Add puglWaitForEvent for blocking main loops.

6 files changed, 47 insertions, 3 deletions

diff --git a/pugl/pugl.h b/pugl/pugl.h
index 3ff66f9..8dca956 100644
--- a/pugl/pugl.h
+++ b/pugl/pugl.h
@@ -362,10 +362,22 @@ PUGL_API void
 puglGrabFocus(PuglView* view);
 
 /**
+   Block and wait for an event to be ready.
+
+   This can be used in a loop to only process events via puglProcessEvents when
+   necessary.  This function will block indefinitely if no events are
+   available, so is not appropriate for use in programs that need to perform
+   regular updates (e.g. animation).
+*/
+PUGL_API PuglStatus
+puglWaitForEvent(PuglView* view);
+
+/**
    Process all pending window events.
 
    This handles input events as well as rendering, so it should be called
-   regularly and rapidly enough to keep the UI responsive.
+   regularly and rapidly enough to keep the UI responsive.  This function does
+   not block if no events are pending.
 */
 PUGL_API PuglStatus
 puglProcessEvents(PuglView* view);
diff --git a/pugl/pugl_osx.m b/pugl/pugl_osx.m
index 85e71a8..47c8138 100644
--- a/pugl/pugl_osx.m
+++ b/pugl/pugl_osx.m
@@ -525,10 +525,24 @@ puglGrabFocus(PuglView* view)
 }
 
 PuglStatus
+puglWaitForEvent(PuglView* view)
+{
+	[view->impl->window nextEventMatchingMask: NSAnyEventMask
+	                                untilDate: [NSDate distantFuture]
+	                                  dequeue: NO];
+
+	return PUGL_SUCCESS;
+}
+
+PuglStatus
 puglProcessEvents(PuglView* view)
 {
-	NSEvent* ev = [view->impl->window nextEventMatchingMask: NSAnyEventMask];
-	[view->impl->app sendEvent: ev];
+	NSEvent* ev = [view->impl->window nextEventMatchingMask: NSAnyEventMask
+	                                              untilDate: [NSDate distantPast]];
+
+	if (ev) {
+		[view->impl->app sendEvent: ev];
+	}
 
 	return PUGL_SUCCESS;
 }
diff --git a/pugl/pugl_win.cpp b/pugl/pugl_win.cpp
index 04bc4b6..850947d 100644
--- a/pugl/pugl_win.cpp
+++ b/pugl/pugl_win.cpp
@@ -425,6 +425,13 @@ puglGrabFocus(PuglView* view)
 }
 
 PuglStatus
+puglWaitForEvent(PuglView* view)
+{
+	WaitMessage();
+	return PUGL_SUCCESS;
+}
+
+PuglStatus
 puglProcessEvents(PuglView* view)
 {
 	MSG msg;
diff --git a/pugl/pugl_x11.c b/pugl/pugl_x11.c
index 6375609..32501da 100644
--- a/pugl/pugl_x11.c
+++ b/pugl/pugl_x11.c
@@ -494,6 +494,14 @@ puglGrabFocus(PuglView* view)
 }
 
 PuglStatus
+puglWaitForEvent(PuglView* view)
+{
+	XEvent xevent;
+	XPeekEvent(view->impl->display, &xevent);
+	return PUGL_SUCCESS;
+}
+
+PuglStatus
 puglProcessEvents(PuglView* view)
 {
 	XEvent xevent;
@@ -544,6 +552,7 @@ puglProcessEvents(PuglView* view)
 		if (view->ctx_type == PUGL_CAIRO) {
 			cairo_xlib_surface_set_size(
 				view->impl->surface, view->width, view->height);
+			view->redisplay = true;
 		}
 #endif
 	}
diff --git a/pugl_cairo_test.c b/pugl_cairo_test.c
index bd97668..9c1bef8 100644
--- a/pugl_cairo_test.c
+++ b/pugl_cairo_test.c
@@ -166,6 +166,7 @@ main(int argc, char** argv)
 	puglShowWindow(view);
 
 	while (!quit) {
+		puglWaitForEvent(view);
 		puglProcessEvents(view);
 	}
 
diff --git a/pugl_test.c b/pugl_test.c
index 248a49a..af51e53 100644
--- a/pugl_test.c
+++ b/pugl_test.c
@@ -191,6 +191,7 @@ main(int argc, char** argv)
 	puglShowWindow(view);
 
 	while (!quit) {
+		puglWaitForEvent(view);
 		puglProcessEvents(view);
 	}