Attachment "0003-Restore-initWithFocusedViewRect-usage.patch" to
ticket [685ac307]
added by
chrstphrchvz
2020-08-18 01:59:47.
From a8e99acf07343fe432d45206f795da7d0d342e56 Mon Sep 17 00:00:00 2001
From: Christopher Chavez <[email protected]>
Date: Thu, 13 Aug 2020 15:47:29 -0500
Subject: [PATCH 3/6] Restore initWithFocusedViewRect: usage
For real window source drawables, TkMacOSXBitmapRepFromDrawableRect()
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/tkMacOSXDraw.c | 54 +++++++++++++++++-------------------------
macosx/tkMacOSXImage.c | 3 +--
2 files changed, 23 insertions(+), 34 deletions(-)
diff --git macosx/tkMacOSXDraw.c macosx/tkMacOSXDraw.c
index 2e820c51b..9d9dcadc6 100644
--- macosx/tkMacOSXDraw.c
+++ macosx/tkMacOSXDraw.c
@@ -112,24 +112,7 @@ TkMacOSXInitCGDrawing(
*
* Extract bitmap data from a MacOSX drawable as an NSBitmapImageRep.
*
- * Currently only used by XGetImage and XCopyArea. And 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 into 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.
+ * Currently only used by XGetImage and XCopyArea.
*
* Results:
* Returns an NSBitmapRep representing the image of the given rectangle of
@@ -176,9 +159,7 @@ TkMacOSXBitmapRepFromDrawableRect(
if (cg_image) {
CGImageRelease(cg_image);
}
- } else if (TkMacOSXDrawableView(mac_drawable) != NULL) {
- TKContentView *tkview = (TKContentView *)view;
-
+ } else if ((view = TkMacOSXDrawableView(mac_drawable)) != nil) {
/*
* Convert Tk top-left to NSView bottom-left coordinates.
*/
@@ -189,20 +170,29 @@ TkMacOSXBitmapRepFromDrawableRect(
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 mark the view as needing
- * display and return NULL.
+ * If a view already has focus, either it is the view for mac_drawable,
+ * or it is some other view (in which case it has not been verified to
+ * be safe to lock the focus to mac_drawable's view). If no view is
+ * focused, then try locking focus to mac_drawable's view now and
+ * unlock it when finished.
*/
-
+ BOOL needsToUnlockFocus = NO;
+ if ([NSView focusView] == nil) {
+ needsToUnlockFocus = [view lockFocusIfCanDraw];
+ }
if (view == [NSView focusView]) {
- bitmap_rep = [view bitmapImageRepForCachingDisplayInRect: view_rect];
+ /*
+ * 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.
+ */
+ bitmap_rep = [[NSBitmapImageRep alloc]
+ initWithFocusedViewRect:view_rect];
[bitmap_rep retain];
- [view cacheDisplayInRect:view_rect toBitmapImageRep:bitmap_rep];
- } else {
- TkMacOSXDbgMsg("No CGContext - cannot copy from screen to bitmap.");
- [tkview addTkDirtyRect:[tkview bounds]];
- return NULL;
+ }
+ if (needsToUnlockFocus) {
+ [view unlockFocus];
}
} else {
TkMacOSXDbgMsg("Invalid source drawable");
diff --git macosx/tkMacOSXImage.c macosx/tkMacOSXImage.c
index 7a0edb346..3604841ee 100644
--- macosx/tkMacOSXImage.c
+++ macosx/tkMacOSXImage.c
@@ -137,8 +137,7 @@ TkMacOSXCreateCGImageWithXImage(
* 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 TkMacOSXBitmapRepFromDrawableRect.
+ * not support.
*
* Results:
* Returns a newly allocated XImage containing the data from the given
--
2.28.0
