Attachment "0003-Aqua-Restore-initWithFocusedViewRect-usage.patch" to
ticket [685ac307]
added by
chrstphrchvz
2021-01-17 10:26:43.
From 983943306f9d6a52efd0fe724724cc6f9260e2e8 Mon Sep 17 00:00:00 2001
From: Christopher Chavez <[email protected]>
Date: Thu, 13 Aug 2020 15:47:29 -0500
Subject: [PATCH 3/5] Aqua: Restore initWithFocusedViewRect: usage
For real window source drawables, CreateCGImageFromDrawableRect()
must be able to to retrieve what was previously drawn to the backing
store; it cannot draw its contents again from scratch. Previously, the
backing store contents were retrieved with initWithFocusedViewRect:,
which was deprecated in macOS 10.14 Mojave. The suggested replacement
cacheDisplayInRect: draws again from scratch, and so will not work for
Tk's use case. Tk should instead continue using initWithFocusedViewRect:
if possible. See https://core.tcl-lang.org/tk/info/685ac30727
TODO: see if a maximum macOS version must be set, e.g. to avoid crashes.
Also see whether removing cacheDisplayInRect: usage has completely
eliminated recursive drawRect: calls.
---
macosx/tkMacOSXImage.c | 60 ++++++++++++++++++++----------------------
1 file changed, 28 insertions(+), 32 deletions(-)
diff --git macosx/tkMacOSXImage.c macosx/tkMacOSXImage.c
index d502def4f..22e45df64 100644
--- macosx/tkMacOSXImage.c
+++ macosx/tkMacOSXImage.c
@@ -485,24 +485,6 @@ TkPutImage(
* or XCopyArea on macOS. Nonetheless, these function are in the stubs
* table and therefore could be used by extensions.
*
- * This implementation does not work correctly. Originally it relied on
- * [NSBitmapImageRep initWithFocusedViewRect:view_rect] which was
- * deprecated by Apple in OSX 10.14 and also required the use of other
- * deprecated functions such as [NSView lockFocus]. Apple's suggested
- * replacement is [NSView cacheDisplayInRect: toBitmapImageRep:] and that
- * is what is being used here. However, that method only works when the
- * view has a valid CGContext, and a view is only guaranteed to have a
- * valid context during a call to [NSView drawRect]. To further complicate
- * matters, cacheDisplayInRect calls [NSView drawRect]. Essentially it is
- * asking the view to draw a subrectangle of itself using a special
- * graphics context which is linked to the BitmapImageRep. But our
- * implementation of [NSView drawRect] does not allow recursive calls. If
- * called recursively it returns immediately without doing any drawing.
- * So the bottom line is that this function either returns a NULL pointer
- * or a black image. To make it useful would require a significant amount
- * of rewriting of the drawRect method. Perhaps the next release of OSX
- * will include some more helpful ways of doing this.
- *
* Results:
* Returns a CGImage representing the image of the given rectangle of
* the given drawable. The caller is responsible for releasing it.
@@ -544,7 +526,7 @@ CreateCGImageFromDrawableRect(
result = CGImageCreateWithImageInRect(cg_image, image_rect);
CGImageRelease(cg_image);
}
- } else if (TkMacOSXGetNSViewForDrawable(mac_drawable) != nil) {
+ } else if ((view = TkMacOSXGetNSViewForDrawable(mac_drawable)) != nil) {
/*
* Convert Tk top-left to NSView bottom-left coordinates.
@@ -556,20 +538,35 @@ CreateCGImageFromDrawableRect(
width, height);
/*
- * Attempt to copy from the view to a bitmapImageRep. If the view does
- * not have a valid CGContext, doing this will silently corrupt memory
- * and make a big mess. So, in that case, we just return NULL.
+ * If a view already has focus, then this is being called while in
+ * drawRect:, either for mac_drawable's view or some other view
+ * (in which case it has not been verified to be safe to lock the
+ * focus to mac_drawable's view instead). If no view is focused,
+ * then try locking focus to mac_drawable's view now and unlock it
+ * when finished, as some usage (e.g. capturing a window with the
+ * TkImg extension via XGetImage()) requires an immediate result
+ * and will not wait until in drawRect: to call this.
*/
-
+ BOOL needsToUnlockFocus = NO;
+ if ([NSView focusView] == nil) {
+ needsToUnlockFocus = [view lockFocusIfCanDraw];
+ }
if (view == [NSView focusView]) {
- bitmapRep = [view bitmapImageRepForCachingDisplayInRect: view_rect];
- [view cacheDisplayInRect:view_rect toBitmapImageRep:bitmapRep];
- result = [bitmapRep CGImage];
- CFRelease(bitmapRep);
- } else {
- TkMacOSXDbgMsg("No CGContext - cannot copy from screen to bitmap.");
- result = NULL;
+ /*
+ * Keep using initWithFocusedViewRect: even though deprecated.
+ * The suggested replacement cacheDisplayInRect: will not work
+ * because it draws from scratch, whereas Tk needs to retrieve
+ * from the backing store what was already drawn; see 685ac30727.
+ */
+ bitmapRep = [[NSBitmapImageRep alloc]
+ initWithFocusedViewRect:view_rect];
+ }
+ if (needsToUnlockFocus) {
+ [view unlockFocus];
}
+ result = [bitmapRep CGImage];
+ CGImageRetain(result);
+ [bitmapRep release];
} else {
TkMacOSXDbgMsg("Invalid source drawable");
}
@@ -655,8 +652,7 @@ CreateCGImageFromPixmap(
* is essentially never used in core Tk. At one time it was called by
* pTkImgPhotoDisplay, but that is no longer the case. Currently it is
* called two places, one of which is requesting an XY image which we do
- * not support. It probably does not work correctly -- see the comments
- * for CGImageFromDrawableRect.
+ * not support.
*
* Results:
* Returns a newly allocated XImage containing the data from the given
--
2.24.3 (Apple Git-128)
