cocoa: draw tabstrip stroke in white in increase-contrast incognito

chrome/browser/ui/cocoa/tabs/tab_view.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/ui/cocoa/tabs/tab_view.h"
 
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
 #include "base/mac/sdk_forward_declarations.h"
 #include "base/strings/sys_string_conversions.h"
@@ skipping 62 matching lines @@
 + (void)drawTabLeftEdgeImage;
 + (void)drawTabMiddleEdgeImage;
 + (void)drawTabRightEdgeImage;
 + (void)setTabEdgeStrokeColor;
 @end
 
 @interface TabHeavyImageMaker : TabImageMaker
 + (void)setTabEdgeStrokeColor;
 @end
 
+@interface TabHeavyInvertedImageMaker : TabImageMaker
++ (void)setTabEdgeStrokeColor;
+@end
+
 @interface TabController(Private)
 // The TabView's close button.
 - (HoverCloseButton*)closeButton;
 @end
 
 extern NSString* const _Nonnull NSWorkspaceAccessibilityDisplayOptionsDidChangeNotification;
 
 namespace {
 
 enum StrokeType {
   STROKE_NORMAL,
   STROKE_HEAVY,
+  STROKE_HEAVY_INVERTED,
 };
 
+Class drawingClassForStrokeType(StrokeType stroke_type) {
+  switch (stroke_type) {
+    case STROKE_NORMAL:
+      return [TabImageMaker class];
+    case STROKE_HEAVY:
+      return [TabHeavyImageMaker class];
+    case STROKE_HEAVY_INVERTED:
+      return [TabHeavyInvertedImageMaker class];
+  }
+}
+
 NSImage* imageForResourceID(int resource_id, StrokeType stroke_type) {
   CGFloat imageWidth = resource_id == IDR_TAB_ACTIVE_CENTER ? 1 : 18;
   SEL theSelector = 0;
   switch (resource_id) {
     case IDR_TAB_ACTIVE_LEFT:
       theSelector = @selector(drawTabLeftEdgeImage);
       break;
 
     case IDR_TAB_ACTIVE_CENTER:
       theSelector = @selector(drawTabMiddleEdgeImage);
       break;
 
     case IDR_TAB_ACTIVE_RIGHT:
       theSelector = @selector(drawTabRightEdgeImage);
       break;
 
     case IDR_TAB_ALPHA_LEFT:
       theSelector = @selector(drawTabLeftMaskImage);
       break;
 
     case IDR_TAB_ALPHA_RIGHT:
       theSelector = @selector(drawTabRightMaskImage);
       break;
   }
   DCHECK(theSelector);
 
-  Class makerClass = stroke_type == STROKE_HEAVY ? [TabHeavyImageMaker class]
-                                                 : [TabImageMaker class];
+  Class makerClass = drawingClassForStrokeType(stroke_type);
   base::scoped_nsobject<NSCustomImageRep> imageRep([[NSCustomImageRep alloc]
       initWithDrawSelector:theSelector
                   delegate:makerClass]);
 
   NSImage* newTabButtonImage =
       [[[NSImage alloc] initWithSize:NSMakeSize(imageWidth, 29)] autorelease];
   [newTabButtonImage setCacheMode:NSImageCacheAlways];
   [newTabButtonImage addRepresentation:imageRep];
 
   return newTabButtonImage;
@@ skipping 12 matching lines @@
   CR_DEFINE_STATIC_LOCAL(
       ui::ThreePartImage, stroke,
       (imageForResourceID(IDR_TAB_ACTIVE_LEFT, STROKE_NORMAL),
        imageForResourceID(IDR_TAB_ACTIVE_CENTER, STROKE_NORMAL),
        imageForResourceID(IDR_TAB_ACTIVE_RIGHT, STROKE_NORMAL)));
   CR_DEFINE_STATIC_LOCAL(
       ui::ThreePartImage, heavyStroke,
       (imageForResourceID(IDR_TAB_ACTIVE_LEFT, STROKE_HEAVY),
        imageForResourceID(IDR_TAB_ACTIVE_CENTER, STROKE_HEAVY),
        imageForResourceID(IDR_TAB_ACTIVE_RIGHT, STROKE_HEAVY)));
+  CR_DEFINE_STATIC_LOCAL(
+      ui::ThreePartImage, heavyInvertedStroke,
+      (imageForResourceID(IDR_TAB_ACTIVE_LEFT, STROKE_HEAVY_INVERTED),
+       imageForResourceID(IDR_TAB_ACTIVE_CENTER, STROKE_HEAVY_INVERTED),
+       imageForResourceID(IDR_TAB_ACTIVE_RIGHT, STROKE_HEAVY_INVERTED)));
 
-  return stroke_type == STROKE_HEAVY ? heavyStroke : stroke;
+  switch (stroke_type) {
+    case STROKE_NORMAL:
+      return stroke;
+    case STROKE_HEAVY:
+      return heavyStroke;
+    case STROKE_HEAVY_INVERTED:
+      return heavyInvertedStroke;
+  }
 }
 
 CGFloat LineWidthFromContext(CGContextRef context) {
   CGRect unitRect = CGRectMake(0.0, 0.0, 1.0, 1.0);
   CGRect deviceRect = CGContextConvertRectToDeviceSpace(context, unitRect);
   return 1.0 / deviceRect.size.height;
 }
 
 }  // namespace
 
@@ skipping 345 matching lines @@
 - (void)drawStroke:(NSRect)dirtyRect {
   // In MD, the tab stroke is always opaque.
   CGFloat alpha = 1;
   NSRect bounds = [self bounds];
   // In Material Design the tab strip separator is always 1 pixel high -
   // add a clip rect to avoid drawing the tab edge over it.
   NSRect clipRect = bounds;
   clipRect.origin.y += [self cr_lineWidth];
   NSRectClip(clipRect);
   const ui::ThemeProvider* provider = [[self window] themeProvider];
-  GetStrokeImage(state_ == NSOnState,
-                 provider && provider->ShouldIncreaseContrast()
-                     ? STROKE_HEAVY
-                     : STROKE_NORMAL)
+  StrokeType stroke_type = STROKE_NORMAL;
+  if (provider && provider->ShouldIncreaseContrast()) {
+    stroke_type =
+        [[self window] hasDarkTheme] ? STROKE_HEAVY_INVERTED : STROKE_HEAVY;
+  }
+  GetStrokeImage(state_ == NSOnState, stroke_type)
       .DrawInRect(bounds, NSCompositeSourceOver, alpha);
 }
 
 - (void)drawRect:(NSRect)dirtyRect {
   [self drawFill:dirtyRect];
   [self drawStroke:dirtyRect];
 
   // We draw the title string directly instead of using a NSTextField subview.
   // This is so that we can get font smoothing to work on earlier OS, and even
   // when the tab background is a pattern image (when using themes).
@@ skipping 487 matching lines @@
 
 // For "Increase Contrast" mode, use flat black instead of semitransparent black
 // for the tab edge stroke.
 + (void)setTabEdgeStrokeColor {
   static NSColor* heavyStrokeColor =
       [skia::SkColorToSRGBNSColor(SK_ColorBLACK) retain];
   [heavyStrokeColor set];
 }
 
 @end
+
+@implementation TabHeavyInvertedImageMaker
+
+// For "Increase Contrast" mode, when using a dark theme, the stroke should be
+// drawn in flat white instead of flat black. There is normally no need to
+// special-case this since the lower-contrast border is equally visible in light
+// or dark themes.
++ (void)setTabEdgeStrokeColor {
+  static NSColor* heavyStrokeColor =
+      [skia::SkColorToSRGBNSColor(SK_ColorWHITE) retain];
+  [heavyStrokeColor set];
+}
+
+@end