Created attachment 4280 [details]
[PATCH] cocoa: allow calling CreateWindowFrom on an NSView

Here's an attempt at allowing CreateWindowFrom to work with NSViews.

It expands the role of the existing sdlContentView field (caches [nswindow contentView] for created windows, since Cocoa complains if contentview is called off the main thread) to hold the NSView for non-created windows as well. All calls to [nswindow contentView] have been replaced with references to sdlContentView.

When an NSView is passed into CreateWindowFrom, it sets sdlContentView directly, and finds the associated window with [nsview window].

Tested with a basic Qt application, and with testdraw2 and testgl2 from the tests directory.

Comment on attachment 4280 [details]
[PATCH] cocoa: allow calling CreateWindowFrom on an NSView

# HG changeset patch
# User Michael Maltese <michaeljosephmaltese@gmail.com>
# Date 1585179643 25200
#      Wed Mar 25 16:40:43 2020 -0700
# Node ID aaec3f2027fc1efe5473bbd8477d5860f97487ff
# Parent  389ce8cfa2a31f765c3d751c911c73abf5c60e33
cocoa: allow calling CreateWindowFrom on an NSView

This lets applications embed SDL with other widgets surrounding it.
Already possible on Windows and X11.

diff -r 389ce8cfa2a3 -r aaec3f2027fc src/video/cocoa/SDL_cocoaopengl.m
--- a/src/video/cocoa/SDL_cocoaopengl.m	Wed Mar 25 09:38:45 2020 -0700
+++ b/src/video/cocoa/SDL_cocoaopengl.m	Wed Mar 25 16:40:43 2020 -0700
@@ -97,17 +97,6 @@
         SDL_WindowData *windowdata = (SDL_WindowData *)newWindow->driverdata;
         NSView *contentview = windowdata->sdlContentView;
 
-        /* This should never be nil since sdlContentView is only nil if the
-           window was created via SDL_CreateWindowFrom, and SDL doesn't allow
-           OpenGL contexts to be created in that case. However, it doesn't hurt
-           to check. */
-        if (contentview == nil) {
-            /* Prefer to access the cached content view above instead of this,
-               since as of Xcode 11 + SDK 10.15, [window contentView] causes
-               Apple's Main Thread Checker to output a warning. */
-            contentview = [windowdata->nswindow contentView];
-        }
-
         /* Now sign up for scheduled updates for the new window. */
         NSMutableArray *contexts = windowdata->nscontexts;
         @synchronized (contexts) {
@@ -362,7 +351,7 @@
 Cocoa_GL_GetDrawableSize(_THIS, SDL_Window * window, int * w, int * h)
 {
     SDL_WindowData *windata = (SDL_WindowData *) window->driverdata;
-    NSView *contentView = [windata->nswindow contentView];
+    NSView *contentView = windata->sdlContentView;
     NSRect viewport = [contentView bounds];
 
     if (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
diff -r 389ce8cfa2a3 -r aaec3f2027fc src/video/cocoa/SDL_cocoashape.m
--- a/src/video/cocoa/SDL_cocoashape.m	Wed Mar 25 09:38:45 2020 -0700
+++ b/src/video/cocoa/SDL_cocoashape.m	Wed Mar 25 16:40:43 2020 -0700
@@ -88,10 +88,10 @@
     [NSGraphicsContext setCurrentContext:data->context];
 
     [[NSColor clearColor] set];
-    NSRectFill([[windata->nswindow contentView] frame]);
+    NSRectFill([windata->sdlContentView frame]);
     data->shape = SDL_CalculateShapeTree(*shape_mode,shape);
 
-    closure.view = [windata->nswindow contentView];
+    closure.view = windata->sdlContentView;
     closure.path = [NSBezierPath bezierPath];
     closure.window = shaper->window;
     SDL_TraverseShapeTree(data->shape,&ConvertRects,&closure);
diff -r 389ce8cfa2a3 -r aaec3f2027fc src/video/cocoa/SDL_cocoawindow.h
--- a/src/video/cocoa/SDL_cocoawindow.h	Wed Mar 25 09:38:45 2020 -0700
+++ b/src/video/cocoa/SDL_cocoawindow.h	Wed Mar 25 16:40:43 2020 -0700
@@ -113,7 +113,7 @@
 {
     SDL_Window *window;
     NSWindow *nswindow;
-    NSView *sdlContentView; /* nil if window is created via CreateWindowFrom */
+    NSView *sdlContentView;
     NSMutableArray *nscontexts;
     SDL_bool created;
     SDL_bool inWindowFullscreenTransition;
diff -r 389ce8cfa2a3 -r aaec3f2027fc src/video/cocoa/SDL_cocoawindow.m
--- a/src/video/cocoa/SDL_cocoawindow.m	Wed Mar 25 09:38:45 2020 -0700
+++ b/src/video/cocoa/SDL_cocoawindow.m	Wed Mar 25 16:40:43 2020 -0700
@@ -297,15 +297,15 @@
     NSWindow *nswindow = data->nswindow;
 
     /* The view responder chain gets messed with during setStyleMask */
-    if ([[nswindow contentView] nextResponder] == data->listener) {
-        [[nswindow contentView] setNextResponder:nil];
+    if ([data->sdlContentView nextResponder] == data->listener) {
+        [data->sdlContentView setNextResponder:nil];
     }
 
     [nswindow setStyleMask:style];
 
     /* The view responder chain gets messed with during setStyleMask */
-    if ([[nswindow contentView] nextResponder] != data->listener) {
-        [[nswindow contentView] setNextResponder:data->listener];
+    if ([data->sdlContentView nextResponder] != data->listener) {
+        [data->sdlContentView setNextResponder:data->listener];
     }
 
     return SDL_TRUE;
@@ -318,7 +318,7 @@
 {
     NSNotificationCenter *center;
     NSWindow *window = data->nswindow;
-    NSView *view = [window contentView];
+    NSView *view = data->sdlContentView;
 
     _data = data;
     observingVisible = YES;
@@ -1360,7 +1360,7 @@
 @end
 
 static int
-SetupWindowData(_THIS, SDL_Window * window, NSWindow *nswindow, SDL_bool created)
+SetupWindowData(_THIS, SDL_Window * window, NSWindow *nswindow, NSView *nsview, SDL_bool created)
 { @autoreleasepool
 {
     SDL_VideoData *videodata = (SDL_VideoData *) _this->driverdata;
@@ -1376,11 +1376,7 @@
     data->created = created;
     data->videodata = videodata;
     data->nscontexts = [[NSMutableArray alloc] init];
-
-    /* Only store this for windows created by us since the content view might
-     * get replaced from under us otherwise, and we only need it when the
-     * window is guaranteed to be created by us (OpenGL contexts). */
-    data->sdlContentView = created ? [nswindow contentView] : nil;
+    data->sdlContentView = nsview;
 
     /* Create an event listener for the window */
     data->listener = [[Cocoa_WindowListener alloc] init];
@@ -1541,7 +1537,7 @@
     [nswindow setContentView:contentView];
     [contentView release];
 
-    if (SetupWindowData(_this, window, nswindow, SDL_TRUE) < 0) {
+    if (SetupWindowData(_this, window, nswindow, contentView, SDL_TRUE) < 0) {
         [nswindow release];
         return -1;
     }
@@ -1571,7 +1567,19 @@
 Cocoa_CreateWindowFrom(_THIS, SDL_Window * window, const void *data)
 { @autoreleasepool
 {
-    NSWindow *nswindow = (NSWindow *) data;
+    NSView* nsview;
+    NSWindow *nswindow;
+
+    if ([(id)data isKindOfClass:[NSWindow class]]) {
+      nswindow = (NSWindow*)data;
+      nsview = [nswindow contentView];
+    } else if ([(id)data isKindOfClass:[NSView class]]) {
+      nsview = (NSView*)data;
+      nswindow = [nsview window];
+    } else {
+      SDL_assert(false);
+    }
+
     NSString *title;
 
     /* Query the title from the existing window */
@@ -1580,7 +1588,7 @@
         window->title = SDL_strdup([title UTF8String]);
     }
 
-    return SetupWindowData(_this, window, nswindow, SDL_FALSE);
+    return SetupWindowData(_this, window, nswindow, nsview, SDL_FALSE);
 }}
 
 void
@@ -1795,8 +1803,8 @@
     NSRect rect;
 
     /* The view responder chain gets messed with during setStyleMask */
-    if ([[nswindow contentView] nextResponder] == data->listener) {
-        [[nswindow contentView] setNextResponder:nil];
+    if ([data->sdlContentView nextResponder] == data->listener) {
+        [data->sdlContentView setNextResponder:nil];
     }
 
     if (fullscreen) {
@@ -1852,8 +1860,8 @@
     }
 
     /* The view responder chain gets messed with during setStyleMask */
-    if ([[nswindow contentView] nextResponder] != data->listener) {
-        [[nswindow contentView] setNextResponder:data->listener];
+    if ([data->sdlContentView nextResponder] != data->listener) {
+        [data->sdlContentView setNextResponder:data->listener];
     }
 
     s_moveHack = 0;

This patch looks promising. I will try to come up with time to try it out myself as well.

This looks reasonable to me. I've put it in revision control at https://hg.libsdl.org/SDL/rev/6d22d6ce725c ... Eric, if you want to try it, just get the latest revision of SDL.

Thanks!

--ryan.

I have tried the newest version from the hg repos.  The problem has not been resolved.

Here is my test code:

    # coding: utf-8

    import os
    import wx

    import sdl2
    import sdl2.ext
    # import sdl2.sdlgfx

    class MainFrame(wx.Frame):
      def __init__(self):
        wx.Frame.__init__(self, None, -1, 'MainFrame', pos=(0, 0), size = (400, 300), style = wx.DEFAULT_FRAME_STYLE)
    
        self.panelLeft = wx.Panel(self, style=wx.BORDER_SUNKEN)
        self.panelRight = wx.Panel(self, style=wx.BORDER_SUNKEN)

        sizer = wx.BoxSizer()
        sizer.Add(self.panelLeft, 1, wx.ALL|wx.EXPAND, border=10)
        sizer.Add(self.panelRight, 1, wx.ALL|wx.EXPAND, border=10)
        self.SetSizer(sizer)

        sdl2.ext.init()
        self.window = sdl2.SDL_CreateWindowFrom(self.panelRight.GetHandle())
        self.renderer = sdl2.SDL_CreateRenderer(self.window, -1, sdl2.SDL_RENDERER_ACCELERATED)
        sdl2.SDL_SetHint(sdl2.hints.SDL_HINT_RENDER_SCALE_QUALITY, b"1")

        self.Bind(wx.EVT_IDLE, self.render)

      def render(self, e):
        sdl2.SDL_SetRenderDrawColor(self.renderer, 225, 0, 0, 255)
        sdl2.SDL_RenderClear(self.renderer)
        # sdl2.sdlgfx.lineRGBA(self.renderer, 0, 0, 100, 100, 255, 255, 255, 255)
        sdl2.SDL_RenderPresent(self.renderer)

    class App(wx.App):
      def OnInit(self):
        self.mainFrame = MainFrame()
        self.mainFrame.Show(True)
        self.mainFrame.CentreOnScreen()
        self.SetTopWindow(self.mainFrame)
        return True

      def getMainFrame(self):
        return self._mainFrame

    app = App()
    app.MainLoop()

The right panel should be filled with red color, but the whole window has beed filled.

@zeb This issue was about CreateWindowFrom not working at all on macOS, leading to crashes or at the least a failure to create a window. That issue has been fixed.

What you're writing about is not the same issue: CreateFromWindow gives you a working SDL window (what this bug fixed), just not the one you want (not part of this but). Honestly it sounds like a wxWidgets issue not giving an NSView for the widget you want.

I'm reclosing this — if you need support for your issue, please take it to the forums. (If in the end it is determined to be an SDL issue, then please create a _new_ bug.)

.