Add viewWithTextView: to ViTabController.

This method returns the ViDocumentView instance in the
tab view corresponding to the given ViTextView, or nil if
there is no such instance.

app/ViTabController.h

@@ -24,9 +24,10 @@
  */
 
 @class ViDocument;
+@class ViDocumentView;
 @class ViTabController;
+@class ViTextView;
 @class ViViewController;
-@class ViDocumentView;
 
 typedef enum ViViewPosition ViViewPosition;
 typedef enum ViViewOrderingMode ViViewOrderingMode;
@@ -164,6 +165,7 @@ enum ViViewOrderingMode {
 
 - (ViViewController *)viewOfClass:(Class)class withRepresentedObject:(id)repObj;
 - (ViDocumentView *)viewWithDocument:(ViDocument *)document;
+- (ViDocumentView *)viewWithTextView:(ViTextView *)aTextView;
 
 - (ViViewController *)viewAtPosition:(ViViewOrderingMode)position
 			  relativeTo:(NSView *)aView;

app/ViTabController.m

@@ -144,6 +144,18 @@ - (ViDocumentView *)viewWithDocument:(ViDocument *)document
 			     withRepresentedObject:document];
 }
 
+- (ViDocumentView *)viewWithTextView:(ViTextView *)aTextView;
+{
+	for (ViViewController *viewController in _views) {
+		if ([viewController isKindOfClass:[ViDocumentView class]] &&
+				[(ViDocumentView *)viewController textView] == aTextView) {
+			return (ViDocumentView *)viewController;
+		}
+	}
+
+	return nil;
+}
+
 - (NSView *)view
 {
 	return _splitView;
@@ -434,7 +446,7 @@ - (NSView *)containedViewRelativeToView:(NSView *)view
 }
 
 - (ViViewController *)viewAtPosition:(ViViewOrderingMode)position
-			  relativeTo:(NSView *)view
+						  relativeTo:(NSView *)view
 {
 	if (view == nil)
 		return nil;