Make the edge where BackgroundGradientView draws a divider selectable.

…and remove the duplicate divider drawing in DownloadShelfView.

BUG=589943

Review-Url: https://codereview.chromium.org/2336463002
Cr-Commit-Position: refs/heads/master@{#418641}

chrome/browser/ui/cocoa/background_gradient_view.h

@@ -11,14 +11,14 @@
 
 // A custom view that draws a 'standard' background gradient.
 // Base class for other Chromium views.
-@interface BackgroundGradientView : NSView<ThemedWindowDrawing> {
- @private
-  BOOL showsDivider_;
-}
+@interface BackgroundGradientView : NSView<ThemedWindowDrawing>
 
-// Controls whether the bar draws a dividing line at the bottom.
+// Controls whether the bar draws a dividing line.
 @property(nonatomic, assign) BOOL showsDivider;
 
+// Controls where the bar draws a dividing line.
+@property(nonatomic, assign) NSRectEdge dividerEdge;
+
 // The color used for the bottom stroke. Public so subclasses can use.
 - (NSColor*)strokeColor;
 

chrome/browser/ui/cocoa/background_gradient_view.mm

@@ -12,14 +12,10 @@
 #import "ui/base/cocoa/nsview_additions.h"
 #include "ui/base/material_design/material_design_controller.h"
 
-@interface BackgroundGradientView (Private)
-- (void)commonInit;
-- (NSColor*)backgroundImageColor;
-@end
-
 @implementation BackgroundGradientView
 
 @synthesize showsDivider = showsDivider_;
+@synthesize dividerEdge = dividerEdge_;
 
 - (id)initWithFrame:(NSRect)frameRect {
   if ((self = [super initWithFrame:frameRect])) {
@@ -37,6 +33,7 @@
 
 - (void)commonInit {
   showsDivider_ = YES;
+  dividerEdge_ = NSMinYEdge;
 }
 
 - (void)setShowsDivider:(BOOL)show {
@@ -46,6 +43,13 @@
   [self setNeedsDisplay:YES];
 }
 
+- (void)setDividerEdge:(NSRectEdge)dividerEdge {
+  if (dividerEdge_ == dividerEdge)
+    return;
+  dividerEdge_ = dividerEdge;
+  [self setNeedsDisplay:YES];
+}
+
 - (NSPoint)patternPhase {
   return [[self window]
       themeImagePositionForAlignment:THEME_IMAGE_ALIGN_WITH_TAB_STRIP];
@@ -68,10 +72,10 @@
   NSRectFillUsingOperation(dirtyRect, NSCompositeSourceOver);
 
   if (showsDivider_) {
-    // Draw bottom stroke
+    // Draw stroke
     NSRect borderRect, contentRect;
     NSDivideRect([self bounds], &borderRect, &contentRect, [self cr_lineWidth],
-                 NSMinYEdge);
+                 dividerEdge_);
     if (NSIntersectsRect(borderRect, dirtyRect)) {
       [[self strokeColor] set];
       NSRectFillUsingOperation(NSIntersectionRect(borderRect, dirtyRect),

chrome/browser/ui/cocoa/download/download_shelf_view_cocoa.mm

@@ -16,7 +16,7 @@
 // For programmatic instantiations in unit tests.
 - (id)initWithFrame:(NSRect)frameRect {
   if ((self = [super initWithFrame:frameRect])) {
-    [self setShowsDivider:NO];
+    self.dividerEdge = NSMaxYEdge;
   }
   return self;
 }
@@ -24,26 +24,11 @@
 // For nib instantiations in production.
 - (id)initWithCoder:(NSCoder*)decoder {
   if ((self = [super initWithCoder:decoder])) {
-    [self setShowsDivider:NO];
+    self.dividerEdge = NSMaxYEdge;
   }
   return self;
 }
 
-- (NSColor*)strokeColor {
-  const ui::ThemeProvider* themeProvider = [[self window] themeProvider];
-  if (!themeProvider) {
-    return [NSColor blackColor];
-  }
-  if (!ui::MaterialDesignController::IsModeMaterial()) {
-    BOOL isActive = [[self window] isMainWindow];
-    return themeProvider->GetNSColor(
-        isActive ? ThemeProperties::COLOR_TOOLBAR_STROKE :
-                   ThemeProperties::COLOR_TOOLBAR_STROKE_INACTIVE);
-  }
-  return themeProvider->GetNSColor(
-             ThemeProperties::COLOR_DETACHED_BOOKMARK_BAR_SEPARATOR);
-}
-
 - (NSPoint)patternPhase {
   // We want our backgrounds for the shelf to be phased from the upper
   // left hand corner of the view. Offset it by tab height so that the
@@ -55,17 +40,10 @@
 - (void)drawRect:(NSRect)dirtyRect {
   [super drawRect:dirtyRect];
 
-  // Draw top stroke
+  // Draw the top highlight
   NSRect borderRect, contentRect;
   NSDivideRect([self bounds], &borderRect, &contentRect, [self cr_lineWidth],
                NSMaxYEdge);
-  if (NSIntersectsRect(borderRect, dirtyRect)) {
-    [[self strokeColor] set];
-    NSRectFillUsingOperation(NSIntersectionRect(borderRect, dirtyRect),
-                             NSCompositeSourceOver);
-  }
-
-  // Draw the top highlight
   borderRect.origin.y -= [self cr_lineWidth];
   if (NSIntersectsRect(borderRect, dirtyRect)) {
     const ui::ThemeProvider* themeProvider = [[self window] themeProvider];