MacPDF: Show current page and page count in subtitle

Meta/Lagom/Contrib/MacPDF/LagomPDFDocument.h

@@ -14,7 +14,7 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
-@interface LagomPDFDocument : NSDocument
+@interface LagomPDFDocument : NSDocument <LagomPDFViewDelegate>
 {
     IBOutlet LagomPDFView* _pdfView;
 }

Meta/Lagom/Contrib/MacPDF/LagomPDFDocument.mm

@@ -68,6 +68,7 @@
         NSLog(@"failed to load 2: %@", @(err.error().message().characters()));
     } else {
         [_pdfView setDocument:_doc->make_weak_ptr()];
+        [self pageChanged];
     }
 }
 
@@ -82,6 +83,8 @@
 {
     [super windowControllerDidLoadNib:aController];
 
+    [_pdfView setDelegate:self];
+
     if (_doc) {
         if (auto handler = _doc->security_handler(); handler && !handler->has_user_password()) {
             [self promptForPassword:aController.window];
@@ -166,4 +169,10 @@
                   }];
 }
 
+- (void)pageChanged
+{
+    [_pdfView.window setSubtitle:
+                         [NSString stringWithFormat:@"Page %d of %d", [_pdfView page], _doc -> get_page_count()]];
+}
+
 @end

Meta/Lagom/Contrib/MacPDF/LagomPDFView.h

@@ -15,11 +15,16 @@
 #include <AK/WeakPtr.h>
 #include <LibPDF/Document.h>
 
+@protocol LagomPDFViewDelegate
+- (void)pageChanged;
+@end
+
 @interface LagomPDFView : NSView
-{
-}
 
 - (void)setDocument:(WeakPtr<PDF::Document>)doc;
 - (void)goToPage:(int)page;
+- (int)page;
+
+- (void)setDelegate:(id<LagomPDFViewDelegate>)delegate;
 
 @end

Meta/Lagom/Contrib/MacPDF/LagomPDFView.mm

@@ -16,6 +16,7 @@
     WeakPtr<PDF::Document> _doc;
     NSBitmapImageRep* _cachedBitmap;
     int _page_index;
+    __weak id<LagomPDFViewDelegate> _delegate;
 }
 @end
 
@@ -82,6 +83,17 @@ static NSBitmapImageRep* ns_from_gfx(NonnullRefPtr<Gfx::Bitmap> bitmap_p)
     _page_index = new_index;
     [self invalidateRestorableState];
     [self invalidateCachedBitmap];
+    [_delegate pageChanged];
+}
+
+- (int)page
+{
+    return _page_index + 1;
+}
+
+- (void)setDelegate:(id<LagomPDFViewDelegate>)delegate
+{
+    _delegate = delegate;
 }
 
 #pragma mark Drawing