Improve keyboard navigation by automatically computing a key view loop

for a window (and tab view item). This implicit key view is created
when a window is made key and does not have an explicit key view loop,
which is detected by checking the initial first responder of the
window.


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/gui/trunk@35632 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,26 @@
+2012-10-04  Wolfgang Lux  <wolfgang.lux@gmail.com>
+
+	Improve keyboard navigation by automatically computing a key view
+	loop for a window (and tab view item). This implicit key view is
+	created when a window is made key and does not have an explicit
+	key view loop, which is detected by checking the initial first
+	responder of the window.
+
+	* Source/NSViewPrivate.h: New header declaring auxiliary key view
+	loop methods.
+
+	* Source/NSWindow.m (-becomeKeyWindow, -recalculateKeyViewLoop):
+	* Source/NSView.m (-_setUpKeyViewLooopWithNextKeyView:,
+	-_recursiveSetUpKeyViewLoopWithNextKeyView:, -_viewWillMoveToWindow:,
+	cmpFrame()):
+	* Source/NSControl.m (-_setUpKeyViewLoopWithNextKeyView:):
+	* Source/NSTabView.m (-dealloc, -selectTabViewItem:, -setNextKeyView:,
+	_setUpKeyViewLoopWithNextKeyView:): Implement code to
+	automatically recalculate the key view loop of a window.
+
+ 	* Headers/AppKit/NSTabView.h: Add new member to maintain the
+	original next key view of a tab view.
+
 2012-10-04  Wolfgang Lux  <wolfgang.lux@gmail.com>
 
 	* Source/NSClipView.m (-setDocumentView:, -setNextKeyView:):

Headers/AppKit/NSTabView.h

@@ -55,6 +55,7 @@ typedef enum {
   BOOL _truncated_label;
   id _delegate;
   NSUInteger _selected_item;
+  NSView *_original_nextKeyView;
 }
 - (void)addTabViewItem:(NSTabViewItem *)tabViewItem;
 - (void)insertTabViewItem:(NSTabViewItem *)tabViewItem

Source/NSControl.m

@@ -49,6 +49,7 @@
 #import "AppKit/NSTextView.h"
 #import "AppKit/NSWindow.h"
 #import "GSBindingHelpers.h"
+#import "NSViewPrivate.h"
 
 /*
  * Class variables
@@ -1120,3 +1121,14 @@ static NSNotificationCenter *nc;
 }
 
 @end
+
+@implementation NSControl(KeyViewLoop)
+
+- (void) _setUpKeyViewLoopWithNextKeyView: (NSView *)nextKeyView
+{
+  // Controls are expected to have no subviews
+  //NSLog(@"%@@%p -_setUpKeyViewLoopWithKeyKeyView:%@@%p", [self class], self, [nextKeyView class], nextKeyView);
+  [self setNextKeyView: nextKeyView];
+}
+
+@end

Source/NSTabView.m

@@ -42,6 +42,12 @@
 #import "AppKit/NSWindow.h"
 #import "GNUstepGUI/GSTheme.h"
 #import "GSBindingHelpers.h"
+#import "NSViewPrivate.h"
+
+@interface NSTabViewItem (KeyViewLoop)
+- (void) _setUpKeyViewLoopWithNextKeyView: (NSView *)nextKeyView;
+- (NSView *) _lastKeyView;
+@end
 
 @implementation NSTabView
 
@@ -82,6 +88,9 @@
 {
   RELEASE(_items);
   RELEASE(_font);
+  // Reset the _selected attribute to prevent crash when -dealloc calls
+  // -setNextKeyView:
+  _selected = nil;
   [super dealloc];
 }
 
@@ -262,11 +271,23 @@
 
       if (selectedView != nil)
         {
+	  NSView *firstResponder;
+
           [self addSubview: selectedView];
           // FIXME: We should not change this mask
-          [selectedView setAutoresizingMask: NSViewWidthSizable | NSViewHeightSizable];
+          [selectedView setAutoresizingMask:
+	    NSViewWidthSizable | NSViewHeightSizable];
           [selectedView setFrame: [self contentRect]];
-          [_window makeFirstResponder: [_selected initialFirstResponder]];
+	  firstResponder = [_selected initialFirstResponder];
+	  if (firstResponder == nil)
+	    {
+	      firstResponder = [_selected view];
+	      [_selected setInitialFirstResponder: firstResponder];
+	      [firstResponder _setUpKeyViewLoopWithNextKeyView:
+		_original_nextKeyView];
+	    }
+	  [self setNextKeyView: firstResponder];
+          [_window makeFirstResponder: firstResponder];
         }
       
       /* Will need to redraw tabs and content area. */
@@ -691,3 +712,63 @@
     }
 }
 @end
+
+@implementation NSTabViewItem (KeyViewLoop)
+
+- (void) _setUpKeyViewLoopWithNextKeyView: (NSView *)nextKeyView
+{
+  [self setInitialFirstResponder: [self view]];
+  [[self view] _setUpKeyViewLoopWithNextKeyView: nextKeyView];
+}
+
+- (NSView *) _lastKeyView
+{
+  NSView *keyView = [self initialFirstResponder];
+  NSView *itemView = [self view];
+  NSView *lastKeyView = nil;
+  NSMutableArray *views = // cycle protection
+    [[NSMutableArray alloc] initWithCapacity: 1 + [[itemView subviews] count]];
+
+  if (keyView == nil && itemView != nil)
+    {
+      [self _setUpKeyViewLoopWithNextKeyView: itemView];
+    }
+  while ([keyView isDescendantOf: itemView] && ![views containsObject: keyView])
+    {
+      [views addObject: keyView];
+      lastKeyView = keyView;
+      keyView = [keyView nextKeyView];
+    }
+  [views release];
+  return lastKeyView;
+}
+
+@end
+
+@implementation NSTabView (KeyViewLoop)
+
+- (void) _setUpKeyViewLoopWithNextKeyView: (NSView *)nextKeyView
+{
+  [_items makeObjectsPerform: @selector(_setUpKeyViewLoopWithNextKeyView:)
+		  withObject: nextKeyView];
+  if (_selected)
+    {
+      [super setNextKeyView: [_selected initialFirstResponder]];
+    }
+  [self setNextKeyView: nextKeyView];
+}
+
+- (void) setNextKeyView: (NSView *)nextKeyView
+{
+  _original_nextKeyView = nextKeyView;
+  if (_selected)
+    {
+      [[_selected _lastKeyView] setNextKeyView: nextKeyView];
+    }
+  else
+    {
+      [super setNextKeyView: nextKeyView];
+    }
+}
+
+@end

Source/NSView.m

@@ -77,6 +77,7 @@
 #import "GSToolTips.h"
 #import "GSBindingHelpers.h"
 #import "GSGuiPrivate.h"
+#import "NSViewPrivate.h"
 
 /*
  * We need a fast array that can store objects without retain/release ...
@@ -422,10 +423,18 @@ GSSetDragTypes(NSView* obj, NSArray *types)
       if (_window != nil)
         {
           [GSDisplayServer removeDragTypes: t fromWindow: _window];
+	  if ([_window autorecalculatesKeyViewLoop])
+	    {
+	      [_window recalculateKeyViewLoop];
+	    }
         }
       if (newWindow != nil)
         {
           [GSDisplayServer addDragTypes: t toWindow: newWindow];
+	  if ([newWindow autorecalculatesKeyViewLoop])
+	    {
+	      [newWindow recalculateKeyViewLoop];
+	    }
         }
     }
   
@@ -5057,3 +5066,54 @@ static NSView* findByTag(NSView *view, int aTag, unsigned *level)
 
 @end
 
+@implementation NSView(KeyViewLoop)
+
+static int
+cmpFrame(id view1, id view2, void *context)
+{
+  BOOL flippedSuperView = [(NSView *)context isFlipped];
+  NSRect frame1 = [view1 frame];
+  NSRect frame2 = [view2 frame];
+
+  if (NSMinY(frame1) < NSMinY(frame2))
+    return flippedSuperView ? NSOrderedAscending : NSOrderedDescending;
+  if (NSMaxY(frame1) > NSMaxY(frame2))
+    return flippedSuperView ? NSOrderedDescending : NSOrderedAscending;
+
+  // FIXME Should use NSMaxX in a Hebrew or Arabic locale
+  if (NSMinX(frame1) < NSMinX(frame2))
+    return NSOrderedAscending;
+  if (NSMinX(frame1) > NSMinX(frame2))
+    return NSOrderedDescending;
+  return NSOrderedSame;
+}
+
+- (void) _setUpKeyViewLoopWithNextKeyView: (NSView *)nextKeyView
+{
+  if (_rFlags.has_subviews)
+    {
+      [self _recursiveSetUpKeyViewLoopWithNextKeyView: nextKeyView];
+    }
+  else
+    {
+      [self setNextKeyView: nextKeyView];
+    }
+}
+
+- (void) _recursiveSetUpKeyViewLoopWithNextKeyView: (NSView *)nextKeyView
+{
+  NSArray *sortedViews;
+  NSView *aView;
+  NSEnumerator *e;
+
+  sortedViews = [_sub_views sortedArrayUsingFunction: cmpFrame context: self];
+  e = [sortedViews reverseObjectEnumerator];
+  while ((aView = [e nextObject]) != nil)
+    {
+      [aView _setUpKeyViewLoopWithNextKeyView: nextKeyView];
+      nextKeyView = aView;
+    }
+  [self setNextKeyView: nextKeyView];
+}
+
+@end

Source/NSViewPrivate.h

@@ -0,0 +1,37 @@
+/* 
+   NSViewPrivate.h
+
+   The private methods of the NSView classes
+
+   Copyright (C) 2010 Free Software Foundation, Inc.
+   
+   This file is part of the GNUstep GUI Library.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; see the file COPYING.LIB.
+   If not, see <http://www.gnu.org/licenses/> or write to the 
+   Free Software Foundation, 51 Franklin Street, Fifth Floor, 
+   Boston, MA 02110-1301, USA.
+*/ 
+
+#ifndef _GNUstep_H_NSViewPrivate
+#define _GNUstep_H_NSViewPrivate
+
+#import "AppKit/NSView.h"
+
+@interface NSView (KeyViewLoop)
+- (void) _setUpKeyViewLoopWithNextKeyView: (NSView *)nextKeyView;
+- (void) _recursiveSetUpKeyViewLoopWithNextKeyView: (NSView *)nextKeyView;
+@end
+
+#endif // _GNUstep_H_NSViewPrivate

Source/NSWindow.m

@@ -89,6 +89,7 @@
 #import "GSToolTips.h"
 #import "GSIconManager.h"
 #import "NSToolbarFrameworkPrivate.h"
+#import "NSViewPrivate.h"
 
 #define GSI_ARRAY_TYPES 0
 #define GSI_ARRAY_TYPE NSWindow *
@@ -1551,6 +1552,10 @@ titleWithRepresentedFilename(NSString *representedFilename)
 
       if ((!_firstResponder) || (_firstResponder == self))
         {
+	  if (!_initialFirstResponder)
+	    {
+	      [self recalculateKeyViewLoop];
+	    }
           if (_initialFirstResponder)
             {
               [self makeFirstResponder: _initialFirstResponder];
@@ -4367,7 +4372,7 @@ resetCursorRectsForView(NSView *theView)
           _f.selectionDirection =  NSSelectingNext;
           [(id)theView selectText: self];
           _f.selectionDirection =  NSDirectSelection;
-              }
+        }
     }
 }
 
@@ -4464,7 +4469,7 @@ resetCursorRectsForView(NSView *theView)
         {
           return;
         }
-       if ([theView respondsToSelector:@selector(selectText:)])
+      if ([theView respondsToSelector:@selector(selectText:)])
         {
           _f.selectionDirection =  NSSelectingPrevious;
           [(id)theView selectText: self];
@@ -4504,8 +4509,10 @@ current key view.<br />
 
 - (void) recalculateKeyViewLoop
 {
-// FIXME
-// Should be called from NSView viewWillMoveToWindow
+// Should be called from NSView viewWillMoveToWindow (but only if
+// -autorecalculatesKeyViewLoop returns YES)
+  [_contentView _setUpKeyViewLoopWithNextKeyView: _contentView];
+  [self setInitialFirstResponder: [_contentView nextValidKeyView]];
 }