANGED) {
- SDL_FilterEvents(RemovePendingSizeChangedAndResizedEvents, &event);
+ /* !!! FIXME: in SDL3, let's make RESIZED/SIZE_CHANGED into one event with a flag to distinguish between them, and remove all this tapdancing. */
+ RemovePendingSizeChangedAndResizedEvents_Data userdata;
+ userdata.new_event = &event;
+ userdata.saw_resized = SDL_FALSE;
+ SDL_FilterEvents(RemovePendingSizeChangedAndResizedEvents, &userdata);
+ if (userdata.saw_resized) { /* if there was a pending resize, make sure one at the new dimensions remains. */
+ event.window.event = SDL_WINDOWEVENT_RESIZED;
+ if (SDL_PushEvent(&event) <= 0) {
+ return 0; /* oh well. */
+ }
+ event.window.event = SDL_WINDOWEVENT_SIZE_CHANGED; /* then push the actual event next. */
+ }
}
if (windowevent == SDL_WINDOWEVENT_MOVED) {
SDL_FilterEvents(RemovePendingMoveEvents, &event);
@@ -207,7 +230,7 @@ SDL_SendWindowEvent(SDL_Window * window, Uint8 windowevent, int data1,
}
}
- return (posted);
+ return posted;
}
/* vi: set ts=4 sw=4 expandtab: */